Specifications fro sewerage plant

AL MADINA AL SHAMALIYA SEWAGE TREATMENT PLANT

Volume 3A – Specifications

July 2014

General Table of Contents

VOLUME 1 Section 1 Section 2 Section 3 Section 4 Section 5

INSTRUCTIONS TO TENDERERS Instructions to Tenderers Form of Tender and Appendix to Tender Form of Initial Bond Glossary of Terms Evaluation Grids

VOLUME 2 Section 1 Section 2 Section 3 Section 4 Section 5 Section 6

CONTRACTUAL DOCUMENTS Form of D/B Contract Agreement General Conditions Form of Performance Bond Form of Advance Payment Guarantee Form of Parent Company Guarantee Form of Operation & Maintenance Contract Agreement

VOLUME 3A Section 1 Section 2 Section 3 VOLUME 3B Section 4 Section 5 Section 6 Section 7 Section 8 Section 9

SPECIFICATIONS General Requirements Process Specifications Civil Specifications SPECIFICATIONS Mechanical Specifications Electrical Specifications ICA Specifications Testing and Commissioning Operations & Maintenance Requirements Schedule of Limits and Basic Conditions for Alternative Proposals

VOLUME 4 Section 1 Section 2 Section 3 Section 4 Section 5 Section 6

SCHEDULES Schedule of Prices Dayworks Schedule and Schedule of Rates Schedule of Guarantees Technical Schedules Cash Flow Schedules Operation and Maintenance Schedule of Prices and Performance Standards

VOLUME 5 Section 1

Design Documents (DRAWINGS) Drawings for Information

VOLUME 6 Section 1 Section 2 Section 3 Section 4 Section 5 Section 6 Section 7

OTHER INFORMATION Soil Investigation Information Bathymetric Data STP Environmental Impact Assessment Executive Summary STP Environmental Management Plan Outfall Environmental Evaluation Report Non-Technical Summary Outfall Construction Environmental Management Plan Outfall Operation Environmental Management Plan

AL MADINA AL SHAMALIYA (AMAS) SEWAGE TREATMENT PLANT Tender Documents

Volume 3 Section 1 General Requirements

July 2014

AL MADINA AL SHAMALIYA STP

Specifications

TABLE OF CONTENTS

1

GENERAL ............................................................................................................................ 1

1.1

Objective of the Works .................................................................................................. 1

1.2

Specification Documents ............................................................................................... 1

1.3

General Information Pertaining to the Site ................................................................... 1

1.4

Architectural Design and Treatment of the works ........................................................ 6

1.5

AMAS STP Landscaping.................................................................................................. 6

2

DESIGN OF THE WORKS .................................................................................................... 7

2.1

General .......................................................................................................................... 7

2.2

Design Lives ................................................................................................................... 9

2.3

Standards and Codes ..................................................................................................... 9

2.4

Planning Permission and Building Control Permits ....................................................... 9

2.5

Contractor's Documents for Review by the Engineer .................................................. 10

2.6

Final Documents to be provided by the Contractor ..................................................... 15

2.7

Other Documents to be provided by the Contractor ................................................... 16

2.8

Quality Assurance/Quality Control System ................................................................. 17

2.9

Contractor’s Company Quality Assurance System....................................................... 17

2.10

Control Plans for the Works included in this Contract ................................................ 17

2.11

Quality Assurance Plan (QAP) ..................................................................................... 17

2.12

Control Plans ............................................................................................................... 18

2.13

Contractor’s Control and Documentation .................................................................... 18

2.14

Defects Liability Period ................................................................................................ 19

2.15

Retention of Documents .............................................................................................. 19

2.16

Post Warranty Service Agreements ............................................................................. 19

3

ENVIRONMENTAL MANAGEMENT SYSTEM ...................................................................... 20

4

CONSTRUCTION OF THE WORKS .................................................................................... 20

4.1

Construction Permits ................................................................................................... 20

Vol 3, Section 1 – General Requirements

Page i of ii


Specifications

4.2

Interpretation of Drawings ......................................................................................... 20

4.3

Continuous Working .................................................................................................... 20

4.4

Signboards ................................................................................................................... 21

4.5

Temporary/Security Fencing of Site ............................................................................ 21

4.6

Setting Out and Checking the Works .......................................................................... 21

4.7

Survey of Site............................................................................................................... 21

4.8

Interference with Land Interests ................................................................................ 22

4.9

Interference with Access to Properties ....................................................................... 22

4.10

Site Cleanliness and Environmental Protection........................................................... 22

4.11

Demolition, Damage and Making Good ....................................................................... 22

4.12

Site Drainage ............................................................................................................... 23

4.13

Monitoring of Existing Structures................................................................................ 23

4.14

Interface with Existing Structures .............................................................................. 23

4.15

Interface with Other Contractors ................................................................................ 24

4.16

Traffic Requirements ................................................................................................... 24

4.17

Maintenance of Access Roads...................................................................................... 24

4.18

Water for Testing ......................................................................................................... 24

4.19

Excavations for Water Mains and Sewers ................................................................... 24

4.20

Existing Services .......................................................................................................... 25

4.21

Electricity, Water Supply and Telecommunications .................................................... 25

4.22

Protection of Work ...................................................................................................... 26

4.23

Materials and Workmanship ........................................................................................ 26

4.24

Site Safety and Welfare ............................................................................................... 29

4.25

Site Offices, Attendance and Site Facilities ................................................................. 38

4.26

Public Relations ........................................................................................................... 43

Appendix I

Drawings and other information forming part of the Contract

Appendix II

Addresses of Statutory Organisations

Appendix III Source Countries Appendix IV Plant species list


Page ii of ii


1

Specifications

GENERAL

1.1

Objective of the Works There are two separately identifiable elements of the Works forming the Al Madina Al Shamaliya Sewage Treatment Plant (AMAS STP) Works included in this Contract. They are: Provision of Sewage Treatment works with all associated intermediary pumping stations, rising mains, discharge pipelines, TSE Storage tank and TSE pumping station and access roads, including landscaping within the works’ boundary wall. Provision of Operation and Maintenance Services of AMAS STP works for a period of five (5) years starting after the Taking Over Certificate for the construction of the AMAS STP works is issued.

1.2

Specification Documents Volume 3 of the Contract Documents comprises the following specification documents: •

Section 1 General Requirements;

•

Section 2 Process Specifications;

•

Section 3 Civil Specifications;

•

Section 4 Mechanical Specifications;

•

Section 5 Electrical Specifications;

•

Section 6 ICA Specifications;

•

Section 7 Testing and Commissioning;

•

Section 8 Operations and Maintenance Requirements.

If there is a conflict of requirements between the above specification documents and MoW Standard Specification for Construction Works 2009, then the above documents take precedence. The Employer’s Requirements may be amended or amplified during subsequent correspondence with Tenderers prior to the award of Contract, or after award by the issue of a variation under Clause 14 of the Conditions of Contract. The Employer’s Requirements are to be found in this section and are amplified in the Specifications and Drawings which shall be considered as part of the Employer's Requirements. 1.3 1.3.1

General Information Pertaining to the Site Location The site is located on a group of reclaimed islands off the north west coast of Bahrain know as Al Madina Al Shamaliya (AMAS). The AMAS STP will be located to the eastern edge of the AMAS development (Island 13c) in a prepared area screened by a landscaped hill from the rest of the development. A Location Plan is included in the Drawings.


Page 1 of 43


Specifications

1.3.2

ACCESS TO SITE AND OTHER CONTRACTS

1.3.3

Contractor’s Access to the Site Access to the Islands is via a causeway/s linking the islands to the mainland with further bunds providing access across the channels between the individual islands making up the development. Access around the islands will generally be via unpaved site roads. It should be noted that the main and secondary access roads will be shared with many contractors carrying out construction at AMAS concurrently with this Contract including the Contractor for the PPP area, MoH Housing & Infrastructure Contractors, EWA Contractors, STP Contractors, Ahliya University Contractors and other Stakeholders (Mosques, Schools, Recreation etc). In particular, the access to Island 13c is via a bund currently wide enough only for single lane traffic. This will be the main access route for construction of the STP and Terminal Lift Pumping Station (TLPS) and will be shared with other contractors, primarily the primary infrastructure contractor for the construction of the TSE pipeline on Island 13c and also the termination of the deep gravity sewer at the TLPS Details of the access arrangements are indicated on the Drawings.

1.3.4

Climate Bahrain has a hot and arid desert climate with low and erratic rainfall. There are two main seasons: a hot and humid summer (June to September) and a cool winter with some occasional rainfall (December to February). Bahrain’s large-scale climate is influenced by a number of regional features, including the Gulf waters, the dust and sand basins of Iraq some 650km to the north-west and the Zagros mountain range in Iran, 220km at their nearest to the north-east. The Gulf provides low level moisture supply, while the Zagros hills influence pressure patterns and direct low level winds to blow mainly from the north-west or south-east. The dust bowls of Iraq and northern Saudi Arabia provide an abundance of fine dust particles, which are easily transported by northwesterly winds and can cause visibility reductions in Bahrain, mainly in the months of June and July. Rainfall Rainfall in Bahrain is rare and irregular. The annual average rainfall is about 70mm, but this figure may vary greatly from almost nothing (<2mm in 1946) to two or three times the annual mean (225mm in 1995). On average, rain falls on about 10 days a year. Two-thirds of the precipitation occurs in December-March. The period between late May and the end of September is associated with a dominant summer drought, in which rainfall is consistently close to zero. Rain generally falls during thundershowers and squalls, and is often heavy, short in duration and localised. Due to low infiltration rates, flash floods in natural drainage channels and depressions are a fairly common occurrence.


Page 2 of 43


Figure 1.1:

Specifications

Rainfall Data

2.5

70 Average no. of rain days 60

Average monthly rainfall Highest rainfall in 1 day

2

Rainfall (mm)

1.5

40 30

1

20 0.5

10 0

No. of Rain Days

50

*29-year averages

0

Jan Feb Mar Apr May Jun

Jul

Aug Sep Oct Nov Dec

Humidity Due to its proximity to the sea, Bahrain is humid throughout the year (except when hot, dry winds blow off the mainland). Relative humidity is higher than in many other parts of the subregion. The mean daily maximum is about 85% and the average daily minimum usually ranges between 50% and 60%. Between May and July the minimum may drop as low as 40%. Potential evapo-transpiration (ETP) rates indicate a variation from about 75mm in January to 250mm in June. Figure 1.2: Humidity Data 100% 90%

Relative Humidity (%)

80% 70% 60% 50% 40% 30% 20%

Average daily relative humidity: max

10%

* 16-year averages

Average daily relative humidity: min

0% Jan


Feb

Mar

Apr

May

Jun

Jul

Aug

Page 3 of 43

Sep

Oct

Nov

Dec


Specifications

Temperature The average temperature in Bahrain is about 27°C. The annual variation is considerable, with temperatures ranging from a mean daily minimum of 14°C in January to a mean daily maximum of 38°C in August. The lowest minimum temperature recorded is 2.8°C and the highest maximum is 46.7°C. Ground surface temperatures are considerably higher, with probable peaks above 60°C. Due to the proximity of the sea in all directions, the difference between day and night temperatures is usually moderate. Figure 1.3: Temperature Data 50

Temperature (deg.Celsuis)

45

*29-year averages

40 35 30 25 20 15

Average daily temperature: max

10

Average daily temperature: min Highest maximum recorded Highest minimum recorded

5 0 Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Wind As a result of its location and low topography, Bahrain’s islands are windswept. The predominant wind direction is from the north-west. Over the course of a year, about 45% of the winds blow either from the WNW, NW or NNW direction. The next most frequent wind directions are west and north. All other directions are almost equally represented with frequencies of more or less 5%. During the summer, the winds are generally light to moderate and blow from the N and NW directions. During the winter, the winds move eastwards as a result of low pressure systems generated over the Mediterranean and Arabian Peninsula. Mean wind speeds range from 6 to 8 knots (11 to 15 km/h), though “shamal” winds blowing from WNW to NNW can reach 10 to 12 knots (18 to 22 km/h). The shamal is the predominant dust-raising wind in the region, bringing airborne silts from Saudi Arabia or Iraq some 400 km to the north-west. 1.3.5

Seismic Conditions There is limited information and data on seismicity for Bahrain and the whole Gulf region. A world-scale seismic hazard map produced by the Global Seismic Hazard Assessment Programme (GSHAP) suggests that Bahrain is in a low risk earthquake zone (see figure below). The nearest active fault zone is the Zagros Fault in southern Iran.


Page 4 of 43


Figure 1.4:

1.3.6

Specifications

Seismic Hazard Map for the Gulf Region

Ground Conditions The topography of AMAS STP is characterized principally by a flat terrain below a boomerang shape hill extending to the northern, western and part of the eastern side of the plant area while the seafront forms the southeastern boundary of the area. The ground elevation in the STP site is approximately 2.65m above sea level. Detailed soil investigation and topographical information are included in Volume 6. The Contractor shall be fully responsible for the interpretation and use of any information included in these reports. The Contractor is deemed to have satisfied himself of the local ground conditions and its suitability for his method of construction.

1.3.7

Hydrology Hydrological information is included in Volume 6, Section 3.

1.3.8

Electricity, Water etc In accordance with Clause 4.20 of the Conditions of Contract, the Contractor shall be entitled to use any supplies of power, water and any other services that may be available on the site. The Contractor shall pay the Employer for the use of such services in accordance with applicable tariffs. If not available, the Contractor shall make his own provisions.

1.3.9

Other Information Information provided to the Contractor in Volume 6 (Other Information) may be utilized by the Contractor in his design but the Contractor is responsible for checking its validity and shall accept full responsibility for any design based on the information used.


Page 5 of 43


1.4

Specifications

Architectural Design and Treatment of the works As part of their works, the Contractor is required to construct the following: 1)

Boundary Wall A 3.5 meter high boundary wall shall be provided to the entire perimeter of the AMAS STP site as indicated on the AMAS STP layout plan. As well as its primary security function, the boundary wall shall also provide screening of the plant to reduce its visual impact when viewed from the surrounding areas. The proposed boundary wall shall consist of precast columns with precast wall panels placed in between. The precast elements shall be textured and coloured as required. The wall shall be designed with a decorative finish so as to present a pleasant, low impact façade. In order to reflect the traditional Bahraini theme, a number of GRC patterns shall be incorporated within the wall.

2)

Higher Structures The Contractor’s architectural design and treatment of the higher structures will be dealt with in such a way to give the impression of traditional Bahraini buildings, which will blend in with the surroundings and ensure the aesthetically acceptable external appearance of the STP. In addition, screening by trees shall be integrated into the design (see also landscaping below).

The Contractor shall submit for the Engineer's approval his detailed architectural design for the boundary wall and all AMAS STP higher structures. 1.5

AMAS STP Landscaping In order to enhance the view of the STP works and reduce visual intrusion on surrounding development, the Contractor is required to implement an integrated landscaping scheme for the whole site of the STP designed by a specialist landscaping consultant familiar with the local conditions. The scheme shall include: 1)

Mass planting within the STP site along the inside of all Boundary Screen walls. Minimum width of boundary planting strip to be three metres.

2)

Mass planting to the STP site entry precinct between the access gate to the main plant area.

3)

Planting works to a minimum of 5% of the total STP site. This 5% site area total may be achieved through installing a number of mass planting beds with the minimum size per planting bed to cover an area of not less than 50m2.

4)

All planting works shall be irrigated using a fully automatic drip irrigation system. The irrigation system shall be designed by an approved irrigation design consultancy. The system shall include but not be limited to: a. Automatic multi-station controller system, directly wired to electrical supply. The Controller shall be located in the Administration Building in an approved location. b. Solenoid valve stations including manual isolation valve upstream of the solenoid valve, disk filter, pressure regulator. c. Inline drip line irrigation application using pressure compensating drippers with a maximum flow rate of 2.3 litres per hour. Dripline shall be UV stabilised. d. Irrigation application system shall include air relief valves and line flushing valves per station.

The landscaping scheme shall be integrated with the architectural design (see above) to provide supplementary screening of the plant structures, particularly any high structures. Vol 3, Section 1 – General Requirements

Page 6 of 43


Specifications

The Contractor is required to submit both planting and irrigation design to Ministry of Housing for approval prior to commencement of any landscape works within the STP site. The planting works stipulated do not refer to areas of turf/lawn. In designing the mass planting beds, the Contractor shall implement the following guidelines:  Tree planting to the Entry Precinct is to be an avenue to either side of the entry road with random tree planting behind.  Tree planting to the Boundary Screen Walls and Retaining wall is to be random spacings.  Tree planting within the STP Site proper is to be random spacings  Tree planting to provide screening to higher structures  60%of the trees to be palm trees. minimum height of palm trees at the time of planting will be 2.5 metres clear trunk height.  Palm spacings are to be in the range of 4m minimum to 6m maximum. Palms are to be planted in groups of minimum 3 No. palms to a maximum of 9 No. palms.  Canopy trees are to be spaced in the range of 6m minimum to 8m maximum. Minimum height of canopy trees at the time of planting will be 2.5 metres clear trunk height.  Shrub, groundcover and vine densities are to be such that the planting mass will provide a continuous covering of plant material within 2 growing seasons from the time of planting.  Plant species (palms, canopy trees, shrubs, ground covers, etc.) will be selected from the list provided in Appendix IV. 2

DESIGN OF THE WORKS

2.1 2.1.1

General Outline The AMAS STP will be located on Island 13C and the contract will be awarded on a Contractor design and build basis. The following outline principles must be adhered to when undertaking the design:

2.1.2

•

The STP shall be located entirely within the boundary indicated on drawing number D7570-01-C002

•

The height of structures and buildings shall not exceed 12m above zero datum

•

The electrical loading shall not exceed 6.0 MVA (including future STP expansion)

•

The STP shall be designed to accommodate phased sewage flows and loads in line with the housing development construction and occupation.

•

The Works shall have a capacity (design flows and loads) as detailed in Volume 3, Section 2 of the Tender Documents.

•

The quality of treated effluent and sludge produced by the Works shall be in accordance with Volume 3 Section 2 of the Tender Documents.

Site Works The Contractor shall investigate on site and verify all available information and inform the Engineer of any discrepancies with information provided in the Tender Documents prior to finalization of his design. The Contractor shall use this information to design the proposed Works.


Page 7 of 43


Specifications

The design shall be undertaken using current best practices and shall comply with the Employer’s Requirements, current Bahrain design regulations and all construction standards currently in force in Bahrain. The Contractor shall be responsible for confirming all necessary site levels and geotechnical information pertaining to the Works prior to tendering. The Contractor shall undertake investigations necessary for the design and construction of the Works. The design of all Works shall facilitate inspection, cleaning and repair and maintenance in a safe environment to ensure satisfactory operation under all service conditions. 2.1.3

Pipelines Pipework and pipelines shall be designed for all foreseeable load cases including the following: a) b) c) d)

2.1.4

maximum working pressures on completed pipelines; minimum working pressures, especially if drain down and surge control vacuum can be a problem; field test pressure on completed parts of the pipeline and the whole of the pipeline (field test pressures); required hydrostatic test pressure on individual pipes and fitting at the place of manufacture (works hydrostatic test pressures).

Buildings and Structures Electrical systems for buildings shall be designed in accordance with the requirements of paragraph 2 of Volume 3B, Section 5. ICA systems for buildings shall be designed in accordance with the requirements of paragraph 2 of Volume 3B, Section 6. Structures shall be designed to resist water loading due to maximum external water level corresponding to ground level, brim of wall or potential flood level. Uplift forces on structures, tanks and pipes shall be calculated assuming they are empty.

2.1.5

Chambers Unless otherwise stated, general chambers not subject to traffic loads shall have anodised, marine grade aluminium open or solid pattern covers. Covers shall be fixed in frames recessed into the top of the chamber walls. Chambers that require man entrance (generally greater than 900 mm deep) shall be provided with minimum access area through the cover of 800 mm x 600 mm. Ladders shall be installed in all chambers over 1.5 m deep. Where vertical ladders are installed in chambers over 2.5 m deep they shall be provided with hoop safety cages. All chambers shall have a nominal floor slope to a sump.

2.1.6

Water Retaining Structures Any structures containing any liquids or excluding any liquids shall be designed to the appropriate standard for liquid retaining structures. Structures that are to be water tested before back filling shall be designed accordingly.


Page 8 of 43


2.1.7

Specifications

Sound Insulation Noise levels at the Site boundary generated by the operational plant shall not exceed 45 dBA during daylight hours and 40 dBA at night. The Contractor will be required to produce calculations to show that noise levels generated at the Site boundary will satisfy these conditions. In addition the noise level within any working area shall not exceed 80 dBA at any time.

2.2

Design Lives The Contractor shall ensure that the design complies with the requirements of the Specification and the following design lives: Facility New civil work including pipelines, sewers, chambers, roads, buildings and concrete structures Mechanical and electrical equipment Instrumentation and Control Systems Analytical and Process Instruments

Design Life 50 years 15 years 7 years 7 years

Notwithstanding the requirements of the Specification the Contractor shall ensure that the Works and all equipment and plant provided therein shall take into account the most extreme conditions that will occur during construction and the life of the works, and will be suitable for the design lives above. 2.3

Standards and Codes Bahrain standards are referred to where appropriate. The Contractor shall be responsible for obtaining these standards and translation if required. During construction, the Works will be inspected by the Employer. The inspectors may require seeing copies of international standards to which the Works have been designed. The Contractor shall allow the Employer access to the Works to undertake the inspections.

2.4

Planning Permission and Building Control Permits The Contractor shall employ an Engineer and/or Architect registered in Bahrain (in accordance with legislative Decrees governing the Practice of Engineering) to prepare the necessary applications for Planning and Building Control Permits. The Contractor shall take note of the requirements to prepare the documentation for the applications for all the permits and endorsements necessary to obtain Planning and Building control permits for the execution of the construction works. The Contractor shall be responsible for securing all necessary approvals of the designs provided and the designs produced by himself, as required by the relevant Bahrain authorities and shall allow for this in his programme at his expense. The Contractor shall allow a realistic timescale for dealing with the third parties responsible, for permits etc., in his planning and programming of the works. Latest by the commencement date of the Works, the Contractor shall submit to the Employer the following: a)

The technical submissions required for obtaining the Planning and Building control permits.


Page 9 of 43


Specifications

The technical submission must be complete in full for all the required authorizations. The Contractor shall be responsible for any rejection of the “Planning and Building control permits” or any other authorization due to technical reasons. Approvals for the design and construction shall be obtained from the Employer. All costs associated for obtaining the “Planning and Building control permits” will be borne by the Employer. 2.5 2.5.1

Contractor's Documents for Review by the Engineer Design Documents The contractor should submit to the Engineer for his approval three hard plus one electronic copies of: 

Process Design Criteria and Calculations for 1. Liquid Treatment processes (including nitrogen and phosphorus removal treatment), 2. Sludge Treatment processes (including aerobic digestion, dewatering, thermal drying, etc.) and 3. Odour treatment facilities



Process flow diagrams (showing mass balance data for max, average and min organic and hydraulic loads)



Hydraulic Design Criteria and Calculations (for max, min, average flows, etc.)



Civil works Design Criteria (appropriate Geotechnical, Structural, etc.)



E/M Design Criteria

 P & ID with tags followed by:  Drawings of all principal components of the works including plans, sections and preliminary elevations of proposed structures suitable for submission for application for Planning and Building control approval 

General Layout Plan of the Sewage Treatment Plant



Hydraulic profile for the STP



Landscape drawings



Security Fencing, alarms and Controls drawings



Lighting arrangement drawings



Laboratory facilities drawings



Hazardous area classification drawings



Electrical Single Line Diagrams



Preliminary motor & Load schedule



PLC/SCADA architecture



Manufacturers’ List for 1st stage approval

The Contractor’s final design shall be submitted to the Engineer for his approval in three hard plus one electronic copies of: -

complete working drawings,

-

all design criteria and calculations and


Page 10 of 43


-

Specifications

details of construction of the works and other apparatus and all other parts as may be required to give full information to the Engineer regarding the proposed design

at least 42 days prior to the programmed activity commencement. Submissions shall be numbered using an agreed referencing system and shall comprise but not be limited to the following: a)

Site Layout and General Arrangement drawings with dimensions and setting out details.

b)

Details of modifications to existing manhole structures and connections to existing structures.

c)

Details of treatment plant elements including mechanical, electrical and ICA equipment, schematic layout of plant, details of pipe layouts, diameters, flow direction, invert levels and cover levels.

d)

Process design calculations for the wastewater, sludge treatment plant.

e)

Hydraulic design calculations for the plant and effluent discharges.

f)

Hydraulic design calculations for the pumping stations, rising mains and other pipework including determination of test pressures.

g)

Drawings and schedules showing all pipework, fittings, chamber and trench details and thrust block arrangements.

h)

Manhole/access chamber schedules, schematic layout of each manhole and access chamber providing details of pipe profile, layout, diameters, flow direction, invert levels and cover level.

i)

Reinforcement drawings and calculations for thrust blocks to pipework and chambers.

j)

Drawings, calculations and method statements for all road crossings and connections to existing pipework.

k)

Design criteria and methods covering the structural and geotechnical design of the Works.

l)

Detail of pumping stations including mechanical and electrical equipment.

m) Detail of maintenance and sludge disposal equipment n)

Details of road construction and reinstatements.

o)

General arrangement and foundation drawings, complete with dimensions, for all buildings, tanks, plant and associated equipment.

p)

Structural calculations and drawings including foundation design.

q)

Reinforced concrete details, structural steelwork and masonry drawings.

r)

Reinforcement drawings and calculations for insitu and precast concrete.

s)

Fabrication drawings for any structural steelwork/metalwork

t)

Architectural and building works drawings including masonry, cladding, roofing, etc, and all specified fixtures and finishes both externally and internally.

u)

Details of protective coating design.

v)

Road construction drawings including kerbing and drainage details.

w)

Landscaping, land drainage, sub and top soiling and all ancillary works.

x)

Design Criteria and calculations for:  Power consumption for wastewater treatment (tanker reception facility pumps, aerators, blowers, mixers, intermediary pumps, screens, washers, grit and grease chambers air requirements, secondary treatment – ASP and FST tanks, Tertiary Treatment, disinfection and all associated wastewater treatment plant, chemical Phosphorus removal, etc.)


Page 11 of 43


Specifications

 Power consumption for the operation of sludge treatment and all associated sludge handling plant including liquor return pumps, etc.  Power consumption for odour control /treatment y)

Design Criteria and calculations for Disinfection chemical consumption (related to disinfection before final effluent disposal)

z)

Design Criteria and calculations for:  Chemicals consumption (related to Phosphorus removal).  Chemicals consumption (related to sludge treatment).  Chemicals required for disinfection

aa) Design Criteria and Calculations for:  Excess Sludge treatment products transport and disposal to landfill and/or land spreading, and  Transport and disposal of residuals (grit and screenings), in accordance with the tender documents. bb) Design Criteria and calculations for mains water consumption for polymer dilution, or elsewhere within the treatment process where treated effluent cannot be used - Criteria and Calculations cc) Technical information (including Design Criteria and Calculations) for noise suppression and insulation, ventilation and odour control, fire protection and alarm systems, etc. dd) Technical and functional description of all works (including the main and ancillary equipment to be installed chemicals to be used, operational issues, etc.) 2.5.2

HAZOP Study The Contractor shall arrange for a full HAZOP Study to be conducted once the STP designs are substantially completed. The purpose of the HAZOP is to identify potential hazards and operability problems which could arise in the AMAS STP through a structured examination of the detailed designs of the project by a joint team of designers and operators drawn from suitably experienced staff from the Client, Contractor and Supervising Engineer organisations. Problem areas identified will be re-examined by the designers to eliminate or reduce the severity of the identified problem. Resulting design amendments will be incorporated in the final designs. The HAZOP involves systematic and structured analysis of P&I drawings and operations and maintenance procedures. During the study, deviations are deliberately introduced into the process variables in normal operating procedures to study their effect on the process, plant and machinery. Adequacy of the protection provided will be critically examined and recommendations are made to improve safety, if the protection provided is found to be inadequate. An internationally accepted HAZOP procedure shall be followed whereby a qualified HAZOP Chairperson will be engaged by the Contractor to conduct the study. A full HAZOP Report will be produced to record the parties in attendance, areas and operations examined, the problems identified, and the recommended actions with sign-off when completed.

2.5.3

Construction and Installation Method Statements Construction and installation method statements shall be prepared for the principal elements of the Works and shall be submitted to the Engineer for review at least 28 days prior to the programmed activity commencement.


Page 12 of 43


Specifications

Construction and installation method statements shall make due allowance for all requirements and restrictions imposed by the Contract. Each method statement shall comprise a step-by-step schedule of specific operations or activities with description, date, times and duration of each step. The statements shall be supported by sketches, diagrams or other supportive detail as necessary to enable a clear understanding of the method and significance of each step of work or operation. The construction and installation method statements shall include, but not be limited to: •

the method of working;

•

construction equipment to be used;

•

measures for controlling noise and vibration;

•

hours of working;

•

layouts of compounds storage facilities;

•

sources of Materials;

•

methods of movements and storage of bulk materials and spoil;

•

haulage routes;

•

site organization;

•

measures of controlling dust;

•

temporary lighting details;

•

temporary works details;

•

details of all disposal sites;

•

maintaining and cleaning of Site roads;

•

safety procedures and risk assessments;

•

pedestrian, light vehicular and emergency access;

•

any proposed demolition methods.

Method statement shall include for dealing with storm drainage and dealing with groundwater. 2.5.4

Production and Submission Procedures The Contractor shall provide the Engineer with three paper copies of all technical documents for review. Submissions will include: 

for drawings: one copy in DWG format and one copy in PDF format on a USB flash drive or CD ROM where applicable (or alternative such as through shared directories on networked site computers)



for calculations, FDS, valve schedules, instrument schedules, equipment schedules, manufacturer’s data, etc: one electronic copy in either pdf, or word/excel format.

On submission, the Contractor shall clearly identify previously submitted inter-related technical documents and also changes to previously reviewed technical documents. Vol 3, Section 1 – General Requirements

Page 13 of 43


Specifications

All designs, drawings and documents submitted by the Contractor to the Engineer for review. shall be checked by the Contractor before submission and shall be signed by a senior member of the Contractor’s staff in accordance with approved QA procedures, to confirm that the check has been conducted. The Contractor shall use SI units only and shall likewise check submissions from his sub-Contractors or from any other source before passing such submissions to the Engineer. A drawing and document register shall be kept and updated continuously by the Contractor. A copy of the register shall be submitted to the Engineer every time a drawing or document is issued. Where it is considered that the technical documents do not comply with the requirements of this Contract, the Engineer shall return one copy to the Contractor indicating where the proposals are considered to be non-compliant. Where a Document requires alteration, the Contractor shall make the necessary alterations and submit three copies of the altered document to the Engineer. Any revisions to drawings and documents shall be clearly highlighted by the Contractor. Drawing amendments shall be listed in the title box. Amendments to Documents shall be redlined, struck out or marked in the margin. All drawings submitted by the Contractor to the Engineer for consent shall be on ISO standard size sheets with a maximum size of A0. Every drawing shall have a title box in the bottom right corner showing: •

Employer’s name;

•

title of scheme;

•

title of Contract;

•

Contractor's name;

•

title of work location;

•

title of drawing;

•

drawing number;

•

date;

•

author;

•

scale;

•

a separate revision box;

•

signature of Contractor to the effect that the drawing, whether his own or from any other source, has been checked by him before submission to the Engineer.

All layout and arrangement drawings submitted by the Contractor shall be drawn to scale and dimensioned and shall include a graphical scale to aid the use of photographic reproductions. All clearances required for the installation, routine operation and maintenance of items of Works shall be noted on the drawings. Designs and documents submitted by the Contractor to the Engineer for review shall include: •

contents list;

•

scope (description of the contents and purpose of the submission);

•

conclusions and recommendations;

•

references, specification requirements, codes, manuals and supporting documents used, drawing numbers and titles of drawings which are based on the design;


Page 14 of 43


Specifications

•

description of design approach;

•

criteria, parameters and methods used;

•

test procedures, analyses and results;

•

calculations and schedules;

•

qualitative description and comments on results;

•

any other relevant information.

A statement explaining the principles of design and type of analysis adopted shall preface all design calculations prepared by the Contractor. The statement shall also indicate the Codes of Practice or Standard(s) upon which the design is based. Any computer programs used in the design shall be fully described, and details of inputs and printouts shall be presented in a manner that can be readily understood. Program manuals and any instructions to program users shall be made available to the Engineer upon request. Final works inspection reports shall be submitted to the Engineer before dispatch of the Works from manufacturer. The following documentation will not be specifically required for review but may be subject to a random audit at the request of the Engineer: All civil and structural calculations;

2.6 2.6.1

•

Services clash checks;

•

Services routing diagrams;

•

Safety Plan and Safety File.

Final Documents to be provided by the Contractor As-built Documents The Contractor shall submit to the Engineer copies of the As-built Drawings as detailed below: •

2 full size, unbound, paper copies in English;

•

3 bound sets of A3 paper reductions in English;

•

2 copies in electronic format on DVD Rom as Microsoft Workstation files (latest release) in English;

Subject to the consent of the Engineer, the Contractor may submit the As-built drawings in an alternative electronic format provided that the Contractor provides to the Employer free of charge the software required to read, edit, save and print the drawings. All As-built drawings submitted by the Contractor to the Engineer shall be on ISO standard size sheets with a maximum size of A1. A0 size drawings will not be acceptable. Every drawing shall have a title box in the bottom right corner as detailed in Clause 2.5.3. All layout and arrangement drawings submitted by the Contractor shall be drawn to scale and dimensioned and shall include a graphical scale to aid the use of photographic reproductions. The Contractor shall use SI units only.


Page 15 of 43


2.7 2.7.1

Specifications

Other Documents to be provided by the Contractor Health and Safety Plan A Health and Safety Plan shall be prepared by the Contractor and submitted to the Engineer for his consent at least 14 days prior to any programmed construction activities on site. The Health and Safety Plan shall include, but not be limited to: •

Construction risk assessment and control measures;

•

Organization and management arrangements for implementing the plan;

•

Appropriate specified safety requirements;

•

Welfare arrangements for staff messing, first aid and sanitary arrangements.

The Contractor shall not take possession of the Site before the Engineer has approved his Health and Safety Plan. 2.7.2

Organization Chart Within 14 days of commencement, the Contractor shall submit to the Engineer details of the Contractor’s Representative and other key personnel including respective job descriptions, addresses, 24-hour telephone numbers and facsimile transmission numbers. The Engineer shall be notified immediately of any changes to the details provided.

2.7.3

Programme The Contractor’s detailed time programme shall be prepared on a programme software package suitable for operation with a Windows operating system, as agreed with the Engineer and shall include:

2.7.4

•

A detailed works contract programme in the form of a Gantt chart which clearly details individual functions, actions and tasks and shows the period for design, approvals, procurement, fabrication, main construction, installation, testing, commissioning and all other such operations as may be applicable with key dates indicated. The planned input of the joint venture partners and sub-contractors (if appropriate) shall be highlighted as well as (in terms of activities undertaken, timing, etc.).

•

An associated Pert chart with all task linkages and the critical path clearly indicated;

•

Resource charts specifically related to but not limited to the activities shown on the programme of work.

Photographic Records A photographic record shall be kept of the Construction work on the following basis: •

Prior to commencement of the Works, a joint photographic survey of the Site and the surrounding area shall be carried out and agreed by the Engineer and Contractor’s Representative;

•

Photographs of each structure shall be taken upon completion of the structure;

•

Photographs of each pipe laid shall be taken at 20m intervals immediately prior to backfill of the trench;


Page 16 of 43


2.7.5

Specifications

•

Photographs of each connection to existing structures shall be taken before and after connection is made;

•

Photographs of each structure affected by Modification shall be taken before and after the work is carried out;

•

Two sets of the photographs shall be provided to the Engineer, together with the digital computer format files. The photographs shall be high resolution, full colour and 150mm by 100mm minimum size. The photographs shall be suitably titled, dated and coded in numerical order.

Relevant Standards The Contractor shall provide one copy of the relevant standards, which he consider applicable to this contract.

2.8

Quality Assurance/Quality Control System A Quality Assurance (QA)/Quality Control (QC) System covering all aspects of the Contract and the Works must be implemented, documented and maintained by the Contractor during the period of the Contract. The system shall comply with a recognized international Quality Assurance Standard to ISO 9001/2000. The System shall as a minimum include the items referred to in 2.9 to 2.15.

2.9

Contractor’s Company Quality Assurance System The Contractor shall provide a Quality Assurance System for the Company showing the overall QA Organization and the lines of responsibility, monitoring and action. Furthermore, the overall principles and procedures for establishing Quality Assurance Plans, Control Plans, QA Organization, etc. for specific projects and contracts, sub-contractors and suppliers shall be provided. The Contractor’s Foreman/Site Agent shall be certified in accordance with Bahrain Laws.

2.10 Control Plans for the Works included in this Contract As a minimum the Contractor shall, as part of his tender, submit the QA System for the Company, Quality Assurance Plan (QAP) and initial Control Plans (CP) for the Works included in this Contract, providing all important and critical activities for controls, inspections and tests to fulfill the specifications. It is a general requirement that works are only sub-contracted to companies with an effective QA System. 2.11 Quality Assurance Plan (QAP) The QAP shall as a minimum cover the following issues: •

The Contractor's staff and management organization for the project, management plan, and the quality assurance organization. The person responsible for the Contractor's QAS shall be authorized and qualified to take decisions on quality assurance issues, and his reference and communication lines to the Company's overall quality assurance organization and its responsible management shall be clearly shown. Persons performing quality control and testing shall be independent of those executing or supervising the Works.


Page 17 of 43


•

Specifications

The Contractor's system of management of current documentation for the execution of the Works shall include his sub-contractors and suppliers, and shall detail: a) how it is ensured that only valid and approved documents are used for the execution of the Works, and b) the method of recording variations and amendments to the documentation.

•

Management of sub-contractors and suppliers, and requirements of their QAS's.

•

Management of documents.

•

Management of procurement.

•

Control of materials and workmanship, defects and material reconciliation, procedures for corrective actions, etc.

•

Handling of deviations, additions or variations to the Contract Documents.

•

The Contractor's initial proposed Control Plans describing important and critical verification activities based on the Tender Documents and the Contractor's own considerations in respect of execution of the Works.

2.12 Control Plans The Contractor shall present for the Engineer's approval his detailed Control Plan (CP) for all quality assurance efforts or measures for the Works or sections thereof. Such CP shall be presented to the Engineer not later than one week before the commencement of the Works or an approved section of the Works. The CP shall include controls as specified in the Contract as well as any other normal and special controls that the Contractor finds necessary in order to ensure the quality of his work. The CP shall for each control activity describe type, method, criteria for approval and documentation and who is responsible for performing the activity. If the Engineer does not give the consent to the CP as submitted, then the CP shall be amended for next submission. Subsequent changes in terms of the quality assurance work will not cause changes in agreed deadlines or contract sums. 2.13 Contractor’s Control and Documentation 2.13.1 General During the Contract period, the Contractor shall, to the satisfaction of the Engineer, document that the Works comply with the quality assurance requirements stipulated in the Contract or approved during the Contract period. Consequently, based on the approved QAP and the CP's, the Contractor shall during the execution of the Works carry out and document the quality control and its compliance with the stipulated requirements. The Contractor's quality control does not limit his responsibility for the Works according to the Contract. If the Engineer, during the period of the Contract, can substantiate that the Contractor's control and/or documentation shall be extended, the Contractor shall follow the Engineer’s written instructions to this effect at his own cost and within the agreed time for completion. 2.13.2 Method of documentation and filing during execution of the Works All control activities specified in the Control Plan shall be documented. The CP's and all other issues related to the QA System shall be kept and maintained by the Contractor in the QA filing system, which shall be kept at the project site throughout the period of the Project. On the basis of the QAP and CP's the Contractor shall produce the necessary forms for registration, log Vol 3, Section 1 – General Requirements

Page 18 of 43


Specifications

books, and check lists, etc. before work is commenced. All documentation shall be provided with identification, the date and signature of the person responsible for the documentation. The identification shall as a minimum comprise: name of project, activity number as defined in the CP, time and place of the control activity. The Engineer shall have full access to the filing system and he may without notice commission a quality audit. 2.13.3 Security The Contractor shall be responsible for the security of all plans, papers, books, typewriters or instruments from theft or fire during the continuance of the Contract and his insurance policies shall cover the office of the Resident Engineer. 2.13.4 Documents at delivery At the time of delivery of materials and goods, the Contractor shall submit the following documentation to the Engineer in two originals or in two certified copies: •

All certificates, documentation of tests etc. of materials and goods to be used in the Works;

•

All documents verifying that inspection, control and tests performed are in accordance with the Specifications;

•

Identification lists with cross-references between documents and material and goods.

2.14 Defects Liability Period The Contractor’s remedial works after completion is subject to the same control conditions as the actual construction work. 2.15 Retention of Documents The Contractor shall keep the filing system with the QA documentation for minimum 5 years after the defects liability period has expired. 2.16 Post Warranty Service Agreements Before taking over the Contractor will submit to the Engineer proposals for post warranty service framework contracts covering all the equipment provided under the Contract. These post warranty service contracts should cover the expected life of the equipment and clearly specify: •

The Bahrain company who will provide the service

•

Qualification of the proposed service company

•

Foreseen service schedule and attached costs

•

Schedules of prices and delivery duration for consumables, spare parts and accessories

•

Recommended minimum stock

•

Response time in assessing the breakdowns and repair works

•

Hourly labour costs and duration for the main repairs and service


Page 19 of 43


•

Specifications

Alternative proposal for provision of spare parts and consumables if these will be out of current manufacture before expire of the equipment lifetime

The post warranty contracts will be agreed with the Engineer during the Defects Liability period. 3

Environmental Management System A Construction Environmental Management Plan (CEMP) covering all aspects of the Contract and the Works must be prepared, implemented and maintained by the Contractor in accordance Bahrain statutory requirements to ensure that impacts on the environment as a result of construction activities are mitigated during the construction phase of the Contract. The system shall comply with a recognised international Environmental Management Standards and the requirements of Bahrain’s Supreme Council for Environment (SCE) including Supreme Council for Environment’s (SCE) EIA-12 “Construction Environmental Management Plan Guidelines” issued on 22 June 2011. The aims of this CEMP are to: •

raise environmental awareness of key personnel associated with the project.

•

provide and suggest practical measures for dealing with specific issues that may affect sensitive receptors (e.g. noise, waste management, etc.).

•

provide easy access to key environmental regulations, roles and contact details of key stakeholders (e.g. the SCE) and standards (and/or guidance) that have specific pertinence to the project.

•

provide a framework for monitoring compliance with key mitigation advice.

CEMPs have been prepared as part of the EIAs for the STP and the long sea outfall. These documents are included in Volume 6 and include reference to the relevant legislation and Ministerial Orders. These documents shall be used as a basis and developed by the Contractor to cover all environmental aspects of the construction. An Environmental Consultant shall be appointed by the Contractor to audit and monitor the implementation of the CEMP. In this capacity, the Environmental Consultant will be responsible for liaising with the SCE and other regulatory authorities, as well as the Contractor’s HSE Manager. 4 4.1

CONSTRUCTION OF THE WORKS Construction Permits The Contractor shall provide copies of any drawings and calculations as required for the issue of construction permits and the cost shall be deemed to be included within the Contract Price.

4.2

Interpretation of Drawings Neither the Employer nor the Engineer accept responsibility for any omissions from or for correctness of the representation on the drawings of existing features.

4.3

Continuous Working If, in the opinion of the Engineer, it is necessary for the safety of the Works or for any other reason the Works, or portion thereof, shall be carried out continuously by day and night.


Page 20 of 43


4.4

Specifications

Signboards Signboards shall be provided, erected, maintained and moved as required at the site, at the offices of the Engineer and at the offices of the Contractor. Primary signboards shall be provided in Arabic and in English giving the names of the Client, Consultant and Main Contractor only. The construction, size and wording of all signboards shall be subject to approval by the Engineer. The signboards shall consist of a supporting structure securely anchored to the ground and with sign plates fitted on it. All working details including siting and positioning shall be submitted for approval and shall be approved before fabrication or erection commences. Secondary signboards shall be provided where necessary to cater for specialist consultants and sub contractors. These shall be of a standard and type of construction equal to the primary signboards and shall be approved before fabrication or erection commences in the same way as primary signboards. Each sign plate shall be the same size as those used for Consultant and Contractor on the primary signboard. Portable signboards shall be provided as necessary. The Contractor shall comply with current regulations of the Municipality and obtain approval of the Municipality. The Contractor shall keep clean and maintain the sign boards and remove them and make good all works disturbed upon completion of the Contract. The Contractor shall provide space for signboards at suitable locations.

4.5

Temporary/Security Fencing of Site Security fencing shall be 2m high chain link fence as a minimum. Other temporary site fences shall be post and wire or chestnut paling or similar approved by the Engineer and shall have a minimum height of 1.2m. For work in roads, the Contractor shall follow the requirements of the Employer and the local Police. The Contractor shall mark all open trenches and other obstructions by approved signs, fences, barricades, and lights for the safety of the public. The Contractor shall instruct all persons engaged in the Construction of the Works not to trespass on land adjacent to or in the vicinity of the Site.

4.6

Setting Out and Checking the Works Works temporary bench marks shall be established at suitable locations on the Site. During the progress of the Works the value of the bench marks shall be periodically checked against the value of the Master Datum. Temporary bench marks shall be located clear of construction works.

4.7

Survey of Site The Contractor shall be responsible for producing an accurate record of the existing site showing the location of the existing structures and features and existing ground levels. The existing ground levels are shown on the Drawings are indicative only. Before any work commences on Site, the Contractor shall take colour photographs in sufficient quantity in agreement with and in the presence of the Engineer to accurately portray the


Page 21 of 43


Specifications

condition of the existing works, plant and equipment and general site area. A set of prints of these photographs of minimum size 200mm by 100mm is to be handed to the Engineer within four weeks of the Commencement Date. 4.8

Interference with Land Interests Constructional operations shall generally be confined within the Site, or such other areas of land as may be negotiated. Contractor's employees shall be instructed not to trespass.

4.9

Interference with Access to Properties Before obstructing the access to any property, satisfactory alternative arrangements must be provided.

4.10 Site Cleanliness and Environmental Protection The Site shall be maintained in a clean and orderly manner and particular attention shall be paid to the protection and conservation of any local environmental features and local habitats. Contractor’s refuse shall not be deposited indiscriminately and arrangements shall be made for all waste and general refuse such as bags, packing cases, surplus concrete, waste timber and tins to be transported to an authorised tip. No refuse is to be deposited into trenches or other excavations before backfilling. Local facilities for recycling of wastes shall be investigated and adopted wherever possible. The public highways leading to the Site, and internal access roads, which are used for access shall be kept clean and free from spoil and rubbish at all times. Site personnel shall be prohibited from urinating or defecating on Site except in properly constructed toilets provided by the Contractor If the Contractor fails to keep the Site clean then the Engineer will instruct a third party to carry out the work and the costs shall be recovered from the Contractor through the Contract. No caravans or huts are to be brought onto the Site for use as sleeping accommodation unless prior approval is obtained from the Engineer. 4.11 Demolition, Damage and Making Good Care shall be taken when demolishing or cutting away existing work or dismantling existing plant such that no adjacent work is unnecessarily damaged. Any work so damaged shall be made good. For major structures in excess of 50 cubic metres the Contractor shall put forward detailed proposals for demolition, dismantling, and temporary supports. All materials arising from demolition work, except as otherwise provided for in this clause, shall be disposed of by the Contractor as surplus material. Any mechanical and electrical equipment, pipes, fittings and valves retrieved from demolished or dismantled structures and pipelines shall, if required by the Employer, be delivered to and stacked at one of the Employer’s depots to the instructions of the Engineer. Pipes, fittings and valves not required by the Employer shall be disposed of as surplus material. Unless otherwise specified, underground structures and chambers shall be demolished to a depth of one metre below finished ground level, cleared out and filled with approved clean material


Page 22 of 43


Specifications

Where existing sewers and conduits are connected to the new systems, the length of pipes which are not incorporated into the new system shall be abandoned. Buried pipelines to be abandoned shall be sealed with a mass concrete plug to a minimum depth of 1,000 mm at either end and at any intermediate manholes. Manholes and abandoned pipelines shall be demolished to a depth of 500 mm below final ground level and the void filled with hard core or other approved fill material and surface reinstated to a finish similar to that of the surrounding area. Exposed raw faces of existing concrete or blockwork which will not have new work built on to them shall be made good with cement rendering or new blockwork as applicable. All trees and shrubs shall be protected, if necessary with fencing, unless written permission is given to fell or lop. Where any building, land, hedge, wall, fence or other existing feature is disturbed or damaged in any way the permanent reinstatement shall be made with materials similar, and not inferior, to those in the undamaged portion. 4.12 Site Drainage At all stages of the work the Site shall be properly drained so that standing pools of water are not allowed to form. Drainage works shall be in accordance with all relevant laws and regulations and the Contractor will be responsible for consultation and liaison with all relevant authorities. All proposals for drainage works shall be approved by the Engineer, but such approval will not absolve the Contractor from his complete responsibility for the Works in this regard. Silt traps shall be provided as required on any permanent or temporary drains which may be required for the removal of water during the construction period. All drains shall be maintained clear of silt until completion of the Contract. Any silting of drains, whether within the Site or not, which arises from the failure to observe this clause shall be removed. 4.13 Monitoring of Existing Structures The Contractor shall monitor any structure in close proximity to any construction activities to ensure that no damage or disturbance is caused to existing structures. The Contractor shall submit his proposals for monitoring to the Engineer for his consent prior to any construction activities on the site. The proposals shall include an assessment of the structures likely to be affected by the construction activities together with details of the proposed monitoring activities and details of proposed temporary support if necessary to ensure no adverse effect on the structures concerned. The Engineer shall have the right to suspend the Works at no cost to the Employer if in the opinion of the Engineer the Works are causing excess or uneven settlement, damage or disturbance to any structure affected by the Works, and the Contractor shall bear the cost of any repairs, reinstatement, temporary supports and the like so occasioned whether by the Contractor’s acts or omissions. 4.14 Interface with Existing Structures Where the Works involve any modifications of, or connections to existing structures, the Contractor shall maintain the integrity of the existing structure and ensure that all anticipated loading conditions are fully considered, to the satisfaction of the Engineer, so that no cracking, Vol 3, Section 1 – General Requirements

Page 23 of 43


Specifications

subsidence or any other adverse effect is caused to the existing structures, and the Contractor shall bear the cost of any repairs. 4.15 Interface with Other Contractors Whilst constructional operations shall generally be confined within the Site, the Contractor should be mindful of interfaces with others at the project boundaries. Particular attention is drawn to the construction of the Inlet Pumping Station (Terminal Lift Pumping Station) where a high level of liaison, interfacing and cooperation will be required with the Contractor responsible for the construction of the incoming Deep Gravity Sewer which will connect to the Inlet Pumping Station. Similarly, the TSE irrigation pipeline from the TSE pumping station will interface with the contractor constructing the TSE network serving the rest of the AMAS development. 4.16 Traffic Requirements The Contractor shall obtain approval from the Responsible Authorities for road closures, road diversions and notifications. The Police and Fire Authority shall also be notified. 4.17 Maintenance of Access Roads The Contractor shall maintain all public and private roads, drives and tracks which he has permission to use during the Contract and shall leave them in the same state of repair as at the commencement of the Contract. The Contractor shall ensure that all the access routes and channel crossings are suitable for his use and allow for any temporary measures that may be required to bring them up to the standard he requires. The Contractor is to restore the routes and channel crossings to their original state upon completion of the Works. Should the use of any access routes arranged by the Contractor be considered by the Employer to be detrimental or contrary to any undertakings or statements given by the Employer regarding environmental aspects of the Contract, the Engineer may withhold his consent to the use of the access route. Prior to any construction work the Contractor shall prepare and agree with the Engineer a schedule recording the condition of all structures, land and surfaces (including the depth and condition of any topsoil, if present) within the site working areas and access routes and site compounds. 4.18 Water for Testing Water will be supplied to the Contractor for testing of pipes and structures after due consultation and agreement with the Employer. The Contractor will pay at cost for the supply of water. Water may be taken subject to at least 24 hours written notice and the Contractor shall adhere to all restrictions applied by the Employer on flow rates and times. 4.19 Excavations for Water Mains and Sewers The Contractor shall comply with all the requirements of any national or local regulations or codes of practice for buried Services. Vol 3, Section 1 – General Requirements

Page 24 of 43


Specifications

If dewatering of excavations is required, the Contractor shall comply with the requirements of any relevant national or local regulations or codes of practice. In roads, compaction shall achieve not less than 95% of the natural ground compaction. The Contractor shall bear the cost of road reinstatement, which shall be undertaken by the relevant authority or an approved agent appointed by the authority in accordance with the requirements of any national or local regulations or codes of practice. 4.20 Existing Services The Contractor’s attention is drawn to the “Code of Practice for Service Installation” prepared by the Ministry of Works, Power & Water. In collaboration with the Engineer and before any work commences outside the STP site, the Contractor shall contact the local officials of each of the service authorities and shall maintain close liaison with them throughout the construction. The Contractor shall establish in advance the positions of all main services liable to interference by the construction and shall mark the position physically on the ground. The Contractor shall be in possession of a cable locator for this purpose. Apart from verifying positions to prevent damage, scrutiny is needed to identify those main services which might conflict with the Permanent Works where this is not indicated on the Drawings. Early scrutiny of these services is essential to enable any such diversions to be made in advance of the construction. Notwithstanding the scrutiny referred to above the Contractor shall take all reasonable precautions to prevent damage to existing buried main services and connections to buildings. The Contractor should note in particular that the Electricity Directorate will not permit work in close proximity to high voltage cables (11kV and above) during periods of high demand (which are normally from about mid May to mid September) other than in exceptional circumstances. The Contractor shall provide adequate temporary support to all existing services and connections that are exposed or partially exposed or otherwise weakened by the excavation. Should any damage occur he shall immediately notify the Engineer and service authority and afford every facility for the immediate repair of the affected service. The Contractor shall carefully preserve and replace all marker tapes and tiles affected by his excavations. In addition to the precautions to be taken with buried services the Contractor shall ensure that his plant and equipment do not damage pipeline or pipe supports above ground or any overhead electricity or telephone cables. He shall also take all precautions to prevent his plant from operating too closely to overhead high tension cables, and he shall, in conjunction with the Engineer and Electricity Directorate establish all necessary precautions for crossing under such cables. The Contractor shall afford the Engineer and the relevant service authorities such assistance as they may require in the preparation of records of existing and diverted services. Existing services on the site of the STP are generally the property of the Employer. Similar procedures shall, however, be followed to also ensure the protection of these services. 4.21 Electricity, Water Supply and Telecommunications Electricity, water supplies and telecommunications shall be provided to the Site for both temporary and permanent requirements. 1.

Water Supply


Page 25 of 43


2.

3.

Specifications

The Contractor shall provide adequate supplies of water for drinking and for all other purposes where required. The Contractor shall take note that it may not be possible to secure the provision of water for commissioning and testing through a connection to a public water supply. The Contractor shall allow for this in his programme for the completion of the works at his expense. Arrangements for permanent supplies shall be made with the Water Supply Directorate P.O. Box 326, Manama. Electricity Supply The Contractor shall make arrangements for the supply of electricity to his own offices, the offices of the Engineer and for use in the Works whether by means of site generators or by connection to the public supply. In the latter case arrangements shall be made with the Electricity Distribution Directorate, P.O. Box 2, Manama. Where a permanent supply will ultimately be provided the Contractor shall not assume that this is available during the construction of the Works. Telephones Where appropriate, the Contractor shall arrange with Bahrain Telecommunications Company, P.O. Box 14, Manama for his telephone connections. He shall also arrange for the telephone connections for the Engineer as specified.

4.22 Protection of Work The Contractor shall, at his own expense, case up and suitably protect all work liable to injury, either by the weather or by the method adopted for execution of the Works. Precautions especially required for the protection of new concrete and brickwork are specified elsewhere. No other work requiring the use of cement or lime shall be carried out when the shade temperature is above 40°C (104°F) nor shall any materials that have been exposed to the direct rays of the sun during hot weather be used until, in the opinion of the Engineer, sufficient time under favourable conditions has elapsed for the materials to reach a suitable temperature for incorporation in the Works. The Contractor shall provide a sufficient number of maximum and minimum thermometers so that the Engineer may observe the shade temperature at each place of mixing, placing and building. 4.23 Materials and Workmanship 4.23.1 Local and Environmental Requirements All materials and manufactured items shall be suitable for the climatic and environmental conditions in Bahrain described in this specification. The environmental conditions may be different in different parts of the Works and materials shall be selected and manufactured items designed accordingly to withstand the relevant corrosive elements. In particular: (i) (ii)

all products or materials in contact with sewage or a sewage environment shall be non-biodegradable. all products or materials in contact with potable water shall not constitute a toxic hazard, shall not support microbial growth, shall not cause taste or odour cloudiness or discolouration of the water, and shall be approved by a recognised certifying authority as being suitable for use in potable water supply systems.


Page 26 of 43


Specifications

All local customs, laws and regulations relating to the supply or source of materials shall be complied with. 4.23.2 Quality of Manufacture and Standards All materials and manufactured items supplied for incorporation in the permanent works shall be new, of high quality and of sound workmanship. They shall be purchased only from approved suppliers who shall be capable of demonstrating the suitability of their products by reference to similar works or certified test results. Materials and manufactured items shall normally be certified as complying with relevant specifications of a recognised national or international standards organisation which shall be subject to the approval of the Engineer. Except where otherwise indicated in the Contract, the edition of an approved standard shall be that current 42 days prior to the date for the return of tenders. The Schedule of Approved Standards and Guidance Publications in Volume 3A, Section 3, Civil Specifications (Section S) lists approved standards as a quality guide for the materials and articles to be provided. This schedule in no way prejudices the approval of any other equivalent or superior national or international standards. Also included in this schedule are publications for guidance on procedure and practice. Where the requirements of this specification and an approved standard differ, the more stringent requirement shall apply. Should the requirements of this specification and an approved standard be incompatible, the requirements of this Specification shall take precedence. Copies of the appropriate edition of any national or international Standards in English which may be called for as being required in the execution of the Contract shall be provided for the sole use of the Engineer. These may include alternative Standards to those to which the materials are manufactured for use as a comparative quality guide. The Standards will remain the property of the Contractor and will be returned to him at the end of the Contract. Any reference to a Manufacturer/product is to be taken as indicative of quality only. 4.23.3 Approval of Suppliers, Manufacturers, Materials and Manufactured Items Prior to the placing of any order for materials or manufactured items, the approval procedure described under this clause shall be followed. All requests for Approval shall be submitted in triplicate. The information shall be clearly and neatly presented in a standard format to be agreed with the Engineer. All submissions shall have a document number and revision reference in accordance with the Contractor’s quality assurance system. No orders shall be placed until one copy of the final Request for Approval has been returned duly signed and dated by the Engineer or his representative. Generally a two stage approval procedure shall be followed as described below. The first stage requires the Contractor to demonstrate that his proposed supplier/manufacturer has the necessary experience, competency and reputation in the field of the proposed supply. The second stage follows approval of the supplier and comprises a full technical submittal. 1.

Approval of Supplier/Manufacturer The Contractor shall submit to the Engineer full supplier/manufacturer. The submission shall include: •


details

Name and address of proposed supplier or manufacturer

Page 27 of 43

of

his

proposed


Specifications

•

Background and history to demonstrate compliance with the specified requirement for experience, competency and reputation in the field of the proposed equipment supply.

•

Reference numbers and title of relevant specifications of a recognised national or international standards organisation with which the materials or manufactured items will comply together with copies of the specifications in English where required by the Engineer.

•

Manufacturers’ literature and data sheets for articles and fabricated items.

•

Details of reference sites.

•

Contact details for referees.

•

Any other information called for in particular clauses of the Specification

Period for approval is 14 days subject to submitted information being of a satisfactory standard. For minor items of supply the approval of Supplier/Manufacturer stage may be waived at the discretion of the Engineer. 2.

Full Technical Submission Following approval of the supplier/manufacturer, a full technical submission shall be made as described elsewhere under this clause. • Evidence (by copy of letter of enquiry or otherwise) that the attention of the proposed supplier or manufacturer has been drawn to the particular climatic and environmental conditions in Bahrain. •

Samples of materials representing the quality of the bulk of such materials the Contractor proposes to use.

•

Sufficient information to demonstrate that the materials or manufactured items are suitable and comply with the Specification including reference to all relevant Specification Clauses.

•

Detailed design calculations and design, fabrication and installation drawings

•

Any other information called for in particular clauses of the Specification.

Provided the information requested is satisfactory, the Engineer’s approval will be given within a period of 21 days. Where additional information or clarification is required, the 21 day approval period will commence on receipt of the satisfactory additional information. Prior to despatch to Site or to a designated place of storage the following shall be provided: i)

Facilities for inspection and testing at suppliers' pits or quarries, manufacturers’ works or at approved independent testing centres as appropriate. Inspection and/or witness testing may be carried out by the Engineer or the Engineer’ Representative or other appointed Inspector.

ii)

Details of the supplier’s or the manufacturer’s quality control test procedures.

iii)

The carrying out of tests as stated in the current quoted or appropriate British Standard or other national standard as appropriate, and such other tests as are necessary in the opinion of the Engineer, to determine that the Works comply with the Specification either under test conditions at the manufacturer’s works, on site or elsewhere under normal working conditions. Where tests and inspection have been completed to the


Page 28 of 43


Specifications

Engineer’s satisfaction and when the test certificates, etc., have been checked the Engineer will confirm acceptance in writing and the items concerned shall not be delivered or incorporated in the Works until this acceptance has been received. iv)

Four copies of all test certificates where appropriate to be supplied to the Inspecting Engineer within two weeks of any witnessed tests.

v)

Shipping and consignment identification details to be submitted to the Engineer.

vi)

Where witness tests are not required the test certificates and/or certificates of compliance with the appropriate standard are to be forwarded to the Inspecting Engineer within two weeks after instructions to waive witness tests have been received.

vii)

Each certificate shall give sufficient information to enable the Engineer to identify the material or equipment to which it refers prior to the issuing of his release order.

viii)

No inspection or passing by the Engineer, or the Inspecting Engineer of the Work, or manufactured item, or materials covered by this Contract, whether carried out or supplied by the Contractor, shall release him from any of his obligations under the Contract.

ix)

The Engineer reserves the right to require the Contractor to meet any extra costs which are occasioned by failure of the Contractor to comply with the above testing and inspection requirements including the provision of test certificates, curves, etc., or, which in the opinion of the Engineer, are due to insufficient care having been taken by the Contractor or his Sub-Contractor before presenting the item for inspection or test. If unauthorised delivery has taken place the Contractor shall if required by the Engineer return the item to the manufacturer for inspection and/or witness testing by the Inspecting Engineer at the Contractor’s expense.

Samples of all building and civil works materials shall be supplied to the Engineer for approval. Where appropriate, sample panels of built materials shall be constructed. 4.23.4 Approval of Construction Methods For all elements of the Works, fully detailed method statements describing proposed construction techniques and programme for execution shall be submitted to the Engineer in duplicate. These shall be supported, where applicable, by calculations for temporary works for supporting excavated faces and shuttering of concrete. Written approval shall be obtained before any work is commenced. Approval of the proposed construction techniques and methods shall not relieve the Contractor of his contractual responsibilities for the care of the Works or of his liabilities for accidents or damage. 4.24 Site Safety and Welfare 4.24.1 Safety, Health and Welfare The Contractor shall be responsible for the health, safety and welfare of all persons working on or visiting the Site. He shall obtain copies of the Ministerial Orders current at the date of Tender and shall comply with these and with any legislation enacted during the Contract Period that affects working conditions, safety, health or welfare of his employees or those of the Engineer or Employer. Vol 3, Section 1 – General Requirements

Page 29 of 43


Specifications

The Contractor’s attention is drawn to the guidance manuals on health and safety referred to in the Schedule of Approved Standard and Guidance Publications in Section S to which reference should be made. The Contractor shall appoint a full time Health and Safety Engineer/Co-ordinator whose role shall be to promote, monitor and enforce safe working practices on the Site for the whole duration of the execution of the contract. The Health and Safety Engineer/Co-ordinator shall be a senior member of the Contractor’s staff. The Contractor shall arrange and undertake regular safety briefings for all of his staff, workmen and sub-Contractor’s staff. In addition, he shall ensure that regular safety liaison meetings are held between the Contractor, Engineer and Employer. The Contractor shall carry out a safety audit of the Site at intervals not exceeding one month. The Contractor shall submit to the Engineer method statements for all safety proposals in advance of the commencement of work, approval of which by the Engineer shall not relieve the Contractor of his obligations to comply with all Decrees, Statutes, Ordinances, Regulations or bye-laws. He shall make available for inspection by the Engineer all registers, reports and certificates which the Contractor is required to keep or issue in respect of safety matters and accidents. Contractor shall ensure that all personnel engaged on this Contract, including his subcontractors, are aware and adhere to the safety requirements relating to the Contract and associated site works and shall only employ personnel who have undergone recognised training and experienced in the works to be undertaken. Experienced personnel shall supervise any unskilled labour or trainees during the works. The Contractor shall note that any site personnel found to be working in breach of the safety requirements or procedures shall be first warned to correct their working methods or procedures, if repeated breaches occur, the personnel shall be removed from site. The Contractor shall ensure his personnel comply with any existing regulations in force at the STP. 4.24.2 Permits to Work All site works shall be covered by a Permit to work, issued by the proper Authorities (Employer, Central Planning Unit, etc.). The Contractor will undertake all the necessary procedures to ensure that all permitting requirements are identified, permits are obtained at an early stage and then used as appropriate. A System for issuing permits for the site works must be implemented, documented and maintained by the Contractor during the period of the Contract. Details of the system proposed shall be submitted for the approval of the Engineer, which if granted will not relieve the Contractor of any of his responsibilities, nor shall reasonable refusal to approve entitle the Contractor to extra payment. The Contractor shall provide detailed method statements as appropriate to complete permit authorisation. These method statements shall identify the working methods, risks and precautions necessary to complete the works. The Contractor shall not commence site works unless a valid Permit to work has been issued for the site works to be undertaken. Permits to site works issued will include, but not be limited: i)

Handover of the site or working area by the Employer to the Contractor.

ii)

Works requiring access into confined spaces


Page 30 of 43


Specifications

iii)

Works associated with existing or live electrical equipment.

iv)

Works requiring excavation.

v)

Pumping operations.

vi)

Hot works.

vii)

Operation and use of mobile or static cranes

All Permits shall be time limited and issued in accordance with the relevant Authority procedures. Blanket permits shall not be issued for the works under any circumstances. The Contractor shall adhere to the requirements of the Permit, including methods of works agreed whilst the Permit to work is in operation. 4.24.3 Site Hazards Hazards on the Site include: i)

Underground pipes and cables.

ii)

Overhead cables.

iii)

Flammable materials.

iv)

Mechanical plant and equipment.

v)

Operational staff and their Contractors and Vehicles.

vi)

Confined spaces.

vii)

Sewage and Sewage products, and the risk of leptospiral jaundice from contact therewith.

viii)

Live electrical equipment or services.

ix)

Deep tanks, chambers and manholes

x)

Sun radiation

xi)

High summer temperatures and high humidity

xii)

Falling excavations

4.24.4 Precautions Against Leptospiral Jaundice The Contractor shall ensure all personnel engaged in the site works are aware of the risks and precautions against Leptospiral Jaundice. The following provides guidance on working in sewage-contaminated sites: i)

After working in contact with sewage, or anything which might have been contaminated by it, wash your hands and forearms thoroughly with soap and water.

ii)

If clothes or boots are contaminated with sewage, wash thoroughly after handling them.


Page 31 of 43


Specifications

iii)

It is particularly important to do this before taking any food or drink.

iv)

Wet protective clothing should be dried as soon as possible.

v)

Infection may enter through breaks in the skin so thorough first aid treatment of all wounds is important.

vi)

Take particular care to wash thoroughly any cut, scratch or abrasion of the skin as soon as possible whether the injury was caused at work or not.

vii)

Apply an antiseptic to the wound with a clean piece of cloth or cotton wool and protect it with a strip of gauze completely covered with adhesive plaster.

viii)

Keep the wound covered until it is quite healed. Antiseptic gauze and impermeable plaster are available at place of work.

ix)

If you suffer any cut, scratch or abrasions of the skin, it must be covered with a waterproof plaster before entering the place of work.

x)

Avoid rubbing your eyes, nose or mouth with hands during work.

xi)

Every accident at work, however trivial, must be reported.

The Contractor shall ensure all personnel, including subcontractors are advised of the risks and precautions relating to Leptospiral Jaundice and shall display the above guidance on site in the appropriate languages of his personnel. 4.24.5 Excavations Excavations shall be adequately supported against collapse. The Contractor shall provide protective safety barriers and appropriate bunting for the protection of the general public and personnel working on the STP. The Contractor shall also provide suitable and safe bridging over trenches and excavations where required for pedestrian and vehicular access. 4.24.6 Work in Public Highways Before work commences, adequate advance warning signs, clearly signposted diversions for traffic and pedestrians and traffic controls shall be provided to the approval and requirements of the Traffic Directorate, the Ministry of Works, Power and Water and the Engineer. The Contractor shall provide and maintain night lights and shall ensure their operation during hours of darkness by night watchmen and/or night patrols. 4.24.7 Safety Equipment All safety helmets, coats, gloves, footwear, goggles, breathing apparatus, ventilation equipment and any other protective apparel or equipment deemed necessary by the Engineer for the protection of the Contractor’s staff shall be provided by the Contractor and maintained in good order.


Page 32 of 43


Specifications

4.24.8 Welfare Facilities and Site Cleanliness The Contractor shall provide and maintain in proper order suitable messing, sanitary conveniences and washroom facilities, for use by all persons connected with the construction of the Works. The welfare facilities shall be provided within 1 week of commencement of the works on site and shall remain in place until handover of the works. The Contractor as a minimum shall keep on site one full stocked first aid kit and adequate potable water for drinking and washing for use of the site personnel. Rubbish, surplus packaging and materials not required for the works shall be removed from the Site on a weekly basis and the Contractor shall ensure that the site is kept in a clean and tidy condition. 4.24.9 Use of Equipment All manufacturer’s instructions and recommendations for the use, application, erection, or construction of any material or item of equipment or plant shall be followed precisely. Care shall be taken to protect all employees when using power tools or materials which will produce a fine dust and in particular all asbestos based products. Precautions may include: (a) (b)

4.24.10

Operator to stand upwind of the operation and wear an approved respirator and goggles. Overalls to be worn consisting of 60% polyester fibre and 40% cotton, to be worn whenever possible. Testing of Contractor's Lifting Equipment

Every hoist, lift, sling, chain, rope, pulley block and any other lifting tackle used in constructing the Works shall be thoroughly examined by a competent person at least once every 6 months, be test loaded to 150% of the safe working load and then tagged with the safe working load and date of successful testing. All parts and working gear, whether fixed or movable, including the anchoring and fixing appliances of every crane and lifting machine shall be of good construction, sound material, adequate strength and be properly maintained. All parts and gear shall be examined by a competent person at least once every twelve months. An up to date register of all such equipment and examinations shall be maintained and shall at all times be available for inspection by the Engineer. 4.24.11

Dangers of Working in Confined Spaces Attention is drawn to the dangers of working in confined spaces. In addition to shafts, tunnels, closed tanks, etc., any confined space with limited ventilation which is also connected with water in or from a closed conduit or borehole, or is below ground level, should be treated as a potentially hazardous location where dangerous gases may be present and prior to entry adequate safety precautions must be taken in accordance with current good practice. Reference shall be made to the relevant guidance publications listed in the Schedule of Approved Standards and Guidance Publications in the document.


Page 33 of 43


4.24.12

Specifications

Dangers of Working in Sewers and at Sewage Treatment Works 1.

All personnel working on the Site shall be made aware of the dangers of working in live sewers and at sewage treatment works; in particular the risks of physical injury, of bacterial infection from contact with sewage, of exposure to dangerous gases; and of explosion of sewage gases.

2.

Safeguards must be taken in accordance with current good practice and attention is drawn to guidance publications listed in the Schedule of Approved Standards e.g. National Joint Health and Safety Committee for the Water Service. Health and Safety Guidelines:

3.

4.

•

No. 2 - Safe Working in Sewers and at Sewage Works

•

No. 3 - Respiratory Protective Equipment.

The Contractor shall not permit any employees to enter “live” chambers without the express permission of the Engineer in writing. Permission will only be given on the standard form “Authority to work within a live Sewer,” copies of which may be obtained from the Engineer. The following equipment shall be available at point of entry for personnel entering sewage manholes, pumping stations or other structures into which sewage or sewage gas can enter: (a)

Oxygen deficiency and flammable gas and hydrogen sulphide gas detectors.

(b)

Rope, safety harness, helmet and safety lamp for each person entering the sewer;

(c)

Two sets of compressed air breathing apparatus including 1800 litre capacity cylinders, at least 70 linear metres of high quality rubber hose all for 45 minutes of man working time;

(d)

One set of emergency escape breathing apparatus with minimum 800 litre capacity cylinders in sling harness and face mask with gas tight seal. Air supply operation to commence automatically when the face mask is fitted and breathing begins.

5.

Naked lights shall not be used in the vicinity of the structure. No smoking shall be permitted.

6.

At least two people shall remain close to the point of entry who shall have noted beforehand the nearest telephone and telephone number of the nearest hospital, and shall be thoroughly familiar with the use of emergency breathing apparatus and other safety equipment and procedures.

7.

Ventilation shall be provided by removing manhole covers to upstream and downstream manholes at least 15 minutes before the structure is entered or such other method as is appropriate for the structure including, where necessary, forced ventilation.

8.

The atmosphere shall be tested at points of entry and exit and continuously monitored while personnel are present. If dangerous gases are present, either (a) breathing apparatus shall be worn or (b) ventilation shall be continued and the atmosphere retested until such time as no dangerous gases are detected.


Page 34 of 43


4.24.13

Specifications

9.

Entry shall be authorised by a responsible person. The Contractor shall supply a list of the names of such persons to the Engineer before any work in live sewers etc., is carried out.

10.

All electrical equipment, e.g. power drills, shall be intrinsically safe (i.e. non-sparking).

11.

All equipment shall be inspected and tested daily and all air cylinders for breathing apparatus shall be filled with air from compressors manufactured for that specific purpose and housed and used in accordance with the manufacturers instructions. Emergency Arrangements

A current list of names, addresses and telephone numbers of the Contractor's staff responsible for organising emergency work outside of normal working hours shall be provided to the Engineer and maintained current. 4.24.14

Contractor’s Plant and Equipment The Contractor shall at all times be responsible for the adequacy, efficiency and sufficiency of his and his sub-contractor’s plant and equipment which shall be of such type and size, and used in such manner, as the Engineer shall approve. Details of the plant proposed shall be submitted for the approval of the Engineer, which if granted will not relieve the Contractor of any of his responsibilities, nor shall reasonable refusal to approve entitle the Contractor to extra payment. If circumstances arise which in the Engineer’s opinion make it desirable that the use of plant or equipment be changed or suspended, the Contractor shall make such changes at his own cost. In particular the exhausts of diesel engined plant shall be modified if necessary to prevent nuisance from smoke and noise. The Contractor shall also ensure minimum pollution of working areas with fuel oils. The Engineer shall be entitled to withhold or withdraw his authority for the use of plant or equipment which is too noisy in the circumstances, or which may endanger members of the public, passing vehicles, or adjacent roads, services and structures.

4.24.15

Abatement of Noise The Contractor shall make every effort to keep the nuisance caused by noise to a minimum and consideration must be given to using the quietest plant available. If instructed by the Engineer, the Contractor shall use electric dewatering/overpumping pumps (with the generator, if required, located remotely to reduce the noise). The cost of providing such electric pumps is to be allowed for in the rates of work. The Contractor shall comply with all relevant regulations, decrees, and statutory requirements relating to restrictions placed on noise from construction work. Blasting shall not be used unless otherwise approved by the Engineer. All pneumatic breakers shall be fitted with mufflers. Noise mitigation measures, agreed by the Engineer, shall be provided for diesel plant when instructed by the Engineer. Methods of working shall be devised and arranged to minimise noise impacts, and experienced personnel with suitable training shall be employed to ensure that these methods are implemented. Particulars of all constructional plant which is likely to cause excessive noise shall be submitted to the Engineer. The particulars shall be submitted before the plant is used on site. Unless


Page 35 of 43


Specifications

otherwise permitted by the Engineer, trials of the plant shall be carried out to demonstrate that the plant can be operated which will minimise noise during the works. The trials shall be carried out in the presence of the Engineer. The plant shall not be used on site until agreed by the Engineer. The noise level of any construction work other than percussive piling, measured at site boundary, shall not exceed an equivalent sound level (Leq) of 75 dB(A). The Contractor shall, prior to commencement of the relevant construction work, carry out baseline monitoring to determine baseline noise levels at the nearest properties along the pipeline route. Baseline monitoring shall be carried out for at least one week, and at locations and to a schedule to be submitted to, and agreed by, the Engineer. Impact noise monitoring shall be carried out at all the agreed locations whenever construction work is being carried out. The measurements will be determined by the Engineer to measure the maximum noise impact during the period. Measurements will not be taken if the Contractor is not working during these periods. Monitoring will be undertaken according to the following schedule: 1. 2.

At least one Leq measurement between 0700 and 1900 Saturday to Thursday, three times each week; and As determined by the Engineer from time to time and when any powered mechanical equipment is operating.

Whenever complaints are received, or if the maximum allowable levels are exceeded, immediate action shall be taken by the Contractor in accordance with an action plan to be submitted to, and as agreed by, the Engineer. A weekly report of all noise monitoring data shall be prepared by the Contractor and submitted to the Engineer, including at least the following: 1. 2. 3. 4. 5.

Copy of all data; Highlighting of any failures to comply with the criteria set out herewith; Implementation of the action plan when the levels are exceeded Identification of reasons for non-compliance Identification of additional mitigation measures take as a result of 2 above.

If monitoring of the noise level shows, in the opinion of the Engineer, an excessive noise level, the Contractor shall take all necessary measures to ensure that the actions of the Contractor are not contributing to the excess. The measures shall include, but not be limited to, the following: 1. 2. 3. 4.

Checking all constructional plant; Maintenance or replacement of any constructional plant contributing to the excess; Installation of constructional plant soundproofing, provision of alternative constructional plant, or erection of sound barriers; and Review and modification of all working methods and scheduling of activities.

The Contractor shall inform the Engineer of all measures taken, and shall submit to the Engineer a written report and proposal for action, whenever monitoring shows that an excessive noise level is arising. If the proposed remedial measures include the use of additional or alternative constructional plant, such plant shall not be used on the works until agreed by the Engineer. It proposed remedial measures include maintenance or modification of previously agreed plant, such plant shall not be used on the works until the proposed maintenance or modification has been completed and the adequacy of the maintenance or modification has been demonstrated and agreed by the Engineer as being satisfactory.


Page 36 of 43


Specifications

If approved remedial measures are not being implemented and serious impacts persist, the Contractor shall cease related parts of the work until the measures are implemented. Nuisance caused by noise shall be kept to a minimum with consideration given to the use of the quietest equipment available. All pneumatic breakers shall be fitted with mufflers. Equipment should not normally be operated during the night, weekends or public holidays except for pumps dealing with sewage flow or dewatering excavations which are to be sited to cause the minimum inconvenience to the public. 4.24.16

Accident Reporting The Contractor shall notify the Engineer in the event of any/all accidents that occur on site, with 24 hours. Each notification shall include the cause of the accident, personnel involved; injuries sustained (if any) and proposed measures/methods to prevent re-occurrence. The Contractor shall notify the Engineer and Divisional Head Occupational Health and Safety in the event of any/all accidents that occur on site which involve lost time, medical treatment etc, within 2 hours of the accident occurring. The Divisional Head Occupational Health and Safety contact details will be provided at the Contract award meeting All accidents notifiable to the Divisional Head Occupational Health and Safety shall be formally reported to the Engineer and Divisional Head Occupational Health and Safety, in the form of an accident investigation report. This accident report shall be submitted within 7 days of the accident.

4.24.17

Electrical Safety All temporary electrical installations required during the works, including generator supplies, shall conform to the Safety Regulations stipulated by Ministry of Labour and Social Affairs Ministerial Order No.33-1997 “Precautions for protection of workers during work from hazards of electricity” and the current edition of the Ministry of Water and Electricity “Regulations for Electrical Installations”. All equipment and cabling shall be in good condition and electrically safe. The installation and equipment shall be tested at regular intervals with copies of test/inspection certificates issued to the Engineer. Any electrical supply derived from the public supply system shall have at its origin a suitably rated earth leakage circuit breaker in addition to overload and short circuit protection devices. The supply shall be distributed to the site from a metal clad MCB distribution board. Each outgoing circuit shall be provided with a suitably rated MCB with neutral and earth connections. The Contractor shall install an earth connection independent to the public supply earth for his temporary electrical installation. This earth shall be in the form of ¾” diameter copper clad earth electrodes driven into the earth, to achieve an earth resistance of not more than 2 ohms. All site temporary distribution or sub-distribution cabling and cabling to fixed equipment/installations shall be carried out using suitably sized multi-core armoured cables with correct glanding arrangements into equipment. The contractor shall not rely upon the cable armouring to provide the earth continuity conductor; one core of the cable shall be connected to earth. The cables shall be routed as to prevent or reduce potential damage from the construction works or equipment. Sub-distribution boards shall be provided to enable portable equipment to be “plugged-in” locally near the work area. The sub-distribution boards shall be metal clad MCB distribution boards, fitted with suitably rated MCB’s, with socket outlets provided for connection of portable equipment. The preferred type of socket outlet and plug is to BS4343 design. The use of plug adaptors is prohibited.


Page 37 of 43


Specifications

Final circuit cabling to portable equipment shall be carried out in suitably rated multi-core rubber sheathed flexible cables. All connections shall be made through proprietary plugs and socket outlets only. One core of all flexible cables shall be connected to earth. Jointing or splicing of cables is strictly prohibited. All electrical equipment and services shall be weather proof to IP54 or provided with suitable weatherproof enclosures. Where equipment is exposed to direct sun light suitable enclosures shall be provided to shade the equipment or services. 4.24.18

Chemical Hazards All chemicals brought onto site shall be stored within the manufactures containers and shall be fitted with secure lids. The containers shall clearly indicate the contents and quantities within the container for identification purposes. Chemicals may be in the form of solvents, resins, alkalidies or acids including paints and adhesives. The Contractor shall issue to the Engineer for approval and retain on site the manufactures or suppliers chemical hazard data sheet. The chemical hazard data sheet shall be issued to the Engineer prior to any deliveries to site. The Contractor shall remove chemicals that are delivered without approval of the Engineer. The Contractor shall limit the storage of chemical on site that are required for that days use. Additional requirements or stocks shall be held off site at the Contractors stores until required. The Contractor shall remove from site all unused chemicals or empty containers prior to handover of the works. All unused chemicals shall be disposed of in accordance with the manufactures instructions and in compliance with the current environmental legislation.

4.25 Site Offices, Attendance and Site Facilities 4.25.1 Location of Contract Offices and Other Contract Facilities The site offices shall be located within the area allocated for the site. A plan shall be submitted within two weeks of the award of the Contract showing the proposed locations on the site of: •

The offices for the Engineer.

•

The Contractor’s site offices.

• The Contractor’s stores, plant and maintenance yard and materials stockpiling facilities. •

Areas for the temporary storage of excavated material.

The Engineer’s office shall be in close proximity to the Contractor’s office and shall have a reasonable view of the site and the traffic entering and leaving the site. The Contractor shall, within 4 weeks of the Commencement Date, hand over to the Engineer a fully completed, furnished and equipped Engineer’s office. The contractor shall provide suitable temporary office space for the Engineer until the office is completed.


Page 38 of 43


Specifications

4.25.2 Offices and Facilities for the Engineer Suitable offices with washing and toilet facilities and adjacent car parking facilities shall be provided for the exclusive use of the Engineer and his staff. They shall be equipped, maintained, cleaned, heated and provided with adequate lighting and power. The offices shall be removed from the site after completion of the Contract and the site reinstated. No offices or associated equipment shall be removed without the written consent of the Engineer. (i)

Accommodation

The following will be required as minimum superficial areas Senior Resident Engineers office 15 square metres Resident Engineer’s Offices 2 no. at 12m2 each Secretary’s office/Reception Area/’hot desk’ 15m2 (the office shall include a visitor “hot desk” with power point, network connection etc.) Meeting Room 25 square metres Additional Staff Offices 6 no at 8m2 each Car Ports shall be provided for 12 cars with a minimum roof area of 15m2/car Kitchen Toilets (internal) The office shall be of approved design, insulated, air conditioned throughout and internally wired for lighting and power. The floors shall be covered with a suitable approved hardwearing surface for easy cleaning. The walls and ceilings shall be well insulated with approved material in keeping with the ambient temperatures in Bahrain. Ceilings shall be flush and flat and the office shall be suitably decorated internally and externally. The height from floor level to ceiling shall be at least 2.300 metres. Windows shall be double glazed with a suitable number of openings which shall be fitted with flyscreens. All window units shall be burglar-proof and fitted with venetian blinds. Adequate tubular electric lighting fitted with diffusers shall be included together with all associated wiring and switchboards, socket outlets and a separate 15 Amp supply to air conditioning units. There shall be 3 No. sockets for each room in addition to the A/C and cooker points. One telephone line shall be provided with a telephone in each office and one fax machine. The line shall be suitable for international calls. Use of the telephone for international calls will be controlled by a method agreed with the Contractor. The site offices shall be provided with a single broadband (min 4mbps, unlimited data) internet connection networked throughout the offices. (ii)

Furnishing and Equipment

The following furniture, fixtures and office equipment shall additionally be supplied to the approval of the Engineer in sufficient numbers to service 10 full time staff, Employer’s staff, visitors and meetings for up to 12 people. The Engineer reserves the right to reject, and require the replacement of, any item which in his opinion is sub-standard. If any item of equipment requires servicing or repair, an equivalent replacement shall immediately be provided in the interim. Vol 3, Section 1 – General Requirements

Page 39 of 43


Specifications

General Items: Air conditioning equipment sufficient to maintain the entire office below 24ºC throughout the year 10 No adjustable padded swivel chairs. 12 No. additional padded chairs 2 No. drawing benches, 1.5m long with plan chest under. 4 No. four drawer lockable steel filing cabinet. 4 No. whiteboards with pens and cleaner. 2 No. table, minimum size 1.8m x 0.9m. 2 No. tables, minimum size 1.2 x 0.9m 4 No. lockable desks, 1.8 m x 0.9m. 6 No. additional lockable desks 1.2m x 0.7m. Computer and printer desks/workstations to suit equipment specified below. 2 No. approved fire extinguishers. 1 No. approved first aid kit (wall mounted) Shelving as required

Office Equipment: 4 number new personal computers with the following minimum specification:

i)

Quad core processor

ii)

4GB RAM

iii)

500GB hard drive

iv)

DVD rewriter (with supply of blank DVD-WR/R & CD-WR/R disks)

v)

Network port

vi)

22” flat panel LCD screen

vii)

All other ancillaries.

The computer shall be loaded with latest versions of Windows, MS Office, MS Project, Abobe PDF reader/writer and drawing software compatible with that used for the Contractor’s design. All software shall be original, licensed versions supplied with original disks. 4 no. additional office computers and ancillaries suitable for word processing, spreadsheets, internet etc loaded with office software. Routers and switches as necessary for full networking of all computers A4 Laser printer (networked) A4 colour printer (networked) with supply of inks 1 no. 500GB portable hard drive (for backup) Vol 3, Section 1 – General Requirements

Page 40 of 43


Specifications

Desk top photocopier with A3 and A4 paper size copying facility and sheet feeder complete with paper supply. Photocopier shall be network compatible to enable printing from networked computers. 4 No. ten-digit scientific calculators. Miscellaneous office equipment such as correspondence trays, waste paper bins, paper punches, staplers etc Supplies of expendable materials including pens, pencils, paper, level books, marker paint etc.

Kitchen Equipment: Electric water heater Small microwave oven Refrigerator with freezer compartment and ice-making facilities Electric kettle Water cooler Sink unit with hot and cold running water Cupboards Working surface Glasses, crockery and cutlery (sufficient to supply meetings of up to 12 people)

Toilet Facilities Two European water closets (separate mens/ladies), each with one hand basin and wallmounted mirror shall be installed together with an approved water heater. 4.25.3 Attendance upon the Engineer Attendance items to be provided for the Engineer and his staff shall be: •

The daily cleaning of offices, toilets, etc. and car washing.

•

The provision of a regular supply of drinking water for the supervisory staff and their visitors.

•

The provision of a regular supply of soap, toilet rolls, towels (including tea towels), tea, coffee, sugar and milk.

•

The arrangement and payment of electricity, water and telephone services including connection and disconnection.

•

Provision of labourers and chainmen as required by the Engineer to assist in any of his supervisory duties at any time of the day or night.

•

Provision of Secretary/Receptionist for sole use.


Page 41 of 43


Specifications

4.25.4 Vehicles for Overseeing Organisations The Contractor shall provide four vehicles as described below for the exclusive use of the Employer and his representatives for any purpose in connection with the Works. The Contractor shall arrange the proper service and maintenance of the vehicles at the dealership workshop. The vehicles shall be licensed and insured for use both off-road and on the public highway and shall have comprehensive cover for any qualified driver authorised by the Employer and/or his representatives together with any authorised passengers and the carriage of goods and samples. The Contractor shall provide maintenance in conformity with the vehicle manufacturer’s recommendations and shall keep the vehicles clean inside and out on a regular basis. A suitable replacement shall be provided for any vehicle out of service for more than eight working hours. The vehicle is to be suitable for off-road use with high ground clearance and an engine of minimum power output of 130 ps, seating for a minimum of 5 persons, 4 wheel drive, all terrain tyres, hill decent control, ABS braking, power steering, front, rear and side airbags and an automatic climate control system. The vehicle shall be supplied free from markings identifying any company associated with the Contract. The equipment shall include fire extinguisher, hazard flashing unit, heavy duty suspension, spare wheel, internal and external mirrors, mud flaps, floor mats to all foot wells and to the rear load bay, tow rope, towing hooks front and rear, laminated windscreen and a roof mounted amber flashing light bar comprising at least two lights. The light bar is to be operable from a clearly identifiable switch mounted on the dashboard of the vehicle. Vehicles shall be in as new condition and no more than 3 years old. The Contractor shall submit a schedule of the proposed vehicles for the use of overseeing organisations for the approval of the Engineer. The schedule shall be based on the above requirements and detail the manufacturer, model and year of registration of each vehicle and the type and duration of insurance for each vehicle. The schedule shall also indicate the proposed date of supply for each vehicle. Following approval of the schedule, the Contractor shall not vary any element of the supply without the written approval of the Engineer. Supply of vehicles is covered by a Provisional Sum in the Schedule of Prices. 4.25.5 Protective Clothing for Engineer and Staff Sufficient protective clothing shall be provided for the sole use of the Engineer and his staff and visitors to site as listed below. Up to 6 sets of the following should be provided for use at all times: •

White safety helmets.

•

High Visibility site jackets.

•

Lightweight site jackets/coats

•

Safety boots

•

Plastic coated working gloves.

The numbers and sizes of each of the required items shall be confirmed on site by the Engineer.


Page 42 of 43


Specifications

4.25.6 Facilities for Checking and Setting Out, Examination, Testing and Measuring the Works The equipment listed below shall be provided, cleaned, serviced and maintained for the sole use of the Engineer and his staff together with any other such items as may reasonably be required for checking the setting out and for measuring the Works. All equipment must be to the approval of the Engineer. The equipment shall not be used by any of the Contractor's staff without authority from the Engineer. All equipment supplied to the supervisory staff will be returned to the Contractor at the end of the Contract. 1 Level, tripod and staff 50m Steel and cloth tapes 4 no. 5m steel tapes Ranging rods Reinforcement cover meter Elcometer for measuring paint thickness Sound level meter Gas detection equipment (to detect hydrogen sulphide, inflammable gases, lack of oxygen). Slump cone and tamping rods Concrete thermometer Asphalt thermometer Maximum and minimum thermometer 3 No. access cover lifting keys 3 No. Waterproof torches and mirror (for pipeline inspection) Electrical/electronic digital multimeter 1 no. digital SLR camera having the following minimum specification: –

>10megapixels

–

18 -55mm lens

–

Including >8GB memory card and carrying case

In addition, the Contractor shall make available to the Engineer upon request, one theodolite and tripod. 4.26 Public Relations The Contractor shall appoint a full time Arabic and English speaking Public Relations Officer whose role shall be to liaise in conjunction with the Engineer with public bodies, service providers, local residents and others affected by the works in order to promote the effective construction of the works with the maximum co-operation of and minimum disruption to the public. Vol 3, Section 1 – General Requirements

Page 43 of 43


Specifications

The Public Relations Officer shall be a senior member of the Contractor’s local staff.


Page 44 of 43


Specifications

APPENDIX I Drawings and other information forming part of the Contract Drawings and other information forming part of the Contract are contained in Volumes 5 and 6.

Vol, 3 Section 1 – General Requirements

I-1


Specifications

APPENDIX II Addresses of Statutory Organisations NOT USED


II-1


Specifications

APPENDIX III SOURCE COUNTRIES The Contractor will be required to provide, prior to the signature of the contract, proof of origin of materials and source of supply and manufacture of any item of plant not of the Contractor’s manufacture in the form of a Certificate of Origin or other official documentation as prima facie evidence. Where the provision of a Certificate of Origin is not possible (in many countries these are only issued against presentation to the Chamber of Commerce of commercial invoices), the Contractor can in these cases submit its own declaration. The official Certificates of Origin must then be submitted with the first invoice. Failing this, the Employer cannot release any funds to the Contractor. The rule of origin applies to all items tendered and supplied. Therefore, it is insufficient that only a certain percentage of the goods tendered and supplied or a certain percentage of the total tender and contract value comply with this requirement. To establish origin, one must determine where the product in question has been obtained or produced. A product cannot originate in a country in which no production process has taken place. On the other hand, the country of production is not necessarily the country of origin. Furthermore, the country of origin is not necessarily the country from which the goods have been shipped and supplied. Where there is only one country of production, the origin of the finished product is easily established. However, in cases where more than one country is involved in the production of goods it is necessary to determine which of those countries confers origin on the finished goods. The country of origin is deemed to be the country in which the goods have undergone their last, economically justified, substantial transformation. The supplier must certify that the goods tendered comply with the origin requirement specifying the country or countries of origin. When tendering for systems comprising more than one item, the origin of each item in the system must be specified. If requested to do so the supplier must provide any additional information and/or a certificate of origin in support of the origin claimed in the tender application. Except where otherwise specified, all materials and workmanship shall conform with the requirements of the latest editions of the relevant Bahrain and International Standards and Codes of Practice and any other Standards which are referred to in the Specifications. The Schedule of Approved Standards and Guidance Publications in Volume 3A, Section 3, Civil Specifications (Section S) lists approved standards as a quality guide for the materials and articles to be provided.


III-1


Specifications

APPENDIX IV PLANT LIST ZONE A - Coastal Exposed, ZONE B - Coastal Protected, ZONE C - Inland Protected, ZONE D - Environmentally Controlled (shading and misting) ITEM

BOTANICAL NAME Palms Caryota mitis

ZONE

DESCRIPTION

C, D

Chamaerops humilis Cocus nucifera

C A

Corypha umbraculifera

C, D

Pandanus veitchii Phoenix canariensis

A, B, C A, B

Phoenix dactylifera

A. B, C

Rhapis excelsa Rhapis humilis Rostonia regia Syagrus romananzoffiana Washingtonia filifera Washingtonia robusta

D C, D D A, B A, B A, B

Clumping palm to 8m high x 4m wide crown Clumping palm to 4.5m x 4m wide crown Solitary palm to 20m high x 7m wide crown Solitary palm to 20m high x 7m wide crown Palmlike to 9m. Solitary palm to 25m high x 10m wide crown Solitary palm to 30m high x 8m wide crown Clumping palm to 2.5m high x 1m wide Clumping palm to 2.0m high x 1m wide Solitary palm to 25m x 5m wide crown Solitary palm to 15M Solitary palm to 18m x 4m wide crown Solitary palm to 30m x 3m wide crown

Trees Acacia aurecoliformis

B, C

Acacia farnesiana

B, C

Acacia tortilus Albizzia julibrissin

A, B C, D

Albizzia lebbeck Arbor vitae (Cypress) Azadirachta indica

C

Bauhinia blakeana

B, C, D

Bombax ceiba

B, C, D

Cassia fistula Cassia javanica Casuarina equisetifolia Chorisia speciosa Coccoloba uvifera Conocarpus Cordia sebestena

A B, C A A, B B, C, D


B,C

IV-1

20-25m tall spreading open canopy shade tree. Bright yellow flowers Small spreading open canopy tree. Flowers yellow with pleasant fragrance. Small open crown spreading tree Spreading tree to 12m. White - pink flowers 8 - 12m open crown deciuous tree. Evergreen Cypress Spreading evergreen shade tree to 20m. Small white flowers Rounded spreading tree to 12m. Purple flowers Tall deciduous tree. Red flowers in spring prior to leaf sprout.

Upright tree to 30m Spreading tree to 15m. Pink to red flowers Vase shaped tree to 15m. White flowers Small spreading tree Small spreadingevergreen tree to 8m. Red flowers in summer


Specifications

Dalbergia sisso

B, C

Delonix regia

B, C, D

Erythrina variegata

A, B

Eucalyptus camaldulensis Ficus altissima Ficus benghalensis

B, C B, C B, C, D

Ficus benjamina

B, C, D

Ficus elastica Ficus jamba Ficus microcarpa Ficus nitida Ficus religiosa Ficus retusa Hibiscus tiliaceus Jacaranda acutifolia

B, C

Lagerstroemia speciosa

B, C, D

Leucaena leuccoephala Melia azedarach

A, B B, C

Olea europea Parkinsonia aculeata

C A, B

Pithecellobium inga-dulce Plumeria obtusa

Polyalthia longifolia

B A, B, C, D A, B, C, D B, C

Pongamia pinnata

A, B

Prosopis alba Prosopis juliflora Psidium guajava Tabebuia pentaphylla

A, B A, B A, B, C, D B, C

Tabebuia rosea alba Tamarindus indica

B,C C, D

Tamarix arabica Terminallia catappa Thespesia populnea Vitex agnus castus Ziziphus spina-crista

A, B A, B

Plumeria rubra acutifolia


A, B B, C, D B, C, D B, C A, B C, D

A, B

IV-2

Erect deciduoud tree to 20m. White/yellowish white flowers Spreading tree 10m high x 15m wide. Red flowers Spreading tree 18m high x 10m wide. Red flowers Tall spreading evergreen tree Tall spreading evergreen tree to 25m high Spreading evergreen shade tree to 12m x 12m. Large spreading tree 20m high x 25m wide. Large spreading tree to 30m high Large spreading tree to 20m high Spreading evergreen 18m x 9m Spreading evergreen tree, 12m x 12m Large spreading tree to 20m high Small tree to 8m high. Yellow flowers Spreading tree to 15m. Ultraviolent flowers Deciduous spreading tree to 20m. Purple flower Small tree with white flowers Rounded crown tree to 15m. Purplish flowers Open canopy tree to 10m Weeping canopy tree to 7m. Yellow flowers Rounded canopy tree to 8m. White flowers Rounded canopy tree to 8m. Red flowers Symmetrical pyramidal tree tp 12m high x 1.2m wide Spreading tree to 13m x 12m. White, pinkpurple flowers Open canopy tree to 15m. White flowers Open canopy tree to 9m Small evergreen tree to 8m Rounded crown tree to 12m. Yellow flowers. Rounded canopy tree to 15m. Pale yellow flowers Small open canopy tree Tall symmetrical tree to 35m

Small open canopy tree to 10m. Yellow green flowers


Shrubs Acalypha wilkesiana Adenium obesum Agave spp. Cassia alata Cassia occidentalis Caesalpinia gillese Caesalpinia pulcherrima

Specifications

B, C, D C A, B, C, D C, D B, C B, C

Callistemon viminalis Carissa grandiflora 'Carpet Green' Cestrun diurnum Clerodendron inerme

B, C

Codiaeum variegatum

D

Dodonea viscosa 'Purpurea' Duranta repens "Golden" Euphorbia milli Gardenia jasminoides

A, B, C C, D B, C D

Hibiscus rosa sinensis Ixora chinensis Ixora coccinea Ixora javanica Jatropha multiflora Lawsonia inermis

B, C D D D B, C B, C

Leucophyllum frutescens Leucophyllum frutescens "Green Cloud" Lycium arabicum Musa paradisica Nerium oleander

B, C B, C

D C, D

Dense shrub to 3m. Multi coloured foliage Succulent shrub to 1.8m. Red flowers Clumping succulent to 1.5m. Open crown shrub to 2.5m. Yellow flowers

Spreading shrub to 2.5m. Orange & yellow flowers Tall open shrub to 5m. Red flowers Open shrub to 2.0m. White flower Shrub to 2.4m. White flower. Poisonous Scrambling dense shrub to 3.0m. White flowers Compact shrub to 1.2m. Variegated leaves Dense shrub to 1.5m. Golden foliage Open canopy shrub. Red flowers Dense canopy shrub to 1.5m. White flowers Shrub to 3m. Yellow, orange, red flowers Dense shrub to 1.5m. Orange flowers Dense shrub to 2m. Red flowers Dense shrub. Scarlet red flowers. Open canopy shrub to 2.5m. Red flowers Tall open shrub to 6m. White, red, pink or yellow flowers.

A, B D A, B, C, D A, B, C, D B, C A, B, C, D C A

Shrub 1.0m x 0.5m

D

Sueada fruiticosa Tecomaria capensis

Clumping strapleaf to 1.2m. Oragne flowers

C, D

Tecoma stans Thevetia peruviana Vitex agnus castus Yucca aloifolia

C, D C, D A, B A,B,C

Scrambling shrub to 3m. Red orange flowers Compact shrub to 7m. Yellow flowers Tall shrub to 5m. Yellow flowers Sprawling shrub to 6m. Purple flowers Clumping strapleaf to1.5m. White flowers

Nerium oleander 'White' Opuntia ficus indica Pittosporum tobira Portulacaria afra Rosmarinus officinalis Scaevola tocata Strelitzea reginea


IV-3

Upright shrub to 5m. Pink flowers Upright shrub to 5m. White flowers Succulent shrub to 1.8m. Red flowers Opn shrub to 3.0m Woody shrub to 1.8m. Pale blue flowers


Specifications

Groundcovers Aerva javanica Aloe vera

A, B B, C

Alternanthera ficoidea var. amoena

D

Alternanthera red Aptenea cordifolia Asparagus sprengerii Atriplex halimus Atriplex semibaccata Bougainvillea 'Nana Red' Canna indica 'Yellow' Carissa prostrata Carnation Carpobrotus edulis Catharanthus rosea Cenchrus cilaris Crinum asiaticum

Clumping groundcover to 0.5m Clumping succulent to 0.8m. Yellow flowers Clumping groundcover to 0.12m. Colourful foliage

C, D A, B A, B B, C, D D

Trailing groundcover.

A, B

Sprawling groundcover to 0.15m high. Yellow flower fading to pink.

A, B C, D

Clumping strapleaf to 1.0m. Yellow flower

Dipterygium glaucum Europs pectinatus Gazania hybrida Gazania rigens Gazania rigens var. Uniflora Gazania rigens white Gazania rigens yellow Heliotropium curassavicum Hymenocallis littoralis

A C, D

Clumping grass to 0.45m high Clumping strap leaf top 1.0m. White flowers Small open shrub to 0.6m Low clumping groundcover. Yellow flower

A, B, C A, B, C

Spreading groundcover. Yellow flower Spreading groundcover. Yellow flower

A, B C, D

Ipomea pes-capre

A, B

Lampranthus spectabilis

C, D

Lantana camara dwarf 'Pink Mound'

C, D

Lantana montevidensis

C, D

Malephora crocea Mammillaria seitziana Nerium oleander 'Pink Petite' Ophiopogon jaburan Osteospernum fruiticosum

Succulent groundcover. White flower Clumping strap leaf groundcover to 1.0m. White flower Sprawling groundcover vine to 30m. Pink flowers. Succulent groundcover to 0.3m. Pink purple flower Clumping groundcover to 0.3m. Pink flowers Clumping groundcover to 0.45m. Lilac flower

A, B C, D D B, C

Pelargonium graveolens

C, D

Pennisetum setaceum

A, B, C

Pennisetum setaceum 'Rubrum'

A, B, C

Petunia hybrid Portulaca grandiflora

C, D


IV-4

Clumping groundcover. Pink flowers CLumping groundcover to 0.3m. White flowers Clumping groundcover to 1m x 1m. Purplish - white flowers. Ornamental grass to 1.0m. Rose coloured flower spikes Ornamental grass to 1.5m. Burgundy red coloured flower spikes Prostrate goundcover to 0.15m. Rose, pink-white flowers.


Specifications

Portulaca grandiflora 'Red'

C, D

Pseuderanthemum atropurpureum

D

Rhoeo discolor Ros marinus prostrata Ruella ciliosa Russellia equisetiformis Sanservia trifasciata Scaevola aemula

D

Senecio cineraria

A, B

Sesuvium 'Green carpet' Setcreasea purpurea

C, D D

Setcreasea purpurea Stenotaphrum secundatum Verbena tenera

C, D C, D

Vinca pacifica 'Red' Wedelia trilobata

D B, C

Zamia furfuracea

D

Fronds to 1.5m in leangth

B, C

Scrambling vine to 3m. Yellow flower

B, C, D B, C, D B, C, D C, D C, D

Scrambling vine to 6m. White flowers Scrambling vine to 6m. Pink flowers Scrambling vine to 6m. White flowers Vine to 3.5m. White flowers Scrambling vine to 3m White flowers

Passiflora caerulea Quisqualis indica

D D

Twining vine to 9m. Blue flowers Scrambling vine to 15m. White - red flowers.

Lawn Paspaulum

C, D

Climbers/Vines Allamanda cathartica Antigonum leptopus Bougainvillea glabra 'White' Boagainvillea 'Pink Pixie' Bougainvillea 'Texus Dawn' Cestrum nocturnum Jasminum sambac


B, C, D C, D D

IV-5

Prostrate goundcover to 0.15m. Red flowers. Low clumping groundcover to 0.15m. Chocolate brown leaves. Clumping strapleaf groundcover to 0.3m

Weeping canes to 1.0m. Red flowers Clumping strapleaf groundcover to 0.75m Sprawling groundcover to 0.5m. Blue lilac, white flowers. Clumping groundcover to 0.6m. Silvergrey foliage Spreading Groundcover to 0.3m high. Purple foliage. Pink - Purple flowers Grass to 60mm high. Low sprawling groundcover to 0.2m high. Purple flowers Clumping groundcover. Sprawling groundcover to 0.25m. Yellow flower

AL MADINA AL SHAMALIYA (AMAS) SEWAGE TREATMENT PLANT Tender Documents

Volume 3 Section 2 Process Specifications

July 2014


Specifications

TABLE OF CONTENTS 1.

GENERAL PROCESS DESIGN REQUIREMENTS .............................................................. 1

1.1

Process Elements ............................................................................................................................... 1

1.2

Design Flows ....................................................................................................................................... 1

1.3

Flow Build-Up and Treatment Trains .......................................................................................... 2

1.4

Design Loads ....................................................................................................................................... 3

1.5

Treated Effluent Quality .................................................................................................................. 3

1.6

Sludge Quality ..................................................................................................................................... 4

1.7

Odour Quality ...................................................................................................................................... 4

2.

INLET PUMPING STATION (TERMINAL LIFT PUMPING STATION) .............................. 5

3.

TANKER RECEPTION FACILITY .................................................................................... 6

4.

INLET WORKS PRELIMINARY TREATMENT AND TANKER RECEPTION FACILITY........ 7

5.

SECONDARY TREATMENT – BIOREACTORS AND FINAL SETTLEMENT TANKS ........... 12

6.

TERTIARY TREATMENT ............................................................................................... 21

7.

DISINFECTION ........................................................................................................... 25

8.

TSE STORAGE TANK AND PUMPING STATION ........................................................... 27

9.

SLUDGE THICKENING ................................................................................................. 29

10.

SLUDGE AEROBIC DIGESTERS................................................................................ 32

11.

SLUDGE DEWATERING ........................................................................................... 34

12.

SLUDGE THERMAL DRYING .................................................................................... 37

13.

CHEMICAL PHOSPHOROUS REMOVAL .................................................................... 41

14.

ODOUR CONTROL ................................................................................................... 42

15.

SCUM & FOAM REMOVAL ........................................................................................ 46

16.

EFFLUENT OUTLETS ................................................................................................ 47

17.

ALLOWANCES FOR FUTURE PLANT EXPANSION .................................................... 48

Vol 3, Section 2 – Process Specification

Page i of i


1.

Specifications

GENERAL PROCESS DESIGN REQUIREMENTS The Process Specifications shall be read in conjunction with the Process Flow and Process and Instrumentation Drawings nos. D7570-01-P100 to P114.

1.1

Process Elements The following principal process elements shall be provided: • • • • • • • • • • • • • •

1.2

Inlet pumping station Tanker reception facility complete with reception sump and transfer pumps. Inlet works with flow measurement; emergency overflow, automatic fine screens with screenings handling, washing, and compacting equipment, grit removal with collection and washing, grease removal and collection; Process tanks with mixers, aeration and recirculation systems, distribution chamber, effluent collection channel and chemical dosing system. Final Settlement Tanks with associated flow distribution, treated effluent and sludge collection; RAS/SAS pumping station; and scum removal system. Tertiary Treatment. Chlorination downstream prior to a chlorine contact tank. Treated final effluent (TSE) storage tank and TSE pumping station for irrigation Long sea outfall. Mechanical sludge thickening utilising gravity belt thickener and associated sludge handling and polymer preparation and dosing. Aerobic sludge digestion with aeration and mixing with outlet balancing tank. Mechanical sludge dewatering utilising double decked gravity belt thickener/belt filter presses or centrifuge and associated sludge handling, polymer preparation and dosing, and sludge cake collection and storage. Thermal sludge drying with associated sludge handling, collection and storage. Odour treatment unit and associated fans, ductwork, covers, enclosures, etc.

Design Flows The AMAS STP shall cater for Islands 3 to 14 flows. The average influent daily flow for Islands 3 to 14 is 39,680 m3/d when fully developed. An allowance of 50% shall be made in the design for future plant expansion, giving a future influent average daily flow of 59,520 m3/d. The process design flows for current and future flows are summarised in Table 1.1. Table 1.1: Process Design Flows Description

Units

Flow

Current Flows (Islands 3 – 14) Average daily flow (ADF) (net of liquor returns) Peak daily flow (PDF) (net of liquor returns) Ultimate peak flow (PHF) (net of liquor returns)


Page 1 of 49

m³/day

39,680

l/sec

459

3

m /day

61,953

l/sec

717

m³/day

85,319

l/sec

987


Specifications

Future Flows (Islands 3 – 19) Average daily flow (ADF) (net of liquor returns) Peak daily flow (PDF) (net of liquor returns) Ultimate peak flow (PHF) (net of liquor returns)

m³/day

59,520

l/sec

689

3

m /day

92,851

l/sec

1,075

m³/day

127,968

l/sec

1481

Sewage treatment plants are usually designed to treat the peak daily flow and any flows above this would overflow to the sea via an outfall. Therefore flows up to 61,953 m3/d (92,851 m3/d future) will receive full treatment and flows above this will receive preliminary treatment (screenings, grit and grease removal) prior to discharge. 1.3

Flow Build-Up and Treatment Trains Since AMAS is a new development, flows will build up over a period of time, based on the domestic dwellings construction phases for Islands 3 to 14. It shall be assumed that 75% occupancy will take place immediately after the completion date of each package. The remaining 25% occupancy is expected to take place over 4 years after the completion of the last scheduled package. The evolution of flows determines the number and sizes of biological process trains as indicated in Table 1.2. This enables flexibility in plant operation during the early stages of flow build-up. Table 1.2: Number and Sizes of Process Streams Sewage Flows (75% Occupancy) Islands 13 & 14 Average Daily Flow, m3/d 3

Islands 11 to 14 Average Daily Flow, m /d 3

9,999 17,904

Islands 9 to 14 Average Daily Flow, m /d

26,904

Islands 3 to 14 Average Daily Flow, m3/d

29,760

Islands 3 to 14 100% Occupancy Average Daily Flow, m3/d

39,680

STP Streams Number of Trains

4

Average Capacity Per Train, m3/d

9,920

2No Process Trains Average Capacity, m3/d

19,840


29,760


39,680

The philosophy shall be to design the Biological treatment process in identical 9,920 m3/d treatment capacity trains, i.e. 4 No. biological treatment streams of 9,920 m3/d capacity each to treat the flows from Islands 3 to 14.


Page 2 of 49


Specifications

Full provision shall be made in the design for the future addition of another 2 No. identical streams (outside of this contract’s scope) to cater for the flows from Islands 15 to 19, giving an ultimate plant capacity of 59,520 m3/d average. 1.4

Design Loads The plant shall be designed to treat the raw sewage with the characteristics presented in Table 1.3. Table 1.3: Influent Concentrations Description

Average Peak Month 95%ile Maximum Concentration Concentration Concentration Concentration

BOD

mg/l

238

286

368

428

COD

mg/l

471

565

759

800

Suspended solids

mg/l

246

295

394

443

Total P

mg/l

6

7

8

9

TKN

mg/l

34

41

52

59

Ammonia

mg/l

22

26

32

40

Alkalinity

mg/l

250

-

286

-

FOG

mg/l

67

80

116

121

-

7.3

-

7.7

9.0

˚C

24 (min)

-

-

36 (max)

pH Temperature

1.5

Units

Treated Effluent Quality

The effluent shall be treated to achieve a quality that will satisfy the end use requirements for unrestricted reuse and also meet the stringent nutrient removal requirements associated with marine discharge, as described in Table 1.4. Table 1.4: Treated Effluent Standard

Parameter

Units

pH

Value

Basis

6.5 - 9

TDS

mg/l

3,500

Monthly average

TCOD

mg/l

40

95%ile

TBOD 5ATU

mg/l

10

95%ile

TSS

mg/l

10

95%ile

Turbidity

NTU

2

95%ile

Turbidity

NTU

5

Maximum

NH 4 -N

mgN/l

1

average

NH 4 -N

mgN/l

2

Maximum


Page 3 of 49


Specifications

Parameter

1.6

Units

Value

Basis

Fats, oil and grease (emulsified)

mg/l

5

Monthly average

SO 4 2-

mg/l

300

Monthly average

Sulphide (S2-)

mg/l

0.5

Monthly average

Faecal Coliforms

MPN/100 ml

< 2.2

Monthly average

Viable Helminth Eggs

MPN/100 ml

<0.1

Monthly average

Parasitic Helminth worms

MPN/100 ml

Nil

monthly average

Chlorine residual

mg/l

0.5

average

Chlorine residual

mg/l

2

maximum

Total Nitrogen

mg/l

10

average

Total Nitrogen

mg/l

15

maximum

Total Phosphorus

mg/l

1

average

Total Phosphorus

mg/l

2

maximum

Sludge Quality The sludge shall be treated to a standard suitable for re-use for landscaping and agriculture, and for landfill disposal, as described in Table 1.5, in line with USEPA 503 guidelines for Class A sludge grade. Table 1.5: Treated Sludge Standard Description

Units

Value

%

>90

% reduction

>40

mgO 2 /hour/g total solids

<1.5

Faecal coliform bacteria

MPN/g DS

<1,000

Salmonella

MPN/4g DS

<3

Helminth ova

No./4g DS

<1

Enteric viruses

PFU/4g DS

<1

Dry solids (DS) Volatile solids o

Specific Oxygen Uptake Rate for biosolids at 20 C

1.7

Odour Quality There shall be no odour nuisance from the STP to the nearby communities. Odour treatment shall therefore achieve the following standard: “5 OU on a 99.8%ile 1 hourly averaging basis measured at the nearest receptor, based on ‘BS EN 13725:2003 standard odour control method’”.


Page 4 of 49


2.

Specifications

INLET PUMPING STATION (Terminal Lift Pumping station) Sewage from AMAS will be collected via a new sewerage system to be constructed (by others) concurrently with the STP. The primary sewerage network comprises shallow and deep gravity sewers terminating at Island 13c with a 1200mm diameter sewer at an invert level of approximately -11.610m. The Inlet Pumping Station is to be constructed under the STP Contract to lift the flows from the deep gravity sewer to the inlet of the STP. A high degree of coordination and cooperation will be required with the sewer contractor during design and construction and the pumping station. Note that the location of the Inlet Pumping Station is fixed as indicated on the drawings based and ensuring a safe distance from the underlying Alat aquifer and associated Water Resources Directorate approvals. The pumping station shall be designed to cater for the current design flows listed in Table 1.1. The following is proposed for the design of the pumping station: Table 2.1 summarises the design parameters and requirements of process units used as part of the Inlet Pumping Station. Table 2.1: Inlet Pumping Station

Item 2.1

Process stage Inlet Pumping Station

Sub Category Inlet Screen

Design Criteria

Process Output

Minimum number of duty units: 1

Protection of pumps from damage by coarse material and debris from the sewerage system

Type: Mechanically raked bar screen Maximum aperture: 40 mm By-pass

Inlet Screenings Washer / Compactor

Peak capacity: 987 l/s Hydraulic by-pass to be provided for the Inlet Screen for automatic by-pass in case of blockage Number: 1 Type: Washpactor or equivalent Capacity per unit: to be agreed based on flowrate, bar spacing and supplier local experience Washer: Must wash organic material from screenings. Washed screenings must have a BOD of less than 20 mg/g of dry solids Compactor: Must achieve a minimum screenings solids content of 40%ds.


Page 5 of 49

Clean, dewatered, disposable end product with a minimum dry solids content of the washed screenings product of 40 % and a BOD of less than 20 mg/g of dry solids


Item

Process stage

Sub Category Station

Specifications

Design Criteria

Process Output

Type: Dry well (dry installed pumps)

Full duty/standby wet wells and rising mains

Wet well: wet wells

Twin duplicate

Rising mains: Twin duplicate with flow measurement Lift Pumps

Number of pumps: 3/wet well (total 6)

To lift flows to the inlet works

Mode of Operation: Duty/assist/standby (may be operated duty/assist/assist if one rising main out of service)

System to be designed with maximum flexible to deal with daily, weekly and seasonal flow variations as well as lower start-up flows.

Capacity: 329 l/s each Indicative total head: 35m Type: Variable speed On-line Monitoring

Minimum number of on-line monitoring instruments for each parameter:1

Early warning of high acid/alkali in sewerage system

Parameters to be monitored: pH Located in common inlet Odour Control

3.

See Section 14

TANKER RECEPTION FACILITY A tanker reception facility shall be provided to receive sewage from AMAS in the early days of plant operation, in the event that the sewerage network is not connected to the STP or some of the new dwellings are not connected to the sewerage network. Table 3.1 summarises the design parameters and requirements of process units used as part of the tanker reception facility.


Page 6 of 49


Specifications

Table 3.1: Tanker Reception Facility Description Item 3.1

Process stage Tanker Reception Facility

Sub Category Delivery area

Design Criteria

Process Output

Number of tanker unloading stations: 6 c/w ‘Bauer’ type connections with Camlock fittings and vent valves, washdown facility of tanker delivery area

Delivery sump

Number of delivery sumps: 1 Volume: 330 m3

Transfer pumps

Minimum number of duty pumps: 1 Minimum number of standby pumps: 1

Transfer sewage from delivery sump to the inlet works

Pump duty: 200 l/s

4.

INLET WORKS PRELIMINARY TREATMENT AND TANKER RECEPTION FACILITY Flows from inlet pumping station and tanker delivery sump will be transferred to the inlet works comprising of screenings, and grit/grease removal. The raw sewage shall first be screened through inlet screens to remove any solids greater than 6mm. The screenings shall then be washed to reduce the quantity of odorous material and compacted in dedicated units, before being discharged to skips for off-site disposal. The pre-screened sewage shall flow by gravity into aerated grit channels for grit and grease removal. The accumulated grit shall be pumped to grit classifiers where it shall be washed and discharged to a skip for off-site disposal. Grease shall be discharged to a skip or tank. From the grit channels, sewage shall pass to a distribution chamber which divides the flow into equal streams for secondary biological treatment. Table 4.1 summarises the design parameters and requirements of process units used as part of the preliminary treatment stage. Table4.1: Inlet Works Description

Item 4.1

Process stage Inlet Flow Measurement


Sub Category

Design Criteria Type: Electromagnetic Number: One per inlet pipe

Page 7 of 49

Process Output


Item 4.2

Process stage Raw Influent Sampling

Sub Category Sampler

Specifications

Design Criteria Type: Automatic refrigerated programmable composite and spot sampler Minimum samplers: 1

On-line Monitoring

4.3

Inlet Chamber

4.4

Emergency Overflow

Process Output

number

Sampling sewage

of

raw

of

Minimum number of on-line monitoring instruments for each parameter:1 Parameters to be monitored: pH Chamber shall be sized to receive all incoming flows (inlet pipelines, flows from tanker reception facility return liquors) Plus allowance for future inlet connection. Overflow weir to be provided in the event of total plant failure or inlet flow exceeding design Ultimate Peak Flow Inlet Works to overflow to the outfall.

4.5

Inlet Screens

Screens

Minimum number of duty units: 2 Minimum number of standby units: 1 Type: Band screens perforated plates

4 channels to be provided (the fourth closed off for future)

with

Maximum aperture: 6 mm Peak capacity: 494 l/s per screen (excluding return liquors) Inlet Screenings Washer / Compactors

Minimum number of duty units: 1 Minimum number of standby units: 1 Type: Washpactor equivalent

or

Indicative capacity per unit: 2m3/h Washer: Must wash organic Vol 3, Section 2 – Process Specification

Page 8 of 49

Clean, dewatered, disposable end product with a minimum dry solids content of the washed screenings product of 40 % and a BOD of less than 20 mg/g of dry solids


Item

Process stage

Sub Category

Specifications

Design Criteria

Process Output

material from screenings. Washed screenings must have a BOD of less than 20 mg/g of dry solids Compactor: Must achieve a minimum screenings solids content of 40% ds. Compactor by-pass with direct chute to screenings skip to be provided in the event of compactor failure.

4.6

Grit / Grease Removal

Inlet Screenings Collection

Inlet screenings shall be collected directly into a large screening bag or into a skip lined with a plastic liner, for ease of transport and off-site disposal and to minimise the development of unpleasant odours.

Grit Channels

Minimum number of duty units: 2 Type: Aerated Grit Channel Hydraulic Capacity: 987 l/s per channel (excluding return liquors) Retention time: not less than 10 minutes per tank at peak flow (grease removal). Indicative Peak grit load: ultimate 2,559 kg/d for Phase 1. Indicative average grit load: 1,200 kg/d. Minimum grit removal: 95% of all grit down to 200 microns. Minimum grit particle specific gravity of 2.65. Design of the aerated grit channel should maximise the level of fine sand removal to prevent settlement within the anaerobic and anoxic zones.


Page 9 of 49

Removal of more than 95% of all grit down to 200 microns. Minimum grit particle specific gravity of 2.65.


Item

Process stage

Sub Category Grit pumps

Specifications

Design Criteria

Process Output

Minimum number of duty units: 1 per grit channel

Removal of grit from aerated grit channels

Minimum number of standby units: 1 per grit channel Type: airlift pumps or grit pumps or screw conveyor and grit pumps (depending on manufacturer) Indicative capacity: 21.16 l/s each nominal to suit classifier capacity. Capacity to be chosen to get a reasonable scour velocity. Hopper flushing using Recycled Effluent (RE) shall be provided to fluidise the settled grit during the grit pumping stage and prevent rat holing and grit build up within the hoppers. A flushing line shall also be included on the suction side of each grit pump which shall allow the grit pumps and transfer lines to be flushed through with clean water to prevent deposition of grit within the pipelines during pump idle time. Grit blowers

Minimum number of duty units: 1, i.e. 1 No. blower can feed both grit channels Minimum number of standby units: 1 Indicative capacity: 1791 m3/hr nominal but Contractor to select (depending on manufacturer)

Grit aeration

Type: Coarse bubble, swingarm wide band diffusers Indicative m3/hr/m operation


air for

Page 10 of 49

flow: 36 average

Air supply for grit and grease removal


Item

Process stage

Sub Category Grit classifier/ washers

Specifications

Design Criteria Minimum number of duty units: 1 Minimum number of standby units: 1 Type: Screw Classifier with washing or equivalent Minimum Capacity: 21 l/s each Minimum organics removal: 95%

Grit Collection

Grit shall be collected directly into a large grit bag or into a skip lined with a plastic liner, for ease of transport and offsite disposal and to minimise the development of unpleasant odours.

Grease Removal

Grease removal shall be combined with grit removal in the aerated grit channel. The design shall be based on the specialist supplier’s best design experience to maximise FOG removal (design shall be supported by reference plant data)

Grease tank

Minimum number of grease tanks: 1 Minimum storage capacity: 7 days Tank to be fitted with Valve and bauer coupling for removal of grease by tanker and include washing down facility and drainage.


Page 11 of 49

Process Output Removal organics no than 95%

of less


Specifications

5. SECONDARY TREATMENT – BIOREACTORS and FINAL SETTLEMENT TANKS The secondary treatment system shall be based on the activated sludge process (ASP) modified for nitrogen removal. Organic constituents in the sewage shall be removed through biological activity. Each bioreactor shall have anoxic and aeration zones and an upstream selector. The influent sewage enters the selector and is mixed with RAS. From there it enters the anoxic zones where it is mixed with recycled biomass (A recycle) from the aerobic zone to remove nitrates. The sewage then flows to the aerobic zone for BOD and ammonia removal. The bioreactors shall be equipped with mixers in the anoxic basins to keep solids in suspension, and fine bubble air diffusers in the aeration tanks. Each bioreactor shall have dedicated sets of submersible recycle pumps. A facility to dose ferric chloride to the bioreactors shall be provided for phosphorous removal. The plant configuration shall allow for the plant to be adapted to either chemical or biological phosphorus removal. To maintain the correct alkalinity balance when dosing with ferric chloride for P removal, provision for dosing caustic soda to the bioreactors shall also be provided. Flow from the bioreactors will then gravitate to the final settlement tanks (FSTs). To control the sludge blanket in the FSTs, sludge must be transferred from the FSTs back to the selectors. This shall be achieved with a set of duty/standby return activated sludge (RAS) pumps. It is proposed for the surplus activated sludge (SAS) to be wasted directly from the bioreactor. This will allow more accurate control of the sludge age as the chemical dose changes. This can be achieved by pumps from each lane or gravity discharge via an actuated penstock in the effluent channel of the bioreactors, prior to flow splitting to the FSTs. Phosphorous can be removed in an ASP via biological methods or via chemical precipitation. Bio-P removal is most effective with strong wastes with a high readily biodegradable COD (rbCOD) fraction. For weak waste waters, as may be expected at AMAS, care must be taken to ensure that this rbCOD is not used preferentially in dentrification. The ASP design shall, therefore, be based on maximising the carbon for N-removal, with chemical dosing for P-removal. The plant shall however also include the facility to allow Bio-P removal, should the waste be suitable. A possible configuration is illustrated in Figure 4.1 below. The lower part of the diagram shows the configuration for N-removal and chemical Premoval. The upper part of the diagram shows that by moving the discharge point of the mixed liquor recycle and extending the unaerated fraction, a configuration to promote biological P-removal can be achieved. The first zone prior to the recycle discharge is now anaerobic and will promote the growth of P-removing organisms. The Contractor may make his own proposals for complying with the specified requirement for flexibility in the method of P removal (chemical, biological, combination of each) with aim of minimising chemical consumption.


Page 12 of 49


Specifications

Figure 5.1: ASP Configuration

Anoxic Zones The anoxic basins are operated in an oxygen deficient mode requiring the bacteria in the biomass to use the nitrates (NO 3 -N) in the returned sludge as their oxygen source to sustain their activity. The stripping of the oxygen from the nitrate compound results in the release of nitrogen gas molecules and its removal from the waste stream. The anoxic basins also perform the task of providing some foam control by inhibiting the growth of filamentous bacteria. The nitrification process consumes alkalinity. The main way to minimise alkalinity depletion is to provide sufficient denitrification in the anoxic zone to recover the alkalinity, as for each g of nitrate converted to nitrogen gas 3 g of alkalinity is recovered. The level of denitrification is governed by four factors: • • • •

Anoxic mass fraction of the reactor Degree of nitrates recycled back to the reactor by the Mixed Liquor Recycle (MLR) pumps (as discussed this may be from the end of the aeration zone/tank) Temperature; like most biological processes the denitrification rate is temperature dependent and so it is important that the anoxic zone sizing is based on the minimum reactor temperature of 24oC COD fractionation; the higher the level of ready biodegradable soluble COD, the quicker the denitrification rate.

The anoxic volumes for alkalinity recovery and for achieving the total nitrogen standard must be sized based on dynamic modelling. Baffling of the anoxic basins shall be installed to create multiple zones to be operated in series. Submersible mixers provide agitation to keep the contents of the basins in suspension.


Page 13 of 49


Specifications

Aeration Zones The aeration system shall be a membrane diffused aeration system. It will be required to provide full-floor coverage in a tapered pattern. This will provide greater air (oxygen) at the start of the basins to match the oxygen demand of the mixed liquor as it exits the anoxic zone. The later portion of the basins shall have a lower concentration of aeration devices providing air to assure mixing while being adequate to provide nitrification. A minimum of 2 separate grids shall be provided per basin to allow adjustment of the air flow to the grid based on the air demand in that portion of the basin. This will allow the Dissolved Oxygen (D.O.) at the start of the aeration basin to be controlled at 2.0mg/l and the D.O at the end of the tank to be controlled at 0.5-1.0mg/l to thus reduce the D.O. of the internal mixed liquor recycle and aeration costs. By configuring the bioreactors in a U shape, a plug flow pattern can be created, optimising the performance of the reactors for nitrification. The U shape also allows the MLR A recycle to occur through or over the wall. In the case of diffused aeration system, the blowers, air piping and diffuser grid, must be sized to provide sufficient air for aerobic treatment of the influent sewage under PHF conditions as well as when one treatment train is out of service. The design must take into account operation during the summer (bioreactor MLSS temperature = 36˚C) as well as during colder conditions (bioreactor MLSS temperature = 24˚C). The design of aeration systems is commonly based on maximum month loading conditions, with one bioreactor off-line for maintenance purposes, i.e. the peaking factor is 1.2 x 4/3 = 1.6. Thus ensuring that sufficient aeration is installed to cope with the design 95%ile influent concentrations. The aeration blowers shall be sized on the peaking factor of 1.6, maximum ambient air temperature (55 degrees Celsius) and MLSS temperature (36 degrees Celsius) and the maximum relative humidity (100% RH). Fine bubble diffusers of the membrane (EPDM) type configured in a full floor grid pattern shall be installed. Separation of the grid pattern into several diffuser grids with isolation valves on the drop lines allows the air to be more efficiently applied where it is needed for treatment. Ten-percent spare diffusers (including membrane disks and holder components) shall be provided for quick replacement. Table 5.1 summarises the design parameters and requirements of process units used as part of the secondary biological treatment stage.


Page 14 of 49


Specifications

Table 5.1: Bioreactors Description Item 5.1

Process Stage Bioreactor

Sub Category Tanks

Design Criteria Number: 4 lanes Type: double-pass arrangement (Ushape) for each bioreactor Indicative sizing: Volume: 11,400 m3 per bioreactor Bioreactor length: 49m Bioreactor width: 35m (7.5m per pass) Water depth: 6.5m Zones per bioreactor: 7 (4 anoxic, 3 aerobic)

Process Output To provide biological treatment of peak daily flow

Total sludge age: 9.5 days Mode of Operation: Plug flow with internal recycle, from end of aerobic zone to the start of the anoxic zone 1. Weir inlet and outlet arrangement must allow free passage of foam through the ASP for eventual collection and removal from the FSTs. 5.2

Selector Zones

Zones

Number: 2 (1 per bioreactor feeding 2 lanes) Designed as a channel to transport the combined wastewater and RAS flow from the distribution chamber to the inlet of the anoxic zone. Indicative sizing: Length 49m Width 3m Depth 3m

Mixers

Number: 1 per zone Minimum mixing energy input: 5 W/m3 Type: Submersible, turbine/propeller


Page 15 of 49

To keep solids in suspension


Item 5.3

Process Stage Anoxic Zones

Sub Category Zones

Specifications

Design Criteria

Process Output

Number: 2 per lane

For denitrification

Indicative sizing: Volume: 1,924 m3 per lane Dimensions of each zone: Depth 6.5m Length 18.5m Width 8m Zones separated by internal baffle walls. Baffle walls shall finish below outlet weir level to allow pass forward of foam and scum to the aerobic zones. Baffle walls shall have bottom orifices so that flow is both through orifices and over the top of the baffle. Mixers

Number: 1 per zone (8 total) Minimum mixing energy input: 5 W/m3

To keep solids in suspension

Type: Submersible, turbine/propeller 5.4

Aerobic Zones

Zones

Indicative sizing:

For BOD and ammonia removal

Number: 3 per lane Volume: 3,120 m3 per lane Dimensions: Depth 6.5m Length 60m total Width 8m

Zone sizing to be refined during detail design to provide best taper and balanced air flow

Aerobic mass fraction: 0.6 Maximum design MLSS concentration: 3,500 mg/l at maximum monthly load Minimum aeration temperature: 24oC

basin

MLSS

Maximum aeration temperature: 36oC

basin

MLSS

Maximum design air humidity: 100% RH Maximum ambient temperature: 550 C Aeration Diffusers


Type: Fine Bubble Diffused Aeration (FBDA) with full floor coverage and multiple grids aeration

Page 16 of 49

To provide mixing to prevent solids settlement and meet peak SOTR


Item

Process Stage

Sub Category Zone DO Control

Specifications

Design Criteria

Process Output

1 DO probe per zone plus 1 modulating air control valve per zone to control DO.

Maintain tight control of aerobic zone DO in order to maintain optimal ammonia removal and minimise aeration energy.

DO set points: Zone 1 minimum DO: 2.0mg/l Zone 2 minimum DO: 0.5 - 2.0mg/l (depending upon ammonia trim control) Type of DO probe: Dissolved Oxygen (LDO)

Luminescent

1 Ammonia probe in the middle of the last aeration zone to detect complete nitrification and automatically reduce the DO set-point in that zone until the air flow is at the minimum mixing level Type of wavelength

ammonia

probe:

UV

1No flowmeter on main air header Design alpha factor, 3,500mg/l MLSS concentration: 0.65

based

on

Maximum Oxygen Transfer Efficiency, OTE: 5.5 %/m (including fouling factor) Blowers

Minimum number of duty blowers: 5 Mode of operation: 4No duty/1No standby Indicative nominal peak air flow rate to bioreactors: 19,210 Nm3/hr The blowers shall have the same capacity.

Blower Type

Type: centrifugal Blowers to be variable output, feeding into a common header, incorporating appropriate isolation valves, discharge silencers, inlet silencers, filters, and Maximum acoustic enclosures. discharge pressure: Not to exceed manufacturers’ requirements. Maximum discharge temperature: Not


Page 17 of 49

To provide aeration for the bioreactors


Item

Process Stage

Sub Category

Specifications

Design Criteria

Process Output

to exceed 80ºC (or lower limit specified by the diffuser supplier) at bottom of down pipe. Heat exchangers to be provided on the discharge line accordingly.

To safeguard process and diffuser system

Pipes external to the tank to be stainless steel and protection to be provided due to high surface temperature. Blower + Design and construction of the blower pipework and associated pipeline systems shall ensure that resonant frequencies are Noise critically damped throughout the operating range of the aeration system. Max air velocity through pipework: 12m/s (to prevent noise). Acoustic enclosures on each blower, with access doors for easy access for maintenance. On-line Monitoring

< 85dBA at 1m

Minimum number of on-line monitoring instruments for each parameter: 1 Parameters to be monitored: pH MLSS Temperature Ammonia (UV type) DO (Luminescent type)

5.5

A Recycle pumps

Pumps

Number: 2 per bioreactor (8 No. in total) Mode of operation: Duty/standby Type: Axial flow / canister pumps Indicative capacity: 694 l/s per pump peak All pumps on variable speed drives to allow adjustment of recycle rate. Duty pump speed linked to influent flow meter so that recycle rate reduces overnight and increases during the day. A facility to monitor and control the A recycle via nitrate monitors positioned on the tertiary filter outlet


Page 18 of 49

To transfer MLSS from the end of aerobic zone 1 to the start of anoxic zone 1 in order to achieve denitrification.


Item

Process Stage

Sub Category

Specifications

Design Criteria

Process Output

shall also be provided. Discharge pipe to be submerged to prevent air entrainment. Maximum design MLSS concentration: 3,500mg/l 5.6

Final Settlement Tank (FST)

Tanks

solids

Number: 3 (with provision to add a fourth tank at a later date)

Separation & removal of solids

Type: Circular settlement tank with peripheral v notch weir, sludge scrapers and scum skimming, collection and removal system. Indicative sizing: Diameter 39 m per tank Side wall depth 4 m Floor slope 6.5 o Maximum design MLSS solids concentration at MML: 3,500 mg/l Maximum design concentration at 3,500mg/l

MLSS average

solids load:

Mixed liquor flow from each bioreactor is to be combined in a common inlet channel and split evenly via a flow distribution chamber. An energy-dissipating inlet (EDI) inside a 20% diameter diffuser drum, provided with scum suppression/removal systems, accessible from the scraper bridge is required. The launders shall be internal with vnotch weirs. Scum boards shall be fitted to prevent discharge of scum with the clarified effluent. Isolation at inlet to each tank using penstocks in the distribution chamber. Auto-Desludging


Number: 1 per tank Type: Actuated telescopic bellmouth in sludge draw-off chamber.

Page 19 of 49

Desludging of Final Tanks


Item

5.7

Process Stage

RAS/SAS Pumping Station

Sub Category Scum removal

Wet Well

RAS Pumps

Specifications

Design Criteria Automatic system for surface scum collection and removal to be provided. System shall include a full surface scum skimmer and high capacity collection system. Scum to be discharged to the aerobic digester or alternative treatment system proposed by the Contractor. Number: 1

Number: 2 Type: Submersible, variable speed, centrifugal. Indicative capacity: 741 l/s per pump

SAS Pumps

Mode of Operation: Duty/standby Number: 2 Type: Submersible, variable speed, centrifugal. Indicative capacity: 17 l/s per pump Mode of Operation: Duty/Standby


Page 20 of 49

Process Output

To house 2 No RAS and 2 No SAS pumps and allow sufficient storage volume to avoid excessive pump starts. Maintain blanket level in FSTs to within required range. Return RAS upstream of the Selector Tank.

Waste surplus activated sludge to sludge treatment process.


6.

Specifications

TERTIARY TREATMENT To consistently meet low effluent solids and nutrient levels, and to achieve high level disinfection, it is necessary to minimise the solids in the effluent that can shield pathogens from the effects of chlorine or ultraviolet light. Tertiary filtration effectively strains the solids out prior to disinfection. Conventional media filtration is the preferred filtration option for AMAS STP. It is a robust process that is well established internationally and in the Middle East. Upstream chemical dosing with ferric and polyelectrolyte is to be employed to meet the tight phosphorus, turbidity and parasite standards. Rapid dispersion of coagulant is essential to ensure maximum efficiency to ensure that the quantity of chemicals required is minimised. In turn this keeps solids loading levels low and cost of chemicals minimised. Mechanical mixing shall be supplied accordingly. In order to promote high hydraulic loading rates, strengthening of floc can be carried out though the addition of a small quantity of polyelectrolyte. The chemical selected for upstream conditioning is dependent upon the function of the filtration system. Ferric is the preferred choice for P-removal and can be dosed from the main storage and dosing facility. Depending upon the quality of the secondary effluent from the FSTs, it may be possible to dispense with the chemical dosing altogether and rely on capturing the biological floc already formed. Disc filtration may also be considered as an alternate filtration method, particularly as it provides a lower footprint solution. Disc filtration may be considered suitable if the Contractor is able to present sufficient process performance guarantees and justification for this alternative to be adopted over conventional filtration. Conventional filtration uses a bed of media to capture suspended particles. Head loss through the media increases over run time, as particles accumulate in the media bed. To remove the particles from the media, a filter cell is taken out of service and backwashed with filtered water. The waste from the backwashing is contained in a storage tank prior to return to the head of the plant for treatment. Conventional filters may be dual media or single media. Where solids blinding is a concern a dual media system (provision of a coarse layer of anthracite above the sand layer) is recommended. However, following the high level of secondary treatment proposed for these works a single media sand filter is considered appropriate. Clean and dirty backwash tanks are to be provided, to allow backwashing of the filters. Table 6.1 summarises the design parameters and details of the process units used for Tertiary Treatment


Page 21 of 49


Specifications

Table 6.1: Tertiary Treatment Description Item 6.1

6.2

Process Stage Coagulation

Tertiary Filtration

Sub Category Tanks

Mixers Sand Filters

Design Criteria Number of tanks: 1 Indicative sizing: Total working volume: 77 (83.4)m3 Tank dimensions: Depth: 6 m Width: 4 m Length: 4 m Mixer type: Paddle Peak filtration rate : All cells in operation = 7.1 m/h 1 cell out backwashing = 8.1 m/h Filter Configuration: Single Indicative sizing: Number of units: 8 Filter bed length: 7 Filter bed width: 7 Bed type: twin

Media

Media depth: 2 m Media type: Sand Media effective size: 1.8 mm Depth from media surface to top of washout weir:

Filter inlet and distribution

Minimum 500 mm – Contractor to confirm & note the effect of TWL on b/w flow rate Free discharge into each filter to allow individual control of filters based upon level. Even hydraulic split between filters. Overflow bypass to pass flows to the outlet channel and thus to the effluent pumping station, flows will then be diverted to the outfall.

Underdrain arrangement

Monolithic Concrete Floor or proprietary floor Nozzle specification : Contractor design

Control

Filter control basis: Level Backwash initiation: In order of priority – operator over-ride, outlet turbidity, headloss, throughput, time.


Page 22 of 49

Process Output


Item 6.3

Process Stage Backwash System

Sub Category Indicative Backwash Regime

Specifications

Design Criteria

Process Output

Backwash: combined air and water Main backwash rate 30 m/h High rate rinse rate: 60 m/h Air scour: 70 m/h Design backwash water per wash: 294 m3 The backwash system shall include chlorination of the backwash water to control growth of algae and parasites in the filters.

Backwash Pumps

Number pumps:2 (duty/assist/standby) Type pump: Centrifugal VSD Indicative peak output: 2,940 m3/h Dirty bed headloss 3.7 m

Air scour Blowers

Number blowers: 2 (duty/standby) Indicative peak output: 3,430 m3/h Temperature compensation is required on the pump output to ensure the correct bed expansion across the operating temperature range of the plant.

Clean backwash water Tank

Dirty backwash tank

Dirty backwash Mixers


Number tanks: 1 Indicative sizing: Working Volume: 590 m3 Width 9 m Length 19 m Minimum depth 3.5 m Floor slope 1o Number tanks: 2 Indicative sizing: Working Volume: 577 m3 each Width 9 m Length 19 m Minimum depth 3.5 m Floor slope 1o Number mixers: 2 Power: 5 kW

Page 23 of 49

(May be combined with the Return Liquors Pumping station)


Item 6.4

6.5

Process Stage Filter effluent Quality

Tertiary Effluent Pumping Station (if required subject to hydraulic design)


Sub Category On-line Monitoring

Tertiary Effluent Pumps

Specifications

Design Criteria

Process Output

Minimum number of on-line monitoring instruments for each parameter: 1 Parameters to be monitored: Turbidity Nitrate Phosphorous Number of pumps: 3 Mode of Operation: Duty/assist/standby Capacity: 386 l/s each Type: Variable speed Space shall be allowed in the pumping station for a minimum of 1 No. extra duty pump to serve ‘future requirements’

Page 24 of 49

To lift flows to chlorine contact tank (if required)


7.

Specifications

DISINFECTION Disinfection shall be provided by chlorine gas injection to ensure compliance with microbiological standards and to provide a residual chlorine concentration for the inhibition of bacterial and algae growth in the TSE storage and distribution system. Effluent from the filters shall be chlorinated with chlorine gas solution prior to entering a chlorine contact tank which will include suitable baffling to provide adequate contact time for disinfection. After disinfection, the treated effluent will be stored in a TSE storage tank for onward distribution to the irrigation system via a final effluent pumping station. Table 7.1 summarises the design parameters and details of the process units used for the disinfection of biologically treated sewage. Table 7.1: Description of Disinfection

Item

Process Stage

7.1

Chlorine Dosing System

Sub Category Dosing

Design Criteria Chemical: Chlorine gas Expected disinfection dose range: 2-8 mg/l, Expected average disinfection dose: 7.5 mg/l Indicative average disinfection chlorine gas consumption: 150 kg/d Indicative maximum chlorine draw-off rate: 20 kg/h at 20˚C

Storage

Chlorine drum storage room to be temperature-controlled to maintain room at >20˚C to guarantee maximum gas draw-of rate. Storage type: chlorine drums or bulk storage Storage period: 21 days Max number of on-line drums: 16 Total number of drums: 16 duty and 16 standby. Total storage capacity: 6,400kg

Disinfection chlorine dosing control

Mixing of chemical with main process stream is to be achieved using a static mixer or alternative proprietary mixing system providing equivalent or better performance. Dosing is to be flow paced using a flowmeter on the Tertiary Filter outlet.


Page 25 of 49

Process Output Disinfection of final effluent


Item

7.2

Process Stage

Chlorine Contact Tank

Sub Category

Tank

Specifications

Design Criteria Chlorine residual to be sampled and measured by on-line chlorine analysers which will trim the chlorine dose to achieve the set residual chlorine concentration. Number: 2 Retention time at maximum future flow (ultimate peak flow): 49 min Tank arrangement: double-pass (Ushape) Indicative sizing: Capacity: 2,278 m3 Length: 26.13 m Width: 8.71 m (4.35 m per pass) Depth: 5 m Tank shall be covered to restrict algae growth and protect against contamination from external sources.

Internal requirements


Flow: The flow should be purely serpentine, with internal baffles to promote plug flow

Page 26 of 49

Process Output

Capacity shall be sized for future plant extension


8.

Specifications

TSE STORAGE TANK AND PUMPING STATION After disinfection, the treated effluent shall be stored in a TSE storage tank for onward distribution to the irrigation system via a final effluent pumping station or to sea via the long sea outfall. The TSE storage tank is required to balance the flows to suit the diurnal irrigation demand. Table 8.1 summarises the design parameters and details of process units used for the balancing and pumping of final effluent. The sea outfall is to be provided under this contract along with the on-site section of the TSE distribution pipeline. The latter will terminate/connect at a point to be agreed in the vicinity of the site boundary to the network irrigation pipeline being provided under a separate contract. A set of pumps should also be provided to feed a final effluent ring main which will provide TSE to a number of process applications such as washwater for the sludge dewatering units, cooling water for dryer exhaust air, inlet screens washwater, on-site irrigation system, etc. Table 8.1: Description of TSE Storage Tank and Pumping Station

Item 8.1

Process Stage

Sub Category

Effluent Storage Tank

Process Output

Design Criteria Number of storage tanks: 1 Retention time at average flow: 6 hours for current flows Minimum Capacity: 10,000 m3

To balance flows going forward to the TSE irrigation network

Minimum number of compartments: 2, to enable isolation of 1 No. compartment in the event of maintenance Tank shall be covered to restrict algae growth and protect against contamination from external sources. 8.2

TSE Pumping Station

Treated Sewage Effluent (TSE) Pumps

Minimum number of pumps: 3 Mode of Duty/assist/standby

Operation:

Capacity: 230 l/s Type: Variable speed Max. pressure: 7.5 bar Mode of operation: auto control to maintain pressure at set-point Space shall be allowed in the pumping station for a minimum of 1 No. additional duty pump to serve ‘future requirements’


Page 27 of 49

To pump TSE to the irrigation network


Item 8.3

Process Stage Washwater

Sub Category Washwater Ring Main Pumps

Specifications

Design Criteria Minimum number of pumps: 3 Mode of operation: Duty/assist/standby

Process Output To feed effluent main

final ring

Sampling effluent

of

Type: Variable speed Capacity: Contractor to design to meet demand from different plant applications. Operating pressure: 6 bar 8.4

8.5

TSE Flow Measurement

TSE Sampling

Type: Electromagnetic Number: One on each TSE outlet (including irrigation, sea outfall and washwater) Sampler

Type: Automatic refrigerated programmable composite and spot sampler Minimum number of samplers: 2 i. TSE to irrigation ii. Effluent/emergency overflows discharged to the Outfall


Page 28 of 49


9.

Specifications

SLUDGE THICKENING A proportion of the wasted sludge (SAS) will be thickened on a gravity belt thickener (GBT) and then blended with unthickened SAS in a mixing and storage tank, to achieve a target solids feed to the aerobic digester of 1.5%. Alternative arrangements may be considered, such as inline mixing with progressive cavitation pumps or the thickened and unthickened sludge fed direct to the aerobic digester. In this latter arrangement the bypass feed pump would be on a direct control loop from the aerobic digester solids monitor. The GBT requires a constant flow of washwater. TSE shall be used for washing, taken from either the site washwater system or a dedicated system for the belts. Filtrate from the belts shall not be used for belt washing. Table 9.1 summarises the design parameters and details of process units used to thickener the sludge. Table 9.1: Description of Sludge Thickeners

Item 9.1

Process Stage Unthickened SAS Tank

Sub Category Tank

Design Criteria Number: 1 Retention time at average flow: 5 hours for current flows (3.3 hrs for future flows)

Process Output To balance SAS feed to the dewatering units

Capacity: 246 m3 Aeration

Air mixing requirement: 1.8 Nm3/m3.h Indicative air flow: 810 Nm3/h

9.2

Thickening System

Thickening units

Type: gravity belt thickener Number: 2 Indicative total Capacity: 117 m3/h peak 98 m3/h average Mode of operation: 1 duty/1 standby Thickened sludge concentration: 6% dry solids Solids capture rate: 95% Operating time: 24hours per day (based on peak sludge flow)


Page 29 of 49

To keep solids in suspension to ensure consistent quality of feed sludge to the thickening system and to keep sludge aerobic. To thicken SAS


Item

Process Stage

Sub Category

Specifications

Process Output

Design Criteria 7 days per week Indicative washwater 920m3/d (Peak)

Thickener feed pumps

requirement

Number: 2 Indicative capacity: 32.5 l/s peak, 27 l/s average

To transfer sludge from SAS Tank to the thickening units

Mode of operation: duty/standby Type: positive displacement, variable speed flow control Common manifold to allow each pump to feed each machine 9.3

Polyelectrolyte Dosing System

Dosing system

Maximum polyelectrolyte dose rate: 6 kg/TDS Number of polyelectrolyte make-up and dosing systems: 1

To condition sludge prior to thickening

Mode of operation: duty Type: system to be suitable to use both powder (25 kg bags) and liquid polyelectrolyte Powder polyelectrolyte make-up and dosing tanks

Number of make-up tanks: 1 (duty) Make-up tank retention time at maximum polyelectrolyte demand: 1 hour at future flows Polyelectrolyte concentration: 0.5% w/w

make-up

Capacity of make-up tank: 1.2 m3 Make-up tank indicative potable water requirements: 910 l/h average (1,370 l/h at peak flows)


Page 30 of 49

System sized for future flows


Item

Process Stage

Sub Category

Specifications

Design Criteria

Process Output

Number of dosing tanks: 1 (duty) Dosing tank retention time at maximum polyelectrolyte demand: 2 hours at future flows Polyelectrolyte dosing concentration: 0.1% Capacity of dosing tank: 0.6 m3 Reclaimed effluent required for postdilution: 1410 l/h (2115 l/h at future flows) Polyelectrolyte dosing pumps

Number: 2 Indicative duty: 316 l/h Type: variable speed (flow paced) Mode of operation: Duty/standby Common manifold to allow each pump to feed each machine

9.4

9.5

Thickened Sludge Pumps

Pumps

Thickened Sludge Tank

Tank

Number: 2 (1 No. per machine) Type: positive displacement, variable speed flow control Number: 1 Type: Tank Retention time at average sludge production: 5 hours for current flows

To transport thickened sludge to thickened sludge tank To blend thickened and unthickened SAS prior to feeding digester

Indicate capacity: 104 m3 Mixing


9.6

Thickener bypass pumps


Pumps

Number: 2 (duty/standby) Indicative capacity: 16.2 m3/h at average production

Page 31 of 49

To keep solids in suspension, mix sludges and keep sludge aerobic


10.

Specifications

SLUDGE AEROBIC DIGESTERS Thickened sludge shall be aerobically digested in two separate tanks. Aerobic digestion will help compliance with the effluent phosphorus limits by minimising the release of phosphorus from the bio-mass and its return to the main process stream. The digesters are periodically oxygenated to stabilise the sludge by biological reduction of the volatile solids and to reduce pathogen levels and risk of odours. Aeration is to be intermittent to provide some denitrification and thereby recover some of the alkalinity destroyed in the nitrification process within the reactor. However, chemical dosing will be required to maintain alkalinity above 50 mg/l as CaCO 3 . The aeration within the aerobic digester can either be diffused aeration system with mechanical mixing during the un-aerated phase or a hybrid aeration/mixing system. Table 10.1: Description of Aerobic Digesters

Item 10.1

Process Stage Digester Tanks

Sub Category Tanks

Process Output

Design Criteria Number: 2 (2 trains, 2 zones per train) Indicative sizing: Capacity: 4 zones, 1,309 m3 each Tank dimensions (each): Depth: 6 m Length: 30 m Width: 15 m Number of digester: 2

pockets/zones

per

Actual design MLSS concentration: 15,000 mg/l. Maximum design MLSS concentration: 18,000 mg/l (if pre-thickening is included) Min aerobic sludge age (ASP aeration tanks + aerobic digesters): 29.5 days Minimum volatile destruction: 40% Maximum SOUR of stabilised sludge: 1.5 mgO 2 /hour/g total solids at 20oC Minimum aeration temperature: 24˚C

basin

MLSS

Maximum aeration temperature: 36˚C

basin

MLSS

Aerobic mass fraction: 0.5 Anoxic mass fraction: 0.5 Vol 3, Section 2 – Process Specification

Page 32 of 49


Item 10.2

Process Stage

Specifications

Sub Category

Aeration & Mixing System

Design Criteria Mode of aeration.

operation:

Process Output

intermittent

i.e. Train 1, Zone 1 and Train 2, Zone 2 aerated, other Zones just mixed and vice versa. Number of mixers: 1 No. per zone Installed power per mixer: 3 kW Aeration type: coarse bubble Blowers

Number: 2 (duty/standby) Indicative nominal peak air flow rate to aerobic digesters 5,879 Nm3/hr

10.3

Alkalinity dosing

Chemical storage Chemical dosing pumps


Number: 1 To store chemicals to replace alkalinity lost due to nitrification in the digester 2 No. duty/standby Intermittent dosing, controlled on ammonia and pH

Page 33 of 49

Chemical may be sodium hydroxide, sodium bicarbonate or other chemical to increase the alkalinity of the digester contents.


11.

Specifications

SLUDGE DEWATERING The stabilised sludge will be taken to a feed averaging tank (FAT) before being mechanically dewatered by duty/standby double-decked gravity belt thickener (GBTs)/belt filter press (BFP) or centrifuges, to achieve a target dry solids of 18%. This minimises the size of the downstream sludge dryers. The liquors recovered from the dewatering process are pumped back to the inlet works via the return liquor pumping station/balancing tank and the dewatered sludge cake is then stored in a sludge silo. Table 11.1 provides the design characteristics for the dewatering system. Table 11.1: Dewatering System Description

Item 11.1

Process Stage Feed Averaging Tank (FAT)

Sub Category Tank

Design Criteria Number: 1 Retention time at average flow: 5 hours for current flows (3.3 hrs for future flows) Indicative capacity: 110 m3

Aeration


11.2

Dewatering System

Dewatering units

Type: centrifuge or double-decked gravity belt thickener and belt filter press Number: 2 Indicative capacity: 31 m3/h average Mode of operation: duty/standby Dewatered sludge 18% dry solids

concentration:

Solids capture rate: 95% Operating time: 24 hours per day (based on peak sludge flow) 7 days per week


Page 34 of 49

Process Output To balance aerobically digested sludge feed to the dewatering units To keep solids in suspension to ensure consistent quality of feed sludge to the dewatering system and to keep sludge aerobic. To dewater digested sludge Peak capacity is provided by increasing run times


Item

Process Stage

Sub Category Dewatering feed pumps

Specifications

Design Criteria Number: 2 Indicative capacity: 10 l/s Mode of operation: duty/standby

Process Output To transfer sludge from FAT to dewatering units

Type: positive displacement, variable speed flow control Common manifold to allow each pump to feed each machine 11.3

Polyelectrolyte Dosing System

Dosing system

Maximum polyelectrolyte dose rate: 6 kg/tds Number of polyelectrolyte make-up and dosing systems: 1

To condition sludge prior to dewatering

Mode of operation: duty Type: system to be suitable to use both powder (25 kg bags) and liquid polyelectrolyte Powder polymer make-up and dosing tanks

Number of make-up tanks: 1 (duty) Make-up tank retention time at maximum polyelectrolyte demand: 1 hour at future flows Polyelectrolyte make-up concentration: 0.5% w/w Capacity of make-up tank: 1.2 m3 Make-up tank potable water requirements: 910 l/h average (1,370 l/h at peak flows) Number of dosing tanks: 1 (duty) Dosing tank retention time at maximum polyelectrolyte demand: 2 hours at future flows Polyelectrolyte dosing concentration: 0.1% Capacity of dosing tank: 2.4 m3 Final effluent required for postdilution: 3,260 l/h (4,880 l/h at future flows)


Page 35 of 49

System to be sized for future flows


Item

Process Stage

Specifications

Sub Category Polymer dosing pumps

Design Criteria

Process Output

Number: 2 Indicative duty: 815 l/h (1,220 l/h at future flows) Type: variable speed (flow paced) Mode of operation: duty/standby Common manifold to allow each pump to feed each machine

11.4

Dewatered Sludge Conveying System

Conveying system

Minimum number of conveying systems: 2 (1 No. per machine) Or discharge direct to the cake silo

To transport dewatered sludge to cake storage silo

Type: belt conveyor 11.5

Dewatered Sludge Storage

Storage

Number: 1 Type: Silo Retention time at average sludge production: 3 days for current flows Fitted with active outloading system Capacity 120 m3

11.6

Liquor Return Pumping Station

Pumping station

Number of pumping station: 1

Liquor return pumps

Minimum number of duty pumps: 2

Flows to be returned to the inlet works include: liquors and washwater from GBT/belt filter press, sand filter backwash, sludge dryer condensate and wet scrubber liquors, tank drains, surface water drainage etc.

Mode of operation: duty/standby Type: variable speed Capacity: to be determined by the Contractor depending on type of technologies chosen for different treatment processes


Page 36 of 49

To store dewatered cake prior to drying


12.

Specifications

SLUDGE THERMAL DRYING A thermal sludge dryer shall be used to produce pellets suitable for re-use for land application and disposal to landfill. Table 12.1 summarises the design parameters and details of process units used to dry dewatered sludge. The thermal drying plant shall dry the dewatered sludge to 90% dry solids. This sludge product will provide the greatest security of operation and minimise the number of truck movements to remove the sludge from the STP. The dying process shall destroy any pathogens in the sludge to produce an end product suitable for unrestricted reuse. The single thermal dryer shall be powered by diesel but shall also be suitable for natural gas. Most of the exhaust gases shall be recycled back to the dryer. A small proportion of air will be wasted and discharged to the main odour control facility. The waste air will be cooled by TSE water in air condensers to reduce the air temperature down to a level suitable for the GRP ductwork and the main odour control facility, approximately 40 degrees Celsius. The TSE will be taken from the TSE ring main, pass through the closed loop condenser and discharge back to the TSE storage tank. The waste air will be pre-treated in a quench tower to remove dust particles prior to receiving further treatment in the odour control unit. The dry sludge shall be processed through a pelletising unit to prevent dust issues during product handling. Pellets shall be stored in a silo before being taken off-site for re-use or disposal to landfill. The Contractor shall also price for a pellet bagging plant (25 kg bags). The sludge dryer system, pellet conveying system, pelletising system, pellet storage and bagging plant shall be designed with safety provisions to minimise the danger of dust explosions and fires. The system shall be designed in line with the UK HSE guideline “Sewage Sludge Drying Plants - 847/9” and demonstrate the basis of safety within the dryer design and operation. It is important that each Vendor has direct experience of sludge drying and sludge pellet handling. Table 12.1: Description of Sludge Drying System

Item 12.1

Process Stage Sludge Conveying System

Sub Category Conveying system

Design Criteria Number: 1 Type: belt conveyor Indicative sludge cake production: Average: 21m3/d (future: 30 m3/d) Peak: 30 m3/d (future: 45 m3/d) Conveying arrangement to cater for transfer of sludge from cake storage silo to thermal dryer or to tanker (for off-site disposal)


Page 37 of 49

Process Output To transport dewatered sludge from cake storage silo to dryer


Item 12.2

Process Stage

Specifications

Sub Category

Dewatered Cake Characteristics

Minimum dry solids concentration: 17% Average 18%

12.3

Sludge Dryer

Process Output

Design Criteria

Dryer

dry

solids

concentration:

Number: 1 Type: Low heat direct belt dryer or drum dryer, c/w dual burner (diesel and natural gas), fans, condensers, heater, cooler, and back mixing systems as required.

To dry dewatered sludge

the

Required dry product concentration: 90% Sludge quality: Grade A US EPA Rule 503 Guidelines Operating time : 24 hours per day Indicative evaporation capacities: Average: 0.5 Tonnes per hour Peak: 1.3 Tonnes per hour

Sized for future flows

Dry sludge final temperature: 400C Open Loop Heat Recovery

Number: 2

To cool dryer exhaust air

Indicative flows: Condenser 1: Cooling water flow: 29 m3/h Condensate flow: 0.5 m3/h Condenser 2: Cooling water flow: 66 m3/h Condensate flow: 1.8 m3/h Cooling water: (disinfected)

final

effluent

Mode of operation: duty/duty, in series Maximum temperature of return line: 60˚C Seasonal temperature range of flow line: 24 - 36˚C


Page 38 of 49


Item 12.4

Process Stage Dryer Fuel

Specifications

Sub Category Fuel

Process Output

Design Criteria Fuel type: Diesel (with an allowance for natural gas in the future) Number of diesel (duty/standby)

pumps:

2

To feed the burners used to produce hot air.

Indicative diesel pump capacity: 207 l/hr Diesel storage requirements: 21 days Number of diesel storage tanks: 2

Storage based on future flows.

Capacity of diesel storage tanks: 42 m3 each (Note that diesel storage does not include for fuel required for emergency power generation on site) 12.5

12.6

Dry Sludge Conveying System

Conveying system

Minimum number systems: 1

of

conveying

Type: screw conveyor

Pelletising System

To transport dried sludge from dryer to sludge pelletiser and/or directly to dry sludge storage silo

A pelletising system may be required depending on the selected type of sludge dryer. If pelletisers are required then: Minimum number of duty pelletisers: 2 Type: Drum mill pelletiser Pellet size: 3-5mm

12.7

Dry Storage

Sludge

Storage

Minimum number of storage tanks: 1 Type: Silo Complete with: pellet conveyor from dry sludge storage silo to bagging plant Retention time at average sludge production: 4.5 days for current flows Indicative capacity: 95 m3


Page 39 of 49

To store dry pellets prior to disposal off-site or bagging


Item 12.8

Process Stage Pellet Plant

Sub Category

Bagging

Specifications

Design Criteria Minimum number of pellet bagging plant: 1 Complete with: pallet stacking and wrapping equipment, fork lift pallet truck.

Process Output To store dry sludge pellets in 25 kg bags

Fully automatic Bag size: 25kg bags 12.9

Dryer Exhaust Air Scrubber


Scrubber

Minimum number of scrubbers: 1 Type: Quench tower

Page 40 of 49

To remove dust particles from the exhaust air


13.

Specifications

CHEMICAL PHOSPHOROUS REMOVAL Chemical dosing is to be to primary means of phosphorus removal under normal operating conditions although the design of the activated sludge plant shall be flexible to allow biological removal of P if the influent proves suitable (see Section 4). Chemical dosing for P removal provides the additional advantage of allowing the final effluent to be tuned to suit its disposal route e.g. phosphorus removal can be turned off when the effluent is to be used for irrigation, improving its nutrient value for the planting and reducing cost - this will also maximise the available carbon for denitrification, improving compliance with the Total N standard and reducing the need for supplementary carbon dosing. Table 13.1 summarises the design parameters and details of process units associated with chemical phosphorous removal. Table 13.1: Description of Chemical Phosphorous Removal System

Item 13.1

Process Stage Chemical Dosing System

Sub Category Dosing system

Design Criteria Chemical: Ferric chloride Indicative dose rate: 972 kg/d as Fe Dose location: RAS Note: ferrous salts may be dosed as an alternative into the aeration lanes.

Storage tank

Number of storage tanks: 2 Storage retention time at maximum demand: 21 days for current flows Storage tank capacity: 25 m3

Dosing pumps

Number: 2 Indicative Duty: 208 l/h (peak 365 l/h) Type: variable speed, 100:1 turndown (for P trim) Mode of operation: duty/standby


Page 41 of 49

Process Output To chemically remove phosphorous


14.

Specifications

ODOUR CONTROL To ensure adequate odour management on site, all tanks, channels, screens, and conveyors that have the potential to release detectable odours off-site shall be enclosed and directly exhausted to an odour control system. Specifically, all pumping, screenings, grit, water surfaces upstream of the aerobic activated sludge process, and sludge processes shall be covered or enclosed and directly exhausted to an odour control system. This includes: • • • • • • • • • •

Inlet pumping station Inlet works tanker reception facility Preliminary treatment: inlet and fine screens, grit removal, screening and grit skips Secondary process inlet distribution chamber Bioreactors inlet channels and tanks Bioreactors anaerobic and anoxic zones Sludge tanks Sludge thickening and dewatering Sludge dryers. Note that dryer air will be pre-treated through a wet scrubber to cool the gases and remove dust particles prior to entering the odour treatment unit Sludge silos

Other process areas to be covered but the extracted air may be dispersed only, (i.e. not treated through an odour control unit) via a stack. This includes: •

Aerobic digester

The position of the extract points must be such that air is drawn across the surface of liquid from the air intake to the point of extract. The level of air extraction shall be sufficient to maintain negative pressure. Odour control systems shall be designed for the following design conditions: • • •

STP will be operated, maintained, and managed under Good Industry Practice. Worst-case meteorological events: calm conditions, wind speed of approximately 1 m/s. Prevent odour complaints from the public by reducing concentrations of hydrogen sulphide, mercaptans, other sulphur-containing compounds and Volatile Organic Carbons (VOCs) such that those from the site are undetectable at the site boundaries.

The boundary standard is normally defined in terms of olfactory requirements but the required standard shall be: “The odour level at the site’s boundary shall not be above 5 OU/m3 on a 99.8%ile, one hourly average basis based on the BS EN 13725:2003 standard odour control method”. The odour control discharge stack shall be tall enough to disperse the discharge and have an exit velocity of 18m/s to aid the dispersion. A silencer may be fitted if required to meet the specified noise levels at the site boundaries. Condensation drains/demister shall be installed at low points of ductwork to drain condensation. Ductwork shall be designed to fall to suit drain location. Two (2) types of dampers shall be required (function may be combined in a single unit): • •

Flow control dampers Isolation dampers shall be 100% isolating to allow maintenance on equipment


Page 42 of 49


Specifications

The Contractor shall design and supply all necessary supports for the odour control covers, with adequate sealing. Sealing arrangements must be such that liquid surface in process tank is not affected and free passage of foam and scum is allowed. Intake and extract points should be positioned to allow cross flow of air over liquid surface across the tanks. A negative pressure must be maintained below the covers to avoid escape of odorous air to outside atmosphere. Table 14.1: Description of Odour Control System Item 14.1

Process Stage Odour Treatment System

Sub Category Odour Control (OCU)

Unit

Design Criteria The OCU needs to achieve < 500 OU/m3 (odour dispersion modelling based on this figure) to achieve the following standard:

Process Output To treat odorous gases

5 OU/m3 on a 99.8%ile 1 hourly averaging basis measured at the site boundary. Fans

Consideration is to be made to the overall pressure drop when specifying the fans. The contractor shall determine whether booster fans are required in order to optimise the selection of the main extraction fans Accoustic enclosure on each fan: <85 dBA at 1m Airflow velocity in GRP ductwork < 10 m/s to prevent noise and vibration and > 3.5m/s to allow for balancing of ductwork

Instruments

Minimum number of on-line monitoring instruments for each parameter: 1 Parameters to be monitored: OCU inlet hydrogen sulphide concentration, range: 0 – 1,000 ppm Stack outlet hydrogen sulphide concentration, range: 0 – 100 ppm

Table 14.2 shows minimum concentration of air contaminants for guidance, the Contractor shall confirm actual design concentrations.


Page 43 of 49


Specifications

Table 14.2: Guidance Minimum Air Contaminants Concentration

Inlet Pumping Station Tanker Reception Sump Screens Area Skips Grit Channel Grit Tanks Reactor Distribution Chamber Reactor Inlet Channel Anaerobic Tanks Anoxic Tanks FAT tank Dewatering Cake Silo Dryers Pellet Silo Aerobic Digesters

Air changes hr-1 12.0

H 2 S (ppm) Av peak 200 600

R-SH (ppm) Av peak 2 4

NH 3 (ppm) Av peak 2 5

VOC (ppm) Av peak 5 60

DMS (ppm) Av peak 1 3

12.0

200

600

2

4

2

5

5

60

1

3

12.0 6.0 12.0 1.2 6.0

200 10 200 200 10

600 20 400 400 30

2 2 2 2 1

4 4 4 4 3

2 2 2 2 0

5 5 5 5 5

5 5 5 30 1

60 60 60 100 3

1 1 1 1 1

3 3 3 3 3

6.0

10

30

1

3

0

0

1

3

1

3

6.0

5

15

1

3

0

0

3

10

2

5

6.0 1.2 10.0 2.0 1.0 2.0 1.2

2 2 2 2 2 2

5 5 5 5 5 5

1 1 0 0 0 0

3 0 0 1 3 0 0 20 1 0 0 2 1 0 0 2 1 0 0 2 1 0 0 2 Aeration: 0.44 OU/m2/s Anoxic: 0.43 OU/m2/s

3 50 5 5 5 5

1 1 1 1 1 1

3 3 3 3 3 3

The required air quality discharged from the OCU is shown in Table 13.3. Table 14.3: Required OCU Discharge Quality Design % removal at peak inlet design load

Maximum discharge concentration at peak load (ppm)

Hydrogen sulphide (H 2 S)

99.9%

0.1

Dimethyl sulphide (DMS)

99.0%

0.03

Mercaptans (R-SH)

99.9%

0.003

Contaminant

VOC (average Mol. Wt 120)


There shall be sufficient removal of VOCs to achieve stack discharge max. concentration specified (at peak load)

Page 44 of 49

Maximum discharge concentration at peak load Total including all contaminants not to exceed 500 OU/m3


Specifications

Table 14.4: Indicative Air Production Rates for Aerated Processes (Based on Future Flow) Process Air m3/hr Aerated grit removal

2,687

Aeration tanks

28,815

Aerobic Digesters

8,819

Negative pressure is to be maintained under the covers of the process tanks. This is to ensure fugitive emissions from the tanks do not occur.


Page 45 of 49


15.

Specifications

SCUM & FOAM REMOVAL To avoid accumulation of filamentous organisms, foam and scum should not be returned to the process.

Table 15.1: Scum & Foam Removal Item

Process Stage

Sub Category

Foam/scum removal system

Design Criteria

Process Output

Foam removal spray system (using recycled effluent) to be included

Drives accumulated foam and scum into suspension so that passes forward to the FSTs.

Inlet and outlet weir arrangements shall be provided on all bioreactors so that accumulated foam and scum flows over weirs and passes forward to the FSTs. A spray bar system connected to the plant washwater network shall be provided at the end of the anoxic/anaerobic zones in each Bioreactor where foam and scum typically collect. The system shall be designed to re-entrain the scum and move it forward over the Anoxic Zone division wall and into the Bioreactor Aerobic Zone.


Page 46 of 49


16.

Specifications

EFFLUENT OUTLETS

The management of effluent from the treatment works needs to be carefully addressed. There will be 2 different types of effluent to be disposed of: • •

Effluent which meets the unrestricted irrigation quality requirements, ‘in-spec’ effluent, during normal plant operation Effluent which does not meet the prescribed unrestricted irrigation quality standards, ‘offspec’ effluent, during plant upsets

The above 2 No. types of effluent shall be managed differently as ‘off-spec’ effluent shall not be allowed to enter and contaminate the irrigation system. During normal operation, ‘in-spec’ effluent shall be pumped from the TSE storage tank to the irrigation network by the TSE pumping station. Any surplus effluent produced during periods of low irrigation water demand shall be discharged to sea via the new plant outfall. During emergency scenarios, any raw sewage or ‘off-spec’ effluent shall overflow directly to the new long sea outfall, by-passing the TSE storage tank (and optionally the Chlorine Contact Tank) to avoid contamination. The proposed system is schematically shown in Figure 16.1 below.

In-spec Effluent

STP

Off-spec Effluent (Alternative)

Chlorine Contact Tank Off-spec Effluent

TSE Storage Tank

Irrigation network

TSE Pumping Station

Outfall

Sea

Figure 16.1: Schematic Diagram of STP Effluent Management Facilities A facility to disinfect/flush the effluent outlet pipes shall be provided in order to prevent the irrigation network from becoming contaminated after a plant upset.


Page 47 of 49


17.

Specifications

ALLOWANCES FOR FUTURE PLANT EXPANSION The first phase of AMAS STP to be built shall cater for Islands 3 to 14 flows. The average influent daily flow for Islands 3 to 14 is 39,680 m3/d when fully developed. An allowance of 50% shall be made in the design for future plant expansion, giving a future influent average daily flow of 59,520 m3/d. The minimum requirements to be put in place under Phase 1 are illustrated in Table 17.1. Critical for the completion of the first phase is the supply, installation and commissioning of the thermal dryer. Long lead times can be expected from suppliers therefore the supply of the thermal dryer must be given the highest implementation priority and procurement procedures shall start at the initial phase of the main contract. Table 17.1: Civil and M&E Staging of STP Phase 1

Phase 2 - Future

Inlet Works Civil M&E Process Tanks Civil M&E Contact Tank, TSE Storage Tank and TSE Pumping Station Civil M&E Aerobic Digesters Civil M&E Sludge Dewatering Civil

M&E

Sludge Dryer Civil M&E

Structures for the ultimate 59,520 m3/d Capacity for 39,680 m3/d

Capacity for 59,520 m3/d

4 No. Process Trains (39,680 m3/d) Capacity for 39,680 m3/d

6 No. Process Trains (59,520 m3/d) Capacity for 59,520 m3/d

-



2 No. aerobic digesters Capacity for 39,680 m3/d

3 No. aerobic digesters Capacity for 59,520 m3/d

Structures for the ultimate 59,520 m3/d Capacity for 39,680 m3/d (2 No. dewatering units) Polyelectrolyte make-up capacity for the ultimate 59,520 m3/d Structures for the ultimate 59,520 m3/d Capacity for the ultimate 59,520 m3/d

-

Capacity for 59,520 m3/d (3 No. dewatering units)

-

Distribution Chambers and Pumping Stations Civil M&E Chemical and Diesel Storage Vol 3, Section 2 – Process Specification


Page 48 of 49



Civil M&E Odour Control Civil M&E Buildings

Specifications

Phase 1 Structures for the ultimate 59,520 m3/d Capacity for the ultimate 59,520 m3/d Structures for the ultimate 59,520 m3/d Capacity for the ultimate 59,520 m3/d All buildings for the ultimate 59,520 m3/d

Phase 2 - Future -

-

Sea Outfall Civil M&E

Pipeline for the ultimate 59,520 m3/d Capacity for the ultimate 59,520 m3/d

-

Notes: • Values quoted in the above table for plant capacity are cumulative • The work for any particular stage is to include all instrumentation, control cabling, piping etc required for the operation of the plant at that stage. • Inlet Works shall include provision for the option to connect a future rising main to the Inlet Chamber to deliver the expanded plant flow.


Page 49 of 49

AL MADINA AL SHAMALIYA (AMAS) SEWAGE TREATMENT PLANT

Tender Documents Volume 3 Section 3 Civil Specifications

July 2014


Specifications

TABLE OF CONTENTS

SECTION A -

PARTICULAR REQUIREMENTS

SECTION B -

Not Used

SECTION C -

EARTHWORKS

SECTION D -

CONCRETE

SECTION E -

PIPELINES AND PIPEWORK

SECTION F -

BRICKWORK AND BLOCKWORK

SECTION G – CORROSION PROTECTION AND SURFACE COATINGS SECTION H -

FITTINGS AND FABRICATED ITEMS

SECTION I -

Not Used

SECTION J -

ROADWORKS AND LANDSCAPING

SECTION K – Not Used SECTION L -

BUILDING WORKS

SECTION M - GRP FABRICATED COVERS FOR ODOUR CONTROL SYSTEM SECTION N – PILE FOUNDATIONS SECTION O -

Not Used

SECTION P -

Not Used

SECTION Q -

Not Used

SECTION R -

Not Used

SECTION S - SCHEDULE OF APPROVED STANDARDS AND GUIDANCE PUBLICATIONS

Vol 3, Section 3 – Civil Specifications

Page i

of i


Specifications

TABLE OF CONTENTS Page No. SECTION A - PARTICULAR REQUIREMENTS A1

A2

1

GENERAL

1

A1.1

Scope of Work

1

A1.2

Description of Works to be Undertaken

1

A1.3

Drawings

2

A1.4

Provision for Future Connection at the Inlet Works

2

DESIGN

3

A2.1

Structural Design Criteria

3

A2.2

Design Standards, Regulations and Other Documents

3

A2.3

Loads

4

A2.4

Structural Stability Factors of Safety

5

A2.5

Exposure Conditions

6

A2.6

Fire Resistance

6

A2.7

Concrete Cover To Reinforcement

6

A2.8

Joints In Structures

6

A2.9

Other Criteria - Crack Width

6

A2.10

Foundation Design - Design Standards and Design Data

6

A3

LAYOUT PLAN AND PROCESS UNITS

6

A4

STP ACCESS ROAD

6

A5

PLANT HYDRAULICS

7

A6

BUILDINGS AND STRUCTURES

7

A6.1

Administration and Control Building

8

A6.2

Workshop, Store and Laboratory Building

8

A6.3

Gatehouse

9

A6.4

ASP Blower House Building

9

A6.5

Tertiary Filter/Aerobic Digester Blower House

9

A6.6

TSE Pump House Building

10

A6.7

Sludge Dewatering & Cake Storage Building

10

A6.8

Sludge Dryer Building

11

A6.9

Dried Sludge Pellet Storage Building

11

A6.10

Polyelectrolyte Storage and Dosing Building

11

A6.11

Odour Control Building

12

A6.12

Chlorination Building

12

A6.13

Emergency Generator Building

12


Page i of iii


A7

A8

A9

Specifications

A6.14

Electrical Sub-station and Control Buildings

12

A6.15

Chemical Storage and Dosing Facility

13

A6.16

Diesel Storage and Fuelling Facility

13

A6.17

Operator ablution block

13

BUILDING SERVICES

13

A7.1

General Requirements

13

A7.2

Lighting

14

A7.3

Small Power

15

A7.4

Air Conditioning

15

A7.5

Ventilation

15

A7.6

Foul drainage

15

A7.7

Potable Water Supply

15

A7.8

Fire Protection, Detection and Alarm

15

A7.9

Telephones

16

A7.10

Lightning Protection

16

A7.11

Furniture

17

ROADWORKS, LANDSCAPING AND OTHER EXTERNAL WORKS

17

A8.1

Roadworks

17

A8.2

Landscaping

17

A8.3

Pathways

18

A8.4

Site Boundary Wall / Fencing and Security Gate

18

A8.5

Potable Water Supply, Irrigation Main and TSE re-use line

18

A8.6

Cable Ducts and Drawpit Chambers

19

A8.7

Other External Works

19

INTERNAL SEWERAGE AND DRAINAGE

19

A10 TERMINAL LIFT PUMPING STATION (Inlet Pumping Station)

19

A10.1

Location

19

A10.2

Coordination and Interfaces

20

A10.3

Future Connection Manhole

20

A10.4


20

A10.5

Earthworks and Retaining Wall

20

A10.6

Access Roads

21

A10.7

Boundary Wall, Compound and Gate

21

A10.8

Landscaping and Irrigation

21

A10.9

Washing Down and Drainage

21

A10.10 Rising Mains

22

A10.11 Site lighting

22

A10.12 Odour Control

22

A10.13 Potable Water Supply

22

A10.14 Buildings and structures

22

A10.15 Other External Works

22


Page ii of iii


Specifications

A11 LONG SEA OUTFALL

22

A11.1

General

22

A11.2

Environmental Impact Assessment

23

A11.3

Outfall Designer

23

A11.4

Design Data

23

A11.5

Other Features

25

A11.6

Initial Outline Design

26

A11.7

Pipeline Stability Analysis

27

A11.8

Pipeline Construction, Materials and Method of Installation

27

A11.9

Hydrographic Surveys

28

A11.10 Materials

29

A11.11 Cleansing of Pipelines

32

A11.12 Testing of Pipelines

32

A11.13 Construction Records and Quality Control

32

A11.14 Operation and Maintenance

32

A10 PLANT SCALE MODEL


32

Page iii of iii


Specifications

SECTION A - PARTICULAR REQUIREMENTS A1

GENERAL

A1.1

Scope of Work The project involves the design, construction, operation and maintenance of a new Sewage Treatment Plant (STP) to be located on Island 13C to treat a projected flow arising from the Al Madina Al Shamaliya development. The extent of the Works includes the design, supply, installation, construction, testing, commissioning and putting to reliable, efficient service of all equipment necessary for a complete, workable installation to treat the specified volumes and quality of raw sewage to a standard suitable for restricted irrigation use as specified. Operation and maintenance of the plant is to be undertaken for a minimum period of five years after which the client will have the option to renew and / or amend the O&M contract. Further details of the scope are given in the Particular Requirements specifications.

A1.2

Description of Works to be Undertaken The new works to be constructed, together with all necessary equipment and ancillaries, shall include, but not be limited to, the following: •

Inlet Pumping Station (Terminal Lift PS at the termination point of the deep gravity sewer constructed by others) with coarse screen, screenings washing and odour control unit

•

Tanker discharge facilities for 6 No tankers

•

Inlet works with flow measurement and storm water overflow facilities

•

Screening (6mm) with screenings washing and compaction

•

Grit and Oil/Grease removal utilising aerated grit channels with associated handling and disposal systems

•

Selector/ Anoxic / Aeration double pass Bioreactor Tanks with internal recycles

•

Final Settlement Tanks (FST’s)

•

RAS/SAS Submersible Pumping Station

•

Tertiary Sand/disc Filters

•

A Chlorination Building for gas storage, preparation of chlorine solution

•

Chlorine Contact Tank

•

TSE Storage Tank, capacity 10,000 m3 with overflow facility

•

TSE Pumping Station

•

Intermediate Lift Pumping Station

•

A Return Liquors Submersible Pumping Station

•

Aerobic Digester Tanks

•

Sludge Dewatering system employing Gravity Belt Thickener, Belt Filter Press, or Centrifuge, with associated sludge conveyance system and building

•

Polyelectrolyte Dosing system

Vol 3, Section3 – Civil Specifications

Page A-1 of 33


A1.3

Specifications

•

Dewatered Sludge Storage Silo

•

Sludge Dryer, dry sludge silo and associated building

•

Diesel Storage Tanks and Pump Room

•

Ferric dosing system, ferric chloride storage tank and dosing pumps

•

Odour Control unit.

•

An Administration/Laboratory/Control Building

•

Workshop and Storage Buildings

•

Blower House Buildings

•

Final effluent high pressure washwater system throughout the STP

•

Architectural screen wall, security gate & kiosk, landscaping of the Site

•

Associated channels, pipelines, pipe work, chambers, manholes and flow meters

•

Electrical works including power supply and distribution, control buildings, ICA system, SCADA system, standby generators, site lighting and other ancillaries

•

Outfall Pipeline from the new works to the approved sea discharge point (approx. 4.5Km).

site road works, filling and

Drawings Tender Drawings are included in Volume 4. Except where otherwise stated, the Drawings indicate the conceptual and outline design of the new plant and show the envisaged arrangement of the finished works. The Drawings shall generally be used as the basis for the development of the design of the new plant.

A1.4

Provision for Future Connection at the Inlet Works The Inlet Works Inlet Chamber, which will receive all flow to the plant, shall include provision for the future connection of a 500mm diameter pumping main. The provision shall include installation of the pipe from the Inlet Chamber to a suitable future connection point at the plant boundary close to the main gate. The pipe shall be tested on completion and blanked off with the termination point marked with a permanent marker stating the diameter and depth at the interface point for future connection.


Page A-2 of 33


A2

Specifications

DESIGN Design calculations and details shall be submitted to the Engineer for approval. Construction will not be permitted to commence before approval of the design. The sizing of structural members shown on the Drawings is indicative only and shall be subject to the Contractor’s detail design, carried out in accordance with the Specification. All concrete shall have additional corrosion protection as specified. Structures shall generally extend a minimum of 200mm above finished ground level (FGL=+2.65m AOD). Excavations for structures will not be permitted to penetrate the local groundwater table estimated to about -6.0m AOD. This will be confirmed in the Geotechnical Investigation Report in to be provided in Volume 6 – Other Information. Handrailing shall be provided where any drop exceeds 500mm and around open tanks where the coping level is less than 900mm above finished ground level. Any consultants employed by the Contractor shall be designated Ministry Grade A and shall be subject to the approval of the Engineer

A2.1

Structural Design Criteria The design shall be carried out in accordance with the relevant codes of practice and standards for all aspects of structural design work. The detailed structural design criteria described here shall apply to:   

A2.2

Structures and sections of concrete structures designed to retain or exclude aqueous liquids. Normal concrete buildings and structures Steel work design

Design Standards, Regulations and Other Documents The structural design shall be carried out by suitably qualified professionals and shall comply with the relevant standards, code of practice, local laws, regulations and requirements of the relevant authorities and all laws in existence in Bahrain. The relevant design standards for civil engineering structures include (see also Section S of the General Technical Specifications): Bahrain Design Standards CP 3

-

Wind Loads

BS 648 -

Schedule of Weights of Building Materials.

BS 8110 -

Structural Use of Concrete

BS 8007 -

Code of Practice for the Design Of Concrete Structures for Retaining Aqueous Liquids.


Page A-3 of 33


Specifications

BS 5950 -

Structural Use of Steelwork in Buildings.

BS 8004 -

Code of Practice for Foundations.

BS5628 -

Code of Practice for use of Masonry

Reference may also be made to the following documents : a)

Reinforced Concrete Designers Handbook – Charles E. Reynolds & James Steadman.

b)

Design Guide to BS 5950: Part 1 : Volume 1 – The Steel Construction Institute.

c)

Steel Designers Manual – The Steel Construction Institute.

The Standards and Codes shall be the latest edition, current at time of Tender. A2.3

Loads a. Units SI units shall be used throughout b. Dead Loads Concrete

24 kN/m3

Water (including sludge)

10 kN/m3

Steel

78 kN/m3 or weight/m for structural members

c. Superimposed Dead Loads Roof Finish

To be assessed as appropriate

Ceiling & minor services

0.5 kN/m2

Floor Finishes


Partitions

To be assessed as appropriate to form of construction but not less than 1 kN/m2.

d. Superimposed Live Loads The minimum assumed loads shall as follows. The designer shall ensure that the loads assumed are adequate for the particular situation. Roof (with access for maintenance only) 0.75 kN/m2 Roof with general access


Stairs

5 kN/m2

Landings

5 kN/m2

Floors

5 kN/m2

e. Equipment and Machinery


Page A-4 of 33


Specifications

The weight of equipment and machinery shall be derived from manufacturer’s data and will include control panels, auxiliary machinery piping, etc. Dynamic loads from mechanical equipment/plant shall be assessed. Where exceptional loads are expected, allowance shall be made for the heaviest loading combination that could occur if plant is stored temporarily near installed units. Where loads are not known, for general areas uniform disturbed load shall be 7.5 kN/m2. f. Crane Loads and Moving Loads Crane and moving loads (e.g. from travelling cranes) shall be assumed at their maximum values, including the lifting capacity as well as maximum horizontal loads caused by braking or acceleration, but not acting simultaneously with maximum wind forces. For the design of each structural element, the most critical position of crane or other moving loads will be considered. For moving loads, an appropriate dynamic factor shall be used. g. Hydrostatic and Soil Pressure All water retaining structures (except in special circumstances) shall be designed to resist internal lateral hydrostatic pressure without the presence of exterior backfill. Density of soil shall be assumed to be 18 kN/m3. Structures buried in ground shall be designed to resist both lateral soil pressure and ground water pressure where appropriate. Division walls in structures such as the Aeration Tanks, shall be designed for lateral hydrostatic pressure in both directions to take account of sections being emptied for maintenance. The structural design shall also include loads from any proposed future extensions where the drawings indicate shared walls. h. Wind Load The wind load on any structure where appropriate shall be based on the wind pressures given in the Code of Practice on Wind Effects and shall not be less than that used locally. The basic design wind velocity for Bahrain is 45m/s. i. Seismic Load Bahrain is located in an area with very minor seismic activity. structures to be designed for earthquake loading. A2.4

It is not necessary for

Structural Stability Factors of Safety a. General The Factors of Safety shall be in accordance with the relevant sections of the BS unless otherwise indicated below. The effect of the specified concrete protection systems shall be carefully considered in the stability calculations. b. Overturning The Factor of Safety against overturning shall not be less than 1.5 due to wind loads and 2 for loads other than wind loads. c. Sliding


Page A-5 of 33


Specifications

The Factor of Safety against sliding shall not be less than 1.5. d. Flotation The Factor of Safety against flotation of the empty structure shall be not less than 1.1. A2.5

Exposure Conditions Exposure conditions are defined in Table 3.2 of BS 8110: Part 1. For water retaining structures the exposure condition shall be “most severe” in accordance with BS 8007. Concrete elements in dry non-aggressive environments shall be subject to “moderate” exposure.

A2.6

Fire Resistance Unless required otherwise the fire resistance period shall be taken as 2 hours.

A2.7

Concrete Cover To Reinforcement Unless otherwise stated, the minimum concrete cover to all reinforcement shall be 75mm (water retaining structures and below ground concrete) and 50mm (above ground).

A2.8

Joints In Structures Movement Joints in structures shall be provided in accordance with the relevant clauses of BS 8110 and BS 8007 with the emphasis on minimising the number of joints where appropriate.

A2.9

Other Criteria - Crack Width The maximum design surface crack width (for direct tension and flexure or restrained temperature and moisture effects) for structural members in contact with soil or water and exposed to damp and corrosive environment shall be 0.2mm, and 0.3mm for all other members.

A2.10

Foundation Design - Design Standards and Design Data The design shall be in accordance with the requirements of BS 8004 – Code of Practice for Foundations, and other applicable standards in accordance with the Specification. Negative skin friction, if applicable, shall be based on ground investigation data and calculated using recognised foundation engineering principles. The effect of the specified concrete protection systems shall be carefully considered.

A3

LAYOUT PLAN AND PROCESS UNITS The preliminary sizing and arrangement of the process units is shown on the layout drawing (Volume 5). Detailed description of process units is given under Volume 3, Section 2 of the tender document.

A4

STP ACCESS ROAD


Page A-6 of 33


Specifications

All roads on Island 13c shall be constructed by the STP Contractor. The extent of the roadworks is indicated on the Drawings and includes: 1. 2. 3. 4. 5.

Connection to the Primary Road on Island 13 at the culverted channel crossing near the TLPS as indicated on the drawings. Road width at connection = 7.5m. Road level at connection = +2.5m. Access road to the north of the TLPS for total distance of approx. 60m including a 90 degree bend in the road (for future car parking area for visitors to the hill). Minimum road width = 7m Access road to the south of the TLPS running close to the water channel for a distance of approximately 250m to the STP entrance gate. Min. Road width = 7.5m. Access road from the main road to the TLPS. Min. width 6m. All road markings and signage including signs to the STP and the TLPS.

Roads shall to be designed with regard to the types of heavy vehicles requiring access including cranes, trucks, tankers etc. Roads shall be provided with a minimum 1.75m wide verge each side and shall have a nominal 2% cross fall for drainage.

A5

PLANT HYDRAULICS The Hydraulic design for the new AMAS STP shall provide accurate and consistent flow splits between parallel process units over the full range of present and future design flows, to assist in the achievement of optimum process performance, while minimising headlosses to reduce construction cost and long-term operating cost. Contractor shall design the plant hydraulics considering the average daily, peak daily and ultimate peak flows for whole design life as given under Volume 3, Section 2- Process Specifications. The major dimensions such as interconnecting pipe diameters, channel widths and levels, weir lengths and levels and tank internal sizes shall be fixed in accordance with the process and hydraulic design. The design shall be subject to the approval of the Engineer. The existing site ground levels are indicated on the Drawings. All process units, chambers and structures top level shall be at least 300mm above finished ground level to minimise intrusion of fine, wind-blown sand and provide a barrier to vehicles.

A6

BUILDINGS AND STRUCTURES In general various buildings (process and control buildings) at STP shall be as indicated on the Layout drawing. Buildings may be either concrete or steel framed structures. Buildings shall be architecturally designed to produce aesthetically pleasing structures and finishes and to minimise the visual impact. All buildings shall be architecturally similar. Contractor shall design the buildings considering regulatory, functional, operational and maintenance requirements and submit the drawings for approval before starting any work on ground. Proposed process/ control buildings and miscellaneous structures includes but not limited to the followings: 1. 2. 3. 4.

Inlet Pumping Station Administration and Control Building Workshop, Store and Laboratory Building Aerated grit/grease removal blower room


Page A-7 of 33


5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21.

Specifications

ASP Blower House Building Tertiary Filter/ Aerobic Digester Blower House Building Intermediate Lift Pumping Station Building TSE Pumping Station Building Sludge Gravity Belt Press & Cake Storage building Sludge Dryer Building Dried Sludge Pellet Storage Building Polymer Storage and Dosing Building Odour Control Building Chlorination Building Emergency Generator Building M.V. Substation Building/s Electrical Substation 1, 2 & 3 Building MCC Control Rooms at various location to cover site mechanical equipments control Chemical (Ferric Chloride) Storage and Dosing Facility Diesel Storage and Dosing Facility Operator ablution block

Contractor can propose a common structure for various buildings based on unit locations, available area, unit functionality and operation and maintenance requirement. Proper care should be taken in the design of safety and fire fighting requirement of such common buildings. Adequate number of MCC control rooms shall be designed to cover the various units mechanicals equipment control. Contractor shall submit a concept design proposal for process and control buildings for approval before details design. All buildings shall include lifting equipment suitable for the removal and installation of equipment and for routine maintenance. It shall be designed so that equipment can be loaded/unloaded from a truck (Hiab) without the need for double handling. A6.1

Administration and Control Building Administration and Control Building shall be a two storey (G+1) structure. Building shall include the following: i. ii. iii. iv. v. vi. vii. viii. ix. x.

Entrance Hall with scale model display area. Elevated control room having panoramic view of the site including desks suitable for SCADA computer and printers and telephone link. Control Panel Room with main control panel. The room size for the Control Panel Room shall be based on actual control panel size. Engineer Office Room (two nos.) with telephone line. Plant Operator Room ( 1 no.) with telephone line Locker Room Kitchen/Mess Room with sink, water heater and kitchen units Toilet with two western style W.C.s, shower and two sink units (on both floors). Office/meeting room with telephone and link to external line. A car parking area for twelve vehicles with sunshade (common for Administration/control and Workshop building)

Building size and various rooms dimensions shall be designed to fulfil functional, operation and maintenance requirement. The structure of the building may be either concrete or steel framed with reinforced concrete foundations. A6.2

Workshop, Store and Laboratory Building Workshop, Store and laboratory Building shall be of two storey (G+1) structure. Building shall include the following: i.


Entrance Hall Page A-8 of 33


ii. iii. iv. v. vi.

Specifications

Workshop rooms for mechanical, electrical and instrumentation (Ground Floor). Equipment/ material store room (Ground Floor). Laboratory Room (First Floor) Office Room (First Floor) Toilet with two western style W.C.s, shower and two sink units (on each floor)

Building size and various rooms dimensions shall be designed to fulfil functional, operation and maintenance requirement and shall be complete with an overhead travelling electric crane. The structure of the building may be either concrete or steel framed with reinforced concrete foundations. A6.3

Gatehouse A gatehouse shall be provided at the main STP entrance to control access to the plant and for security. The building shall include the following: i. ii. iii. iv. v. vi. vii. viii. ix. x.

A6.4

Windows to provide a clear view of the main access area and approach road Local and general site lighting control as specified CCTV system monitoring base as specified Security alarm system base Vehicle logging system as specified Sufficient space for a minimum of two personnel Kitchen and toilet facilities Gate remote operation Telephone connection to Administration building Local car parking for two vehicles

ASP Blower House Building The ASP blowers and associated equipment shall be housed in the Blower House. The Blower House shall include a separate control panel room. The Blower equipment and pipework shall be supplied as a complete single package from a reputable, experienced, specialist manufacturer and supplier. Equipment arrangements and details shall be generally as required by the supplier but subject to the Engineer’s approval. A cross flow ventilation system shall be provided in the blower room. A minimum of 4 air changes/hour shall be provided. The building shall be sized to suit the equipment supplied with adequate access to all areas for maintenance and an overhead travelling electric crane shall be provided. The building structure shall be designed to minimise the noise pollution. Aluminium folding, double or roller shutter doors, of sufficient width for blower installation and removal, shall be provided for each blower with ramp up from road level. Pipe and cable trenches shall be covered with RTR or aluminium chequer plate installed in a frame. The covers shall be designed with regard to the likely loads from any equipment passing over the trenches.

A6.5

Tertiary Filter/Aerobic Digester Blower House The Tertiary Treatment and Aerobic Digester blowers and associated equipment shall be housed in the Blower House. The Blower House shall include a separate control panel room. The Blower equipment and pipework shall be supplied as a complete single package from a reputable, experienced, specialist manufacturer and supplier. Equipment arrangements and details shall be generally as required by the supplier but subject to the Engineer’s approval.


Page A-9 of 33


Specifications

A cross flow ventilation system shall be provided in the blower room. A minimum of 4 air changes/hour shall be provided. The building shall be sized to suit the equipment supplied with adequate access to all areas for maintenance and an overhead travelling electric crane shall be provided. The building structure shall be designed to minimise the noise pollution. Aluminium folding, double or roller shutter doors, of sufficient width for blower installation and removal, shall be provided for each blower with ramp up from road level. Pipe and cable trenches shall be covered with RTR or aluminium chequer plate installed in a frame. The covers shall be designed with regard to the likely loads from any equipment passing over the trenches. A6.6

TSE Pump House Building TSE pumps, washwater/irrigation pumps along with associated equipment shall be housed in TSE pump house building. The Building shall include a separate control panel room for pumps and adjoining equipment control. Equipment arrangements and details shall be generally as required by the supplier but subject to the Engineer’s approval. The building shall be sized to suit the equipment supplied with adequate access to all areas for maintenance and an overhead travelling electric crane shall be provided. The building structure shall be designed to minimise the noise pollution. Aluminium folding, double or roller shutter doors, of sufficient width for pump installation and removal, shall be provided with ramp up from finished level.

A6.7

Sludge Dewatering & Cake Storage Building It will be a two storey (G+1) building. The sludge Gravity Belt Presses and associated equipment or alternative Centrifuges shall be housed on the first floor having sludge cake silo at Ground Floor. A cross flow ventilation system shall be provided in the building. A minimum of 4 air changes/hour shall be provided. The building shall be sized to suit the equipment supplied with adequate access to all areas for maintenance and an overhead travelling electric crane shall be provided. Specifically, for the belt press, space must be provided for routine maintenance operations such as roller removal and belt changing. Floors and wall finish shall be as per Civil Specification Section G. All pipework and ducts laid beneath the building foundation shall be surrounded in concrete. Rigid pipelines shall have flexibility at the edge of the concrete surround. Floor drains and washing down connection points, shall be provided in the building. Floors shall have a fall to the drains. All drains from the building shall be trapped. Drainage from the dewatering equipment and the building shall discharge back to the Liquor Return sump. Equipment installation access provision shall be made to the silo room and dewatering room. A potable water supply connection shall be taken from the water supply ring main to a hand wash basin located in the belt press / centrifuge room. The building shall be designed for the loads from the equipment installed, the overhead electric travelling crane and the specified wind and other imposed loads.


Page A-10 of 33


A6.8

Specifications

Sludge Dryer Building The sludge Belt Dryer and associated equipment shall be housed in the dryer building. A cross flow ventilation system shall be provided in the building. A minimum of 4 air changes/hour shall be provided. The building shall be sized to suit the equipment supplied with adequate access to all areas for maintenance and an overhead travelling electric crane shall be provided. Specifically, space must be provided for routine belt dryer maintenance operations such as roller removal and belt changing. Floors and wall finish shall be as per Civil Specification Section G. Floor drains and washing down connection points, shall be provided in the building. Floors shall have a fall to the drains. All drains from the building shall be trapped. Drainage from the dryer building shall be back to the Liquor return sump. Aluminium folding, double or roller shutter doors, of sufficient width for dryer installation and removal, shall be provided with ramp up from finished level. A potable water supply connection shall be taken from the water supply ring main to a hand wash basin located in dryer room. The building shall be designed for the loads from the equipment installed, the overhead electric travelling crane and the specified wind and other imposed loads.

A6.9

Dried Sludge Pellet Storage Building The sludge pallet silo, bagging plant and associated equipment shall be housed in the pellet storage building. The building shall be sized to suit the equipment supplied with adequate access to all areas for maintenance and an overhead travelling electric crane shall be provided. Specifically, space must be provided for baggage storage. Floor drains and washing down connection points, shall be provided in the building. Floors shall have a fall to the drains. All drains from the building shall be trapped. Drainage from the building shall be back to the Liquor Return sump. Equipment installation access provision shall be made to the silo building.

A6.10

Polyelectrolyte Storage and Dosing Building The building shall have separate rooms for polymer storage and polymer preparation and dosing. Powder polymer bags and equipment for polymer transfer shall be stored in the storage room. Another room shall house polymer preparation (making-up) and dosing tanks, dosing pumps and associated equipments. The building shall be sized to suit the equipment supplied with adequate access to all areas for maintenance and an overhead travelling electric crane shall be provided. GRP open mesh flooring (anti skid) shall be provided at the working area. All pipework and ducts laid beneath the building foundation shall be surrounded in concrete. Rigid pipelines shall have flexibility at the edge of the concrete surround. Floor drains and washing down connection points shall be provided in the make-up and dosing room. Floors shall have a fall to the drains. All drains from the building shall be trapped. Drainage from building shall be back to the liquor return sump. The polymer makeup room door shall be sized according to the make-up and dosing tank sizes.


Page A-11 of 33


Specifications

A potable water supply connection shall be taken from the ring main to the site. The water shall supply a header tank which will provide water for polymer make-up and a supply to a hand wash basin. The polymer store shall be sized to provide at least 30 days supply of polymer at average loading rates. A6.11

Odour Control Building The Odour Control Building shall comprise Odour control units and odour extraction fans with associated equipment. The building shall be sized to suit the equipment supplied with adequate access to all areas for maintenance and an overhead travelling electric crane shall be provided. Building shall have a separate MCC control room for equipment control.

A6.12

Chlorination Building The Chlorination Building shall comprise a chlorine drum store, a chlorinator room, a control panel room, motive water pump room and any other additional equipment rooms required for the chlorination system. The chlorination system shall be designed by a reputable, experienced, specialist manufacturer and supplier. The chlorine drum store shall be sized to suit the number of chlorine drums to be supplied. The equipment shall be designed so that the delivery vehicle can draw up alongside the drum store and the drums lifted directly from the vehicle into their final position. A folding or roller shutter door shall be provided for access to the drums. All materials used in the drum store shall be suitable for exposure to low levels of chlorine. All services and process pipework beneath the building foundation shall be laid in sleeves with concrete surround. Chlorine dosing pipes shall be laid either in covered pipe trenches or against interior room walls. All interior pipework shall be protected from accidental damage. The drum store shall include an emergency shower and eye-wash and hand wash basin. Doors in the drum store and chlorinator room shall have panic bars and windows to allow inspection of the rooms before entering. Gas detection, ventilation and other safety aspects of the design of the Chlorination Building are specified in the Mechanical Specification.

A6.13

Emergency Generator Building The Generator Building shall house standby generators, day fuel tank with associated equipment. The building shall be sized to suit the equipment supplied with adequate access to all areas for maintenance. Building shall have a separate MCC control room for equipment control. A cross flow ventilation system shall be provided in the building. changes/hour shall be provided.

A minimum of 4 air

The building shall be designed for the loads from the equipment installed, the overhead electric travelling crane and the specified wind and other imposed loads. A6.14

Electrical Sub-station and Control Buildings Following electrical buildings are proposed based on plant base line design: 1. M.V. Substation Building 2. Electrical Substation no. 1,2 &3 3. MCC Control Rooms


Page A-12 of 33


Specifications

Details of various electrical buildings are give in Volume 3, Section 4.2 – Electrical specifications. The buildings shall be sized to suit the equipment (panels, transformers, switchgear etc) supplied with adequate access to all areas for maintenance and as per regulatory requirement. A6.15

Chemical Storage and Dosing Facility FRP Chemical storage tank and dosing pumps shall be house within the reinforced concrete bunded area to contain the any leakages from the tank. Volumetric capacity of bund shall be equal to the 110% of the capacity of chemical storage tank. Chemical transfer area shall be designed to contain and transfer, any spillage occur during the chemical transfer, to the bunded area. Facility shall be covered from the top by steel/concrete roof structure. Eyewash and shower facility shall be provided near chemical storage facility. Facility shall be designed considering health and safety issues.

A6.16

Diesel Storage and Fuelling Facility Steel Diesel storage tanks for dryer and generators shall be house within the reinforced concrete bunded area to contain the any leakages from the tank. Volumetric capacity of bunds shall be equal to the 110% of the capacity of diesel storage tank. Diesel storage area shall be covered from the top. Diesel transfer pumps for dryer and generators shall be housed in the diesel pump house. Pump house shall be sized to suit the equipment supplied with adequate access to all areas for maintenance

A6.17

Operator ablution block A separate building comprising toilet and shower facilities shall be provided for the use of plant operators. The building shall be designed to suit the likely number of plant operators but shall as a minimum include three WCs and two showers along with sinks and changing areas.

A7

BUILDING SERVICES

A7.1

General Requirements Building services shall be provided to all buildings, control panel enclosures and generator housings. The building services installation shall generally be in accordance with the electrical and mechanical specifications. In particular the design and installation of all building services shall take into account the requirements of the following standards: a.

Chartered Institution of Building Services Engineers Guides i. ii. iii. iv. v. vi.

b.

CIBSE CIBSE CIBSE CIBSE CIBSE CIBSE

Guide A - Environmental Design. Technical Memoranda TM04 – Design notes for the Middle East. Guide C – Reference Data. Guide B2 – Ventilation and Air Conditioning. – Code for Interior Lighting. Technical Memoranda TM12 – Emergency Lighting.

British Standards i.


BS 5266 Part 1: 1988 – Emergency Lighting – Code of Practice for the emergency lighting of premises other than cinemas and other specified premises used for entertainment.

Page A-13 of 33


ii. iii. iv. v. vi. vii. c.

BS 5839: All relevant parts - Code of practice for fire detection and alarm systems for buildings. BS 7430: 1998 – Code of Practice for earthing. BS 7671: 2001 – Requirements for electrical installations (IEE wiring regulations 16th Edition). BS 5250: 1995 – Code of practice for control of condensation in buildings. BS 7120: 1989 – Specification for rating and performance of air to liquid and liquid to liquid chilling packages. BS 7206: 1990 – Specification for unvented hot water storage units and packages.

Bahrain Standards i.

A7.2

Specifications

Ministry of Electricity and Water: EDD/R-1: 1985 - Regulations for electrical installations.

Lighting Lighting shall be provided for operation and maintenance function to be undertaken safely. The contractor shall submit all lighting design schemes for the Engineers approval. The following minimum illumination levels shall be achieved at floor level: a. Control Rooms – 500 lux using modular fluorescent fitting with Category 3 louvers. b. Offices - 500 lux using modular fluorescent fitting with Category 2 louvers. c. Control panel rooms, substations and Generator enclosures – 300 lux using liner fluorescent fittings with prismatic diffusers. IP 65 rated fittings shall be provided in the generator enclosures. d. Kitchen/Mess room, locker rooms and toilets – 300 lux using modular fluorescent fittings or compact fluorescent fittings fitted with prismatic diffusers. e. Process plant areas – 300 lux using linear fluorescent fittings IP 65 rated prismatic diffusers. All Other Rooms/Corridors. The average illumination in these areas shall be 300 lux. All fluorescent fittings shall be provided with T8 colour 3500 lamps, the contactor shall design the lighting systems to minimise the number of different fluorescent lamp wattage ratings. All lighting shall be switched from manual switches located at doorways to suit the installation. Two way switching shall be provided as required. All buildings shall be provided with emergency lighting to provide illumination of the escape routes. The minimum illumination level at floor level to be achieved is 2 lux. Emergency lighting shall be self-contained non-maintained type, fitted with 3-hour duration batteries. Each emergency lighting circuit shall be provided with a secret key test switch. The contractor shall issue test and completion certificates within the test log book for the emergency lighting systems installed. External Lighting - A comprehensive site lighting system shall be provided to illuminate all areas around the whole of the new works including the areas of the existing works which are to be modified and incorporated into the new works. An illumination level of 150 lux average shall be provided to illuminate each major item of mechanical plant, valves, penstocks, remote mounted instrumentation etc. An illumination level of 20 lux average shall be provided to illuminate all walkways and paving areas. The main switch system for all external site lighting shall be located within the control room.


Page A-14 of 33


A7.3

Specifications

Small Power Small power services shall be provided in the form of 13A twin switched socket outlets in office type areas, BS4343 style socket outlets (240V and 415V) in process areas and switched fused spurs for connection to fixed equipment. The contractor shall submit the small power schemes for the Engineers approval. The number of socket outlets required in any area shall be determined by the contractor to suit the equipment to be installed/supplied and the requirements for undertaking maintenance operations on the equipment/plant installed. In addition to the socket outlets required the contractor shall install 50% additional socket outlets for future development. The minimum number of sockets to be provided in any area is two.

A7.4

Air Conditioning The Administration, Workshop and Control building shall be air-conditioned. Control panel rooms in other buildings shall be similarly air-conditioned using split units. RTR enclosures for MCCs and any other enclosure where contained equipment may generate high temperatures, or where the contained equipment is temperature sensitive, shall also be air conditioned in accordance with this specification. The contractor shall submit the air conditioning schemes for the Engineers approval. The units shall be sized and thermostatically controlled to maintain the temperature within each room below 23ºC under the specified climatic conditions.

A7.5

Ventilation Ventilation shall be required for process buildings, pump house wet wells, valve chambers and underground structures. In general a minimum of four-air changes/hour shall be provided. The contractor shall submit the ventilation schemes for the Engineer’s approval. The ventilation system shall comprise ductwork and in-line ventilation fans. The location of the duct terminal grills shall be determined to suit the location of the plant/equipment installed. RTR panel enclosures shall have a cross flow ventilation system of at least 2 air changes/hour.

A7.6

Foul drainage The foul drainage system shall consist of PVC or HDPE pipe. Floor gulleys shall be of PVC or other approved material to suit likely loadings. All drains shall be trapped. All foul drainage shall discharge to the STP drainage system.

A7.7

Potable Water Supply Potable water shall be supplied to building roof tanks from the potable water supply network.

A7.8

Fire Protection, Detection and Alarm Buildings shall be protected by fire protection systems according to local fire and Civil Defence Regulations. The contractor shall submit the fire protection, detection and alarm schemes for the Engineers approval. The administration/control building, blower houses, sludge belt press house, dryer room, diesel storage area, control panel rooms, intake substation, chlorination building and any other buildings housing sensitive equipment which may be susceptible to fire shall be fitted with an automatic fire detection and alarm systems. The detection system shall be based


Page A-15 of 33


Specifications

upon optical smoke detectors and where necessary fixed temperature heat detectors. A minimum of two sounder circuits shall be utilised in the design. All fire detection and sounder circuits shall be wired in fire resistant cabling such as MICC with orange oversheaf. The contractor shall issue test and completion certificates within the test log book for the fire detection and alarm systems installed. A7.9

Telephones The security kiosk, administration, workshop and MCC control Building shall have telephone connections. Each telephone connection shall terminate in a RJ-45 socket, the location of which to be agreed on site. The installation of the telephone service shall be in accordance with BATELCO requirements and standards. Each telephone socket shall be provided with a BATELCO compliant handset.

A7.10

Lightning Protection 1.

Assessment of Risk

The Contractor shall assess the risk of lightning strikes and whether lightning protection is necessary for the building fabric. This assessment shall be carried out in accordance with BS 6651: Code of Practice for Protection of Structures against Lightning - 1999. All the contractors’ calculations shall be issued to the Engineer, as part of the Contractors detailed design. 2.

Protection System

If the risk assessment shows that lightning protection is required, it shall be carried out in accordance with BS 6651: 1999. The protection system shall provide protection for the building fabric and internal electrical and electronic equipment, to comply with a risk level of low exposure level. 3.

Design Requirement for Protection System (Building Fabric)

The lightning protection system shall be designed in accordance with BS 6651: 1992 and the contractor shall consider using the rolling sphere method to determine zones of protection to ensure the sides of the structure are protected from damage. The Contractor may consider using reinforcement bars, structural steelwork etc. as part of the down conductor system providing it can be demonstrated that they offer good electrical conductivity. Earthing rods shall be installed and connected to each down conductor to provide a low resistant earth connection. This resistance shall not exceed 10 times the number of earth electrodes provided. The whole earth termination network resistance shall not exceed 10 ohms, without taking account of any bonding to other services. The Contractor shall carry out a soils resistivity survey to calculate the number and depths of earth electrodes necessary to achieve the specified resistance. 4.

Design Requirements for Protective System (Electronic Equipment)

The contractor design shall incorporate the following measures within the design of the protective system. Earthing and bonding of all electrical services, cabling entering/existing structure to a common earth point.


Page A-16 of 33


Specifications

Power and data cabling between building/structures to be installed within metallic conduit or trunking with all metalwork bonded to the common earth reference at both ends. The Contractor shall consider locating sensitive equipment away from those areas in which lightning currents will preferentially flow. Earthing systems between adjacent building/structures to be interconnected creating a single earth reference for all equipment. Protection of incoming mains power supply and telephone lines from transient overvoltages. Minimisation of inductive coupling loops between mains and data cabling by installing on/in adjacent conduit/trunking/tray work. Note requirements of circuit segregation still remain. The system of protection shall prevent lightning surge voltages/currents from entering the electrical system with the building. Mains borne lightning surges shall be limited to a let through voltage of 600 volts. Each source of incoming supply shall be provided with surge protection. A7.11

Furniture The adequate furniture and utilities shall be provided in the Control/Administration and Workshop/Laboratory Buildings to meet the functional and operational requirement of buildings. Furniture/ utilities shall be new and of good quality. The Contractor shall submit full details of his proposed furniture and utilities for the Engineer’s/Employer’s approval.

A8

ROADWORKS, LANDSCAPING AND OTHER EXTERNAL WORKS

A8.1

Roadworks Minimum of 6m wide Roads shall provide vehicular access to all the major items of plant generally as shown on the layout drawing. Road shall be designed as per governing regulatory authority standards. Roads shall be kerbed with gullies at low points. Drainage system for road shall be designed in co-ordination with whole site. Raised kerbs shall generally be provided where protection is required to adjacent structures or services or to protect sloping embankments. In other areas flat kerbs shall be used with drop kerbs at the transitions. In addition, drop kerbs and lengths of flat kerbs shall be provided at suitable locations to give access off the road. In some areas this may include the construction of suitable access ramps from the road. Suitable vehicle standing areas shall be provided at areas where loading/off-loading is planned and at planned crane locations for equipment maintenance. The standing areas shall be designed so that access and free flow of traffic is not impeded during loading/unloading/maintenance operations.

A8.2

Landscaping Plant landscaping shall be designed to suit the island landscaping. Hard landscaping of concrete interlocking paving block may be required between units and road to access the plant and equipments. The landscaping scheme shall i. ii.

Wherever feasible use trees and bushes of different types and sizes suitable for the climate in Bahrain. Provide local areas of greenery around the main Administration/Control Building.


Page A-17 of 33


iii.

Specifications

Include any necessary soil conditioning and fertiliser (sludge from the existing drying beds may be utilised).

The final landscaping scheme shall be subject to the approval of the Engineer. A8.3

Pathways Frequently used accesses (this applies to all external doors to buildings and to main access points to external tanks), shall be accessible by means of minimum 900 wide pathways. For the balance of accesses, such as building and process tank perimeters, access shall be by means of minimum 700 mm wide pathways. Pathways shall include steps as appropriate. Pathways shall be edged with hydraulically pressed, precast concrete edgings with concrete backing, laid flush with the surfacing. Pathways laid against structures shall have a slope of 1:50 away from the structure. Pathways shall be constructed from either: i. 75mm thick structural concrete placed on 1000 gauge polythene sheet with brushed finish and suitable joints. ii. Interlocking block paving. iii. Pre-cast concrete paving slabs. Pathways shall be provided to give access as follows: i. Around buildings to all accesses. ii. Along the edge of the new Aeration Tank. iii. Around the perimeter of each Final Settlement Tank. iv. To and around the FST distribution chamber. v. Around the Tertiary Filters. vi. To all the filter access staircases. vii. To all access staircases indicated on the Drawings viii. To all pumping stations and associated valve chambers. ix. To all control equipment. x. To all washwater tap locations. The pathway in front of the Administration/Control Building shall be interlocking block paving with pre-cast concrete edgings.

A8.4

Site Boundary Wall / Fencing and Security Gate Contractor shall provide a pre-cast boundary wall around the entire perimeter of the STP site. The wall shall be architecturally designed to produce an aesthetically pleasing façade and reduce the visual impact of the STP plant and equipment. A full road width security gate and security kiosk will also be provided at the main STP access point. The gate shall be automatic sliding type to suit a minimum 6m wide clear opening with recessed wheel running on raised rail. Minimum height shall be 2.4m. Wheel/s shall be cast iron with sealed bearings. Gate shall be fabricated from mild steel in a decorative pattern coordinating with the boundary and finished with high quality epoxy paint. The gate shall retract along the inside of the boundary wall into a guide rail system. The gate shall be provided with internal and external sensor systems to prevent closing when obstructed. Gate opening and closing shall be controlled remotely from inside the Security Kiosk.

A8.5

Potable Water Supply, Irrigation Main and TSE re-use line Potable water shall be required for drinking, washing, shower, polymer makeup and emergency eyewash/ shower purpose at various process units and buildings. TSE water


Page A-18 of 33


Specifications

shall be used for landscaped area irrigation and at various process units wash-down, cleaning purpose. Contractor shall provide a potable water ring main, irrigation ring main and TSE re-use ring main along the plant road to cover various process units/ buildings/ landscaped area potable water/ irrigation water/ TSE reuse water demand. A8.6

Cable Ducts and Drawpit Chambers Cable ducts shall be 150mm diameter uPVC bedded and surrounded with sand. All cable ducts shall be threaded with nylon draw cord and have warning tape. Ducts crossing roads and other trafficked areas shall be surrounded in grade C45/20 concrete and have additional spare capacity of 30% for future use. In general main duct routes in other areas shall have additional spare capacity of 20%. Chambers shall be located at all changes of direction and generally at a spacing not exceeding 30m. Exceptions will be subject to the Engineer’s approval. The chambers shall generally be constructed from reinforced concrete in accordance with the Contractor’s detail design. Plastered blockwork construction will only be permitted in non trafficked areas where the entire chamber is above the maximum groundwater level. Concrete protection shall be as specified for other reinforced concrete structures. Chamber covers shall be appropriate to the likely loading in the location of the chamber – generally medium duty. Solid pattern anodised aluminium decking covers (as specified for the Inlet Works, Clause 6.2.1) may also be used as an alternative to the cover details shown provided it can be demonstrated to the Engineer’s satisfaction that the cover is suitable for the required loading condition.

A8.7

Other External Works Other external works include foundations and base slabs for equipment such as control panels (and enclosures), generators and skips. These shall be designed by the Contractor to suit the equipment being supplied in accordance with the principles described in this specification. Concrete protection shall be as specified here and indicated on the drawings.

A9

INTERNAL SEWERAGE AND DRAINAGE Contractor shall provide the internal sewerage system covering administration and workshop buildings and other control/ process buildings with sanitary facility. Site drainage system shall be designed considering surrounding area topography, plant units and road profile. In particular the drainage system should intercept surface water / stormwater flows from the adjacent hill.

A10

TERMINAL LIFT PUMPING STATION (Inlet Pumping Station)

A10.1

Location The TLPS is to be constructed at the location shown on the Drawings at the termination point of the main deep gravity sewer serving the AMAS Islands. The location is on west Island 13c on the opposite side of the screening hill to the STP. The location has been fixed on the basis of ensuring a safe distance from the underlying Alat aquifer and associated Water Resources Directorate approvals.


Page A-19 of 33


A10.2

Specifications

Coordination and Interfaces The deep gravity sewer is to be constructed by others concurrently with the STP. The interface point between the sewer and the pumping station is at the termination point of the deep gravity sewer at the entry to the pumping station excavation shaft as indicated on the drawings. Close coordination with the tunnelling contractor will be essential for completion of the final tunnelling operations to the TLPS since the STP contractor is responsible for the excavation of the TLPS shaft to suit the pumping station design. The invert level of the deep gravity sewer at the interface point is -11.610m.

A10.3

Future Connection Manhole A manhole shall be constructed on the incoming deep gravity sewer within the TLPS excavation shaft for future connections. The requirements for the manhole are outlined below:

A10.4

−

Manhole details shall generally be in accordance with the details shown on the manhole standard details drawings

−

Minimum internal diameter to be 3100mm to at least 2m above the crown of the sewer pipe. Diameter may reduce to not less than 2100mm at higher level.

−

Manhole to have full internal RTR liner and heavy duty cover

−

1200mm diameter stub-out pipe, extending a minimum of 3 metres outside the manhole wall, is to be provided as indicated on the Drawings.

General Requirements Outline general arrangement details of the TLPS are included in the Drawings. The arrangement details are to be developed by the Contractor based on his proposed equipment whilst maintaining the indicated concept. The TLPS will be visible from the private development area on Island 13. The station shall therefore be designed so that the visual impact is minimised. This shall include a decorative boundary wall (matching the STP wall), carefully considered structure designs and architecture and external landscaping with graded slopes, bunds, plants and trees.

A10.5

Earthworks and Retaining Wall The area allocated for the TLPS is currently raised as indicated by the contours and existing ground levels shown on the Drawings (G002). The ground level in the area of the TLPS is between approximately +7m and +8m rising steeply at the east side up to approx.. +12m (and up to +16m at the top of the hill). The Contractor shall be responsible for preparing and grading the area to a suitable level for the TLPS construction. It is likely that a retaining wall will be required along the east side of the pumping station compound area. The maximum slope allowed to the side of the screening hill is 1:3. Overall it is expected that the TLPS excavation shaft for the station construction will be approximately 20m deep.


Page A-20 of 33


A10.6

Specifications

Access Roads The TLPS shall have a min. 6m wide access road from the STP access road which connects with the main Islands. The access road bend radii and slopes shall be designed to suit the heavy vehicles requiring access to the station including cranes, trucks and tankers. Internal access roads shall be provided for access to all equipment. Equipment requiring regular service and maintenance access such as the standby generator, screenings skip and odour control equipment shall be provided with drive through access where possible within the compound limitations imposed by the slope of the screening hill. Where provision of suitable drive through access is impractical, turning areas shall be provided. Internal access roads shall also provide access for cranes/hiabs for pump, screen and other M+E equipment maintenance and removal.

A10.7

Boundary Wall, Compound and Gate The TLPS and all associated equipment shall be enclosed in a compound. This shall include the substation, standby generator, odour control equipment, valve chambers and the main station. The compound wall shall be as specified for the STP although contrasting, rather than matching, designs are acceptable The main compound gate shall be hinged and comprise twin leaves opening inwards. The gate shall be constructed from epoxy coated mild steel or aluminium and shall have a high quality design and finish in keeping with the overall architectural design concept for the with pumping station and compound. Separate gated pedestrian access shall be provided either as part of the gate construction or entirely separate. All gates shall have provision for padlocking and appropriate, high security padlocks shall be supplied.

A10.8

Landscaping and Irrigation A landscaping scheme shall be implemented at the TLPS similar in concept to that specified for the STP. The aim of the landscaping shall be to create a pleasant vista when viewed from the main AMAS Islands area and thereby minimise the visual impact of the station. The landscaping scheme shall include perimeter plant and tree planting around the perimeter of the compound, outside the perimeter wall. A minimum width of 2m outside the wall shall be landscaped (min. clearance of 3m to be provided between the compound wall and the STP access road). The landscaping scheme shall include and automatic irrigation system coving all planted areas utilising TSE supplied from the STP washwater system.

A10.9

Washing Down and Drainage The compound shall be provided with a drainage system connected to the pumping station wet well. The system shall be provided with water traps to prevent odours and gas escaping from the station. As well as general site drainage, the drainage system shall also accommodate run from the adjacent hill (including any retaining wall seepage holes). Washing down points comprising 12mm taps supplied from the STP washwater system shall be provided around the compound, in particular, washing shall be provided at the screenings skip area.


Page A-21 of 33


A10.10

Specifications

Rising Mains Twin rising mains shall be constructed from the TLPS to the STP inlet works. Cross connection valves and chamber shall be included to allow either main to be used by either set of wet well pumps.

A10.11

Site lighting The compound shall be provided with lighting to the specified lux levels. Lighting columns shall be standard roads design and lighting shall generally be directed downwards.

A10.12

Odour Control The pumping station shall include an odour control system as specified in the Mechanical Specification. The isolation, inlet, screen chambers, wet wells and any other potential source of odour shall be covered with sealed covers and connected to the odour control system.

A10.13

Potable Water Supply The Contractor shall apply to the EWA for a potable water supply to the station in accordance with standard procedures. Potable water shall be supplied to roof mounted storage tank/s for supply to showers, toilet, kitchen and hand washing areas.

A10.14

Buildings and structures Buildings shall comply with the specification for the STP buildings and the standard specification. This shall include fire protection and alarms. The EDD substation shall be in accordance with EDD standard design and include independent access from outside the compound.

A10.15

Other External Works Other external works include foundations and base slabs for equipment such as generators and skips. These shall be designed by the Contractor to suit the equipment being supplied in accordance with the principles described in this specification. Concrete protection shall be as specified here and indicated on the drawings.

A11

LONG SEA OUTFALL

A11.1

General A sea outfall is to be provided to discharge treated effluent from the STP during periods when flow is in excess of the irrigation demand and STP storage capacity. The outfall will also provide a disposal route for emergency overflows and “out-of-spec” effluent not suitable for delivery to the TSE irrigation network. Preliminary outline details of the outfall are shown on the Drawings (Volume 5). The details shown shall form the basis of the Contractor’s design and shall be developed into the final design to suit the Contractor’s construction methods.


Page A-22 of 33


A11.2

Specifications

Environmental Impact Assessment An EIA has been prepared for the outfall in accordance with Bahrain legislation and the requirements of Bahrain’s Supreme Council for Environment. The EIA included hydrodynamic modelling of the outfall discharge and the discharge location has been finalised accordingly. Further details of the EIA for the outfall and associated environmental management plans are included in Volume 6. The Contractor is required to develop the Construction and Operation Environmental Management Plans for the outfall included in Volume 6 and comply with the stated requirements. All dredging work shall be carried out in compliance with the Construction Environmental Management Plan (ref. Volume 6) and the Supreme Council for the Environment document EIA-9 – “Guidelines on the TSS Monitoring Program of Large Scale Projects Involving Intensive Dredging and Reclamation Operations”.

A11.3

Outfall Designer The Contractor shall employer a suitably qualified, specialist outfall designer with a minimum of 10 years experience in similar work. The designer shall be subject to the Engineer’s approval.

A11.4

Design Data

A11.4.1

Concept The design concept for the outfall is for gravity discharge of the specified flows from the TSE Storage Tank overflow, various TSE Tank by-passes and Inlet Works emergency overflows. It is expected that the flows will be collected at an Outfall Chamber which will also function as an air release chamber to prevent air being carried into the outfall. The head available at the chamber shall then be sufficient for gravity discharge via the outfall of the peak specified design flows.

A11.4.2

Flows • • • •

Initial Average Flow (IAF) Future Average Flow (FAF) Future Peak Daily Flow (FPDF) Future Ultimate Peak Flow (FUPF)

= = = =

39,680 m3/day (459 l/s) 59,520 m3/day (689 l/s) 92,851 m3/day (1075 l/s) 127,968 m3/day (1481 l/s)

The outfall shall be designed with sufficient capacity for gravity discharge of the Future Peak Daily Flow. Space shall be allocated for a future outfall pumping station to meet the requirement for any further increase in capacity which may be required in the future. A11.4.3

Design Pressure The outfall shall be designed for a minimum operating pressure of 1.5 bar (to allow for capacity increases). Pipes shall have a minimum pressure rating of 2.5 bar.

A11.4.4

Route & Discharge Point


Page A-23 of 33


Specifications

The new outfall pipeline shall run along the route indicated on the Drawings to the effluent discharge point. The total length of the outfall is approximately 4,510m with approx. 3,492m in the channel sections (canals) between islands and the remaining length of 1,018m offshore from the AMAS islands. The coordinates of the discharge point of the outfall are E 445230, N 2904170. Sea bed level at the discharge point is approximately -7.9m. Channel bed level is approximately -3.3m. A11.4.5

Design Life The required design life of the outfall is 50 years.

A11.4.6

Waves and Current Marine pipelines shall be designed to provide stability against a wave with 100 year return period and a current speed of 1 in 10 years. The Contractor shall obtain the latest data on extreme wave heights at the project location. Wave and current design data is summarised below: Offshore • • • •

Significant wave height Hs at -7.9mMSL = Contractor to obtain latest data Wave Direction to Outfall = 90 deg (worst case) Current at -7.9mMSL = 1.0m/sec. Current Direction to Outfall = 45 deg

Channel Sections (waterways between islands) • • • • A11.4.7

Significant wave height Hs at -3.3mMSL = 1.0m (assumed sheltered to offshore conditions) Wave Direction to Outfall = 90 deg (worst case) Current at -4.0mMSL = 0.5m/sec. Current Direction to Outfall = 45 deg

Bathymetry and Geotechnical Data Bathymetry data and geotechnical data is included in Volume 6. The Contractor shall be responsible for any additional survey or investigation required for his design.

A11.4.8

Tide Levels Tide level data for the area is given in the following table. The outfall hydraulic design shall be based on satisfactory discharge of the specified flow at the HAT.

Datum Elevation

Mean Sea level (mMSL)

Highest Astronomical Tide (HAT)

+1.3


Page A-24 of 33


Specifications

Datum Elevation

Mean Sea level (mMSL)

Mean High Water Springs (MHWS)

+0.9

Mean High Water Neaps (MHWN) +0.4 Mean Sea Level (MSL) = Bahrain National +0.0 Survey (NSD) Datum Mean Low Water Neaps (MLWN) -0.5

A11.4.9

Mean Low Water Springs (MLWS)

-0.9

Lowest Astronomical Tide (LAT)

-1.4

Chart Datum (CD)

-1.5

Diffusers and Initial Dilution The diffuser configuration indicated in the tender drawings has been designed to provide at least 1:10 near field initial dilution. Flanged Wide-Bill Variable Orifice Duckbill Diffuser Check Valves (Tideflex or equivalent) are to be installed at each discharge port to enable a higher velocity of discharge and to mitigate the risk of sediment and saline intrusion, during no flow periods. Specification for the check valves is included under the outfall materials specification below.

A11.4.10 Air Transport The outfall shall be designed with sufficient gradient over the initial section within the tidal zone to ensure that air is not transported forward in to the outfall pipeline. Air release shall be provided at the STP end (e.g. at the Outfall Chamber). The indicative minimum critical pipe gradient at the FDPF is 1 in 99 for gravity flow. A11.4.11 Pipe Roughness Hydraulic calculations shall be based on the Colebrook White formula using a value for the roughness coefficient ‘ks’ of 1.0mm for all pipe materials. The ‘ks’ values is based on pipelines that have been in operation over a number of years. A11.5

Other Features

A11.5.1

Maintenance Access Access for observation and maintenance shall be provided at strategic points along the outfall including close to major bends. Typical details of access manholes are included in the Drawings. The access manholes will be mainly used for inspecting the internal conditions of the pipe by CCTV or ROV, man entry will not be available.

A11.5.2

Diffuser Protection Domes The diffusers are to be provided with protection domes for protection against damage from shipping. The domes shall be reinforced concrete with openings for discharge of the effluent and removable top opening for inspection and access.


Page A-25 of 33


Specifications

The size, dimensions and material of the diffuser protection domes is to be further developed by the Contractor during his detail design. A11.5.3

Scour Protection The seabed area around the diffuser discharge location shall be protected from scour with rock armour. The diffuser pipe section and dome protection units are to be founded on suitable granular bedding and surround material approx. (40 - 100mm gravel, 0.20m minimum cover to pipe) with the scour protection (min 10 - 100kg rock armour, minimum layer thickness 0.50m) placed above the surround material to the existing seabed level. All imported rock is to be in accordance with CIRIA Report 169 ‘Manual on the use of rock in Hydraulic Engineering’. Additional scour protection shall be provided to ensure proper protection of the pipeline for its design life to suit the contractor’s design e.g. type of ballast used.

A11.5.4

Marking of Outfall and Discharge Marking of discharge location for navigational purposes and the route of the outfall shall be in accordance with local regulations.

A11.5.5

Flowmeter All flow discharged via the outfall shall be metered by an electromagnetic flowmeter. The meter shall be installed in a chamber and appropriately located to ensure full bore pipe flow (unless special meter designed for partially full pipe flow metering is employed).

A11.5.6

Automatic Sampler An automatic sampler shall be provided for sampling of the effluent discharged via the outfall.

A11.6

Initial Outline Design The initial outline design for the outfall is included in the Drawings. The basis of the design and the results of the preliminary hydraulic analysis are given in the following table:

Flow Scenario

IAF

FAF

FPDF

FUPF

Pipe I.D (mm)

1100

1100

1100

1100

Pipe roughness (mm)

1.0

1.0

1.0

1.0

Flow velocity (m/s)

0.5

0.7

1.1

1.6

Diffuser length (m)

10

10

10

10

No of Risers / Riser I.D.(mm)

2 / 500

2 / 500

2 / 500

2 / 500

No. of Ports / Port I.D (mm)

8 / 300

8 / 300

8 / 300

8 / 300

Duckbill Valves (no.)

8

8

8

8

Port Jet velocity (m/s)

1.7

2.1

2.6

3.1


Page A-26 of 33


Specifications

Flow Scenario

IAF

FAF

FPDF

FUPF

Total system loss (m) Required hydraulic level at HAT (mMSL)

1.2

2.6

6.1

11.5

2.7

4.1

7.6

13.0

This indicates that a minimum water level of +7.6m is required at the Outfall Chamber for satisfactory discharge of the Future Peak Daily Flow (FPDF) and +13m is required for the Future Ultimate Peak Flow (FUPF). A11.7

Pipeline Stability Analysis A pipeline stability analysis shall be carried out for the outfall to ensure it has sufficient weight to resist the action of wave and current generated forces. The analysis shall be based on the wave and current data given above and shall be carried out as prescribed in BS PD 8010-2:2004, Code of Practice for pipelines - Part 2: Subsea pipelines. Ballast shall be provided accordingly to ensure the stability of the pipeline under all operating conditions. Ballast may be in the form of either traditional, discrete concrete collars or continuous concrete collars.

A11.8

Pipeline Construction, Materials and Method of Installation

A11.8.1

Minimum Cover The outfall pipeline shall be laid in a trench with a minimum cover of 1.0m within the channels and 1.5m in the offshore area.

A11.8.2

Material Options The pipe material for the offshore section of the outfall shall be HDPE. The outfall laid in the channels/canals between the islands may be HDPE or RTR.

A11.8.3

Methods of Installation Suitable measures are to be taken during the installation operation to ensure that stresses induced in the pipeline do not exceed the safe limits. Before commencing any installation works or purchasing any pipe materials, the Contractor shall submit calculations proving that the method of installation proposed will not over-stress the pipeline and that the wall thickness and class of pipeline shown on the Drawings is suitable for installation. The Contractor shall make his own investigations regarding the risks of storm or other weather conditions and the effects of the movement of the sea bed material in terms of either delaying the installation or other operations and/or damaging the pipeline or temporary works. It is expected that the most appropriate method of installation for the offshore section of the pipeline will be a float and flood method. Installation tolerance for this section shall be within 3m horizontally and to a vertical tolerance of plus zero and minus 300mm. In the channels and the shallow area near the STP, it is likely that sections may be bunded off and dewatered so that the pipeline may be laid in dry conditions utilising conventional methods thus allowing the use of RTR pipe. In this case, installation tolerances shall be in accordance with the standard specifications for pipe laying. The Contractor shall be responsible for construction of suitable bunds and shall not rely on any existing bunds installed by others. Bunds shall be properly designed to ensure


Page A-27 of 33


Specifications

stability under all conditions and the Contractor’s method of working shall include regular, documented inspection of all bunds to ensure construction safety when working inside the dewatered sections. The following shall also be noted with regard to construction of the outfall in the channel sections: •

A number of services, including HDPE duct banks with concrete surround, cross the channels and the outfall will need to be laid below these services.

•

A number of temporary bunds are currently installed at several locations. These shall be retained and will need to be crossed in sections e.g. lay to half way and complete backfill before commencing second half. The Contractor shall develop his method of working accordingly.

•

Bridges will be constructed at the main road crossings of the main channel between Islands 10/11 and 9/12. This work is likely to be carried out concurrently with the outfall installation. Careful coordination will be required with the bridge Contractor.

The Contractor shall also make arrangements for having standby plant available to complete the installation operation in the event of mechanical breakdown, including full standby dewatering pumps. A11.9

Hydrographic Surveys The Contractor shall provide and operate a hydrographic survey vessel for echo sounding and side-scan sonar surveying of the trench areas, outfall pipelines and backfilling. The hydrographic survey vessel shall be available throughout the duration of the Marine Works and for the specified surveys. For the reduction of soundings an automatic recording tide gauge is to be installed at a location as close to the Site as possible and checked daily for correct operation for the duration of the Marine Works and the specified surveys. The detailed requirements of the surveys are to be agreed by the Contractor before the start of each survey. In the inter-tidal area land survey methods may be adopted during suitable tides. The Contractor shall be required to carry out the following surveys: a)

Initial Surveys

Following the award of the Contract the Contractor shall carry out an initial bathymetric survey and side-scan survey of the pipeline route. The surveys shall consist of longitudinal lines with cross-checks across survey lines taken along the pipeline route as agreed with the Engineer. The survey shall also extend over the proposed temporary spoil areas, which the Contractor is proposing to occupy. b)

Pre-Excavation / Dredging Survey

As soon as the Contractor intends to commence excavation / dredging works the Contractor shall carry out a bathymetric survey of the area to be excavated / dredged. c)

Pre-Installation Survey

Immediately prior to installing the pipeline sections the Contractor shall carry out a bathymetric pre-installation survey of the pipeline trench. Survey charts and crosssections showing all results of the survey shall be produced. Vol 3, Section3 – Civil Specifications

Page A-28 of 33


d)

Specifications

Pre-Backfilling, Backfilling and Armour Surveys

After the installation of the pipeline and prior to backfilling the pipe trench or constructing the rock armouring, the Contractor shall repeat the survey detailed in (b) above. The surveys shall be again repeated during backfilling and construction of the scour protection as deemed necessary in order to establish the extent of fill placed. e)

Diver Video Surveys

The Contractor shall carry out diver video surveys of the diffuser section of the outfall. These surveys shall be carried out immediately following backfilling and within one month prior to the expiry of the Maintenance Period. f)

Maintenance Period Surveys

As agreed with the Engineer. A11.10

Materials

A11.10.1 Concrete All concrete shall comply with the Standard Specifications. Minimum cover to reinforcement to be 75mm. A11.10.2 Steel All steel exposed directly to seawater shall be either designed for a 50 year corrosion allowance or be marine grade stainless steel minimum grade 316 L or 254 SMO (where appropriate) or similar approved. A11.10.3 RTR Pipes RTR pipes shall be accordance with the Standard Specifications A11.10.4 Flanged Wide-Bill Variable Orifice Duckbill Diffuser Check Valve

Supplier The supplier shall have at least ten years experience in the manufacture of “duckbill” style elastomeric, variable orifice valves for diffuser applications, and shall provide references and a list of installations. Technical Submittals The technical submittal for the valves shall include the following documentation: A.) Product literature that includes information on the performance and operation of the valve, materials of construction, dimensions and weights, elastomer characteristics, and pressure ratings. B.) Diffuser Dimensional Drawing – the drawing shall be a scaled version of the actual nozzle, generic drawings with listed dimensions will not be accepted. C.) Hydraulic curves for each inlet nozzle showing headloss, jet velocity, and effective open area all versus flow rate. The hydraulic curves must accurately reflect the variable orifice characteristics inherent to duckbill valves. The backpressure rating of diffuser shall be indicated. D.) Verification of independent hydraulic testing to determine headloss and jet velocity characteristics on a minimum of eight (8) sizes of duckbill valves ranging from 2” Vol 3, Section3 – Civil Specifications

Page A-29 of 33


E.)

F.)

G.)

H.)

I.)

Specifications

through 48”. The testing must include multiple constructions (stiffness) within each size and must have been conducted for free discharge (discharge to atmosphere) and submerged conditions. Verification of Independent Laboratory Testing for Manufacturing Consistency - the nozzle manufacturer shall provide summary documentation of a report conducted by an Independent Laboratory for hydraulic testing where multiple nozzles (at least four) of the same size and construction (stiffness) were tested to validate the submitted headloss characteristics and to prove the repeatability and consistency of the manufacturing process to produce the same hydraulic characteristics. Verification of Finite Element Analysis (FEA) - the nozzle manufacturer shall provide summary documentation of Finite Element Analysis modeling on representative duckbill nozzle sizes to determine deflection, stress and strain characteristics under various load conditions. Modeling must have been done for flowing conditions (positive differential pressure) and reverse differential pressure. Report of independent testing that studied the flow distribution characteristics of duckbill valves installed on multiport manifolds. The manufacturer must have been in the business of manufacturing duckbill valves at the time the report was published. Report of independent testing that studied the initial dilution characteristics of duckbill valves. The manufacturer must have been in the business of manufacturing duckbill valves at the time the report was published. Report of independent testing that studied the salt water purging characteristics of duckbill valves. The manufacturer must have been in the business of manufacturing duckbill valves at the time the report was published.

Technical Details J.) The Flanged Diffuser Check Valves are to be all rubber and the flow operated check type fabricated integrally with a wire-reinforced riser and elbow. The port area shall contour down to a duckbill, which shall allow passage of flow in one direction while preventing reverse flow. The flange, riser, elbow, and Duckbill Diffusers shall be onepiece rubber construction with nylon reinforcement. K.) The integral riser and elbow shall consist of an elastomer inner tube, a fabric reinforced body section with a helical wire reinforcement embedded in the body. The elbow shall be covered with a synthetic rubber cover stock for protection against abrasion and gouging. L.) The linear bill slit dimension to nominal valve size ratio shall be greater than 2.0. M.) The flange drilling shall be to PN16 standard. The valves shall be furnished with stainless steel 316 back-up rings for installation. N.) The Diffuser Check Valves shall be a variable orifice providing a non-linear jet velocity vs. flow characteristic, which maximizes jet velocity at low flow rates compared to fixed orifice nozzles, and a linear headloss vs. flow characteristic. O.) Manufacturer shall have conducted an independent hydraulic test where multiple valves (at least four) of the same size and construction (stiffness) were tested to validate the submitted headloss characteristics and to prove the repeatability of the manufacturing process to produce the same hydraulic characteristics. P.) Manufacturer shall have conducted independent hydraulic testing to study the flow distribution characteristics of duckbill valves installed on multiport manifolds. Q.) The inlet ports/nozzles shall discharge an elliptically shaped jet. The nozzle must have been modeled by an independent laboratory using Laser Induced Fluorescence (LIF). R.) Company name, plant location, valve size and serial number shall be bonded to outside of the check valve. Function


Page A-30 of 33


Specifications

S.) When line pressure inside the valve exceeds the backpressure outside the valve, the differential pressure forces the bill of the valve open, allowing flow to discharge. This restriction causes an increase in the jet velocity of the discharge, while the shape of the opening creates a flattened elliptically-shaped jet to increase dispersion. When backpressure exceeds the line pressure, the bill of the valve is forced closed preventing backflow. Installation T.) Valve shall be installed in accordance with manufacturer’s written Installation and Operation Manual and approved submittals. A11.10.5 Polyethylene Pipe All Polyethylene pipe work shall be solid wall black, PE100 and in compliance with WIS 432-03. Minimum SDR as specified below: • • • •

PE PE PE PE

100 100 100 100

1200mm OD SDR 26 (Main Outfall and Diffuser) 560mm OD SDR 21 (Diffuser Risers) 355mm OD SDR 21 (Diffuser Ports) 1000mm O.D SDR 26 (Inspection Chamber).

Polyethylene pipes complying with the provisions of German Standards DIN 8074 and DIN 8075, or Finnish Standards SFS 2336:E, SFS 3421 and SFS 2335 shall also be acceptable. A11.10.6 Jointing of Polyethylene Pipes Pipe ends are to be finished square to the axis of the pipe for jointing by butt fusion welding in accordance with UK Water Industry Specification WIS 4-32-08, April 2002 or equivalent. Only welding using purpose made, pipe manufacturer approved automatic welding equipment shall be allowed. All operators shall be trained in the use of the equipment and certified by the equipment supplier. The equipment shall automatically record all the weld parameters and reject any non-compliant welds. Records of all joints shall be logged and downloaded for record purposes. Pipes and fittings shall be supplied by the same manufacturer. Approximately one in every twenty welds shall be tested in accordance with BS 2782 Part 3 (Method 320). The weld bead shall be removed cleanly from both sides of the test piece. The weld shall be deemed satisfactory if: • •

The weld factor is not less than 0.95, and The weld itself shows a large elongation prior to failure.

For all flanged and mechanical connections, all flange backing rings bolts and nuts are to be designed for a 50 year corrosion allowance or be marine grade stainless steel minimum grade 316 L or 254 SMO (where appropriate) or similar approved. A11.10.7 Rock Armour All imported rock is to be in accordance with CIRIA Report 169 ‘Manual on the use of rock in Hydraulic Engineering’.


Page A-31 of 33


A11.11

Specifications

Cleansing of Pipelines If, in the Engineer’s opinion, the Contractor fails to keep an inspected pipeline satisfactorily isolated after it has been inspected and shown to be clean, he shall, if instructed, again clean it and demonstrate the cleanliness, as described above, before issue of a Certificate of Completion.

A11.12

Testing of Pipelines Testing of pipelines shall be carried out in accordance with the Standard Specifications.

A11.13

Construction Records and Quality Control The Contractor shall carry out all necessary tests for the purposes of checking the compliance of materials and workmanship with the requirements of the specification in accordance with the approved test procedure. The Engineer may require his representative to be present at any test or tests. The result of such tests shall be submitted to Engineer at the times specifically stated or if none is stated, as soon as possible. The Contractor shall operate strictly in accordance with the approved QA system that will provide assurance on the quality of the work and that complies with ISO 9001. The Test reports are part of the Contractor’s Documents. In the execution of the Works the Contractor shall be responsible for accurately recording services, features and strata encountered. Prior to the Completion of the Works, the Contractor shall furnish the Engineer with a full copy of these records. Prior to the commencement of the Works, the Contractor shall provide a photographic record of the working areas including inter-tidal areas and any adjacent buildings, structures, roads, paths and walls. The Contractor shall supply two sets of progress photographs at monthly intervals submitted in time for the monthly progress meeting. Each set will comprise a minimum of 12 No. colour photographs, and shall be issued as both a hard copy and in an electronic format approved by the Engineer. Upon completion of the Works, the Contractor shall prepare as built drawings and provide all information required for incorporation into the health and safety file.

A11.14

Operation and Maintenance Potentially the outfall will be operated intermittently and flows will be introduced to the STP on a phased basis. The operating regime shall consider periodic flushing of the outfall (once every 2 months) with flows generating velocities within the main pipe of greater than 0.7m/s to allow sediments to be mobilised and reduce the potential for marine growth to develop. The frequency of this flushing shall be determined once the operating regime is finalised. In terms of inspection surveys, annual inspection of the diffuser should be carried out by diver surveys (visual and CCTV) to observe flows and operation. CCTV or ROV surveys should also be carried out at the maintenance manhole locations provided for internal inspection of the pipe condition. Any maintenance then deemed necessary shall be carried

A10

PLANT SCALE MODEL A high quality scale model of the plant shall be provided for display purposes. The model shall normally be housed in the entrance of the Administration Building.


Page A-32 of 33


Specifications

The model shall be supplied by a professional artistic model building company having a minimum of 10 years experience of industrial model building. Details of the proposed the model building company shall be submitted for approval, including photographic details of previously constructed models of a similar nature, before any building work is commenced. The model shall: − − − − − − − − −

Be of high quality in keeping with its intended use for display purposes Use high quality paints and finishes matched to the actual plant finishes Have a minimum area of 3m2 Be a life-like and accurate representation of the plant, accurately built to scale Incorporate sufficient detail to illustrate the workings of the plant including equipment installed in tanks and buildings Include plant and equipment labelling plus name plate with the plant name and Employer’s logo Include a high quality finish wooden display stand/cabinet Have a removable acrylic cover Be designed so it can be dismantled and safely transported for use by the Employer at exhibitions etc.

A representative from the model building company shall be on-site for the model installation to check the model is undamaged and properly assembled. The Administration Building shall include lighting, with local switch, designed specifically for the best illumination of the finished model.


Page A-33 of 33


Specifications

CONTENTS Page No.

SECTION B - GENERAL OBLIGATIONS B1

B2

B3

B4

1

DEFINING AND MAINTAINING THE SITE

1

B1.1

Setting Out and Checking the Works

1

B1.2

Survey of Site

1

B1.3

Interference with Land Interests

1

B1.4

Interference with Access to Properties

1

B1.5

Site Cleanliness and Environmental Protection

1

B1.6

Demolition, Damage and Making Good

2

B1.7

Location of Existing Pipelines, Services, Manholes and Chambers

2

B1.8

Not used

2

B1.9

Site Drainage

2

B1.10 Billposting and Advertising

3

OTHER UTILITIES

3

B2.1

Existing Services

3

B2.2

Electricity, Water Supply and Telecommunications

4

SITE SAFETY AND WELFARE

4

B3.1

Safety, Health and Welfare

4

B3.2

Permits to Work

5

B3.3

Site Hazards

5

B3.4

Precautions Against Leptospiral Jaundice

6

B3.5

Excavations

7

B3.7

Protective Clothing and Safety Equipment

7

B3.8

Welfare Facilities and Site Cleanliness

7

B3.9

Use of Equipment

8

B3.10 Testing of Contractor's Lifting Equipment

8

B3.11 Dangers of Working in Confined Spaces

8

B3.12 Dangers of Working in Sewers and at Sewage Treatment Works

8

B3.13 Emergency Arrangements

10

B3.14 Contractor’s Plant and Equipment

10

B3.15 Accident Reporting

10

B3.16 Electrical Safety

10

B3.17 Chemical Hazards

11

PROCEDURES AND PRACTICE

12

B4.1

Interpretation of Drawings

12

B4.2

Continuous Working

12

B4.3

Interface with Other Contractors

12

B4.4

Abatement of Noise

12

B4.5

Pollution

14

B4.6

Protection of Work

14

Volume 3, Section3 – Civil Specifications

Page

i of ii


Specifications

CONTENTS (Continued) Page No. B5

MATERIALS AND WORKMANSHIP

14

B5.1

Local and Environmental Requirements

14

B5.2

Quality of Manufacture and Standards

15

B5.3 Approval of Suppliers, Manufacturers, Materials and Manufactured Items 15 B5.4 B6

Approval of Construction Methods

18

DESIGN

18

B6.1

Planning Permission and Building Permit

18

B6.2

Design Life - General

18

B6.3

Pipelines

18

B6.4

Structures

18

B6.5

Chambers

18

B6.6

Water Retaining Structures

19

B6.7

Sound Insulation

19

B6.8

Calculations and Drawings for Approval

19

Volume 3, Section3 – Civil Specifications

Page ii

of ii


Specifications

SECTION B - GENERAL OBLIGATIONS B1

DEFINING AND MAINTAINING THE SITE

B1.1

Setting Out and Checking the Works Works temporary bench marks shall be established at suitable locations on the Site. During the progress of the Works the value of the bench marks shall be periodically checked against the value of the Master Datum. Temporary bench marks shall be located clear of construction works.

B1.2

Survey of Site The Contractor shall be responsible for producing an accurate record of the existing site showing the location of the existing structures and features and existing ground levels. The existing topography and ground levels shown on the Drawings in Volume 6 – Other Information are indicative only. Before any work commences on Site, the Contractor shall take colour photographs in sufficient quantity in agreement with and in the presence of the Engineer to accurately portray the condition of the existing works, plant and equipment and general site area. A set of prints of these photographs of minimum size 200mm by 100mm is to be handed to the Engineer within four weeks of the Commencement Date.

B1.3

Interference with Land Interests Constructional operations shall generally be confined within the Site, or such other areas of land as may be negotiated. Contractor's employees shall be instructed not to trespass.

B1.4

Interference with Access to Properties Before obstructing the access to any property, satisfactory alternative arrangements must be provided.

B1.5

Site Cleanliness and Environmental Protection The Site shall be maintained in a clean and orderly manner and particular attention shall be paid to the protection and conservation of any local environmental features and local habitats. Contractor’s refuse shall not be deposited indiscriminately and arrangements shall be made for all waste and general refuse such as bags, packing cases, surplus concrete, waste timber and tins to be transported to an authorised tip. No refuse is to be deposited into trenches or other excavations before backfilling. Local facilities for recycling of wastes shall be investigated and adopted wherever possible. The public highways leading to the Site, and internal access roads, which are used for access shall be kept clean and free from spoil and rubbish at all times. Site personnel shall be prohibited from urinating or defecating on Site except in properly constructed toilets provided by the Contractor If the Contractor fails to keep the Site clean then the Engineer will instruct a third party to carry out the work and the costs shall be recovered from the Contractor through the Contract.


Page 3B-1 of 20


Specifications

No caravans or huts are to be brought onto the Site for use as sleeping accommodation unless prior approval is obtained from the Engineer. B1.6

Demolition, Damage and Making Good Care shall be taken when demolishing or cutting away existing work or dismantling existing plant such that no adjacent work is unnecessarily damaged. Any work so damaged shall be made good. For major structures in excess of 50 cubic metres the Contractor shall put forward detailed proposals for demolition, dismantling, and temporary supports. All materials arising from demolition work, except as otherwise provided for in this clause, shall be disposed of by the Contractor as surplus material. Any mechanical and electrical equipment, pipes, fittings and valves retrieved from demolished or dismantled structures and pipelines shall, if required by the Employer, be delivered to and stacked at one of the Employer’s depots to the instructions of the Engineer. Pipes, fittings and valves not required by the Employer shall be disposed of as surplus material. Unless otherwise specified, underground structures and chambers shall be demolished to a depth of one metre below finished ground level, cleared out and filled with approved clean material Where existing sewers and conduits are connected to the new systems, the length of pipe which is not incorporated into the new system, shall be abandoned. Buried pipelines to be abandoned shall be sealed with a mass concrete plug to a minimum depth of 1,000 mm at either end and at any intermediate manholes. Manholes and abandoned pipelines shall be demolished to a depth of 500 mm below final ground level and the void filled with hard core or other approved fill material and surface reinstated to a finish similar to that of the surrounding area. Exposed raw faces of existing concrete or blockwork which will not have new work built on to them shall be made good with cement rendering or new blockwork as applicable. All trees and shrubs shall be protected, if necessary with fencing, unless written permission is given to fell or lop. Where any building, land, hedge, wall, fence or other existing feature is disturbed or damaged in any way the permanent reinstatement shall be made with materials similar, and not inferior, to those in the undamaged portion.

B1.7

Location of Existing Pipelines, Services, Manholes and Chambers The exact positions of existing pipelines, services, manholes and chambers shall be agreed with the Engineer, after trial excavations if necessary have been made to locate existing services and other buried features.

B1.8

Not used

B1.9

Site Drainage At all stages of the work the Site shall be properly drained so that standing pools of water are not allowed to form.


Page 3B-2 of 20


Specifications

Drainage works shall be in accordance with all relevant laws and regulations and the Contractor will be responsible for consultation and liaison with all relevant authorities. All proposals for drainage works shall be approved by the Engineer, but such approval will not absolve the Contractor from his complete responsibility for the Works in this regard. Silt traps shall be provided as required on any permanent or temporary drains which may be required for the removal of water during the construction period. All drains shall be maintained clear of silt until completion of the Contract. Any silting of drains, whether within the Site or not, which arises from the failure to observe this clause shall be removed. B1.10

Billposting and Advertising Billposting or advertising of any kind shall not be permitted on the Works without the written consent of the Engineer.

B2

OTHER UTILITIES

B2.1

Existing Services As the STP site is located on a recently dredged island there should be no existing services present. However, the Contractor’s attention is drawn to the “Code of Practice for Service Installation” prepared by the Ministry of Works, Power & Water. In collaboration with the Engineer and before any work commences outside the STP site, the Contractor shall contact the local officials of each of the service authorities and shall maintain close liaison with them throughout the construction. The Contractor shall establish in advance the positions of all main services liable to interference by the construction and shall mark the position physically on the ground. The Contractor shall be in possession of a cable locator for this purpose. Apart from verifying positions to prevent damage, scrutiny is needed to identify those main services which might conflict with the Permanent Works where this is not indicated on the Drawings. Early scrutiny of these services is essential to enable any such diversions to be made in advance of the construction. Notwithstanding the scrutiny referred to above the Contractor shall take all reasonable precautions to prevent damage to existing buried main services and connections to buildings. The Contractor should note in particular that the Electricity Directorate will not permit work in close proximity to high voltage cables (11kV and above) during periods of high demand (which are normally from about mid May to mid September) other than in exceptional circumstances. The Contractor shall provide adequate temporary support to all existing services and connections that are exposed or partially exposed or otherwise weakened by the excavation. Should any damage occur he shall immediately notify the Engineer and service authority and afford every facility for the immediate repair of the affected service. The Contractor shall carefully preserve and replace all marker tapes and tiles affected by his excavations. In addition to the precautions to be taken with buried services the Contractor shall ensure that his plant and equipment do not damage pipeline or pipe supports above ground or any overhead electricity or telephone cables. He shall also take all precautions to prevent his plant from operating too closely to overhead high tension cables, and he shall, in


Page 3B-3 of 20


Specifications

conjunction with the Engineer and Electricity Directorate establish all necessary precautions for crossing under such cables. The Contractor shall afford the Engineer and the relevant service authorities such assistance as they may require in the preparation of records of existing and diverted services. Existing services on the site of the STP are generally the property of the Employer. Similar procedures shall, however, be followed to also ensure the protection of these services. B2.2

Electricity, Water Supply and Telecommunications Electricity, water supplies and telecommunications shall be provided to the Site for both temporary and permanent requirements. 1.

Water Supply The Contractor shall provide adequate supplies of water for drinking and for all other purposes where required. Arrangements for temporary supplies shall be made with the Water Supply Directorate P.O. Box 326, Manama.

2.

Electricity Supply The Contractor shall make arrangements for the supply of electricity to his own offices, the offices of the Engineer and for use in the Works whether by means of site generators or by connection to the public supply. In the latter case arrangements shall be made with the Electricity Directorate, P.O. Box 2, Manama. Where a permanent supply will ultimately be provided the Contractor shall not assume that this is available during the construction of the Works.

3.

Telephones Where appropriate, the Contractor shall arrange with Bahrain Telecommunications Company, P.O. Box 14, Manama for his telephone connections. He shall also arrange for the telephone connections for the Engineer as required by Section A.

B3

SITE SAFETY AND WELFARE

B3.1

Safety, Health and Welfare The Contractor shall be responsible for the health, safety and welfare of all persons working on or visiting the Site. He shall obtain copies of the Ministerial Orders current at the date of Tender and shall comply with these and with any legislation enacted during the Contract Period that affects working conditions, safety, health or welfare of his employees or those of the Engineer or Employer. The Contractor’s attention is drawn to the guidance manuals on health and safety referred to in the Schedule of Approved Standard and Guidance Publications in Section S to which reference should be made. The Contractor shall submit his Health and Safety Manual at the commencement of the works to demonstrate how he intends to comply with current Health & Safety legislation and manage the health, safety and welfare of all staff engaged on the works site.


Page 3B-4 of 20


Specifications

The Contractor shall submit to the Engineer method statements for all safety proposals in advance of the commencement of work, approval of which by the Engineer shall not relieve the Contractor of his obligations to comply with all Decrees, Statutes, Ordinances, Regulations or bye-laws. He shall make available for inspection by the Engineer all registers, reports and certificates which the Contractor is required to keep or issue in respect of safety matters and accidents. Contractor shall ensure that all personnel engaged on this Contract, including his subcontactors, are aware and adhere to the safety requirements relating to the Contract and associated site works and shall only employ personnel who have undergone recognised training and experienced in the works to be undertaken. Experienced personnel shall supervise any unskilled labour or trainees during the works. The Contractor shall note that any site personnel found to be working in breach of the safety requirements or procedures shall be first warned to correct their working methods or procedures, if repeated breaches occur, the personnel shall be removed from site. The Contractor shall ensure his personnel comply with any existing regulations in force at the STP. B3.2

Permits to Work All site works shall be covered by a Permit to work, issued by the Engineer. The Contractor shall not commence site works unless a valid Permit to work has been issued by the Engineer for the site works to be undertaken. The Contractor shall provide detailed method statements as required by the Engineer to complete permit authorisation. These method statements shall identify the working methods, risks and precautions necessary to complete the works. Permits to works will be issued to the Contractor as detailed below: i)

Upon handover of the site or working area by the Employer to the Contractor.

ii)

Works requiring access into confined spaces

iii)

Works associated with existing or live electrical equipment.

iv)

Works requiring excavation.

v)

Pumping operations.

vi)

Hot works.

vii)

Operation and use of mobile or static cranes

All Permits shall be time limited and issued in accordance with the Employers procedures. Blanket permits shall not be issued for the works under any circumstances. The Contractor shall adhere to the requirements of the Permit, including methods of works agreed whilst the Permit to work is in operation. B3.3

Site Hazards Once the construction programme has been established and detailed planning for the works commenced, the Contractor will arrange for a HAZCON study to be conducted for


Page 3B-5 of 20


Specifications

each of the major elements of work. The HAZCON will be attended by the Client, Engineer and essential Contractor staff. Hazards on the Site include:

B3.4

i)

Underground pipes and cables.

ii)

Overhead cables.

iii)

Flammable materials.

iv)

Mechanical plant and equipment.

v)

Operational staff and their Contractors and Vehicles.

vi)

Confined spaces.

vii)

Sewage and Sewage products, and the risk of leptospiral jaundice from contact therewith.

viii)

Live electrical equipment or services.

ix)

Deep existing tanks, chambers and manholes

Precautions Against Leptospiral Jaundice The Contractor shall ensure all personnel engaged in the site works are aware of the risks and precautions against Leptospiral Jaundice. The following provides guidance on working in sewage-contaminated sites: i)

After working in contact with sewage, or anything which might have been contaminated by it, wash your hands and forearms thoroughly with soap and water.

ii)

If clothes or boots are contaminated with sewage, wash thoroughly after handling them.

iii)

It is particularly important to do this before taking any food or drink.

iv)

Wet protective clothing should be dried as soon as possible.

v)

Infection may enter through breaks in the skin so thorough first aid treatment of all wounds is important.

vi)

Take particular care to wash thoroughly any cut, scratch or abrasion of the skin as soon as possible whether the injury was caused at work or not.

vii)

Apply an antiseptic to the wound with a clean piece of cloth or cotton wool and protect it with a strip of gauze completely covered with adhesive plaster.

viii)

Keep the wound covered until it is quite healed. Antiseptic gauze and impermeable plaster are available at place of work.

ix)

If you suffer any cut, scratch or abrasions of the skin, it must be covered with a waterproof plaster before entering the place of work.

x)

Avoid rubbing your nose or mouth with hands during work.


Page 3B-6 of 20


xi)

Specifications

Every accident at work, however trivial, must be reported.

The Contractor shall ensure all personnel, including subcontractors are advised of the risks and precautions relating to Leptospiral Jaundice and shall display the above guidance on site in the appropriate languages of his personnel. B3.5

Excavations Excavations shall be adequately supported against collapse. The Contractor shall provide protective safety barriers and appropriate bunting for the protection of the general public and the Employer’s operations staff working on the existing STP. The Contractor shall also provide suitable and safe bridging over trenches and excavations where required for pedestrian and vehicular access.

B3.6

Work in Public Highways Before work commences, adequate advance warning signs, clearly signposted diversions for traffic and pedestrians and traffic controls shall be provided to the approval and requirements of the Traffic Directorate, the Ministry of Works, Power and Water and the Engineer. The Contractor shall provide and maintain night lights and shall ensure their operation during hours of darkness by night watchmen and/or night patrols.

B3.7

Protective Clothing and Safety Equipment The Contractor shall provide all safety and protective clothing necessary for his staff and if necessary his subcontractors, to carryout the works. All safety and protective clothing shall be maintained in good condition and replaced when required. All site personnel shall be provided with the following minimum safety and protective clothing: i)

Safety helmet.

ii)

Overalls.

iii)

Gloves.

iv)

Safety shoes.

v)

Goggles (if undertaking cutting or grinding works).

vi)

Face masks (if undertaking activities which produce dust or vapours).

vii)

High visibility jackets or waistcoats when working in or adjacent to roads or public thoroughfares.

All safety equipment such as harnesses, breathing apparatus, ventilation equipment, gas detectors and any other equipment deemed necessary by the Engineer for the protection of the Contractor’s staff shall be provided by the Contractor and maintained in good order. B3.8

Welfare Facilities and Site Cleanliness The Contractor shall provide and maintain in proper order suitable messing, sanitary conveniences and washroom facilities, for use by all persons connected with the


Page 3B-7 of 20


Specifications

construction of the Works. The welfare facilities shall be provided within 1 week of commencement of the works on site and shall remain in place until handover of the works. The Contractor as a minimum shall keep on site one full stocked first aid kit and adequate potable water for drinking and washing for use of the site personnel. Rubbish, surplus packaging and materials not required for the works shall be removed from the Site on a weekly basis and the Contractor shall ensure that the site is kept in a clean and tidy condition. B3.9

Use of Equipment All manufacturer’s instructions and recommendations for the use, application, erection, or construction of any material or item of equipment or plant shall be followed precisely. Care shall be taken to protect all employees when using power tools or materials which will produce a fine dust and in particular all asbestos based products. Precautions may include:

B3.10

(a)

Operator to stand upwind of the operation and wear an approved respirator and goggles.

(b)

Overalls to be worn consisting of 60% polyester fibre and 40% cotton, to be worn whenever possible.

Testing of Contractor's Lifting Equipment Every hoist, lift, sling, chain, rope, pulley block and any other lifting tackle used in constructing the Works shall be thoroughly examined by a competent person at least once every 6 months, be test loaded to 150% of the safe working load and then tagged with the safe working load and date of successful testing. All parts and working gear, whether fixed or movable, including the anchoring and fixing appliances of every crane and lifting machine shall be of good construction, sound material, adequate strength and be properly maintained. All parts and gear shall be examined by a competent person at least once every twelve months. An up to date register of all such equipment and examinations shall be maintained and shall at all times be available for inspection by the Engineer.

B3.11

Dangers of Working in Confined Spaces Attention is drawn to the dangers of working in confined spaces. In addition to shafts, tunnels, closed tanks, etc., any confined space with limited ventilation which is also connected with water in or from a closed conduit or borehole, or is below ground level, should be treated as a potentially hazardous location where dangerous gases may be present and prior to entry adequate safety precautions must be taken in accordance with current good practice. Reference shall be made to the relevant guidance publications listed in the Schedule of Approved Standards and Guidance Publications in the document .

B3.12

Dangers of Working in Sewers and at Sewage Treatment Works 1.

All personnel working on the Site shall be made aware of the dangers of working in live sewers and at sewage treatment works; in particular the risks of physical injury, of bacterial infection from contact with sewage, of exposure to dangerous gases; and of explosion of sewage gases.


Page 3B-8 of 20


2.

3.

Specifications

Safeguards must be taken in accordance with current good practice and attention is drawn to guidance publications listed in the Schedule of Approved Standards e.g. National Joint Health and Safety Committee for the Water Service. Health and Safety Guidelines: •

No. 2 - Safe Working in Sewers and at Sewage Works

•

No. 3 - Respiratory Protective Equipment.

The Contractor shall not permit any employees to enter “live” chambers without the express permission of the Engineer in writing. Permission will only be given on the standard form “Authority to work within a live Sewer,” copies of which may be obtained from the Engineer.

4.

The following equipment shall be available at point of entry for personnel entering sewage manholes, pumping stations or other structures into which sewage or sewage gas can enter: (a)

Oxygen deficiency and flammable gas and hydrogen sulphide gas detectors.

(b)

Rope, safety harness, helmet and safety lamp for each person entering the sewer;

(c)

Two sets of compressed air breathing apparatus including 1800 litre capacity cylinders, at least 70 linear metres of high quality rubber hose all for 45 minutes of man working time;

(d)

One set of emergency escape breathing apparatus with minimum 800 litre capacity cylinders in sling harness and face mask with gas tight seal. Air supply operation to commence automatically when the face mask is fitted and breathing begins.

5.

Naked lights shall not be used in the vicinity of the structure. No smoking shall be permitted.

6.

At least two people shall remain close to the point of entry who shall have noted beforehand the nearest telephone and telephone number of the nearest hospital, and shall be thoroughly familiar with the use of emergency breathing apparatus and other safety equipment and procedures.

7.

Ventilation shall be provided by removing manhole covers to upstream and downstream manholes at least 15 minutes before the structure is entered or such other method as is appropriate for the structure including, where necessary, forced ventilation.

8.

The atmosphere shall be tested at points of entry and exit and continuously monitored while personnel are present. If dangerous gases are present, either (a) breathing apparatus shall be worn or (b) ventilation shall be continued and the atmosphere retested until such time as no dangerous gases are detected.

9.

Entry shall be authorised by a responsible person. The Contractor shall supply a list of the names of such persons to the Engineer before any work in live sewers etc., is carried out.

10.

All electrical equipment, e.g. power drills, shall be intrinsically safe (i.e. nonsparking).


Page 3B-9 of 20


11.

B3.13

Specifications

All equipment shall be inspected and tested daily and all air cylinders for breathing apparatus shall be filled with air from compressors manufactured for that specific purpose and housed and used in accordance with the manufacturers instructions.

Emergency Arrangements A current list of names, addresses and telephone numbers of the Contractor's staff responsible for responding / organising emergency works outside of normal working hours shall be provided to the Engineer and maintained as necessary.

B3.14

Contractor’s Plant and Equipment The Contractor shall at all times be responsible for the adequacy, efficiency and sufficiency of his and his sub-contractor’s plant and equipment which shall be of such type and size, and used in such manner, as the Engineer shall approve. Details of the plant proposed shall be submitted for the approval of the Engineer, which if granted will not relieve the Contractor of any of his responsibilities, nor shall reasonable refusal to approve entitle the Contractor to extra payment. If circumstances arise which in the Engineer’s opinion make it desirable that the use of plant or equipment be changed or suspended, the Contractor shall make such changes at his own cost. In particular the exhausts of diesel engined plant shall be modified if necessary to prevent nuisance from smoke and noise. The Contractor shall also ensure minimum pollution of working areas with fuel oils. The Engineer shall be entitled to withhold or withdraw his authority for the use of plant or equipment which is too noisy in the circumstances, or which may endanger members of the public, passing vehicles, or adjacent roads, services and structures.

B3.15

Accident Reporting The Contractor shall notify the Engineer in the event of any/all accidents that occur on site, with 24 hours. Each notification shall include the cause of the accident, personnel involved; injuries sustained (if any) and proposed measures/methods to prevent reoccurrence. The Contractor shall notify the Engineer and Divisional Head Occupational Health and Safety in the event of any/all accidents the occur on site which involve lost time, medical treatment etc, within 2 hours of the accident occurring. The Divisional Head Occupational Health and Safety contact details will be provided at the Contract award meeting All accidents notifiable to the Divisional Head Occupational Health and Safety shall be formally reported to the Engineer and Divisional Head Occupational Health and Safety, in the form of an accident investigation report. This accident report shall be submitted within 7 days of the accident.

B3.16

Electrical Safety All temporary electrical installations required during the works, including generator supplies, shall conform to the Safety Regulations stipulated by Ministry of Labour and Social Affairs Ministerial Order No.33-1997 “Precautions for protection of workers during work from hazards of electricity” and the current edition of the Ministry of Water and Electricity “Regulations for Electrical Installations”. All equipment and cabling shall be in good condition and electrically safe. The installation and equipment shall be tested at regular intervals with copies of test/inspection certificates issued to the Engineer.


Page 3B-10 of 20


Specifications

Any electrical supply derived from the public supply system shall have at its origin a suitably rated earth leakage circuit breaker in addition to overload and short circuit protection devices. The supply shall be distributed to the site from a metal clad MCB distribution board. Each outgoing circuit shall be provided with a suitably rated MCB with neutral and earth connections. The Contractor shall install an earth connection independent to the public supply earth for his temporary electrical installation. This earth shall be in the form of ¾” diameter copper clad earth electrodes driven into the earth, to achieve an earth resistance of not more than 2 ohms. All site temporary distribution or sub-distribution cabling and cabling to fixed equipment/installations shall be carried out using suitably sized multi-core armoured cables with correct glanding arrangements into equipment. The contractor shall not rely upon the cable armouring to provide the earth continuity conductor; one core of the cable shall be connected to earth. The cables shall be routed as to prevent or reduce potential damage from the construction works or equipment. Sub-distribution boards shall be provided to enable portable equipment to be “plugged-in” locally near the work area. The sub-distribution boards shall be metal clad MCB distribution boards, fitted with suitably rated MCB’s, with socket outlets provided for connection of portable equipment. The preferred type of socket outlet and plug is to BS4343 design. The use of plug adaptors is prohibited. Final circuit cabling to portable equipment shall be carried out in suitably rated multi-core rubber sheathed flexible cables. All connections shall be made through proprietary plugs and socket outlets only. One core of all flexible cables shall be connected to earth. Jointing or splicing of cables is strictly prohibited. All electrical equipment and services shall be weather proof to IP54 or provided with suitable weatherproof enclosures. Where equipment is exposed to direct sun light suitable enclosures shall be provided to shade the equipment or services. B3.17

Chemical Hazards All chemicals brought onto site shall be stored within the manufactures containers and shall be fitted with secure lids. The containers shall clearly indicate the contents and quantities within the container for identification purposes. Chemicals may be in the form of solvents, resins, alkalides or acids including paints and adhesives. The Contractor shall issue to the Engineer for approval and retain on site the manufactures or suppliers chemical hazard data sheet. The chemical hazard data sheet shall be issued to the Engineer prior to any deliveries to site. The Contractor shall remove chemicals that are delivered without approval of the Engineer. The Contractor shall limit the storage of chemical on site that are required for that days use. Additional requirements or stocks shall be held off site at the Contractors stores until required. The Contractor shall remove from site all unused chemicals or empty containers prior to handover of the works. All unused chemicals shall be disposed of in accordance with the manufactures instructions and in compliance with the current environmental legislation.


Page 3B-11 of 20


Specifications

B4

PROCEDURES AND PRACTICE

B4.1

Interpretation of Drawings Neither the Employer nor the Engineer accept responsibility for any omissions from or for correctness of the representation on the drawings of existing features.

B4.2

Continuous Working If, in the opinion of the Engineer, it is necessary for the safety of the Works or for any other reason the Works, or portion thereof, shall be carried out continuously by day and night.

B4.3

Interface with Other Contractors The construction of the STP and associated infrastructure will be carried out concurrently with other works on the AMAS islands including earthworks, roads, bridges, utilities, buildings and housing. This will generate large volumes of construction traffic and possible intermittent access restrictions. The Employer’s proposed access arrangements to and around the islands are indicated on the Drawings. The STP Contract has a number of specific interfaces with other contracts: •

At the Terminal Lift Pumping Station; interface between the TLPS inlet and the incoming tunnelled deep gravity sewer (DGS) pipe. The interface point with the DGS will be immediately outside the station inlet within the TLPS excavation shaft. The TLPS excavation shaft will also be the reception pit for the DGS tunnelling equipment. This work will require close coordination with the Contractor constructing the DGS.

•

At the plant boundary; interface between the TSE irrigation pipeline from the TSE Pumping Station and the primary TSE distribution pipeline.

•

Close the TLPS; interface between the STP access road and the AMAS spine road.

Interfaces are indicated on the Drawings Close coordination will also be required with the bridge contractors constructing the bridges over the main channel along which the new STP outfall will run. B4.4

Abatement of Noise The Contractor shall make every effort to keep the nuisance caused by noise to a minimum and consideration must be given to using the quietest plant available (Refer to Clause B3.14). If instructed by the Engineer, the Contractor shall use electric dewatering/overpumping pumps (with the generator, if required, located remotely to reduce the noise). The cost of providing such electric pumps is to be allowed for in the rates of work. The Contractor shall comply with all relevant regulations, decrees, and statutory requirements relating to restrictions placed on noise from construction work. Blasting shall not be used unless otherwise approved by the Engineer. All pneumatic breakers shall be fitted with mufflers. Noise mitigation measures, agreed by the Engineer, shall be provided for diesel plant when instructed by the Engineer. Methods of working shall be devised and arranged to minimise noise impacts, and experienced personnel with suitable training shall be employed to ensure that these methods are implemented.


Page 3B-12 of 20


Specifications

Particulars of all constructional plant which is likely to cause excessive noise shall be submitted to the Engineer. The particulars shall be submitted before the plant is used on site. Unless otherwise permitted by the Engineer, trials of the plant shall be carried out to demonstrate that the plant can be operated which will minimise noise during the works. The trials shall be carried out in the presence of the Engineer. The plant shall not be used on site until agreed by the Engineer. The noise level of any construction work other than percussive piling, during the period 0700 to 1900 hours on any day not being a general holiday, including Fridays, measured at site boundary, shall not exceed an equivalent sound level (LEQ) of 75 dB(A). The Contractor shall, prior to commencement of the relevant construction work, carry out baseline monitoring to determine baseline noise levels at the nearest properties along the pipeline route. Baseline monitoring shall be carried out for at least one week, and at locations and to a schedule to be submitted to, and agreed by, the Engineer. Impact noise monitoring shall be carried out at all the agreed locations whenever construction work is being carried out. The measurements will be determined by the Engineer to measure the maximum noise impact during the period. Measurements will not be taken if the Contractor is not working during these periods. Monitoring will be undertaken according to the following schedule: 1.

At least one LEQ measurement between 0700 and 1900 Saturday to Thursday, three times each week; and

2.

As determined by the Engineer from time to time and when any powered mechanical equipment is operating.

Whenever complaints are received, or if the maximum allowable levels are exceeded, immediate action shall be taken by the Contractor in accordance with an action plan to be submitted to, and as agreed by, the Engineer. A weekly report of all noise monitoring data shall be prepared by the Contractor and submitted to the Engineer, including at least the following: 1.

Copy of all data;

2.

Highlighting of any failures to comply with the criteria set out herewith;

3.

Implementation of the action plan when the levels are exceeded

4.

Identification of reasons for non-compliance

5.

Identification of additional mitigation measures take as a result of 2. Above; and

If monitoring of the noise level shows, in the opinion of the Engineer, an excessive noise level, the Contractor shall take all necessary measures to ensure that the actions of the Contractor are not contributing to the excess. The measures shall include, but not be limited to, the following: 1.

Checking all constructional plant;

2.

Maintenance or replacement of any constructional plant contributing to the excess;

3. Installation of constructional plant soundproofing, constructional plant, or erection of sound barriers; and


Page 3B-13 of 20

provision

of

alternative


4.

Specifications

Review and modification of all working methods and scheduling of activities.

The Contractor shall inform the Engineer of all measures taken, and shall submit to the Engineer a written report and proposal for action, whenever monitoring shows that an excessive noise level is arising. If the proposed remedial measures include the use of additional or alternative constructional plant, such plant shall not be used on the works until agreed by the Engineer. It proposed remedial measures include maintenance or modification of previously agreed plant, such plant shall not be used on the works until the proposed maintenance or modification has been completed and the adequacy of the maintenance or modification has been demonstrated and agreed by the Engineer as being satisfactory. If approved remedial measures are not being implemented and serious impacts persist, the Contractor shall cease related parts of the work until the measures are implemented. Nuisance caused by noise shall be kept to a minimum with consideration given to the use of the quietest equipment available. All pneumatic breakers shall be fitted with mufflers. Equipment should not normally be operated during the night, weekends or public holidays except for pumps dealing with sewage flow or dewatering excavations which are to be sited to cause the minimum inconvenience to the public. B4.5

Pollution All necessary precautions shall be taken to prevent the pollution or siltation of surface water drains and ground surface by poisonous, noxious or polluting matter arising from his operations.

B4.6

Protection of Work The Contractor shall, at his own expense, case up and suitably protect all work liable to injury, either by the weather or by the method adopted for execution of the Works. Precautions especially required for the protection of new concrete and brickwork are specified elsewhere. No other work requiring the use of cement or lime shall be carried out when the shade temperature is above 40°C (104°F) nor shall any materials that have been exposed to the direct rays of the sun during hot weather be used until, in the opinion of the Engineer, sufficient time under favourable conditions has elapsed for the materials to reach a suitable temperature for incorporation in the Works. The Contractor shall provide a sufficient number of maximum and minimum thermometers so that the Engineer may observe the shade temperature at each place of mixing, placing and building.

B5

MATERIALS AND WORKMANSHIP

B5.1

Local and Environmental Requirements All materials and manufactured items shall be suitable for the climatic and environmental conditions in Bahrain described in this specification.


Page 3B-14 of 20


Specifications

The environmental conditions may be different in different parts of the Works and materials shall be selected and manufactured items designed accordingly to withstand the relevant corrosive elements. In particular: (i)

all products or materials in contact with sewage or a sewage environment shall be non-biodegradable.

(ii)

all products or materials in contact with potable water shall not constitute a toxic hazard, shall not support microbial growth, shall not cause taste or odour cloudiness or discolouration of the water, and shall be approved by a recognised certifying authority as being suitable for use in potable water supply systems.

All local customs, laws and regulations relating to the supply or source of materials shall be complied with. B5.2

Quality of Manufacture and Standards All materials and manufactured items supplied for incorporation in the permanent works shall be new, of high quality and of sound workmanship. They shall be purchased only from approved suppliers who shall be capable of demonstrating the suitability of their products by reference to similar works or certified test results. Materials and manufactured items shall normally be certified as complying with relevant specifications of a recognised national or international standards organisation which shall be subject to the approval of the Engineer. Except where otherwise indicated in the Contract, the edition of an approved standard shall be that current 42 days prior to the date for the return of tenders. The Schedule of Approved Standards and Guidance Publications in Section S lists approved standards as a quality guide for the materials and articles to be provided. This schedule in no way prejudices the approval of any other equivalent or superior national or international standards. Also included in this schedule are publications for guidance on procedure and practice. Where the requirements of this specification and an approved standard differ, the more stringent requirement shall apply. Should the requirements of this specification and an approved standard be incompatible, the requirements of this Specification shall take precedence. Copies of the appropriate edition of any national or international Standards in English which may be called for as being required in the execution of the Contract shall be provided for the sole use of the Engineer. These may include alternative Standards to those to which the materials are manufactured for use as a comparative quality guide. The Standards will remain the property of the Contractor and will be returned to him at the end of the Contract. Any reference to a Manufacturer/product is to be taken as indicative of quality only.

B5.3

Approval of Suppliers, Manufacturers, Materials and Manufactured Items Prior to the placing of any order for materials or manufactured items, the approval procedure described under this clause shall be followed. All requests for Approval shall be submitted in triplicate. The information shall be clearly and neatly presented in a standard format to be agreed with the Engineer (a sample approval sheet is attached at the end of his Clause). All submissions shall have a document number and revision reference in accordance with the Contractor’s quality assurance system. No orders shall be placed until


Page 3B-15 of 20


Specifications

one copy of the final Request for Approval has been returned duly signed and dated by the Engineer or his representative. Generally a two stage approval procedure shall be followed as described below. The first stage requires the Contractor to demonstrate that his proposed supplier/manufacturer has the necessary experience, competency and reputation in the field of the proposed supply. The second stage follows approval of the supplier and comprises a full technical submittal. 1.

Approval of Supplier/Manufacturer The Contractor shall submit to the Engineer full details of his proposed supplier/manufacturer. The submission shall include: •

Name and address of proposed supplier or manufacturer

•

Background and history to demonstrate compliance with the specified requirement for experience, competency and reputation in the field of the proposed equipment supply.

•

Reference numbers and title of relevant specifications of a recognised national or international standards organisation with which the materials or manufactured items will comply together with copies of the specifications in English where required by the Engineer.

•

Manufacturers’ literature and data sheets for articles and fabricated items.

•

Details of reference sites.

•

Contact details for referees.

•

Any other information called for in particular clauses of the Specification

Period for approval is 14 days subject to submitted information being of a satisfactory standard. For minor items of supply the approval of Supplier/Manufacturer stage may be waived at the discretion of the Engineer. 2.

Full Technical Submission Following approval of the supplier/manufacturer, a full technical submission shall be made as described elsewhere under this clause. •

Evidence (by copy of letter of enquiry or otherwise) that the attention of the proposed supplier or manufacturer has been drawn to the particular climatic and environmental conditions in Bahrain.

•

Samples of materials representing the quality of the bulk of such materials the Contractor proposes to use.

•

Sufficient information to demonstrate that the materials or manufactured items are suitable and comply with the Specification including reference to all relevant Specification Clauses.

•

Detailed design calculations and design, fabrication and installation drawings

•

Any other information called for in particular clauses of the Specification.


Page 3B-16 of 20


Specifications

Provided the information requested is satisfactory, the Engineer’s approval will be given within a period of 21 days. Where additional information or clarification is required, the 21 day approval period will commence on receipt of the satisfactory additional information. Prior to despatch to Site or to a designated place of storage the following shall be provided:

i)

Facilities for inspection and testing at suppliers' pits or quarries, manufacturers’ works or at approved independent testing centres as appropriate. Inspection and/or witness testing may be carried out by the Engineer or the Engineer’ Representative or other appointed Inspector.

ii)

Details of the supplier’s or the manufacturer’s quality control test procedures.

iii)

The carrying out of tests as stated in the current quoted or appropriate British Standard or other national standard as appropriate, and such other tests as are necessary in the opinion of the Engineer, to determine that the Works comply with the Specification either under test conditions at the manufacturer’s works, on site or elsewhere under normal working conditions. Where tests and inspection have been completed to the Engineer’s satisfaction and when the test certificates, etc., have been checked the Engineer will confirm acceptance in writing and the items concerned shall not be delivered or incorporated in the Works until this acceptance has been received.

iv)

Four copies of all test certificates where appropriate to be supplied to the Inspecting Engineer within two weeks of any witnessed tests.

v)

Shipping and consignment identification details to be submitted to the Engineer.

vi)

Where witness tests are not required the test certificates and/or certificates of compliance with the appropriate standard are to be forwarded to the Inspecting Engineer within two weeks after instructions to waive witness tests have been received.

vii)

Each certificate shall give sufficient information to enable the Engineer to identify the material or equipment to which it refers prior to the issuing of his release order.

viii) No inspection or passing by the Engineer, or the Inspecting Engineer of the Work, or

manufactured item, or materials covered by this Contract, whether carried out or supplied by the Contractor, shall release him from any of his obligations under the Contract.

ix)

The Engineer reserves the right to require the Contractor to meet any extra costs which are occasioned by failure of the Contractor to comply with the above testing and inspection requirements including the provision of test certificates, curves, etc., or, which in the opinion of the Engineer, are due to insufficient care having been taken by the Contractor or his Sub-Contractor before presenting the item for inspection or test. If unauthorised delivery has taken place the Contractor shall if required by the Engineer return the item to the manufacturer for inspection and/or witness testing by the Inspecting Engineer at the Contractor’s expense.

Samples of all building and civil works materials shall be supplied to the Engineer for approval. Where appropriate, sample panels of built materials shall be constructed.


Page 3B-17 of 20


B5.4

Specifications

Approval of Construction Methods For all elements of the Works, fully detailed method statements describing proposed construction techniques and programme for execution shall be submitted to the Engineer in duplicate. These shall be supported, where applicable, by calculations for temporary works for supporting excavated faces and shuttering of concrete. Written approval shall be obtained before any work is commenced. Approval of the proposed construction techniques and methods shall not relieve the Contractor of his contractual responsibilities for the care of the Works or of his liabilities for accidents or damage.


Page 3B-18 of 20


Specifications

B6

DESIGN

B6.1

Planning Permission and Building Permit Planning permission will be confirmed by the Contractor with the Ministry at the outset of the project The Contractor shall consult the Ministry of Industry regarding building permits when sufficient details are available for the Ministry to assess whether a permit is required.

B6.2

Design Life - General The design life for the permanent Works shall be as follows unless otherwise stated Civil structures, pipelines and buildings

50 years

Mechanical and Electrical Plant

15 years

Instrumentation and Control Systems

7 years

Analytical and Process Instruments

7 years

The design shall take into account the most extreme conditions that will occur during construction and the life of the works, including inter alia, highest and lowest water levels and water pressure, construction methods, climatic conditions B6.3

Pipelines Pipework and pipelines shall be designed for all foreseeable load cases including the following:

B6.4

a)

maximum working pressures on completed pipelines;

b)

field test pressure on completed parts of the pipeline and the whole of the pipeline (field test pressures);

c)

required hydrostatic test pressure on individual pipes and fitting at the place of manufacture (works hydrostatic test pressures).

Structures Structures shall be designed to resist water loading due to external water level corresponding to ground level. Uplift forces on structures, tanks and pipes shall be calculated assuming they are empty.

B6.5

Chambers Unless otherwise stated, general chambers shall have anodised aluminium open grid or chequer plate covers. Covers shall be fixed in frames recessed into the top of the chamber walls. Chambers that require man entrance (generally greater than 900 mm deep) shall be provided with minimum access area through the cover of 800 mm x 600 mm. Ladders shall be installed in all chambers over 1.5 m deep. Where vertical ladders are installed in chambers over 2.5 m deep they shall be provided with hoop safety cages. All chambers shall have a nominal floor slope to a sump.


Page 3B-18 of 20


B6.6

Specifications

Water Retaining Structures Any structures containing any liquids or excluding any liquids shall be designed to the appropriate standard for liquid retaining structures. Structures that are to be water tested before back filling shall be designed accordingly.

B6.7

Sound Insulation Noise levels at the Site boundary generated by the operational plant shall not exceed 45 dBA during daylight hours and 40 dBA at night. The Contractor will be required to produce calculations to show that noise levels generated at the Site boundary will satisfy these conditions. In addition the noise level within any working area shall not exceed 80 dBA at any time.

B6.8

Calculations and Drawings for Approval The Contractor shall submit to the Engineer for his approval all Working Drawings and calculations including details for the construction and completion of the Works. Submissions shall be numbered using an agreed referencing system. The Contractor shall prepare the complete working drawings, all design calculations and details of construction of the works and other apparatus and all other parts as may be required to give full information to the Engineer regarding the proposed design. Three copies shall be submitted for approval by the Engineer.

B6.8.1

Civil and Building Works The requirements for civil and building shall comprise the following: Pipelines: Hydraulic calculations, including determination of test pressures. Site plan and general arrangement drawings. Pipeline profiles. Drawings and schedules showing all pipework, fittings, chamber and trench details and thrust block arrangements. Reinforcement drawings and calculations for thrust blocks to pipework and chambers. Drawings, calculations and method statements for all road crossings and connections to existing pipework. Civil, Building and Structural works: General arrangement and foundation drawings, complete with dimensions, for all buildings, tanks, plant and associated equipment. Structural calculations and drawings including foundation design. Reinforced concrete details, structural steelwork and masonry drawings. Reinforcement drawings and calculations for insitu and precast concrete.


Page 3B-19 of 20


Specifications

Fabrication drawings for any structural steelwork/metalwork Architectural and building works drawings including masonry, cladding, roofing, etc, and all specified fixtures and finishes both externally and internally. Details of protective coating design. Road construction drawings including kerbing and drainage details. Landscaping, land drainage, sub and top soiling and all ancillary works.


Page 3B-20 of 20


Specifications

TABLE OF CONTENTS Page No. SECTION C - EARTHWORKS C1

C2

C3

1

EXCAVATION

1

C1.1

Pre-Construction and Land Drainage Records

1

C1.2

Trial Excavations

1

C1.3

Topsoil and Surfacing Materials

1

C1.4

Handling Excavated Material

1

C1.5

Formation

2

C1.6

Rock and Hard Materials

2

C1.7

Use of Explosives

2

C1.8

Hand Excavation

2

C1.9

Support and Protection of Excavations

2

C1.10

Control of Water

3

FILL

4

C2.1

Definitions

4

C2.1.1

General Backfill

4

C2.1.2

Class 2 Fill

4

C2.1.3

Class 3 Fill

4

C2.1.4

Hardcore

5

C2.1.5

Lean Concrete for Backfill

5

C2.1.6

Topsoil

5

C2.2

Backfilling Excavations - General Requirements

6

C2.3

Placing of General Backfill

6

C2.4

Placing of Class 2 and Class 3 Fill

6

C2.5

Testing of Backfill

6

C2.6

Geotextile Filter Fabrics

7

REINSTATEMENT AND EMBANKMENT PROTECTION

7

C3.1

Reinstatement of Unpaved Land

7

C3.2

Reinstatement of Paved Roads

7

C3.3

Stone Pitching and Stone Revetment

8


Page i of i


Specifications

SECTION C - EARTHWORKS C1

EXCAVATION

(Note: Additional specifications for earthworks required for road construction are given in Section J). C1.1

Pre-Construction and Land Drainage Records Before an excavation is commenced the Contractor shall, if directed by the Engineer, assist in the preparation of a record of the state of the surface which shall detail ground levels, all features that may require reinstatement, and as much information as possible about surface and underground drainage. Where necessary it shall include photographs illustrating existing damage to adjacent building etc., or other conditions which may prove contentious at the time of reinstatement. The Contractor shall liaise with the Engineer, and where appropriate with owners and occupiers, in preparing this record. The record shall if necessary be updated with details of any further subsoil drainage or other underground features that are uncovered as work proceeds.

C1.2

Trial Excavations Prior to all machine excavation the Contractor shall excavate by hand pilot trenches to locate services in and around the area of the proposed Works. The Engineer may order the Contractor to carry out additional trial excavations to reveal existing buried services as referred to in Clause B2 or for other reasons. The trial excavations shall normally be carried out by hand unless otherwise agreed with the Engineer. The Contractor shall submit to the Engineer a written report or sketch drawing of the data obtained from each trial excavation in a form to be agreed with the Engineer indicating the type of service, its condition and depth below ground level, and any relevant factors and shall not backfill the excavation until the report or sketch has been supplied and the Engineer has given his agreement.

C1.3

Topsoil and Surfacing Materials Turf, topsoil, paving and other surfacing materials shall be stripped separately from the subsoil and stored separately for re-use or disposal, as directed by the Engineer. Excavations for structures shall be over areas designated by or agreed with the Engineer. For trenches, excavation shall be for the width of the trench, and turf and topsoil shall also be removed for the additional width agreed with the Engineer as required by the Contractor for the passage of vehicles etc., and for storage of subsoil.

C1.4

Handling Excavated Material Unless otherwise specified in the Contract the excavated material required for backfilling shall be stockpiled on site or stored locally. The Contractor shall dispose of surplus excavated material only to tips approved by the Municipality, and proof of authorised use of these tips shall be submitted to the Engineer. All excavated material shall be deposited so that it will cause as little damage and inconvenience as possible. It shall not be stored on footpaths or carriageways and shall always be kept at a safe distance from the top of the trench. Any spillage of spoil etc., on


Page C-1 of 9


Specifications

highways attributable to transport operated by, or on hire to, the Contractor or any of his sub-contractors shall be removed so as to restore road surfaces, verges, etc., to a clean and safe condition. Where different classes of material are excavated they shall be handled separately and the most suitable retained for backfilling. Where natural subsoil drainage depends on the relative positions of pervious or impervious strata, special care shall be taken to separate these materials and replace them in their natural positions. C1.5

Formation The Contractor shall carry out his operations in such a way as to avoid damage to the formation of excavations. This shall normally include bottoming-up by hand excavation immediately before pipelaying or placing concrete. Where in the opinion of the Engineer the required bearing capacity will not be obtained at formation level, or if the formation is damaged, it shall be further excavated and refilled with concrete, or compacted Class 2 fill material (refer to Clause C2.2), as instructed by the Engineer. No Permanent Works of any kind shall be constructed on an excavated surface until the formation has been approved.

C1.6

Rock and Hard Materials For the purpose of this Contract rock is defined as natural material that is so hard that, in the opinion of the Engineer, it cannot be removed by the ordinary methods of hand or machine excavation without undue difficulty, or without preliminary work to break or loosen the material by use of rippers, pneumatic tools, or similar procedures. Hard material is similarly defined as artificial material such as blockwork, brickwork or concrete that, in the opinion of the Engineer, is so hard that it cannot be removed by the ordinary methods of hand or machine excavation without undue difficulty or without preliminary work to break or loosen the material.

C1.7

Use of Explosives The use of explosive for any purpose whatsoever during the Contract is prohibited.

C1.8

Hand Excavation Where ordered or necessary for reasons of limited access, proximity to other services, or any other reason, excavation shall be carried out by hand. The Engineer may forbid the use of machine excavators or other plant at any time.

C1.9

Support and Protection of Excavations Excavations shall be adequately supported at all times to the satisfaction of the Engineer, to prevent any ground movement which could diminish the width of the trench, cause injury or delay or endanger adjacent services, structures or road surfaces. Supports shall be properly maintained until the Permanent Work is sufficiently advanced to permit their removal and shall be left in if specified or instructed by the Engineer. Trench supports shall be so arranged to permit withdrawal during the placing of the pipe bedding so as to prevent voids. Battered sides to trenches or other excavations will only be permitted if they can be constructed within the limits of the Site, without damage or interference to existing


Page C-2 of 9


Specifications

services, properties or structures, and without undue interference with pedestrians and traffic. Side slopes shall be sufficiently flat to ensure stability of the ground. Excavations shall be provided with adequate protective safety barriers and appropriate warning signs, lighting and bunting. C1.10

Control of Water All excavations shall be kept free from water. In this respect the Contractor’s attention is drawn to the very high water table throughout much of Bahrain and the relatively high permeability of much of the strata. Reference should be made to the ground investigation data (refer to Volume 6). The Contractor shall submit detailed proposals for dewatering the excavations to the Engineer for his approval. Dewatering methods may include cofferdams, temporary drains, intercepting ditches, cutoff drains, sub-drains, sumps, wells, pumps, well-points or other dewatering equipment and shall include all other materials and equipment necessary to keep surface water and groundwater out of the excavations. The water table shall be maintained at least 300mm below formation level continuously until construction therein has been completed to ensure that no damage occurs due to flotation, hydrostatic uplift or other causes. If excavations should flood then there is a danger that partly completed process units, pipelines and structures may float. Any damage or expense arising from the Contractor’s failure to heed this warning shall be the Contractor’s liability. All necessary precautions shall be taken to prevent any adjacent ground from being adversely affected by loss of fines through any dewatering process. Silt traps shall be provided on pumped ground water discharges where directed by the Engineer. Ground water systems shall be designed and controlled to ensure that any induced ground subsidence does not adversely affect adjacent services or structures. Unless otherwise agreed by the Engineer, all well points, sub-drains, sumps and similar temporary works shall be kept clear of the Permanent Works and when they cease to be used shall be finally filled with compacted load bearing fill material, grout, or sealed with concrete at intervals to the level of the underside of the Permanent Works. Particular care shall be taken to avoid undermining any part of the new or existing works due to the method adopted for the removal and disposal of water. Method Statements shall include proposals for dewatering systems and disposal of the water arising from them. No pipes or culverts in the new or existing works shall be used for the removal and disposal of water without permission in writing from the Engineer. The Contractor shall also obtain the written permission of the Ministry of Works, Power and Water or other public authorities (using the appropriate permit application form) and owners before connecting temporary drainage to existing drains, sewers and watercourses. Should such permission be given, the Contractor shall be responsible for cleaning out and removing all silt, etc., and for making good any damage whatsoever resulting from such use. The Contractor should note that such approval may not be given and shall allow for the provision of an alternative disposal system in his Tender.


Page C-3 of 9


Specifications

The Contractor shall not allow water arising from his works to discharge on to areas of open ground. Groundwater may be discharged to sea. If the Contractor proposes to use an existing water course or drainage channel he shall ensure that the water course is not blocked by development downstream and that it will carry the disposal water without causing damage or flooding to property. C2

FILL

C2.1

Definitions (Note: Class 1 fill material is not included in this Specification).

C2.1.1

General Backfill Selected site excavated material free from particles greater than 150mm nominal size, roots and other vegetable matter, and capable of being compacted to the specified requirements. (Refer to Clause C2.3). Where necessary, excavated material shall be sieved or sorted to remove large stones, rocks, or other particles which, in the opinion of the Engineer, may impede compaction.

C2.1.2

Class 2 Fill Class 2 fill shall be good hard well graded material screened and crushed as necessary to lie within the grading envelope given in the table below when tested in accordance with BS 1377 Test 7. The material shall have a CBR greater than 30% when tested in accordance with Clause B5.1.4 of BS 1377 at the density specified in Clause C2.4 of this Specification. The liquid limit shall not be more than 25% and the plasticity index shall not exceed 6%. The total soluble salts shall not exceed 2%. Grading envelope for Class 2 Fill Sieve Size 75.0 37.5 10.0 5.0 600 75

C2.1.3

% by Mass Passing

mm mm mm mm microns microns

85 45 20 8 0

100 -

100 100 65 45 20

Class 3 Fill Class 3 fill shall be clean, hard, granular material free from clay and deleterious substances. The total soluble salts shall not exceed 2% and the grading of the fill shall be within the grading envelope given in following table when tested in accordance with BS 1377 Test 7.


Page C-4 of 9


Specifications

Where the percentage passing the 75 micron sieve is greater than 8%, the plasticity index shall not exceed 20% when tested in accordance with BS 1377. Grading envelope for Class 3 Fill Sieve Size

% by Mass Passing

100 mm 5 mm 75 microns C2.1.4

100 0 - 50 0 - 20

Hardcore Hardcore shall consist of broken stone or other suitable hard material. It shall be free from clay, dust or other deleterious matter, shall not contain pieces exceeding 100mm and not more than 5% shall pass through a 20mm sieve. The fill shall not be susceptible to breakdown under moist conditions. The total soluble salts shall not exceed 2% and the total sulphate content (as SO 3 ) shall not exceed 1%.

C2.1.5

Lean Concrete for Backfill Aggregate for lean concrete shall consist of an all-in aggregate, having a maximum nominal size not exceeding 20mm. Aggregate quality and cleanliness shall comply with the relevant requirements of Clause C1.5 and the overall grading of the aggregate shall lie within the limits shown in following table. Grading of Aggregate for Lean Concrete Percentage by mass passing BS sieve Nominal maximum size 20mm

Sieve size mm 20.0 10.0 5.0 microns 600 300 75

45 - 100 35 - 100 25 - 100 8 - 65 5 - 40 0 - 10

The ratio of cement to aggregate by mass shall be sufficient to produce an average 7 day strength of 3.5 N/mm2 for each batch of five test specimens. The moisture content of the mixed material, when determined by the vibrating hammer method test in BS 1924, shall be within the range of optimum to optimum plus 2%. C2.1.6

Topsoil Only such soil which, in a loosened state, besides the normal inorganic components also contains mineral elements in adequate quantity to serve as a nutrient medium for vegetation when watered, will be taken as topsoil.


Page C-5 of 9


C2.2

Specifications

Backfilling Excavations - General Requirements Backfilling around structures and in pipe trenches from 300mm above the crown of the pipe shall normally be carried out as detailed below:Backfilling shall be carried out using general backfill (see C1. C2.1.1), unless otherwise directed by the Engineer. Where the Engineer designates the excavated site material as unsuitable, a Class 3 fill shall be imported and used for backfilling in lieu of the excavated material. Except where directed by the Engineer, excavations in classified major roads shall be backfilled with dry lean concrete placed in layers not exceeding 150mm thick and mechanically compacted to refusal. Elsewhere, Class 2 fill or concrete shall only be used where directed by the Engineer.

C2.3

Placing of General Backfill Soils shall be placed and compacted in layers not greater than 150mm thick such that throughout each layer placed the dry density is not less than 95% of the maximum dry density determined in the standard vibrating hammer test (for granular soils) or standard 4.5kg rammer compaction test (for cohesive soils) as detailed in BS 1377. The placement moisture content shall be adjusted and maintained close to the optimum moisture content as determined in the appropriate standard compaction test so that the specified degree of compaction may be readily achieved.

C2.4

Placing of Class 2 and Class 3 Fill Class 2 and Class 3 fill shall be placed and compacted in layers not greater than 150mm thick such that throughout each layer placed the dry density is not less than 95% of the maximum dry density determined in the standard vibrating hammer compaction test. The placement moisture content shall be adjusted and maintained close to the optimum percentage determined in the vibrating hammer compaction test so that the specified degree of compaction may be readily achieved.

C2.5

Testing of Backfill The Contractor shall provide testing apparatus and carry out tests as is necessary for the monitoring of backfilled soil properties. He shall maintain a daily log of tests carried out, and provide the Engineer with a copy of the log to be countersigned by the Engineer. Tests to determine the dry density/moisture content relationship and insitu density and moisture content shall be carried out as directed on site by the Engineer. The frequency of testing will depend on the consistency of material and test results but unless otherwise instructed or agreed shall be as follows: dry density/moisture content relationship

- one test per 150m of trench

dry density and moisture content of compacted soil

- 10 tests per 150m of trench - for other earthworks, 1 test per 500 m3 per day with minimum 1 per day.


Page C-6 of 9


Specifications

Prior to the commencement of excavation, the Contractor shall submit to the Engineer for approval a method statement for testing backfill. This statement shall include details of:

C2.6

(i)

the methods and equipment proposed for measuring dry density/moisture content relationship, moisture content and insitu density (including sources of pouring sand where required for the sand replacement method).

(ii)

the name and address of any proposed independent testing laboratory.

Geotextile Filter Fabrics The required physical, mechanical, chemical and hydraulic properties for filter fabrics will, if applicable, be specified in Particular Requirements Specification. The material will be supplied in rolls to widths to suit the work. After excavation and trimming to the required profile the filter fabric shall be unrolled over the prepared formation care being taken in the case of trenches to ensure that the material is dressed well into the sides and bottom of the trench so that subsequent placement of the filter or fill material does not impose a strain on the fabric or cause it either to tear or to pull away from the trench side leaving voids. Joints or laps between successive sheets shall be formed in accordance with the manufacturer’s instructions. No vehicles will be allowed to run directly over filter fabrics. Any damaged sections shall be cut out and removed and, after restoration of the surface to its required formation, replaced with new fabric overlapping the undisturbed and undamaged sections by a minimum margin of 500mm at any point.

C3

REINSTATEMENT AND EMBANKMENT PROTECTION

C3.1

Reinstatement of Unpaved Land In general the reinstatement of stripped areas of unpaved land shall restore the ground to a condition not inferior to that which existed before the site was occupied. All initial reinstatement shall be complete within 7 days of completion of backfilling. The compacted backfill shall be taken up to a level which allows for settlement. In cultivated areas and parks the surface to be topsoiled shall then be loosened to a depth of 200mm and topsoil replaced on it to the specified depth without compaction. The Contractor shall import additional topsoil required to make up any deficiency. Areas where grass is to be sown shall be worked to a fine tilth, levelled, graded and rolled with a light roller. The seed shall be sown evenly at the specified rate of application in the proper season and in suitable weather conditions, and the areas again rolled. Restoration and re-seeding of any areas where the new grass is unsatisfactory or inadequate shall be carried out by the Contractor as instructed. Newly sown grass shall be regularly watered and shall receive at least one cutting. Alternative methods of planting may be required by the Engineer and may include the planting at 225mm centres of “Bermuda” or similar tropical grass tufts.

C3.2

Reinstatement of Paved Roads For the purpose of this Specification all public asphalted roads will be considered as P.W.A. Highways.


Page C-7 of 9


Specifications

In general the final reinstatement of public roads will be carried out by the Roads Department of the Ministry of Works and Agriculture, but the Contractor may be instructed to carry out some of this final reinstatement in accordance with the specifications issued by the Ministry of Works and Agriculture current at the time. Initial asphalt reinstatement shall be placed without delay following completion of backfilling to any excavation where it is proposed to re-open that part of the road to traffic. Initial asphalt reinstatement may only be delayed where the work dictates that traffic should still be generally excluded from the particular section. Prior to surface reinstatement the edges of the existing surfacing shall be cut back to give a regular shaped, straight sided area free of deformed or cracked surfacing and at least 150mm outside the edge of the excavation. The surfacing shall be cut cleanly by pneumatic or hydraulic breaker or by saw to give a vertical edge. The formation shall be finished 450mm below existing road level and Class 2 sub-base shall be spread, graded, watered and compacted in accordance with Clause C2.4. The finished surface shall be treated with a prime coat of road oil sprayed at a rate of 0.8 sq. m per litre and exposed faces of existing asphalt shall be painted with hot bitumen. A layer of asphaltic wearing course to the required thickness is to be laid such that the top surface provides a smooth transition between the existing wearing course on each side of the trench. The initial reinstatement shall be maintained to ensure a satisfactory surface until final reinstatement is carried out or until the issue of the Maintenance Certificate as appropriate. In the event of settlement of initial reinstatement which in the opinion of the Engineer or Traffic Directorate represents a hazard to pedestrians or traffic, the Contractor shall break out the asphalt, re-compact the sub-base to the required specification and reasphalt. Asphalt paving shall be laid to the thickness given in the following table: Thickness of Initial Asphalt Road Reinstatement Original Road Thickness

Initial Reinstatement

less than 50 mm 50 - 75 mm over 75 mm

50 mm Original thickness 75 mm

Asphalt shall normally be mix type L20 and shall only be obtained from suppliers holding current compliance certificates issued by the Ministry of Works, Power and Water. If mix type L20 is not available, mix type W20 or L10 shall be used as directed by the Engineer. Before commencing reinstatement of paved road, the Contractor shall agree his method in writing with the Engineer. C3.3

Stone Pitching and Stone Revetment Stone for pitching or for revetment shall be hard durable natural stone of minimum nominal dimension 200mm but in no case shall any stone be less than 0.01 m3 in volume or 25kg in weight. Stones shall be of suitable shape and rounded boulders shall not be used on prepared ground surfaces having slopes steeper than 1 in 2. Flat or needle shaped stones will not be accepted unless the thickness of each individual piece is greater than one third of its length.


Page C-8 of 9


Specifications

The sides or bed of the watercourse or embankment shall first be carefully trimmed to the required profile. Stones shall be placed by hand, dumping of stone directly onto the prepared bed or embankment will not be permitted. For pitching, stone shall be hand placed on a 75mm thick graded sand/gravel bed laid over an approved UV resistant filter cloth of minimum weight 280g/sq.m. For revetment, stone shall be hand placed and embedded a minimum of 75mm in Grade 40/20 concrete 125mm thick. Stones in pitching or revetment shall be fitted closely together to leave the minimum of interstices and these shall not be filled. Courses shall be laid to break joint with their longitudinal axes horizontal and at 90º to the embankment or bed face. The final appearance shall be neat and tidy and the local irregularities in the finished surface shall not vary from the designed plane of the slope by more than 50mm over a surface distance of 300m. The minimum weight of stone is based on the volume stated above and a minimum density of local stone of not less than 2500 kg/cu.m.


Page C-9 of 9


Specifications

TABLE OF CONTENTS Page No. SECTION D - CONCRETE

1

D1

CONCRETE MATERIALS AND THEIR HANDLING 1 D1.1 Concrete Materials - General Requirements 1 D1.2 Water for Concreting 1 D1.3 Cement 2 D1.3.1 Materials 2 D1.3.2 Packaging and Delivery 3 D1.4 Storage and Usage of Cement 3 D1.4.1 Storage 3 D1.4.2 Usage 4 D1.5 Aggregates 4 D1.5.1 Aggregate Sources 4 D1.5.2 Aggregate Sampling and Testing 5 D1.5.3 Fine Aggregates 7 D1.5.4 Coarse Aggregate 7 D1.5.5 Aggregates for Heavy Duty Concrete Floor Finishes (Granolithic Concrete) 8 D1.5.6 Aggregate Grading 8 D1.6 Storage and Handling of Aggregates 12 D1.7 Steel Reinforcement 12 D1.8 Storage, Cleaning and Protection of Steel Reinforcement 14 D1.9 Concrete Admixtures 16 D1.10 Curing Compounds 19

D2

CONCRETE MIXES D2.1 Definitions D2.2 General D2.3 Ready Mixed Concrete D2.4 Mix Design Constraints

21 21 24 25 25

0.35 25 D2.5 Design Mixes D2.5.1 General D2.5.2 Design Mixes for New Batching Installations D2.5.3 Design Mixes from a Continuing Source D.5.4 Method Statements D2.6 Prescribed Mixes for Minor Works D2.7 Concrete Quality Control D2.7.1 General Requirements D2.7.2 Test Cubes


Page i of ii

26 26 27 27 Error! Bookmark not defined. 28 28 28 29

AL MADINA AL SHAMILYA STP

Specifications

D2.7.3 Workability D2.7.4 Density D2.7.5 Temperature D2.7.6 Climatic Conditions D2.7.7 Compliance Requirements D2.7.7.1 Non-compliance

29 30 30 30 30 31

D3

FORMWORK AND CONCRETING PRACTICE D3.1 Blinding Concrete (Sealing Coat) D3.2 Formwork D3.3 Tolerances and Finishes for Concrete Surfaces D3.3.1 Tolerances for Exposed Surfaces D3.3.2 Tolerances for Unexposed Surfaces D3.3.3 Surface Finishes D3.4 Bending, Placing and Fixing of Reinforcement D3.5 Formation of Holes for Fixing D3.6 Batching, Transporting and Placing of Concrete D3.7 Batching of Admixtures D3.8 High Temperature Concreting D3.9 Curing and Protection of Concrete D3.9.1 Exposed Surfaces D3.9.2 Formed Surfaces D3.9.3 Tanked Surfaces D3.9.4 Damaged Concrete D3.10 Striking Formwork D3.11 Re-use Formwork D3.12 Heavy Duty Concrete (Granolithic) Screeds to Benching and Channels D3.13 Cracks in Concrete Structures

32 32 32 33 33 34 34 34 35 35 37 37 38 38 38 39 39 39 40 40 40

D4

JOINTS IN CONCRETE STRUCTURES D4.1 Classifications D4.4.1 Movement Joints D4.1.2 Construction Joints D4.2 Size and Sequence of Concrete Pours D4.3 Water Bars D4.4 Bond Breakers D4.5 Expansion Joint Fillers D4.6 Joint Sealing D4.7 Joint Bond Breaking for Contraction Joints and Sliding Joints D4.8 Bond Breaking Compound for Dowel Bars D4.9 Dowel Bars

41 41 41 41 41 42 42 43 43 44 44 44

D5

PRECAST CONCRETE

45


Page ii of iii


D5.1 D5.2 D5.3 D5.4 D5.5 D6

Specifications

Precast Concrete Production Bedding Precast Concrete Units Chamber Rings and Cover Slabs Precast Concrete Paving Slabs Precast Concrete Kerbs

TESTING OF WATER RETAINING CONCRETE STRUCTURES


Page iii of iii

45 46 46 46 46 47


Specifications

SECTION D - CONCRETE D1

CONCRETE MATERIALS AND THEIR HANDLING Where ready-mixed concrete is proposed, the Contractor shall use concrete from an approved supplier and source, with the written permission of the Engineer. Ready-mixed concrete and all its constituent materials shall conform to this Specification.

D1.1

Concrete Materials - General Requirements In addition to the detailed requirements specified in this Section, materials for concreting shall contain no harmful substances that will affect the strength and durability of the concrete.

D1.2

Water for Concreting The Contractor shall arrange for an adequate supply of water, complying the with quality limitations of this clause, and BS 3148 wherever it is required on the Works for :(i) washing of aggregates (ii) the production of concrete (iii) curing of concrete All such water for concreting shall be obtained from an approved source. Samples of water not less than 5 litres shall be taken in the presence of the Engineer, sealed and sent for testing at an approved, independent, laboratory both prior to the approval of any water source and periodically during the continuance of its use. No source of water shall be used until the required tests have demonstrated its suitability for concreting. Tests shall include :1.

Chemical analysis to determine the concentrations of sulphate and chloride.

2.

Physical analysis to determine pH, suspended solids, colour, smell and opacity.

3. Comparative tests for initial setting times and compressive strengths of cement pastes prepared with water from the proposed source and with distilled water. Any one of the following conditions shall make the proposed source of water unsuitable for concreting : (a) Sulphate measured as sulphur trioxide in excess of 1 000 mg/l. (b) Chloride content in excess of 500 mg/l chloride ion. (c)

Alkali carbonates and bicarbonates in excess of 1 00 mg/l.

(d) pH values outside the range 6.5 to 8.0. (e) Suspended solids in excess of 2 000 mg/l. (f)

Total dissolved solids in excess of 2 000 mg/l.

(g) Presence of organic substances indicated by colour or odour.


Page D-1 of 47


Specifications

(h) In comparative tests with distilled water, variations in initial setting times in excess of 30 minutes or reductions of compressive strength in excess of 10 per cent. In addition to the above, water for concrete shall be included in the assessment of total chloride and sulphate contents in a proposed concrete mix. D1.3

Cement

D1.3.1

Materials Cement shall be Portland cement complying as required with one of the following standards : (i)

Ordinary Portland cement complying with BS12 except that the proportion of C 3 A by weight shall be not less than 8% nor greater than 13%.

(ii)

Moderately sulphate resisting Portland cement complying with BS12 except that the proportion of C 3 A by weight shall be greater than 3.5% but less than 8%.

(iii)

Sulphate resisting Portland cement complying with BS 4027.

Unless otherwise approved by the Engineer all cements shall comply with the following requirements : (a)

The heat of hydration shall not exceed 325 kJ/kg at 7 days when tested in accordance with ASTM C-186.

(b)

The specific surface shall not be greater than 325 m2/kg when tested in accordance with BS 4550.

(c)

The temperature of cement shall not exceed 75°C at the time of incorporation into a concrete mix.

(d)

The cement shall be “low alkali” having a total acid soluble alkali content (Na 2 0+0.685K 2 0) of not more than 0.6% as determined in accordance with BS 4550.

Extra rapid hardening, rapid hardening, super-sulphated, high alumina cements, and cements containing calcium chloride shall not be used. Suitable type of cement shall be used in conformity with the relevant applicable standards. The choice of cement type to be used for underground structures shall depend on the classifications of soils for chemicals aggressive to concrete. The tenderer shall verify the characteristics of different types of Portland cement and blended cements and consider in his offer the usage of OPC/SRPC/MSRPC/Blended cement with mineral additions may be required for underground /above ground structures. For above ground structures normal OPC made to BS 12 shall be used The Contractor shall be responsible for satisfying himself that the performance characteristics of cement are not such as to necessitate excessive cement contents or be likely to cause or accentuate any undesirable properties in the fresh or hardened concrete, notwithstanding apparent compliance with this Specification. Samples of cement shall be taken in accordance with BS 4550 on the request and in the presence of the Engineer for testing in an approved independent laboratory. The Engineer shall have access to the cement store at all reasonable hours.


Page D-2 of 47


D1.3.2

Specifications

Packaging and Delivery Cement shall be delivered to site in consignments of sufficient quantity to ensure that there is no suspension or interruption to the work of concreting at any time. Unless approval is given in writing for the handling of cement in bulks cement shall be packaged by the manufacturer in bags which are so designed as to prevent any contamination and to minimise the adverse effects of moisture and high humidity during transportation and storage. The Contractor shall supply to the Engineer two unused sample bags for approval and retention. The bags shall be marked with the manufacturer’s name, the brand name (if appropriate), the name of the producing works, the cement type, the Standard to which it was made, and the date of manufacture, or date code. Where bulk cement deliveries are proposed the Contractor shall provide all information required by the Engineer concerning off-site storage and loading arrangements and shall provide reasonable facilities for the Engineer to inspect these arrangements for approval purposes. The Contractor shall obtain and provide to the Engineer a certificate for each consignment of cement which shall include the following information :(a) The manufacturer’s bulk average test results for the manufacturing batch including chemical composition and physical properties determined in accordance with the approved relevant specification for the cement. (b) The date of manufacture, the date of original loading and the date of intended delivery to site.

D1.4

Storage and Usage of Cement

D1.4.1

Storage Cement shall be stored immediately upon receipt at site. The Contractor shall provide a method statement for the storage of cement, in the terms of B5.5 which shall be approved and implemented before any cement is delivered to site. Bags shall be stacked close together to reduce circulation of air but shall not be stacked against outside walls. Each consignment and type of cement shall be stored separately for ease of access, identification, inspection and sampling. If bagged cement is stored in silos it shall be charged into the silos through a 6mm mesh screen which is welded or bolted to and covers the entire feed area of the silo charging hopper. Cement stored in silos shall be adequately protected against rain, humidity and dewfall, and all silo charging and discharging points shall be properly sealed. Silo aeration equipment shall, if necessary, incorporate de-humidifiers. Sufficient stocks shall be maintained on site to ensure the proper progress of the Works and at least sufficient cement for one week’s consumption shall be left in store and the stockholdings shall be to the approval of the Engineer.


Page D-3 of 47


D1.4.2

Specifications

Usage Consignments shall be used in the order in which they were delivered. Differing types or brands shall not be mixed together for use in the Works. Cement shall not be used after 6 months from its manufacture date or after it has been held in store for more than 3 months, unless it is retested and satisfies the relevant standard. A re-test certificate will only be valid for a further period of 6 months. All cement shall be used within 12 months of date of manufacture. Cement which the Engineer considers to have deteriorated in any way shall not be used and shall be removed from site without delay. No cement from any consignment shall be used in Permanent Works without the approval of the Engineer. The type of cement required for each structure will normally be stipulated elsewhere in the Contract Documents. Where no such stipulation exists, and unless otherwise directed by the Engineer, cement shall be used as follows :

D1.5

(1)

Ordinary Portland cement for reinforced concrete above ground level.

(2)

Sulphate resisting Portland cement for reinforced concrete below ground level and for mass concrete.

(3)

Moderately sulphate resisting Portland cement where directed by the Engineer, typically where there is considered to be a risk of both chloride and sulphate attack.

Aggregates Unless otherwise specified aggregates shall comply with BS 882 or ASTM C.33.

D1.5.1

Aggregate Sources Primary and secondary sources of both coarse and fine aggregate shall be proposed In assessing the Contractor’s request for approval to a proposed source of aggregate in the terms of Clause B5.3 the Engineer may require to: (i)

Accompany the Contractor to the source for examination of the types of deposit and the methods of extraction, stockpiling, loading and quality control.

(ii)

Supervise the sampling of aggregates both at the point of production and at the stockpiles in accordance with BS 812.

(iii)

Inspect physical, chemical and petrological analyses of the samples carried out by an approved independent laboratory.

The limits for deleterious substances and physical property requirements are listed in Table D1. The Contractor is advised that natural Bahrain aggregates are normally contaminated by layers and pockets of gypsum and have high salt contents particularly in zones within the range of capillary moisture. Sources of rock for crushed aggregate are likely to show potential alkali aggregate reactivity when the derived coarse aggregate is used in concrete


Page D-4 of 47


Specifications

manufacture. Selective quarrying together with careful processing involving the use of multiple scalping and vigorous washing will be required to produce aggregates of an acceptable quality. Aggregates are imported from the United Arab Emirates which have non-alkali reactive properties generally superior to those of local sources in Bahrain, therefore the use of local aggregates for structural concrete will not usually be permitted. The information given in this paragraph is provided for the assistance of the Contractor but in no way relieves the Contractor of his responsibility to supply materials in compliance with this Specification and may not be used as the basis of any contractual claim. D1.5.2

Aggregate Sampling and Testing When an aggregate source has been approved, representative samples shall be taken of each aggregate type and retained on site for reference purposes by both the Engineer and the Contractor. Fresh samples shall be taken in accordance with BS 812 and be analysed regularly throughout the Contract Period to demonstrate consistency of quality and of grading. The frequency of such sampling will be dependent on the continued adequacy of the samples as demonstrated by the results of the analyses, but shall not be less than once per week. Aggregates shall be hard, strong and durable and shall contain no harmful material that will adversely affect the strength and durability of the concrete or attack steel reinforcement. Aggregates shall not be composed of or contain any inclusions of materials likely to cause staining or otherwise to disfigure finished concrete surfaces.


Page D-5 of 47


Specifications

TABLE D1 Limits of Deleterious Substances and Physical Property Requirements of Aggregates for Concrete Maximum Allowable % by Weight Property

Aggregate Type Fine

Coarse

3 (a)

1 (b)

3

1 (b)

Flakiness index (determined in accordance with BS 812).

Not applicable

30 (c)

Elongation index.

Not applicable

30 (c)

2.5

2.5 (b)

0.4 (e)

0.4 (e)

Total acid soluble chloride ion measured in 10% nitric acid solution.

0.06 (e)

0.03 (e)

Five cycles of soundness as specified in ASTM C88 with magnesium sulphate

15 (d)

18 (d)

Not applicable

80kN

3

Not applicable

Materials finer than 75 micron sieve (determined in accordance with BS 812, decantation method). Clay lumps and friable particles (determined in accordance with ASTM C142).

Water absorption (determined in accordance with BS 812). Total acid soluble sulphate as sulphur trioxide (SO 3 ) measured in 10% hydrochloric acid solution.

10% fines value not less than figure indicated using the standard 10mm to 14mm test fraction. Hollow shells (likely to form voids) retained on 2.4mm sieve and determined visually. NOTES (a)

In the case of concrete not subject to abrasion this percentage may be increased to 5 for crushed stone sand.

(b)

This figure is for each fraction of the nominal sizes aggregate.

(c)

This figure is for the predominant size fraction of each nominal sized aggregate.


Page D-6 of 47


Specifications

(d)

Maximum allowable loss unless otherwise approved.

(e)

These maximum limits must not be individually exceeded and must be reduced if any of the following overriding limitations for the total mix are exceeded :-

The total sulphate content (as SO 3 ) of any mix, including any present in the other materials, shall not exceed 4% by weight of cement in the mix.

-

The total chloride content (as chloride ion) of any mix, including any chloride present in the other materials, shall not exceed 0.6% by weight of cement in the mix for mass concrete, 0.3% for reinforced concrete made with ordinary and moderately sulphate resisting Portland cement, and 0.2% for reinforced concrete made with sulphate resisting Portland cement.

The properties of the aggregates shall be such that the drying shrinkage when prepared and tested in an approved laboratory shall not exceed 0.05% unless the Engineer relaxes this requirement to suit practical supply constraints. It should be noted that this test involves a testing period of about eight weeks. The Contractor shall produce evidence that aggregate sources do not contain material that is potentially reactive to alkalis. (This requirement may be waived by the Engineer where the source is well established and the aggregate is well proven in Bahrain). D1.5.3

Fine Aggregates Except where otherwise approved on the basis of evidence of acceptable performance in concrete, the grading of a fine aggregate, or of a combined fine aggregate, shall comply with the limits in BS 882. Fine aggregates shall be natural sand, manufactured crushed rock sand, or a combination of both. The Contractor shall note that the term “manufactured crushed rock sand” does not include crushed rock fines which are by-products of coarse aggregate production. A combination of natural sand and manufactured crushed rock sand will only be permitted where the two materials are separately batched and where each material separately complies with the requirements of this Specification. In addition the evidence of full scale comparative site trials shall clearly demonstrate that a combined fine aggregate provides improved concrete in relation to the use of either material as a sole fine aggregate. The organic content of fine aggregate shall be determined in accordance with ASTM C40. The Engineer will decide on the basis of trial mixes whether a failure to meet the limits suggested in ASTM C40 is sufficient grounds to reject the sample.

D1.5.4

Coarse Aggregate Coarse aggregates shall be either crushed gravel or crushed rock which shall be prepared as single sized aggregates and blended at the time of mixing to produce the required nominal grading. Where an aggregate comprises a mixture of natural and crushed material the proportion of natural (uncrushed) particles shall not vary by more that + 10% from the proportion contained in the aggregates used in those full scale site trial mixes which are subsequently approved.


Page D-7 of 47


D1.5.5

Specifications

Aggregates for Heavy Duty Concrete Floor Finishes (Granolithic Concrete) Aggregates for heavy duty floor finishes (granolithic concrete) shall comply with the requirements of BS 882 except as modified by Clauses D1.5 to D1.5.4 and other requirements of this Specification. They shall be suitable for a wearing finish and selected for hardness, surface texture and particle shape. The aggregates shall consist of crushed rock with a 10% fines value of not less than 150kN. They shall not contain deleterious substances such as clay, flaky, elongated or laminated particles, inorganic impurities, iron pyrites or soluble salts.

D1.5.6

Aggregate Grading All aggregates shall be produced to the grading limits in BS 882. These are reproduced in Tables D2, D3 and D4 for convenience. Grading shall be consistent for all deliveries and the proportion of coarse and fine aggregate shall be selected to comply with the requirements of Clause D2 (Concrete Mixes). For concrete Grades C45/20 and C40/20 the coarse aggregate shall be graded from 20mm to 5mm and be produced by a combination of single size grading. For blinding grade and mass concrete the coarse aggregate may be either an all-in grading or a combination of single size grading. For heavy duty concrete floor finish the aggregate shall be produced by combining coarse and fine grading or by using an all-in grading.


Page D-8 of 47


Specifications

TABLE D2 Grading of single sized aggregates Percentage by mass passing BS sieve for nominal sizes

(1)

Sieve size (mm)

40mm

20mm

14mm

10mm

5mm (1)

50.0

100

-

-

-

-

37.5

85-100

100

-

-

-

20.0

0-25

85-100

100

-

-

14.0

-

-

85-100

100

-

10.0

0-5

0-25

0-50

85-100

100

5.0

-

0-5

0-10

0-25

45-100

2.36

-

-

-

0-5

0-30

Used mainly in precast concrete.


Page D-9 of 47


Specifications

TABLE D3 Grading of Aggregate for Concrete Percentage by mass passing BS sieve Coarse (1) Aggregate

Fine Aggregate (2,4) Overall Limits

All in (3)

Sieve Size (mm)

Nominal size 20mm - 5mm

Additional Limits for grading

37.5

100

100

20.0

90-100

95-100

14.0

-

-

10.0

30-60

100

-

5.0

0-10

89-100

35-55

2.36

-

60-100

60-100

65-100

80-100

-

1.18

30-100

30-90

45-100

70-100

-

microns 600

15-100

15-54

25-80

55-100

10-35

300

5-70

5-40

5-48

5-70

-

150

0-15(5)

C

M

F

Nominal size 20mm

0-8(6)

Notes (1) From BS 882 Table 4 (2) From BS 882 Table 5 (3) From BS 882 Table 6 (4) In addition to complying with the overall limit, not more than 1 in 10 consecutive samples shall have a grading outside of any one of gradings, C, M or F. (5) Increased to 20% for crushed rock fines except when they are used for heavy duty floor finishes. (6) Increased to 10% for crushed rock fines.


Page D-10 of 47


Specifications

TABLE D4 Grading of Aggregates for Heavy Duty Concrete Floor Finishes (Granolithic Concrete) Percentage by mass passing BS sieve Sieve Size (mm)

Coarse (1) Aggregate 10mm single nominal size

Fine Aggregate (2,4) Overall Limits

C

All in (3) M

10mm nominal size

14.00

100

100

10.00

85-100

100

95-100

5.00

0-25

89-100

30-65

2.36

0-5

60-100

60-100

65-100

20-50

1.18

30-100

30-90

45-100

15-40

microns 600

15-100

15-54

25-80

10-30

300

5-70

5-40

5-48

5-15

150

0-15

0-8

Notes (1)

From BS 882 Table 4

(2)

From BS 882 Table 5

(3)

From BS 882 Table 6

(4)

In addition to complying with the overall limits, not more than 1 in 10 consecutive samples shall have a grading outside of either grading C or M.


Page D-11 of 47


D1.6

Specifications

Storage and Handling of Aggregates All aggregates shall be processed, transported, stockpiled, handled and batched such that they are not contaminated or otherwise affected adversely in either physical or chemical respects. Dense concrete or bituminous slabs shall be laid to cover all aggregate stockpile areas and shall extend to cover all surrounding areas where aggregates are likely to be discharged or handled. These areas shall be sloped to provide free drainage and kept swept clean to ensure that the aggregates are not contaminated by the adjacent ground through trafficking or otherwise and shall be sufficiently strong to withstand all trafficking for the duration of use. Shade shall be provided where required by the Engineer to keep the temperature of the aggregate down to a level suitable for concreting, see Clause D3.8. The Engineer may also require the aggregate to be cooled by spraying with mixing quality water in which case the Contractor shall ensure that the contaminant levels are not thereby increased. Windbreaks shall be provided where aggregates might suffer excessive contamination by windblown materials. Adequate stocks of tested and approved aggregates shall be maintained on site or at the source of supply to maintain continuity of work. The general or localised build-up of fines in aggregate stockpiles shall not be allowed and any material which, in the opinion of the Engineer, is so affected will be rejected. Any aggregates which have suffered segregation or contamination or which otherwise do not comply with the requirements of this Specification shall be rejected and removed from site. The Contractor may submit re-processed aggregates for approval. The Contractor may be required to carry out supplementary processing and/or effective washing of aggregate on site if:

D1.7

(i)

The aggregate producer’s methods do not satisfy the Engineer that the end products will consistently comply with the requirements of this Specification, or

(ii)

The aggregate suffers unacceptable changes either during handling, transportation or storage.

Steel Reinforcement This work shall consist of furnishing, fabricating and placing steel reinforcement bars of the grade, type, quality, size, shape and quantity designated, all in accordance with these Specifications. All reinforcement bars shall be of a deformed type in accordance with BS 4449, except that plain bars may be used where specifically required. Plain bars shall be in accordance with BS 4449. All steel reinforcement shall conform to the requirements of the Specifications for Deformed High Yield Steel Bars, Grade 460 Type 2 (ribbed bars), unless otherwise specified by the Engineer.


Page D-12 of 47


Specifications

Table D5 - High Yield Steel Reinforcement Bars – Compliance Requirements Test Method BS 4449: 1988, Grade 460 Property Bar Diameter 6mm 8mm 10mm 12mm 16mm 20mm 25mm 32mm 40mm 50mm Yield Stress (N/mm2) Tensile Stress (N/mm2)

Elongation, % (gauge length) Bend Test Rebend test

Mass per metre (kg) Minimum Nominal 0.202 0.222 0.369 0.396 0.576 0.616 0.848 0.888 1.508 1.579 2.355 2.466 3.681 3.854 6.029 6.313 9.420 9.864 14.719 15.413 Characteristic = 460 Absolute minimum = 428 Either: a) at least 10% greater than the actual yield stress, or b) between 5 and 10% greater than the actual yield stress, provided the actual yield stress is not less than the value determined using the formula A(2.1 – B) where A = 460 B = ratio of measured tensile strength to actual yield stress 12 minimum (5 x nominal size of test piece) 180o on former of three times the nominal size of the bar 45o on former of five times the nominal size of the bar. 23o return bend

Maximum 0.242 0.421 0.656 0.928 1.650 2.577 4.027 6.597 10.308 16.107

Test Results

Chemical Analysis Carbon %

0.25 max

Phosphorous %

0.050 max

Sulphur %

0.050 max

Mild steel where specified or called for shall be either deformed or plain bars complying with BS 4449 or any equivalent National Standard as directed and approved by the Engineer. Tying wire shall be No.18 gauge stainless steel wire or the equivalent BS specification for tying wire.


Page D-13 of 47


Specifications

Welded wire fabric shall be used as reinforcement for concrete where shown on the Drawings and as directed. Welded wire fabric shall conform to the requirements of BS 4483- Table 1. Testing of Reinforced Steel A. Testing shall be carried out on steel bars in accordance with BS 4449 unless otherwise specified here in and shall submit a compliance statement in accordance with the summary sheet attached. B. The following tests shall be carried out for each delivery of reinforcement. 1. 2. 3. 4. 5. 6. 7. 8. 9.

Cross-sectional area and mass Deformation/bond characteristics of deformed bars Tensile test Yield stress Elongation Bend test Re-bend test Chemical composition Carbon equivalent value

C. Testing frequency shall be in accordance with BS 4449. D. Test results for each bar size shall be submitted to the Engineer three (3) weeks before concrete work commences on site. E. Further tests may be called for when the source of supply of reinforcement changes in which case the cost of such extra testing will be borne by the Contractor. F. When any test results do not confirm to the relevant standard, the reinforcement steel shall be removed from the site and all costs resulting therefrom shall be borne by the Contractor.

D1.8

Storage, Cleaning and Protection of Steel Reinforcement All reinforcement storage shall be on wooden supports on a dense, impervious concrete or bituminous slab specially placed for the purpose. The slab or slabs shall be free from dust, sand, soil or other materials which may encroach on the area by reason of wind, vehicular or foot traffic or otherwise. These requirements shall apply equally to reinforcement bending and cleaning areas and to any prefabricated reinforcement storage areas. The concrete or bituminous slabs shall be constructed and fully completed before any reinforcement is delivered to the site. Prior to fixing and when not being handled all reinforcement shall be protected from the corrosive effects of windblown dust and dewfall by close wrapping with impervious sheeting or other approved method, and from any other detrimental effects. At the time of fixing, reinforcement shall be free from loose mill scale or rust scale, and shall not be contaminated by grease, dirt, oil, paint, soil, sulphates, chlorides or any other agency which may impair the bond or initiate or accentuate any reinforcement corrosion. This may be achieved by grit/sand blasting or other approved methods. Whatever method the Contractor proposes to use must be demonstrated as being capable of producing the reinforcement to the above standard. Before ordering reinforcing steel, the Contractor shall prepare bar bending schedules and submit them to the Engineer for his approval. Bar schedules shall show the weight of each


Page D-14 of 47


Specifications

bar, the total weight of each bar size and the total weight of bars, and bending diagrams for bars in accordance with BS 4466. The Contractor shall also provide and submit to the Engineer for approval any working drawings additional to the Construction/ Shop Drawings which may be found necessary for the production of bar bending schedules or for the completion of the Works. The Engineer’s approval of the Contractor’s working drawings and bar bending schedules shall in no way relieve the Contractor of responsibility for the correctness of such drawings or schedules. Steel reinforcement shall be bent accurately to the shapes and dimensions shown on the approved bar bending lists or drawings. Bars shall be bent round mandrels of the requisite diameter. Steel reinforcement shall be cut and bent in accordance with BS 4466. Cutting or bending by the application of heat is not permitted. Where fabric reinforcement is required to be bent it shall be done cold, either using a bending machine or swage blocks and hooks. Fabric reinforcement shall be cut to cover the areas detailed plus the following laps: a. Rectangular mesh: 450 mm for longitudinal members; 75 mm for transverse members. b. Square mesh: 300 mm in each direction. Welding of reinforcement shall only be permitted when approved in writing by the Engineer. If such approval is given then the workmanship shall be in accordance with BS 5135. The Contractor shall submit full technical details of his proposed procedures prior to seeking approval. Hot rolled high yield bars shall not be straightened or bent again, having once been bent. If the Engineer gives approval to bend mild steel reinforcement projecting from the concrete, the internal radius of bend shall not be less than four times the nominal size of the bar. Links, hoops, stirrups are generally to be bent round pins of the same diameter as the bars they are to embrace. Where however, such bars are less in diameter than twice the diameter of the link, the radius of the bend shall be equal to the diameter of the link. The number, size, form and position of all reinforcement shall, unless otherwise directed or authorised by the Engineer, be strictly in accordance with the approved Construction/ shop Drawings. Nothing shall be allowed to interfere with the disposition of the reinforcing bars. Lapping of the bars other than the lap splices shown on the Drawings should be avoided. The Engineer may approve certain lap lengths under special conditions. All lap lengths should comply strictly with the BS/ASTM specifications, namely Article 1.5.6. Clause "c". All intersecting bars shall be bound together with stainless steel wire with the ends of the wire turned into the main body of the concrete. Concrete cover blocks shall, unless otherwise directed, be used between the reinforcement and the bottom and sides of the forms to ensure correct placing and cover of the bars. The strength of such concrete cover blocks shall be not less than that of the main concrete. The reinforcement shall be assembled as dimensioned on the Drawings within tolerances appropriate to the structure. It shall be firmly held in position by wire ties and concrete blocks or other approved spacers designed to maintain the correct clear cover of concrete


Page D-15 of 47


Specifications

over steel reinforcement. They shall be as small as possible consistent with their purpose, and of a shape acceptable to the Engineer. Minimum cover to reinforcement shall be as specified. The position of spacers and their method of use shall be approved by the Engineer. No concrete or reinforcement shall be cut in any way except by permission in writing from the Engineer. Concrete cover blocks shall be manufactured to the same specification as the surrounding concrete, refer to Clause A2.7. When tested in accordance with the approved standard the water absorption shall not exceed 2% for samples up to the age of one month at the time of test. Wire cast in the block for the purpose of tying it to uncoated reinforcement shall be of stainless steel or epoxy coated wire and shall be rust and contaminant free. Spacers shall be of rust-proof material and shall not produce staining, or otherwise be detrimental to the concrete or steel. Nothing shall be allowed to interfere with the disposition of any member of the reinforcement and the Contractor shall take special precautions that it is not only correctly placed, but remains undisturbed during the placing and setting of the concrete, and that it has not been contaminated with release agent or any other substance which will prevent the best possible bonding of steel and concrete. With the approval of the Engineer mild steel reinforcement may be temporarily bent aside at construction joints. This shall be done with care to a minimum internal bending radius of 4 bar diameters and to avoid damage to the concrete during bending and restraightening. The bending of high yield bars and fabric reinforcement at construction joints is not permitted. The greatest care shall be taken to prevent any displacement or bending of the members of the reinforcement adjusted and temporarily fixed in position before commencement of the concreting. Reinforcement temporarily left projecting from the concrete at construction of other joints shall be adequately protected against displacement both during concreting and afterwards and shall not be bent out of position unless agreed by the Engineer's Representative. During the concreting competent steel fixer shall be in attendance to re-set any reinforcement inadvertently displaced. The Contractor shall in all cases request the approval of the reinforcement by the Engineer's Representative in sufficient time to allow an inspection to be made and shall not commence concreting until such approval is obtained. The period between the Contractor's request for approval and his intention to commence concreting shall not be less than one clear normal working day and the Engineer's Representative may require a longer period if, in his opinion, the reinforcement is of such complexity as to require it. Such approval shall not absolve the Contractor of his responsibilities under the Contract Concrete shall be placed not more than three days after commencement of fixing reinforcement which shall be covered at night and whenever it is not being worked upon. Where fixed reinforcement cannot be concreted for extended periods it shall be protected from windblown dust and dewfall by means of close wrapped polythene sheets or other approved methods. D1.9

Concrete Admixtures Concrete admixtures and cements containing additives shall not be used unless specified or approved by the Engineer in writing.


Page D-16 of 47


Specifications

Where not specified, approval will not be given unless the Contractor can demonstrate that there is a clear technical advantage resulting from their use which cannot be obtained by reasonable variation of the constituents of the concrete mix. Admixtures shall comply with one of the following standards, unless otherwise approved by the Engineer. a)

ASTM C494, ASTM C260, ASTM C1017: as applicable The Contractor shall provide at least the following technical data for each type of admixture. 1. 2. 3. 4. 5. 6. 7.

Solid content Specific gravity The typical dosage and the effects of under dosage and over dosage. The generic type(s) of the main active constituent(s) in the admixture Whether or not the admixture contains chloride Whether or not the admixture leads to the entrainment of air when used at the proposed dosage. Where more than one admixture is used simultaneously in the same concrete, details shall be provided on their interaction and compatibility.

When admixtures are used in the Works very strict control is to be maintained to ensure that the correct quantity of admixture is used at all times. The equipment to be used for dispensing and the method of incorporating the admixture in the concrete shall be to the approval of the Engineer. Dispensing equipment for admixtures shall be of an approved type. It shall be capable of controlling the measurement of varying quantities of admixture by amounts not exceeding +–5% of the required quantity. The equipment shall contain a fail safe device and a calibrated sight glass for visual checking of the measured quantity. Ability to draw-off liquid from the sight glass shall be provided. The equipment shall be regularly serviced and cleaned and to assist in this, the equipment shall be fitted with a flushing device. The range over which the equipment will operate within the required accuracy shall be clearly marked on the equipment Where approved or specified air entrainment agents, admixtures, waterproof powder or microsilica shall be used as a means of:       

b)

Increased workability of the concrete without increasing water/cement contents Controlled and limited retardation of setting Increasing concrete durability Reducing bleeding and associated settlement and cracking Increasing water proof properties Reducing heat of hydration Reducing water permeability Hydrophobic Pore Blocking Admixture

Where directed by the Engineer a hydrophobic pore blocking admixture based on Ammonium Stearates and Hydrocarbon Resin shall be used at no additional cost to the Employer. a) Admixture is to be added at a rate recommended by the manufacturer at the time of mixing. b) Manufacturer’s representative is to be present for all additions of the hydrophobic pore blocking compound to ensure correct dosage rates are used.


Page D-17 of 47


Specifications

c)

For self compacting concrete, hyperplasticisers and viscosity enhancing agents shall be used to provide necessary workability.

d)

Viscosity Enhancing Admixture The viscosity enhancing admixture having high workability and viscosity shall be used for making self compacting concrete that can become compact without vibration even with strongly reinforced structures. It shall be chloride free and compatible with all type of cement.

e)

Corrosion Inhibiting Admixture 1.

2.

3.

4.

The corrosion-inhibiting admixture shall be added in an aqueous solution form at batching plant and shall be specially formulated for Gulf area of hot weather. The manufacturers of this product shall be ISO 9001 and ISO 14001 certified. With the above certificates the manufacturer/supplier shall submit documented case histories. The corrosion inhibiting admixture product, when used in accordance with the manufacturer’s recommendations, shall impart changes to three important properties of concrete compared to similar concrete without the product. The changes are increased corrosion resistance (durability); no adverse effects on physical properties of concrete and effective even where corrosion is active. Corrosion inhibitor when used in accordance with the manufacturer’s recommendation, shall form a suitable alternative for compliance with design to the relevant sections of BS 1881, ASTM C1202-91, ASTM G109. The corrosion inhibitor shall comply with international standards such as ANSI / NSF standard 61 certification confirming the products compatibility with potable water. The corrosion inhibitor shall be incorporated into the mixing water for the purpose of determining the water cement ratio of the concrete. The corrosion inhibitor shall be added to all reinforced concrete works (piles, substructures & superstructures) In order not to effect the W/C ratio, the corrosion inhibitor dosage shall not exceed 1.0 lit/m3. The addition shall be made at the concrete plant.

f)

High Performance Concrete Superplasticiser based on modified Polycarboxylic Ether A high performance superplasticiser based on sulphonated melamine and naphthalene formaldehyde condensates at the time of mixing shall be used for ready mixed concrete for ‘precast units’. Normal dosage shall be as recommended by the product manufacturer.

g)

Anti-Washout Admixture Anti-washout liquid admixture specially developed for concrete placed under water shall be used for all ‘underwater concrete’. It shall have superior resistance to washout of cement and fines. The minimum dosage use shall be as recommended by the product manufacturer. Samples of proposed admixtures shall, if required, be submitted to an approved testing authority by the Contractor in order to ascertain its suitability for use in the Works. The test shall be carried out for the properties specified in Table D6. The cost of such admixtures or water proof powder or microsilica and polypropylene fibres shall be included in the cost of concrete and no extra payment shall be made if they are used. The proportions of cement, fine aggregate and water shall be


Page D-18 of 47


Specifications

determined by the Contractor before concreting commences and submitted together with mix design test results that are required by the Engineer for approval and the Contractor shall not commence concreting before such approval is given nor shall he alter or vary in any way the proportion of mix unless he submits fresh test results and mix proportions to the Engineer for approval. Mix design of all classes of concrete shall be verified by approved laboratory prior to approval by the Engineer. The approval by the Engineer of such mix designs does not in any way absolve the Contractor of any of the requirements of the Specifications. If two or more admixtures are to be used simultaneously in the same mix, they shall not be pre-blended before use and the required data shall be provided to asses their interaction to ensure compatibility. Table D6 – Testing Admixtures

D1.10

S.N o.

Uniformity Test

1.

Colour

Test Method & Requirements as per ASTM C494 –

2.

Settlement

–

3.

Specific gravity

4. 5. 6. 7.

Solid content pH Ash content Chloride content

Manufacturer’s value ±10% Ditto ±5% – – –

8. 9.

Chlorine content Alkali content

– –

10.

Infra-red Spectrum

11.

Air void characteristics

Essentially similar to manufacturer’s reference BSEN 480-11 as described in the standard

stated

Test method & Requirements as per BSEN 934 Similar to manufacturer’s description Not to exceed manufacturer’s limit Manufacturer’s stated value ±0.03 Ditto ±5% Ditto ±1 – BSEN 480 – Part10 <0.1% or less than manufacturer’s stated value <0.1% or Ditto BSEN 480-12 Manufacturer’s stated value Essentially similar to manufacturer’s reference BSEN 480-11 as described in the standard

Curing Compounds Liquid curing compounds for use on concrete shall comply with the following: (i)

Only products which have been proved to be effective through extensive use shall be proposed and manufacturer’s literature shall include the recent test certificates illustrating effective quality control and high curing efficiencies.

(ii)

All materials shall be supplied in the containers marked by the manufacturer with his name, date of manufacture, shelf life, pot life and instructions for handling and application.


Page D-19 of 47


Specifications

(iii)

The liquid shall contain a white or silver colour pigment in sufficient quantity to give a uniform colour when applied to the concrete surface.

(iv)

The liquid shall be of such chemical composition and consistency that it can be applied by an approved mechanical sprayer in fine spray to produce an even, uniform, impervious, continuous film within one hour of application which will not crack, peel or disintegrate within three weeks of application. The compound shall not be poisonous, odorous or explosive and shall not react chemically with cement.

(v)

curing compounds shall not be applied to surfaces to which further concrete or a surface finish is subsequently to be bonded.


Page D-20 of 47


D2

CONCRETE MIXES

D2.1

Definitions

Specifications

The following definitions are used in this Specification: 1. Design Mix A mix in which the Engineer specifies the strength required to ensure durability and sets the limits for aggregate size, cement content and water cement ratio. The Contractor or ready-mix manufacturer is responsible for the selection of the mix proportions. 2. Prescribed Mix A mix for which the Engineer specifies the proportions by weight and accepts the resultant strengths, provided the Contractor has produced a properly mixed concrete containing the constituents in the specified proportions. 3. Minimum Cement Content The lowest permitted mean mass of cement present in one cubic metre of fully compacted concrete. 4. Free Water / Cement Ratio The ratio by mass of free water to cement where free water is the water in the concrete mix in excess of that absorbed by the aggregates which is available for the hydration of the cement and for workability of the fresh concrete. 5. Moisture Content of the Aggregate This is the mass of free water in the aggregate expressed as a percentage of the mass of saturated surface dry aggregate and does not include any absorbed moisture. 6. Density of Fresh Concrete Mass of a quantity of compacted fresh concrete divided by its volume expressed in Kg/m3. 7. Characteristic Strength The value of compressive cubes strength below which 5% of all possible strength measurements of the specified concrete are expected to fall. 8. Governing Strength The value of average 28 days’ concrete cube compressive strength obtained from the approved trial mix 9. Mean Strength The mean strength of all the cubes tested. 10. Working Margin The difference between the characteristic strength and the mean strength. 11. Certified Average Alkali Content Certified Average Alkali Content means the average of 25 consecutive determination of equivalent alkali content carried out on samples each of which is representative of a days production. 12. Declared mean alkali content means the alkali content expressed as the sodium oxide(Na2O) equivalent, which is not exceeded without prior notice from the cement or additive manufacturer. 13. Guaranteed alkali content means the alkali limit expressed as the sodium oxide(Na2O) equivalent which the constituent material supplier guarantees will not be exceeded by any test result on any spot sample. 14. “Cementitious Materials” shall mean cement or cement plus GGBS, or cement plus GGBS plus Microsilica or cement plus water proof powder. 15. “Admixtures” shall mean a material other than water, aggregate, cementitious materials or fiber reinforcement, used as an ingredient of concrete or mortar. 16. “Hot weather” shall mean when the shade temperature is above 40oC on a rising thermometer or 43oC on a falling thermometer. 17. “Coarse Aggregate” shall be considered as that size predominately passing a 28mm sieve and predominately retained on a 5mm sieve. 18. “Fine Aggregate” shall be considered as that size predominately passing a 5mm sieve and predominately retained on a 0.075mm size.


Page D-21 of 47


19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29.

Specifications

“OPC” shall mean ordinary portland cement. “SRPC” shall mean sulphate resisting Portland Cement “MSRPC” shall mean moderate sulphate resisting portland cement. “GGBS” shall mean ground granulated blastfurnace slag. “MS” shall mean Microsilica. “Gap-graded aggregate” shall mean graded aggregates without one or more of the intermediate sizes. “Single-sized Aggregates” shall mean aggregates containing a major proportion of particles of one size. “Target Mean Strength” shall mean the specified strength plus the margin. ‘Acceptable or Accepted” shall mean acceptable or accepted by the Engineer. “Approval or approved” shall mean approval from the Engineer or approved by the Engineer. “All-in” aggregate shall mean the materials composed of a mixture of coarse aggregate and fine aggregate. Glossary Air entrainment

:

Autogenous healing

:

Bleeding

:

Blended cement

:

The intentional incorporation into a concrete mix by means of an admixture, of minute discrete bubbles of air typically less than 0.3mm (300 microns). The natural sealing of a crack in concrete by siltation together with further hydration of cement or by the deposition of calcium hydroxide with consequent conversion to calcium carbonate. The phenomenon of water migrating to the surface of fresh concrete due to settlement of particulate materials. See Composite cement.

Cohesiveness

:

The degree to which fresh concrete resists segregation.

Cold joint Cold weather concreting

:

Compressive Strength Class

:

Compactibility

:

Cement content

:

Composite cement

:

Combination

:

Consistence Core

:

Creep

:

Curing

:

Curing Initial

:


Plane of weakness caused by interruptions to placing which results from new concrete being cast against unprepared stiffened concrete. Cold weather placing and finishing concrete when air temperatures are below 5°C or when freezing is likely to occur soon after concreting Classification comprising the type of concrete, the minimum characteristic 150mm cube strength and the 150mm dia x 300 mm cylinder strength. The ease with which the entrapped air in concrete can be expelled. Mass of cement contained in a cubic metre of fresh, fully compacted concrete expressed in Kg/m3. A cement or combination containing two or more main constituents, one of which is Portland cement, mixed at a cement works or at a ready-mix plant or on site. Restricted range of Portland cement and additions which having been combined in the concrete mix. The resistance to flow of fresh concrete The innermost part of a (thick) concrete section which is generally unaffected by external ambient temperatures. The continuing deformation of concrete under sustained stress. The action of preventing or minimizing the loss of moisture from fresh concrete and maintaining a satisfactory temperature so that desired properties may develop. Deliberate action taken between placement and final finishing Page D-22 of 47


Specifications

Curing final

:

Evaporation Reducer

:

Design Chemical Class (D,C Class)

:

Drying shrinkage

:

Early age thermal contraction

:

Finishing

:

Fresh concrete

:

Hardened concrete

:

Heat of hydration Hot weather concreting

:

Joint construction Joint movement

: :

Laitance

:

Matrix

:

Minimum cover Mobility Nominal cover

: : :

Placing

:

Plastic concrete Plastic settlement cracks Plastic shrinkage cracks Restraint

: :

Re-tempering

:

Rheological Segregation

: :


: :

of concrete to reduce the loss of moisture from the surface of the concrete. Deliberate action taken between the final finishing and termination of curing. A material that generates a continuous thin film when spread over water on the surface of fresh concrete and thus retards the evaporation of bleed water. Designations used to describe a concrete quality capable of resisting the selected aggressive chemical environment for the concrete The long-term reduction in size of a concrete element caused by the loss of water upon drying. The reduction in length of a concrete element caused by its cooling from the elevated temperatures developed during hydration of the cement. Mechanical operations carried out on the surface of placed concrete to achieve the required texture, appearance and serviceability. Concrete which has insufficient reaction between the cement and water to exhibit significant mechanical properties. Concrete which exhibits mechanical properties as a result of the reaction of cement and water Heat generated by the chemical reaction of cement and water. Placing and finishing concrete when the shade temperature is above 40oC on a rising thermometer or 43oC on a falling thermometer and the combination of temperature and humidity is such that the quality of fresh or hardened concrete may be impaired unless preventive measures are taken. A monolithic joint with no provision for movement. A joint formed or induced to allow movement to occur with one or more degrees of freedom A layer of cement and fine sand with excess water content on top of concrete The part of concrete which is composed of cement paste and sand. Cover to reinforcement assumed for the purpose of durability The ease with which fresh concrete can be made to flow. Cover to reinforcement shown on the drawings comprising the minimum cover plus a tolerance ∆c to accommodate fixing precision. All operations necessary for introducing the fresh concrete into form work or other enclosures. See fresh concrete Cracks which form due to differential settlement of concrete while still in a fresh (plastic) state. Cracks which form because of excessive loss of moisture from concrete while still in a fresh (plastic) state Anything (internal or external) which prevents the free movement of concrete Addition of water and remixing of concrete to increase its workability Pertaining to the flow of concrete Loss of uniformity of fresh concrete mix due to separation of

Page D-23 of 47


D2.2

Specifications

one or more of the constituents of the mix. Sedimentation or the act of the heavy solid particles settling in fresh concrete. See Cohesiveness. Time beyond which reworking of concrete would be detrimental.

Settlement

:

Stability Stiffening time

: :

Tensile strain capacity Transporting

:

The tensile strain at which a concrete will crack.

:

The conveying of fresh concrete from the point of discharge from the mixer to the point of discharge into the form work or other enclosure

Warping

:

Consistency

:

The distortion of a slab caused by temperature or moisture gradients across the depth of section. The rheological properties of fresh concrete influencing the ease with which it can be placed, compacted and finished

General Except where otherwise required by BS 5337 or as otherwise specified herein, concrete shall comply with the recommendations contained in BS 8110 or such modifications as may be agreed with the Engineer. All below ground concrete structures are to be tanked as a protection from the aggressive groundwater both below the ground water table and in the capillary zone above. 





 



The concrete mix for water retaining structures shall be designed to achieve the structural performance level to “HIGH” as given in the table ‘5’ of BRE Special Digest No.1 part 3: 2003 and Table A-3 of BS8500-1:2002.It shall also be watertight as described in BS 8007. Concrete to be used in aggressive ground shall be designed as recommended in Part 2 of BRE Digest No.1Part 2 and 3 and for precast products it shall be as specified in Part 4 of BRE Digest No.1. The choice of cement to be used for underground structures shall depend on the sulphate and chloride concentrations in ground water and the soil. The tenderer shall consider in his offer the sampling and testing of soil and ground water in accordance with BS 5930. The concrete mix is to be designed after assessing the classification of aggressive ground conditions at site. (Refer BRE special DigestNo.1and CIRIA guide recommendation). The chemical classification of the site is to be decided after considering step No.1 to 5 specified in BRE Digest No.1:2003 Part I cl:6. The choice of constituent materials of concrete and its limitations given in BS 8007:1987 BRE Digest No.1 and BS 8500:2002 are to be taken into consideration to satisfy the structural performance level of buried concrete (Ref. Section ‘6’ of BS 8007 and BRE Digest No.1:2003 part 1-4). The qualities of concrete that are required to resist chemical attack shall be as recommended in CL 4 to 6 of BRE Digest No.1:2003 Part 2. Usage of fibrillated polypropylene fibres in concrete may reduce the rate and amount of bleeding as well as the effect of plastic settlement cracks in concrete. Therefore where approved/ or use by the Engineer fibrous concrete shall be designed as stated in the mix design specification. Controlled Permeability formwork(CPF) on structural concrete shall be used a) To prevent loss of fines from concrete during Vibration. b) To evacuate the excessive air from concrete, avoid air voids on concrete surface and improve the surface quality (Ref. CIRIA guide CL 15.5.4 and 17.6.3) c) To substitute an insulation layer on external concrete surface to control the in situ concrete temperature gradient and concrete surface temperature.


Page D-24 of 47


Specifications

d) To increase the concrete surface and wear resistance. e) To decrease the ratio of chloride penetration, water penetration and carbonation effect. f) For textured surface finish to avoid sand blasting before painting and to acquire an ideal substrate base. g) To reduce bacterial and algae growth due to dense surface without cracks and blow holes. Unless otherwise indicated on the Drawings all concrete shall be Grade C45/20. All concrete below ground will be protected in accordance with Section G. Whether ready mixed or site batched, designed or prescribed, all concrete shall be dense, durable and in accordance with either Table D7 or D8. D2.3

Ready Mixed Concrete The Contractor may use ready-mixed concrete from an approved source with the written authorisation of the Engineer. Ready-mixed concrete and all constituent materials shall conform to this Specification.

D2.4

Mix Design Constraints All design mixes shall comply with the following constraints. TABLE D7 Concrete Design Mixes Grade

C60/20*

Nominal Max. Aggregate Size (mm)

20

Cement Content Kg/m3 of Finished Concrete

Max Free Water Cement Ratio

Characteristic Cube Strength N/mm2 28 days

Min.

Max.

400

500

0.35

-

C45/20

20

370

500

0.42

45

C40//20

20

350

500

0.45

40

Blinding

20

220

500

-

-

Heavy duty 10 420 500 0.42 floor finish Note:* Self compacting concrete for insitu piling works and concrete having congested reinforcement Characteristic strengths are basic mix strengths and do not allow for any reduction in strength due to the use of air entrainment agents. Air entrainment agents will be used only where specified.


Page D-25 of 47


Specifications

Air entrainment agents or other admixtures will not normally be approved for concrete having a water cement ratio exceeding 0.18. Only air entrainment agents based on vinsol resins will be approved. Where air entrainment is specified, the average air content by volume of fresh concrete (measured in accordance with BS 1881) shall be 5% for 20mm nominal maximum aggregate size. This will produce concrete having a strength approximately 70% that of non-air entrained concrete. If bleeding occurs in any trial mix it shall be assessed in accordance with ASTM C232 and where necessary the mix design or sand grading shall be adjusted to prevent recurrence. The mix proportions shall be adjusted to achieve the maximum density from the available materials. Unless otherwise agreed by the Engineer, the saturated surface dry density of fully compacted cubes shall be not less than 2350 Kg/m3 for those concrete for which air entrainment has not been specified. As a guide the Contractor should note that for nonair entrained concrete, Ras Al Khaimah aggregates and dredged sand normally achieve densities greater than 2450 Kg/m3, and local Bahrain aggregates and dredged sand normally achieve densities greater than 2390 Kg/m3. In-situ concrete shall be well compacted to a minimum of 98% of the density of the relevant cube strength. In general the actual cement content will need to be higher than the minimum value specified to ensure adequate workability and compliance with the maximum water / cement ratio. Mean strengths may exceed those required to achieve the characteristic strength in order to comply with the maximum water / cement ratio. The initial drying shrinkage of all the proposed concrete mixes, prepared and tested in an approved laboratory in accordance with BS 1881 shall not exceed 0.05%. It should be noted that the above involves a testing period of about eight weeks. Unless an alternative method statement is approved the workability of the concrete shall be measured by means of the slump test. The Contractor shall provide the apparatus as detailed in BS 1881 : Part 102. Under no circumstances shall a slump test be used as a means of monitoring water content and it shall be noted that for any concrete mix the slump will reduce with increasing temperature. Concrete mixes shall be designed such that the minimum workability at the time of placing is adequate to allow the concrete to be placed and compacted as specified. The workability at the time of placing shall be in the range 50mm to 100mm. In those situations where vibration of the concrete is difficult, the Engineer will not unreasonably withhold permission to use self-compacting concrete incorporating approved hyperplasticiser and viscosity enhancing agents. D2.5

Design Mixes

D2.5.1

General For guidance the Contractor’s attention is drawn to the ‘CIRIA Guide to Concrete Construction in the Gulf Region’.


Page D-26 of 47


Specifications

Where directed by the Engineer concrete mix designs which include an admixture shall have trial mixes prepared and tested both with and without the admixture to give a clear indication of its effects on the physical characteristics of the mix. The workability of the mix shall be the minimum necessary to allow satisfactory placing and compaction. (Refer to Clause D2.4). D2.5.2

Design Mixes for New Batching Installations A potential mix design shall first be subjected to preliminary testing on one batch. If this preliminary batch achieves cube strengths which exceed the characteristic strength by an acceptable margin (an assessment based on 7 day strengths may be accepted) at the specified free water cement ratio and produces concrete of the required workability and even consistency the mix may be prepared for trial mix analysis. If the batch fails the Contractor shall experiment with the mix proportions and submit another design. Trial batches shall be prepared under strictly monitored conditions in the presence of the Engineer. Materials shall be typical of the proposed supply and special care must be taken to record aggregate moisture contents and to determine the required free water content. Preferably full scale production equipment should be used - if circumstances make this impractical the batches may be mixed in a laboratory. Three separate trial batches shall be made using the proposed design mix. The temperature, workability and the fresh concrete density of the trial batches shall be determined and six cubes made from each batch, three cubes for testing at 28 days and a further three cubes for testing at 7 days as a quality control guide. Cubes for testing shall be submitted to an approved testing facility six days after they have been made. The proposed mix design will be accepted provided:

D2.5.3

i)

The plastic properties are compatible with the requirements of the Contract having due regard to bleed capacity and minimum workability necessary to allow placing and compaction as specified with the equipment proposed in any situation.

ii)

The specified free water/cement ratio is not exceeded.

iii)

The mean strength of the nine cubes exceeds the specified characteristic strength by not less than 10N/sq.mm.

Design Mixes from a Continuing Source For mixes proposed from a continuing source for which the necessary test results are available and for a batching installation which has been operated for a sufficient period to produce the required cube results the following procedure shall be adopted. The means strength calculated from ‘n’ cube results from separate batches of concrete shall exceed the specified characteristic strength by a margin equal to: 1.64 x SD (0.86 + 2 n½) Where: ‘SD’ is the standard deviation from ‘n’ results but not less than 3N/sq.mm. ‘n’ is the number of results not less than 10 and not greater than 100


Page D-27 of 47


Specifications

When ‘n’ exceeds 100, the margin shall be calculated as : 1.64 x SD Where ‘SD’ is as defined above. Previous production data for use in the above criteria shall be 28 day cube test results from separate batches of concrete sampled at random over an immediately prior period exceeding one month and not exceeding one year using materials and plant which are proposed for the Works. For new proposals to use a continuing source, such as a ready mix concrete supplier, a trial batch shall be prepared and tested to demonstrate compliance with the strength and workability requirements of this Specification.

D2.6

Prescribed Mixes for Minor Works Prescribed mixes shall only be used with the Engineer’s agreement and where isolated quantities of less than one cubic metre are required. They shall comply with Table D8 and be either site batched or supplied dry in bags ready for mixing with a set volume of water. Concrete shall not be hand mixed. TABLE D8 Prescribed Concrete Mixes Grade

Nominal Max. Aggregate Size mm

Fine Aggregate Content Kg/m3

Coarse Aggregate Content Kg/m3

Cement Content

20

650

1150

450

C30/20P

Weight requirements given are per cubic metre of compacted concrete. grading shall comply with Table D3 D2.7

Concrete Quality Control

D2.7.1


Kg/m3

Aggregate

A Materials Approval Statement shall be submitted for the proposed methods of controlling and recording the quality of concrete and shall include the following: (i) (ii) (iii) (iv) (v) (vi)

Cube strengths Workability (Slump) Density of fresh concrete Density of hardened concrete Temperature of mix during placing Climatic conditions during placing


Page D-28 of 47


Specifications

This information shall be recorded on a standard from, which must be submitted to the Engineer for approval. The Engineer will record the ease of placement, and the subsequent condition of the concrete after stripping of formwork. If the quality is unsatisfactory the concrete shall be repaired or replaced and the mix design or method of placing altered to prevent any recurrence of the problem. D2.7.2

Test Cubes Testing Plan A shall be the method used except where the Engineer directs the use of Testing Plan B. (i)

Testing Plan A A single sample shall be obtained from one randomly selected batch of concrete representing an average volume of not more than 20 m3 except that at least one sample shall be taken on each day for each grade used. From each sample a total of four cubes shall be made of which two are for testing at 7 days as a quality guide and two are for testing at 28 days.

(ii)

Testing Plan B Testing Plan B shall be used when directed by the Engineer and is for testing single batches of concrete and for those occasions where the Engineer requires assurance that concrete placed in a particular part of the Works is of adequate quality. A single representative sample shall be taken from each batch of concrete. Two cubes shall be made from the sample for testing at 28 days. Additional cubes shall be made from the same samples for testing at an earlier age as ordered by, or agreed with, the Engineer.

The rate of sampling may be varied by the Engineer to suit particular circumstances. Sampling and making of cubes shall be carried out in accordance with BS 1881. The samples shall, where practicable, be taken at the point of discharge. The Contractor is responsible for initial curing of the cubes to the requirements of BS 1881. As soon as is practicable between 3 and 6 days after the cubes have been made, all the cubes shall be submitted to the Ministry of Works, Power and Water. D2.7.3

Workability The workability of the concrete, both at the batching plant and the point of placement, shall be measured by means of slump tests. The mix design shall be adjusted, if necessary, within the approved design limits until the workability of the concrete is suitable for that particular category of concrete and is accepted by the Engineer.


Page D-29 of 47


D2.7.4

Specifications

Density The density of the fresh concrete shall be recorded by the Contractor. The average density of the two cubes crushed at 28 days will be used to determine the average cube density.

D2.7.5

Temperature The temperature of the concrete shall be measured and recorded by the Contractor at the batching plant and at the point of placement, (Clause D3.8 refers). A thermometer complying with the requirements of BS 1704 or other approved temperature measuring devices shall be used.

D2.7.6

Climatic Conditions Maximum, minimum and wet bulb shade temperatures shall be recorded daily by the Contractor.

D2.7.7

Compliance Requirements Compliance with characteristic requirements shall be based on the compressive strength of the cubes crushed at 28 days. For test plan A (see Clause D2.7.2): the average strength of the two 28 day cubes made from each sample shall be called a “test result”. If the test results from any four consecutive test results and any individual test result provide the strength margins indicated in the table D9 the concrete shall be deemed to comply with the characteristic strength requirements. In the case of small or new works where there are less than four test results, the first two or first three test results and any individual test result shall be considered.

TABLE D9 Concrete Strength Compliance Requirements Test Result

The average test result shall exceed the specified characteristic strength by at least:

Any individual test result shall not be less than the specified characteristic strength minus:

First 2

1 N/mm2

3 N/mm2

First 3

2 N/mm2

3 N/mm2

any consecutive 4

3 N/mm2

3 N/mm2


Page D-30 of 47


Specifications

If the range of individual cube strengths made from one sample exceeds 15% of their mean, then the method of making and curing the cubes shall be reviewed. If the range of individual cube strengths made from one sample exceeds 20% the result shall be considered unacceptable. The 7 day cube strengths shall be used as a quality guide only and may not be extrapolated to represent 28 day cube strengths for compliance purposes. Comparison with 7 day cube strength from the trial mixes will give an indication of the quality of a sample. If due to exceptional circumstances concrete is placed at a mix temperature of more than 30° C the Contractor may, notwithstanding compliance of the concrete with the strength requirements, be required to carry out field tests and/or further laboratory tests to allow the Engineer to determine any structural implications. For test plan B (see Clause D2.7.2) compliance with the characteristic strength will be assumed only if both the following conditions are met: (i)

The average strength determined from any sample exceeds the specified characteristic strength by 3N/sq.mm.

(ii)

The strength determined from any single result is not less than specified characteristic strength minus 3N//sq.mm.

D2.7.7.1 Non-compliance If cubes fail to comply with the foregoing requirements or if a series of cube results suggests an inconsistency in batching or quality of materials the Engineer may require the associated concrete to be cut out from the works and replaced and may also withdraw his approval of the design(s) of the concrete mix(es) or of the batching equipment. The Contractor may be instructed to carry out field tests and/or further laboratory tests to allow the Engineer to determine any structural implications.


Page D-31 of 47


Specifications

D3

FORMWORK AND CONCRETING PRACTICE

D3.1

Blinding Concrete (Sealing Coat) Immediately following the hand excavation to formation level for floors or foundations where shown on the Drawings or as ordered by the Engineer a sealing coat of blinding concrete shall be placed on the surface of the formation and carefully spade finished to an even surface. Utmost care shall be taken to preserve the natural water content of the ground below formation level as far as possible. Should the ground be exposed to the weather by delay on the part of the Contractor in placing the blinding and become wetter or drier than its natural state the Contractor shall excavate such ground as may be affected and replace it with concrete of the same grade as the blinding. Floors of foundations shall be laid on the blinding as soon as may be practicable, this being especially important during hot weather. If required by the Engineer the blinding shall be kept thoroughly damp by watering.

D3.2

Formwork Formwork is defined as the casing into which concrete is poured and its supporting falsework. It shall be designed and constructed so that the concrete can be efficiently placed and compacted without displacing or deforming the reinforcement. It shall be firmly supported, braced, guyed or tied back so that is stable against vertical and horizontal forces. It shall be capable of adjustment and sufficiently strong not to distort significantly by the pressure of the concrete or by other loads and influences. Ties shall be of types that do not produce holes completely through the concrete and any permanently embedded metallic parts shall not be nearer the finished surface than the cover to the reinforcement. Cover blocks and spacers shall be designed to maintain the correct clear cover of concrete over steel reinforcement. They shall be as small as possible consistent with their purpose, and of a shape acceptable to the Engineer. Minimum cover to reinforcement shall be 50mm unless otherwise detailed. Concrete cover blocks shall be manufactured to the same specification as the surrounding concrete. When tested in accordance with BS 1881 Part 122 the water absorption shall not exceed 2% for samples up to the age of one month at the time of test. Wire cast in the block for the purpose of tying it to the reinforcement shall be of annealed soft iron and shall be rust and contaminant free. Spacers shall be of rust-proof material and shall not produce staining, or otherwise be detrimental to the concrete or steel. Joints in the formwork shall be close fitting to prevent leakage. Temporary openings shall be provided, if necessary, for cleaning and inspection. The arrangement shall allow for removal of formwork from the sides of members without disturbing soffit formwork. Rough-faced formwork (Grade II) may be used only for surfaces which are normally never exposed to view. Where such surfaces are to be tanked, by covering with paint or sheeting, the formwork shall be capable of achieving a finish suitable for the proposed tanking. Excavation support timbering may not be used as formwork.


Page D-32 of 47


Specifications

Fair faced formwork (Grade I) shall be used for surfaces of concrete which will be exposed to view or to liquids. It shall be constructed from material of sufficiently high quality to produce a smooth concrete surfaces of uniform texture and appearance without visible imprint of grain or steppings or ridges. Where lined the same type of lining shall be used throughout any one structure. If the use of metal faced formwork is proposed details shall be submitted to the Engineer for approval prior to use. Metal forms shall be insulated to prevent excessive temperature fluctuations at the concrete surface. If movement or deflection of the formwork or loss of liquid occurs, and if the Engineer so directs, the Contractor shall cut out and replace the concrete supported by such formwork at his own expense. Formwork shall be used for upper inclined surfaces of concrete where the slope is greater than 30° to the horizontal. Formwork shall be designed so that splays, fillets, chamfers and projections are cast as the work proceeds. The Drawings, particularly those prepared to small scales, may not detail chamfers but unless specifically deleted all external angles on exposed concrete shall have a 25mm by 25mm chamfer. Before placing the concrete all extraneous matter shall be removed from the interior of formwork. All faces of formwork against which concrete is to be placed shall be carefully cleaned and treated with an approved non-staining chemical release agent to prevent adhesion of the concrete. Care shall be taken to ensure that the reinforcement is kept free from the release agent and that any excess is removed from the forms and that wind blown dust does not adhere to any surface. The surface temperature of the reinforcement and formwork shall not exceed the temperature of the concrete at the time of placing. The Contractor shall provide facilities for examination of the formwork after its erection and before concrete is placed and shall give 24 hours notice to enable the Engineer to examine the formwork if he so wishes. The Contractor shall place concrete only after obtaining approval from the Engineer but this shall in no way relieve the Contractor of any of his responsibilities under the Contract. D3.3

Tolerances and Finishes for Concrete Surfaces Unless tolerances for particular surfaces are specifically shown on the Drawings they shall be as follows :-

D3.3.1

Tolerances for Exposed Surfaces (Note: For the purpose of this clause, “exposed surfaces” includes those with RTR or PVC liners). (i)

Floor and Roof Slabs The level of the surface at any point shall be within plus or minus 5mm of the level derived from the Drawings. There shall be no abrupt irregularities.

(ii)

Walls The position of the face at any point shall be within 10mm of its position derived from the Drawings. There shall be no irregularity exceeding 3mm in a 3m template.


Page D-33 of 47


Specifications

The level at any point on the top of the wall shall be within plus or minus 3mm of the value derived from the Drawings. (iii)

Beams and Columns The position of each face at any point shall be within 3mm of its position derived from the Drawings.

(iv)

Measuring flumes Any point on the invert of the flume channel shall be within plus or minus 2mm of the level derived from the Drawings. The width of the throat at any cross section shall be within plus or minus 2mm of the required width and the surfaces shall be smooth.

(v)

Weirs Any point on a weir shall be within plus or minus 2mm or the level derived from the Drawings and the surfaces shall be smooth.

D3.3.2

Tolerances for Unexposed Surfaces Tolerances are not specified but thicknesses shall subject to Engineers approval.

D3.3.3

Surface Finishes Exposed concrete finishes shall comply with the following: (i)

General There shall be no abrupt irregularities or visible surface imperfections.

(ii)

Concrete roads Surfaces shall have a brushed or tamped finish with float finished edges.

(iii)

External walkways Surfaces shall be float finished and then except for margins at exposed edges, slightly roughened by brushing to produce an even textured surface.

(iv)

Concrete floors and tops of walls Surfaces shall be steel float finished to be uniform and smooth.

The surfaces of walls and other exposed surfaces cast against formwork that will be exposed to view or to liquids shall be rubbed down smooth in an approved manner within three days after formwork has been removed. After inspection by the Engineer any holes shall be filled with matching cement mortar. D3.4

Bending, Placing and Fixing of Reinforcement Unless otherwise specified laps, hooks and bends shall be to the dimensions detailed in BS 4466. The Contractor’s attention is drawn to the following general requirements: (i)

Lapped joints shall not be less than forty times the diameter of the bar unless approved by the Engineer in writing on the basis of design calculations submitted by the Contractor


Page D-34 of 47


Specifications

(ii)

Hooks shall be semi-circular with a straight end length of at least four bar diameters beyond the curve.

(iii)

Internal bend diameters shall be at least four bar diameters for mild steel and six bar diameters for high yield steel.

All bending shall be done before the reinforcement is placed in position and no heating or welding will be allowed. Where fabric reinforcement is required to be bent, it shall be done cold, either using a bending machine or swage blocks and hooks. Fabric reinforcement shall be cut to cover the areas detailed plus the following laps: (a)

Rectangular mesh

(b)

Square mesh

- 450mm for longitudinal members - 75 mm for transverse members - 300mm in each direction

The reinforcement shall be assembled as dimensioned on the Drawings within tolerances appropriate to the structure. It shall be firmly held in position by wire ties and concrete blocks, or other approved spacers. Minimum cover to reinforcement shall be as per Clause A2.7 unless otherwise detailed. The position of spacers and their method of use shall be approved by the Engineer. No concrete or reinforcement shall be cut in any way except by permission in writing from the Engineer. Nothing shall be allowed to interfere with the disposition of any member of the reinforcement and the Contractor shall take special precautions that it is not only correctly placed, but remains undisturbed during the placing and setting of the concrete, and that it has not been contaminated with release agent or any other substance which will prevent the perfect bonding of steel and concrete. With the approval of the Engineer mild steel reinforcement may be temporarily bent aside at construction joints. This shall be done with care to a minimum internal bending radius of 4 bar diameters and to avoid damage to the concrete during bending and re-shaping. The bending of high yield bars and fabric reinforcement at construction joints if not permitted. D3.5

Formation of Holes for Fixing Where the Contract includes the formation of holes and pockets for the later building in of holding down bolts, other fixing devices, services and structural steelwork, boxes for the formation of such holes shall be adequately supported and preferably fixed rigidly to the main formwork. All holes shall be formed in positions to be detailed for the various items of machinery. Where a group of holes has to be formed for a number of bolts for fixing one item, the formers shall be securely fixed together before the concrete is poured around them. The boxes shall be suitably protected to avoid extraneous matter falling onto them. Refer also to Clause H2.2 (Fixing Metalwork and Machinery).

D3.6

Batching, Transporting and Placing of Concrete All concrete used on the Works shall be made at batching plants where quality can be monitored and controlled. Measurement of all the aggregates and cement shall be by weight. Allowance shall be made for the water content or absorption of the aggregates as appropriate.


Page D-35 of 47


Specifications

For this purpose the Contractor shall determine the moisture content of aggregates at least twice a day during continuous concrete production using an approved method. The quantity of water added to the mix shall normally be the target value determined from the trial mixes. If however, the moisture content of the aggregate varies from that of the trial mix aggregate, the quantity of water must be varied to maintain the true water content. The quantity of water for each batch shall be accurately measured by means of a calibrated device. Concrete shall be mixed with a machine of a type and size complying with BS 1305 and shall be used within 80-100% of its rated capacity unless otherwise approved. All plant and equipment used in mixing concrete shall be maintained in good working order and shall be kept clean and free of hard or partially set concrete. Each consignment of concrete dispatched from the batching plant to site must be conveyed in truck mixers or agitators and must be accompanied by a delivery certificate in duplicate stating: (i)

Grade of concrete and design slump

(ii)

Origin

(iii)

Time and date of mixing

(iv)

Temperature of mixing

(v)

Additives (if any)

(vi)

Cement type, cement content and water / cement ratio

(vii)

Mix code number

Each certificate must be countersigned by the Engineer or a member of his staff and one copy retained on site, prior to incorporation of the concrete into the Works. Such signature shall not constitute acceptance of the concrete. The following additional information shall be recorded by the Contractor and shall be supplied by him to the Engineer within 24 hours: (a)

Position in the structure where the concrete was placed.

(b)

Time of placing.

(c)

Whether test cubes were taken on delivery.

(d)

Slump on delivery.

(e)

Mix and ambient temperatures.

Concrete shall be conveyed to the place of final deposit as rapidly as possible after mixing, by methods which will prevent the segregation, loss or contamination of any of the ingredients. No additional water shall be added after the concrete has been discharged from the mixing plant, and the concrete shall be placed and compacted not more than two hours after mixing.


Page D-36 of 47


Specifications

Detailed method statements shall be supplied for the batching of concrete and for the methods of placement for each structure or type of structure including any proposals for the use of spouts, chutes or pumps as a means of transporting concrete. The concreting of a section of the work shall be continuous until it is completed and shall be carried out as quickly as possible. The concrete shall be deposited in regular courses and spread out in layers of not more than 500mm thickness and compacted with immersion vibrators used by properly trained and supervised operators. Concrete shall not be dropped into place from a height exceeding 2 metres. Vibrators shall penetrate the full depth of the layer of concrete and where the underlying layer is of fresh concrete shall enter and re-vibrate that layer to achieve effective knitting together. Vibrators shall not be allowed to remain in contact with the reinforcement or formwork. Over and under vibration shall be avoided and vibrators shall be withdrawn slowly to prevent void formation. Care shall be taken to compact the concrete fully around reinforcement but without causing displacement of the bars. Hand compaction will not be permitted. Sufficient vibrators shall be provided at each pour location to ensure that the concrete is fully compacted without delay. At least one reserve vibrator and power source shall be provided on site and not less than one reserve for every two in use at one time. Immediately before the mixing and pouring of concrete each day the necessary vibrators shall be started and tested to the satisfaction of the Engineer. Undue difficulty in starting a vibrator shall be sufficient grounds for rejection. External vibrators shall not be used without written approval. Concrete floors and inverts shall be cast in one layer except where otherwise specified or when written approval has been obtained to an alternative construction method. Care shall be taken to prevent men engaged in placing concrete from introducing foreign matter into the concrete from their footwear or in any other way and where concrete is placed directly against the surfaces of excavations any softened material shall first be removed. D3.7

Batching of Admixtures Where air entrainment agents or other admixtures are specified or approved they shall be added at the mixer. Unless alternative methods to the recommendations of the admixture supplier are approved the admixture shall be batched in solution in a portion of the mixing water by means of a mechanical batcher which is capable of dispensing the agent in quantities varying by not more than 5 per cent from the quantities required and in such a manner as to ensure uniform distribution of the agent throughout the batch during the time of mixing. The capability of the apparatus to achieve the required dosing and mixing requirement shall be demonstrated to the Engineer and the apparatus shall be checked each day before concrete mixing commences.

D3.8

High Temperature Concreting Concrete shall not be placed when the shade temperature exceeds 40°C. The temperature of batched concrete at time of placing shall not exceed 30°C.


Page D-37 of 47


Specifications

The recommendation in standard publications (see Section S) on hot weather concreting practice shall be followed. Measures shall be taken to provide cool concrete and cool concreting conditions in order to reduce workability loss, premature drying of concrete and the development of high temperatures and temperature gradients in placed concrete. Proposed measures must be described in method statements and may include:

D3.9

(i)

Painting white or silver all storage vessels, hoppers, pipes, walls or roofs which contain or convey aggregates, cement or mixing water.

(ii)

Shading and/or watering of aggregates.

(iii)

Removal of aggregates from stockpiles by techniques designed to avoid the direct use of surface aggregate.

(iv)

Use of iced mixing water or crushed ice.

(v)

Shading of concrete during and after placement.

(vi)

Provision of wind breaks.

(vii)

Night working.

Curing and Protection of Concrete Method statements for the curing of concrete shall comply with the following minimum requirements and shall propose effective means of preventing premature drying and the resulting effects of plastic shrinkage.

D3.9.1

Exposed Surfaces Exposed surfaces of concrete shall be completely covered with polythene sheeting within 20 minutes of placing and compaction and within two or three hours this shall quickly be replaced by wet hessian covered with polythene. Polythene sheeting may be temporarily removed for surface finishing where required. The hessian shall be kept damp continuously using water of the quality specified for concreting for a period of at least seven days or such longer period as the Engineer may direct. When air temperatures exceed 30°C in any part of the day or when lower temperatures in combination with high wind speeds are likely to lead to premature drying, the surface shall be sprayed with an approved curing compound after removal of hessian and polythene. Curing compounds may be applied earlier to supplement use of wet hessian and polythene. (Refer to Clause D1.10). In addition to the above measures, shading from direct sunlight and wind breaks may be proposed or may be required by the Engineer to give added protection.

D3.9.2

Formed Surfaces Formed surfaces shall be completely covered by wet hessian and polythene within half an hour of stripping the formwork and shall then be treated in accordance with Clause D3.9.1.


Page D-38 of 47


Specifications

Formwork shall be shaded and/or wetted to prevent high temperatures accelerating cure. For formed surfaces which are to be exposed, effective approved measures shall be taken to prevent concrete surfaces from drying out and to ensure adequate curing whilst rubbing down is taking place and before application of any approved curing membranes or other curing methods. D3.9.3

Tanked Surfaces External surfaces which are to be tanked with bituminous paints or bituminous membranes as specified in Section G may, for small structures, and with the written agreement of the Engineer, have these products applied in lieu of the above curing methods but shading or wetting may be required to control surface temperatures, particularly if the products are dark in colour.

D3.9.4

Damaged Concrete Measures shall be taken to prevent damage to concrete either in mass or on the surface during the period of setting and thereafter by shock, vibration, water or any other agent and no loads shall be placed on any structure without the prior permission of the Engineer. Any concrete which is damaged or deemed unsatisfactory due to inadequacies of constituents or any mixing, transporting, placing or curing methods shall be broken out and replaced.

D3.10

Striking Formwork Formwork shall not be struck until the structure has attained sufficient strength to carry its own weight, plus any constructional or other loads likely to come upon it, without excessive deformation. Also the concrete shall have matured sufficiently to resist physical damage. Formwork shall be struck in such a manner that no damage shall result to the concrete. Formwork shall not be struck except with the Engineer’s permission. The work of striking or removing such moulds, shuttering or centring shall be conducted only under the direct supervision of a competent foreman. The method statements for each structure shall include proposals for the methods and times for the striking of shutters. Table D11 is included showing the minimum intervals of time between the placing of concrete and the striking of shuttering at 16°C and above but these periods may be varied by the Engineer if environmental conditions make this permissible or desirable. Striking times shall not be less than 24 hours. Method statements may include proposals for different periods by reference to recognised standard publications on concreting practice. Where it is proposed to remove soffit shuttering in advance of props the method statement shall clearly indicate the sequence and means of dismantling the soffit shuttering with a view to maintaining adequate support. The Contractor shall be responsible for any injury to the work and any consequential damage caused by or arising out of the removal of the formwork. Any advice, permission or approval given by the Engineer relative to the removal and striking of the formwork shall not relieve the Contractor from the responsibility here defined.


Page D-39 of 47


Specifications

TABLE D11 Minimum Formwork Striking Times Type of Formwork

Beam sides, walls, columns and foundations

D3.11

Ordinary and Sulphate Resisting Portland Cement Concretes (surface temperature 16°C and above)

24 hours

Soffits to slabs (props left under)

4 days

Soffits to beams (props left under)

9 days

Props to slabs

10 days

Props to beams

14 days

Re-use Formwork Care should be taken, when re-using formwork, that its surface shall be smooth and clean and that it shall be free from warping, twisting or other deformations. Any formwork which has, in the opinion of the Engineer, deteriorated sufficiently to render it unsuitable for the work shall be rejected and must be removed from the Site within 48 hours or must be broken up at once, new formwork being provided at the Contractor’s expense.

D3.12

Heavy Duty Concrete (Granolithic) Screeds to Benching and Channels Heavy duty concrete screeds should preferably be placed and compacted within three hours of casting the base in which case the base concrete shall be left rough and the screed shall be spread and consolidated on to the whole of each bay or structure. Where this cannot be achieved the base concrete shall be cast with a rough surface. Weak surface laitance and any other contaminating material must be completely removed and the coarse aggregate cleanly exposed. This surface shall be thoroughly cleaned and then soaked overnight, any surplus water being removed. The surface shall then be brushed with a 1:1 sand/cement grout and the heavy duty concrete screed applied. The concrete shall be compacted and screeded to levels or falls with a screeding board and wood float. Further trowelling shall be done with a steel trowel after about two hours. The thickness of a surfacing where it is inclined at 45° or greater to the horizontal shall not exceed a nominal 15mm and if this is inadequate to complete the work the surface shall be left rough and keyed with a trowel. A further surfacing coat shall be applied within 24 hours.

D3.13

Cracks in Concrete Structures The filling of cracks will not be permitted unless approval is given by the Engineer in writing.


Page D-40 of 47


Specifications

D4

JOINTS IN CONCRETE STRUCTURES

D4.1

Classifications There are two classifications of joints in structural concrete.

D4.4.1

Movement Joints Movement joints are provided for expansion, contraction or flexibility. They are detailed in this Specification and on the Drawings. Where the positions of movement joints are not shown on the drawings, they shall be designed by the Contractor in accordance with the requirements of the Specification. All movement joints are required to be leak-proof. Expansion and contraction joints shall be formed as detailed in this Specification and on the Drawings. The Contractor shall ensure that there is no adhesion between the two concrete faces of the joint and that debris does not enter the joints. A bond breaker shall be incorporated into all expansion and contraction joints to prevent adhesion between the joint sealant and the filler in the case of expansion joints, and the base concrete in contraction joints. All jointing materials used in a particular joint shall be chemically compatible with each other and with their contact environment.

D4.1.2

Construction Joints Construction joints are provided for convenience of construction and, in some instances, to assist in the control of shrinkage cracking. Where the positions of construction joints are not shown on the Drawings they may be proposed by the Contractor to suit his methods of working. Construction joints are required to give monolithic construction and to be leak-proof. Method statements for the detailed design of construction joints shall generally comply with the following guidelines. Where practicable wooden battens of trapezoidal pattern shall be inserted in the face of the unfinished concrete at a construction joint, and later withdrawn, to form a continuous dovetail key. The surface of the previously poured concrete at construction joints must be clean and dry and all laitance and scum must be removed to show the tips of the coarse aggregate before the adjacent concrete is placed; where practicable the aggregate exposure is to be done by bush hammering, wire brushing or water jetting while the concrete is still green. Any defective concrete shall be removed before the adjacent concrete is cast. At horizontal construction joints the first layer of new concrete shall not exceed 150mm in depth and particular care shall be taken to prevent loss of fines from the bottom of the new lift. Where, in the opinion of the Engineer, the placing of concrete is interrupted long enough for the concrete to have hardened beyond acceptable workability limits, the surface of the unfinished concrete shall be treated as though it were a construction joint.

D4.2

Size and Sequence of Concrete Pours The Contractor shall include in his method statement for each structure his detailed proposals for the sequence of placing concrete and for the positions of vertical and horizontal construction joints not shown on the Drawings.


Page D-41 of 47


D4.3

Specifications

Water Bars Water bars shall be manufactured of extruded PVC or of nitrile rubber. They shall be of the types and general shapes indicated on the Drawings. They shall be obtained from experienced manufacturers and shall be to the latest shapes and forms generally adopted in the industry. Water bars shall comply with Table D12. TABLE D12 Waterbar Characteristics at 25°C Property

Rubber (BS 903)

PVC (BS 2782)

Density

1100 kg/m3 (+ 5%)

1300 kg/m3 (+ 5%)

Hardness

60-65 I.R.H.D.

70-75 I.R.H.D.

Softness Number

-

42-52

Tensile Strength

not less than 20 N/mm2

not less than 15 N/mm2

Elongation at Break Point

not less than 450%

not less than 285%

Water Absorption (48 hrs immersion)

not exceeding 5%

not exceeding 0.7%

Web Thickness

10mm

10mm

Centre Bulb Dimension

18mm

18mm

Rubber and PVC waterstops shall be suitable for storage, handling, installation and service within a range of 15°C to 50°C. Care shall be taken to prevent damage to water bars. Water bars shall normally include eyelets for fixing and shall not be nailed unless they incorporate a reinforced outer nailing flange. Water bars shall not be displaced during the placing of concrete which shall be fully compacted around them. Jointing of water bars shall normally be carried out by clamping and welding or adhesion and shall be in accordance with the recommendations of the manufacturer. Water bars shall be arranged so that there is a minimum distance of 25mm from the water bar to the reinforcement. D4.4

Bond Breakers Bond breakers shall be polyethylene tape, closed cell expanded polyethylene foam in flat strip or solid circular core section, or another approved material which is suitable for preventing short or long term adhesion between the sealant and the base material of the sealant groove.


Page D-42 of 47


D4.5

Specifications

Expansion Joint Fillers Unless otherwise shown on the Drawings joint fillers will be resin bonded cork to ASTM D1752-67 with the following minimum characteristics:

D4.6

Density

200 kg/m3

Maximum load to compress to 50% of original thickness

0.55 N/mm2

Recovery after compression

95%

Joint Sealing Sealant slots to expansion, contraction and, where included, construction joints shall be carefully constructed to the dimensions detailed on the Drawings, or, subject to approval of the Engineer, to the manufacturer’s recommendations. The Contractor shall take care to avoid spalling of concrete on the edges of slots. Slots to expansion joints may be formed by installing joint filler to the concrete surface and then using a special cutter to remove filler to the required depth. Alternatively, and for contraction joints, slots may be formed by pre-formed PVC or timber formers with sloping sides to assist removal. Before placing sealants, the slots must be thoroughly cleaned and all laitance and oil removed by an abrasive method. Immediately prior to sealing the slots, all loose surface debris, sand and dust must be blown out using compressed air, and the slots must be dry and free from collected rainwater etc. to ensure maximum adhesion. Bitumenised foamed polyurethane sealing strip shall be 9mm thick uncompressed. It shall compress to 25% of its original thickness under a load of 0.045 N/mm2. Hot poured joint sealants shall comply with the requirements of BS 2499 for Ordinary Type Al sealant. Cold poured polymer based joint sealants shall comply with the requirements of BS 5212 for Normal Type N sealant. Two part polysulphide based sealants shall comply with the relevant requirements of BS 4254. Pouring grade shall be applied to horizontal upward facing joints and gungrade to joints or any other aspect or inclination. Other two-part polymer-based sealants of gun or trowel grade shall comply with the physical and test requirements of BS 4254. Sealants must in all cases be carefully selected as appropriate for their climatic and environmental exposure and must, where appropriate, be resistant to bio-degradation. The Contractor must supply to the Engineer copies of written recommendation(s) and guarantee(s) from the manufacturer as to the suitability of the product(s) for each individual structure and for the methods of installation. Primers for use with joint sealants shall be compatible with, and obtained from the same manufacturer as, the adjacent sealant. Primers shall have no harmful effects on concrete. Where required by the Engineer masking tape shall be applied to protect the concrete surface on either side of the joint priming and sealing operations. Such masking tape must be carefully stripped away after joint sealing to leave neat edges to the seal.


Page D-43 of 47


D4.7

Specifications

Joint Bond Breaking for Contraction Joints and Sliding Joints Contraction joints to be sealed with polysulphide based sealants shall not have concrete faces painted with bituminous products due to reactivity. In such cases bond breaking shall be achieved by polyethylene tape or a plastic slip membrane. Sliding joints shall be formed with two layers of any approved plastic slip membrane 1mm thick.

D4.8

Bond Breaking Compound for Dowel Bars Bond breaking compound for dowel bars shall consist of a bitumen paint containing 66 per cent of 200 pen bitumen, blended hot with 14 per cent light creosote oil with the addition, when cold, of 20 per cent solvent naphtha. It shall in no way retard or otherwise affect the setting of concrete.

D4.9

Dowel Bars Dowel bars for expansion joints in concrete shall consist of mild steel complying with the relevant requirements of BS 4449. Dowel bars shall be straight, free from burred edges or other irregularities, and shall have their sliding ends sawn. The sliding half of each dowel bar shall be painted with a thin coat of bond breaking compound, and the end of this half shall be provided with a close fitting plastic or waterproof cardboard cap at least 100mm long, the end 20mm of which shall be filled with a disc of joint filler or a pad of cotton waste.


Page D-44 of 47


Specifications

D5

PRECAST CONCRETE

D5.1

Precast Concrete Production Details of the design of all precast units shall be submitted to the Engineer for his approval before manufacture. Precast copings shall be to BS 5642; precast concrete flags shall be to BS 368 and shall be hydraulically pressed; precast concrete kerbs and edgings shall be to BS 340. Precast concrete gullies shall comply with the relevant requirements of BS 5911: part 2. Precast concrete units, unless otherwise specified or ordered shall be constructed from Grade C45/20 concrete but the coarse aggregate shall be 10mm to 5mm. Precast units shall be either: (i)

Cast in vibrated moulds.

(ii)

Formed in hydraulically compressed moulds.

(iii)

Cast in a spun process.

(iv)

Cast in open moulds with approved compaction techniques.

In every process, the formwork shall be of adequate quality to produce a completely smooth finish. Curing methods shall be as specified in Clause D3.9. Units shall not be transported until they have matured under suitable conditions for a period of not less than 14 days. The units shall be so handled, stacked, stored and transported that they are not subjected to undue stress or damaged in any way and large units shall have suitable lifting holes or hooks incorporated into their design. No unit shall be built into the work until it has matured for 28 days. Units may be rejected if they have any of the following defects: (a) (b) (c) (d) (e) (f)

Broken edges Cracks (other than hair cracks) Repairs Misplaced reinforcement Honeycombing or air holes Finishes dimensions different from those specified or shown on the Drawings.

The Engineer may order extra precast units to be manufactured for testing to destruction. These units will be paid for if the tests show that they comply with the Specification.


Page D-45 of 47


D5.2

Specifications

Bedding Precast Concrete Units Precast concrete units, except where otherwise specified, shall be bedded and jointed in 1:3 cement mortar, each unit being firmly pressed into position and the joints flush pointed as the work proceeds. Where units are to be subjected to internal or external water pressure, mortar joints shall be completely watertight.

D5.3

Chamber Rings and Cover Slabs Precast concrete chamber and shaft sections and cover slabs shall all be to BS 5911:Part 2 and be constructed to the dimensions on the Drawings. Details of the design of all chamber cover slabs shall be submitted to the Engineer for his approval before manufacture. They shall be suitably protected internally and externally in accordance with Section G. Cover slabs shall be arranged so that they are supported ion the surround concrete and not on the chamber or shaft sections. The slabs shall be designed to support their own weight, imposed dead loads from any shafts, backfill and access covers and live loads based on individual wheel loads of 112kN.

D5.4

Precast Concrete Paving Slabs Precast concrete paving slabs shall be to BS 368 and shall be laid on 1:3 lime mortar using five pats not less than 150mm dia for each slab. They shall be laid at a level not exceeding 4mm above the top of the kerb or concrete edging. The joints shall be thoroughly cleaned out and grouted with cement mortar well brushed in and flushed off. No cracked or broken slabs shall be used.

D5.5

Precast Concrete Kerbs Precast concrete kerbs and edgings shall be to BS 340 and shall be hydraulically pressed. Kerbs shall be bedded true to line and level in cement mortar on a 150mm thick foundation of concrete Grade C15/20 and backed with concrete of the same grade. The foundation shall be laid before the approved sub-base is laid.


Page D-46 of 47


D6

Specifications

TESTING OF WATER RETAINING CONCRETE STRUCTURES This test shall, where practicable, be carried out before any backfilling and before the application of any external concrete protection has taken place. On completion of a water retaining structure, it shall be cleansed and made ready for testing for water tightness. The structure shall be filled with water at an approved rate. After allowing a period for absorption e.g. 3 days, the depth of water shall be recorded and the water allowed to stand for a period of 7 days during which the total permissible drop, after allowing for evaporation and rainfall, shall not exceed 1/500th of the average water depth of the full structure or 10mm whichever is the lesser. The Contractor, where required by the Engineer, shall provide a test tank for assessing the influence of evaporation and rainfall. Notwithstanding the satisfactory completion of the test, any seepage visible on the outside faces of the structure shall, where practicable, be carried out from the face that is to be subjected to water pressure under operating conditions. Method statements for all repairs shall be submitted to the Engineer for approval. In the event of any water-retaining structures failing to pass the test, the Contractor shall make good and re-test at his own expense.


Page D-47 of 47


Specifications

TABLE OF CONTENTS Page No. SECTION E - PIPELINES AND PIPEWORK E1

E2

4

PIPE AND PIPELINE MATERIALS

4

E1.1


4

E1.2

Definitions

4

E1.3

Pipes and Pipeline Components for Water Supply

4

E1.4

Classification of Pressure Pipes

4

E1.5

Pipe Classification & Pressure Rating

5

E1.6

Dimensional Requirements

7

E1.7

Marking of Pipes and Fittings

7

E1.8

Group A (Rigid) Pipes

8

E1.9

Concrete Pipes and Fittings

8

E1.10

Clayware Pipes and Fittings

8

E1.11

Pitch Fibre Pipes and Fittings

9

E1.12

Cast (Grey) Iron Pipes and Fittings

9

E1.13

Crushing Strengths for Group A (Rigid) Pipes

9

E1.14

Stiffness for Group B (Flexible) Pipes

10

E1.15

Thermoplastic Pipes

11

E1.16

Glass Reinforced Plastic (GRP) Pipes

12

E1.16.1

Definitions and Requirements

12

E1.16.2

GRP Pipe and Fittings for use in Gravity and Pressure flowsystems conveying Sanitary Sewage 14

E1.16.3

Compulsory Requirements Particular to Sewer Pipes, Couplers and Joints

17

E1.16.4

Type Tests for GRP Pipes and Joints

19

E1.16.5

GRP Pipe and Fittings for Pumping Stations and Valve Chambers

26

E1.16.6

GRP Pipes and Fittings for Irrigation and Potable Water Distribution and Transmission

27

E1.17

Ductile Iron Pipes

35

E1.18

Steel Pipes

38

E1.19

Stainless Steel Pipe

43

E1.20

Carbon Steel Pipe

51

E1.21

Mechanical Joints - General

56

E1.22

Flanged Joints for Iron and Steel Pipework

56

E1.23

Flange Gaskets

56

E1.24

Flexible Mechanical Couplings and Flange Adapters

56

E1.25

Flexible Joints - Sleeve and Integral Socket Types

57

E1.26

Elastomeric Joint Sealing Rings

58

E1.27

Lubricants for Joint Assembly

58

E1.28

Granular Materials for Pipe Bedding and Surrounds

58

E1.29

Selected Excavated Material for Pipe Bedding and Surrounds

60

E1.30

Maintenance of Quality

60

TYPE TESTING, ROUTINE TESTING, AND VISUAL INSPECTION OF PIPES


Page i of iii

62


E3

E4

Specifications

E2.1


62

E2.2

Visual Inspection Requirements for Group A (Rigid) Pipe & Pipeline Components63

E2.3

Not Used

64

E2.4

Type and Routine Tests for Metal Pipes

64

E2.5

Visual Inspection Requirements for Metal Pipes

65

E2.6

Type and Routine Tests for Thermoplastic and RTR/GRP Pipes

66

E2.7

Visual Inspection Requirements for Thermoplastic and RTR/GRP Pipes and Pipeline Components

71

E2.8

Holiday Detection Test

72

PIPELINE CONSTRUCTION

74

E3.1

74

Storage and Handling of Pipes

Glass Reinforced Plastic Pipes (GRP)

74

Thermoplastic Pipes (uPVC)

75

E3.2

Trench Widths for Pipelines - General Requirements

75

E3.3

Trench Widths for Flexible Pipes - Additional Requirements

76

E3.4

Pipelaying - General

77

E3.5

Not Used

78

E3.6

Welded Joints for Thermoplastic Pipes

78

E3.7

Pipelines with Concrete Beds and Surrounds

80

E3.8

Pipelines with Granular Beds or Surrounds

81

E3.9

Compaction of Granular Pipe Surrounds

82

E3.10

Pipelines Bedded on Trench Bottom

83

E3.11

Stanks to Pipelines with Granular Bedding

83

E3.12

Backfilling of Pipe Trenches

84

E3.13

Deformation Measurements on Flexible Pipes

84

E3.14

Thrust and Anchor Blocks in Pressure Pipelines

86

E3.15

Pipes Protruding from Structures

87

E3.16

Plastic Pressure Pipes Encased in Concrete

88

E3.17

Marker Posts for Water Mains and other Pressure Pipelines

88

E3.18

Cutting Pipes

88

E3.19

Flanged and Flexible Mechanical Joints

89

E3.20

Pipework within Structures - General Requirements

89

STRUCTURAL DESIGN OF PIPELINES

90

E4.1

General

90

E4.2

Polyethylene Pipes

90

E4.3 & E4.4 Not Used

90

E4.5

Steel Pipes

90

E4.6

Ductile Iron Pipes

91

E4.7 to E4.9 Not Used

92

E4.10

Design Requirements

92

E4.11

Loading Criteria

92

E4.12

Environmental Criteria

92

E4.13

Loading Combinations to be Considered

92

E4.14

Approved Calculation Procedures

93


Page ii of iii


E4.15 E5

Additional Structural Design Requirements

93

NON DISRUPTIVE METHOD (NDM) FOR PIPELINE CONSTRUCTION

94

E5.1

Scope of Work

94

E5.2

Related Work

94

E5.3

Design

94

E5.4

Submittals

94

E5.5

Quality Assurance

95

E5.6

Delivery Storage and Handling

95

E5.7

Site Investigation

95

E5.8

Health and Safety

96

E5.9

Skilled Operators and Supervision

96

E5.10

Pipe Materials

97

E5.11

Joint Packing

98

E5.12

Lubricant

98

E5.13

Joint Sealant

100

E5.14

Grout

100

E5.15

Thrust and Reception Pits

100

E5.16

Pipe Installation within Sleeves

102

E5.17

Microtunnelling

102

E5.18

Line and Level

103

E5.19

Thrust System

104

E5.20

Lubrication Holes

104

E5.21

Grouting

104

E5.22

Records

104

E5.23

Testing

105

E5.24

Monitoring Ground Surface Movement

105

E5.25

Tunnelling-General Requirements

106

E5.25.1 General

106

E5.25.2 Submissions

107

E5.25.3 Safety

107

E5.25.4 Control of Water

108

E5.25.5 Testing and Records

109

E5.26 E6

Specifications

Undertaking

110

INSPECTION AND TESTING OF PIPELINES

111

E6.1

Cleaning and Inspection of Pipelines

111

E6.2

Testing of Pipelines - General Requirements

111

E6.3

Testing of Non-Pressure Pipelines

111

E6.4

Testing of Pressure Pipelines

112


Page iii of iii


Specifications

SECTION E - PIPELINES AND PIPEWORK E1

PIPE AND PIPELINE MATERIALS

E1.1

General Requirements Pipes, fittings, specials and joints shall be manufactured to the approved national or international Standard and to the additional requirements of this Specification. All materials and workmanship shall be subject to the general requirements of Section B, of this Specification. Protective coatings and/or linings to be applied at the factory of the pipe manufacturer, or his sub-contractor, are generally specified in this section of the Specification. Coatings and linings to be applied on Site, or highly specialised factory coatings, are specified in Section G, or elsewhere in this Specification. All pipes in any particular length of pipeline shall be from a single manufacturing source and of uniform type and size.

E1.2

Definitions For the purposes of this Specification, the following definitions shall apply:

E1.3

"Pipes"

-

straight pipes with either plain ends or with an integral joint at one or both ends.

"Fittings"

-

all bends, branches, tees and similar items which are made to the requirements and dimensions in Standard Specifications or are included in manufacturers' standard ranges.

"Specials"

-

any pipework item which is not covered by Standard Specifications, or is not normally in manufacturers' standard ranges of items, or has any special features which render it different from the standard pipes and fittings.

"Joints"

-

any joint assembly or components to connect items of pipework together.

Pipes and Pipeline Components for Water Supply Pipes and pipeline components, including their protective coatings and joint materials, that will or may come into contact with potable water shall not constitute a toxic hazard, shall not support microbial growth, shall not cause taste or odour, cloudiness or discolouration of the water, and shall be approved by a recognised certifying authority as being suitable for use in potable water supply systems.

E1.4

Classification of Pressure Pipes Pressure pipelines shall be those pipelines through which fluid is pumped or which at any point operate under an internal pressure in excess of 3.0 metres head of water. Pressure pipes shall generally be designated according to their pressure rating. However since national and international standards, procedures and conventions do not all follow the same practice, the pressure ratings established under approved manufacturing standards will not necessarily be accepted as the basis for classification. The pressure


Page E-4 of 115


Specifications

ratings which will be adopted for use with this specification will be calculated using the material strengths, allowances and factors of safety indicated in the appropriate pipe material clauses of this specification. E1.5

Pipe Classification & Pressure Rating For structural purposes pipes shall be classified into two groups: Group A

Rigid pipes, which fail ultimately by fracturing, before sustaining unacceptable deformations. Rigid pipe materials include: Abbreviation

Material

Conc PSC Clay AC

Concrete (except PTC) Prestressed concrete Clayware Asbestos cement

Group B Flexible pipes, which can deform to unacceptable extents without fracture occurring. Flexible pipe materials include: Abbreviation

Material

PE uPVC ABS RTR (GRP)

Polyethylene Unplasticised polyvinyl chloride Acrylonitrile butadiene styrene Reinforced thermosetting resin/glass reinforced plastic. Steel Ductile iron Pretensioned concrete

ST DI PTC Notes: (a)

ST, DI and PTC pipes often have sufficient strength to support loadings without assistance from the bedding and trench sides but for structural purposes are considered to be flexible.

(b)

Polyethylene, uPVC and ABS are further classified as 'thermoplastic' materials.

Group A pipes shall be designated according to their crushing strengths (see Clause E1.13) and Group B pipes according to their stiffness (see Clause E1.14). Gravity pipes shall be supplied to the following classes: RTR/ GRP (P)

:

For sewer application 5000 N/m2 stiffness class made to BS 5480 /ASTM D 3262 : 2004. for storm water application 5000 N/m2 stiffness class made to BS 5480 / ASTM D 3517:2004

uPVC Concrete encased microtunnelling pipe


GRP

:

for sewer or storm water application 4KN/m2 stiffness class made to BSEN 1401 – 1: 1998

:

strength class ‘90’ made to BS 5911:120

Page E-5 of 115


Ductile Iron

Specifications

:

Pipe & Fittings made to BS 548 for sewer (G) application

Pressure pipes shall be supplied to the following rated pressure classifications: Asbestos Cement

:

Class 18 (18 bar Test Pressure & 9 bar rated working Pressure Class) for storm water applications made to ISO 160/BS512

RTR/ GRP (P)

:

a) 12 bar rated working Pressure class for sewer made in accordance with BS 5480/ASTM D 3754. b)12 bar rated pressure class pipe for water or TSE made in accordance with BS 5480/ASTM D 3517.

uPVC (P)

:

a)16 bar (16 bar rated pressure class PVC pipes used to allow for temperature derating )for pipes upto and including 160mm ø, made to BSEN 1452 – 2: 2000 b)12.5 bar (rated pressure class pipes used to allow for temperature derating) above 160mm ø, made to BSEN 1452 – 2: 2000

HDPE (P)

:

16 bar rated Pressure Class made to ISO: 4427:1996

Stainless steel Gr.316L: Sch40

:

Pressure class pipes made to PN 16 rated ASTM A167, A240, A269, A774, A778

Carbon Steel Pipe (P)

:

Galvanized steel (P)

:

Ductile Iron (P)

:

A182, A304,

A193, A312,

A 194,A234, A325, A403,

PN 16 Rated Pressure Class made to ASTM A36, ASTM A106, A197, A53, A234 PN 16 Rated Pressure Class made to ASTM A120, ASTM A197 PN 16 Rated Pressure Class made to BS 545 for water application

Selected pipe material should be suitable for its application. Suggested pipe schedule for sewage treatment plant site is given in Table E1. Contractor should take Engineer’s approval before ordering the pipe material. TABLE E1 SCHEDULE OF PIPE APPLICATION SYSTEM Sr.

Applications

Type of Pipe

1 2

Liquid stream Interconnecting pipe Sludge stream pipe

3

Scum Line

GRP GRP (sludge consistency <3%), SS 316L (sludge consistency >3%) GRP


Page E-6 of 115


Specifications

Sr.

Applications

Type of Pipe

4 5

Grit Line Chemical line

6 7 8 9 10 11 12 13 14 15 16 17

Air Line Fuel Line (Diesel) Chlorination Potable water line TSE Pressure line Internal Sewage Line Internal Drainage Line Fire fighting Irrigation line Pump House internal piping Cable ducting Ventilation and ducts

SS 316L SS316 for Polymer, uPVC for Ferric chloride SS316L Carbon Steel Seamless Carbon Steel GRP/ HDPE GRP uPVC (<315mm), GRP (>315mm) uPVC (<315mm), GRP (>315mm) GRP GRP GRP/ SS uPVC uPVC (<315mm), GRP (>315mm)

Diameter Range (mm) Abbreviations: 1. GRP: Glass Reinforced Plastic 80 – 4,000 2. A.C: Asbestos Cement 80 – 1,800 3. C.S: Carbon Steel 25 – 400 4. S.S: Stainless Steel 25 – 400 5. uPVC: Unplasticized Polyvinyl Chloride 12 – 500 6. HDPE: High Density Polyethylene 32 – 630 7. MDPE: Medium Density Polyethylene 20 – 300 8. LDPE: Low Density Polyethylene 12 – 150 9. PP – R: Polypropylene Random 20 – 110 (for sanitory application) 10. G:I: Galvanized Iron 12 – 160 mm 11. CU: Copper 15 – 54 mm E1.6

Dimensional Requirements Unless otherwise indicated in this Section of the Specification, and apart from special lengths of pipe required for flexibility adjacent to structures, pipes may be supplied in any standard lengths allowed in the approved Standard. The tolerance allowed on special lengths shall be +25mm, unless otherwise detailed. Unless otherwise specified a manufacturing tolerance of +2 per cent shall be allowed on the nominal internal diameter of the pipe. The dimensions and tolerances applying to the jointing surfaces, and sealing rings or gaskets, of pipes, fittings and special shall be such as to ensure that the required sealing performance of the joints is maintained under service conditions, and will not be impaired by normal installation practices.

E1.7

Marking of Pipes and Fittings Each pipe, special and fitting shall be clearly and indelibly marked at the place of manufacture with: (i)

The name or distinctive mark of the manufacturer.

(ii)

The date of manufacture.

(iii)

The class or pressure rating.


Page E-7 of 115


Specifications

(iv)

The nominal diameter.

(v)

The manufacturing standard to which it has been produced.

(vi)

For rigid pipes - crushing strength (in kN/m or strength class).

(vii)

For flexible pipes - stiffness (in N/m2).

(viii

The angle of bends or branches.

(ix)

The name of the Employer and the Project or Contract.

(x)

where appropriate the pipework item reference number.

E1.8

Group A (Rigid) Pipes

E1.9

Concrete Pipes and Fittings Precast concrete pipes and fitting with flexible joints shall comply with the relevant provisions of BS 5911 Part 1. Ogee jointed concrete pipes bends and junctions for drainage shall comply with BS 5911 Part 3. Additionally, pipes and fittings shall comply with the following requirements as appropriate: (i)

Cement shall be sulphate resisting Portland cement unless otherwise specified.

(ii)

Concrete shall be dense, homogeneous and without honeycombing or other discontinuities.

(iii)

Admixtures shall not be used without the written permission of the Engineer.

The Contractor shall ensure that, in addition to complying with any strength requirements detailed in the Contract, pipes supplied for installation by pipe jacking techniques can withstand the thrusting forces to which they will be subjected during installation, without cracking or spalling. A certificate confirming that the pipes are suitable for jacking and indicating allowable distributed jacking forces shall be supplied. The characteristic strength of concrete used in the manufacture of pipes for jacking shall be not less than 65 N/sq.mm. E1.10

Clayware Pipes and Fittings Flexibly joined clay pipes and fittings for drains and sewers shall comply with the relevant provisions of BS EN 295. The remaining types of clay pipes, fittings, joints and ducts shall conform to BS 65 1st November 1991. Pipes and fittings shall be fully vitrified and unless specifically designated on the Drawings may be glazed or unglazed. Any glazing shall be ceramic type applied prior to firing. Salt glazes are not acceptable. Joints shall be an approved flexible type with elastomeric sealing rings and may be either spigot and socket or of the separate push-on sleeve type. Proprietary joints may only be used with the Engineer’s approval. Fully vitrified clay pipe is defined as the complete fusion of silica and clay that is achieved by firing at sufficient temperature and time. In addition to compliance with BS EN 295, sections of the pipe shall be examined under low-power magnification, and shall not exhibit non-fused, loose or flaky particles.


Page E-8 of 115


Specifications

Pipe strengths shall not be less than 22 kN/m for DN 100 & 150, class 120 for all larger sizes. All pipes used for the specified strength tests shall be thoroughly saturated, by immersion in water or other approved method, prior to testing. The minimum period of immersion in water shall be: Wall Thickness

Minimum Preconditioning Time (Hours) Unglazed, Glazed only on interior or exterior surfaces, salt glazed

E1.11

Ceramic glazed

(mm)

(hr)

(hr)

up to 20

18

42

>20< 35

42

66

>35

66

90

Pitch Fibre Pipes and Fittings Pitch fibre pipes and fittings shall conform to BS 2760.

E1.12

Cast (Grey) Iron Pipes and Fittings Cast grey iron pipes and fittings shall conform to BS 4622. Unless otherwise detailed, grey iron pipes shall be of the spigot and socket type with elastomeric sealing rings. Pressure pipes shall be rated for 10 bar working pressure unless a higher working pressure is specified elsewhere for pipeline duty. Fittings and specials shall be of the same (or higher) pressure rating as the pipeline of which they are part. Puddle flanges shall be cast integrally with the pipelines unless otherwise agreed by the Engineer.

E1.13

Crushing Strengths for Group A (Rigid) Pipes In addition to the requirements of the approved national standard, concrete, clayware and pitch fibre pipes shall be supplied to the minimum proof crushing strengths (crushing load per metre divided by the nominal diameter) shown in Table E1.


Page E-9 of 115


Specifications

TABLE E1 Minimum Proof Crushing Strengths for Rigid Pipes Nominal Diameter

Minimum Proof Crushing Strength (kN/m)

(mm)

Class L

Class M

Class H

100

12.5

16

22

150

14

17.5

22

200

15

20

25

225

16

20

30

250

17.5

24

35

300

25

25

40

400

27

35

45

450

27

35

45

500

32

38

48

600

32

45

56

700

36

52

62

800

40

55

65

900

45

65

75

1000

50

75

90

1000

52

80

105

1200

55

85

110

1500

65

105

130

1800

85

125

160

The ultimate load at which pipe failure occurs in the three edge crushing strength test shall be not less than 125% of the minimum proof crushing strength specified above. E1.14

Stiffness for Group B (Flexible) Pipes Pipes for non-pressure purposes shall have minimum specific tangential initial stiffness, at the ambient temperature stated in Clause A2.2 or at 20°C where no such temperature is stated, in accordance with one of the following classes: Class Class Class Class

L1 L2 M H

1,250N/m2 2,500N/m2 5,000N/m2 10,000N/m2

The initial stiffness of pipes having diameter of 500mm or more, shall not exceed the minimum stiffness value of the next higher class. Stiffness shall be calculated as EI/D3, where E is the modulus of elasticity of the pipe wall material in ring bending, I the moment of inertia per unit length of pipe wall in ring bending and D the mean diameter of the pipe.


Page E-10 of 115


Specifications

Pipes for pressure pipelines shall have stiffnesses at least corresponding to Class L1. E1.15

Thermoplastic Pipes (i)

General Requirements Thermoplastic pipe materials include polyethylene, uPVC, ABS, PP and PB. The only additives which may be used during pipe manufacture are those which are necessary for the manufacture of the basic polymer feedstock and for its satisfactory further processing to produce a finished product complying with the Specification. All additives shall be thoroughly dispersed throughout the material. Thermoplastic components shall be stabilised against ultra-violet light degradation. The material shall be thoroughly and consistently fused throughout the component. Unless otherwise specified, polyethylene, polypropylene and polybutylene pipes shall be jointed by fusion welding in accordance with Clause E3.6, and uPVC and ABS pipes shall be jointed using integral sockets and spigots, in accordance with Clause E1.25. Solvent-welded joints shall not be used except where shown on the drawings or agreed by the Engineer. Compliance with the appropriate stiffness class of Clause E1.14 shall be verified by parallel plate loading tests in accordance with Clause E2.4, carried out at the ambient temperature stipulated in Section A, or at 20oC where no such temperature is stipulated. The hoop tensile strength of the material shall be obtained by stress rupture testing in accordance with Clause E2.4 and the estimated minimum hoop tensile strength at 50 years, obtained by extrapolation of the test results shall be in accordance with the following table: Minimum 50 Year Hoop Tensile Strength for Thermoplastic Group B Pipes Material

PVC-U

Hydrostatic Design Stress @ 20°C (MPa)

Temperature Derating Factors

25°C

30°C

35°C

40°C

12.5

1.0

0.88

0.78

0.70

PE/MRS 100

6.3

0.9

0.81

0.72

0.62

PE/MRS 80

6.3

0.9

0.81

0.72

0.62

PE/MRS 63

5.0

0.9

0.81

0.72

0.62

PE/MRS 40

2.5

0.82

0.65

0.47

0.30

PE/MRS 32

2.0

0.82

0.65

0.47

0.30

The pressure ratings of the pipes, as defined in Clause E1.4, shall be obtained by using the hydrostatic design stress from the above table, and applying the derating factor appropriate to the design temperature as specified in the particular specification.


Page E-11 of 115


Specifications

The finish of pipes shall comply with the requirements of Clause E1.4. (ii)

Polyethylene Plastics Copolymerisation with small quantities of propylene is permitted. The specific gravities of polyethylene plastics shall be in the following ranges: low density 0.710 to 0.925, medium density 0.926 to 0.950, high density 0.951 and over. Polyethylene pipes shall be jointed by fusion welding in accordance with Clause E3.6, unless otherwise specified.

(iii)

uPVC Plastics PVC material shall be unplasticised and of an impact resistant or high impact grade. High molecular orientation uPVC may be used. The material shall have a fracture toughness of not less than 3.25 MN/m3/2. PVC pipes shall be provided with socket and spigot joints, sealed by elastomeric sealing rings, unless otherwise specified.

(iv)

ABS Plastics ABS plastics may be either copolymers of, or blends of homopolymers of, the constituent monomers. The maximum content of acrylonitrile shall be 15%, of butadiene shall be 6% and of styrene (or substituted styrene) shall be 15%. The total content of the three basic monomeric constituents shall be not less than 95% and the specific gravity shall be in the range 0.990 to 1.200. ABS pipes shall be provided with socket and spigot joints, sealed with elastomeric sealing rings, unless otherwise specified.

E1.16

Glass Reinforced Plastic (GRP) Pipes

E1.16.1

Definitions and Requirements The following definitions are used in this specification. GRP Pipe: A tubular product containing glass-fiber reinforcements embedded in or surrounded by cured thermosetting resin with or without aggregate. Aggregate: Siliceous sand conforming to ASTM C33, except the gradation requirement need not apply. E-glass: Low Alkali content glass fiber. ECR-Glass: Form of glass fiber specially developed for acid resistance. C-Glass: Alkali -Lime glass with added boron used for surface layer reinforcement. (Good chemical resistance). Reinforcement: Glass fibers used to provide strength and stiffness to a composite material. Resin: A polymer that has high molecular weight with no definite melting point used as a basic material for plastics.


Page E-12 of 115


Orthophthalic resin: temperature resistance.

Specifications

A general purpose polyester resin of limited chemical and

Polyester resin: Type of thermo-set resin with two or more ester group. Thermo-set Resin: Resin which hardens irreversibly by use of additives. Once cured, a thermo-set resin cannot be re-melted and insoluble. Epoxy resin: A polymer containing two or more three membered rings, each consisting of one Oxygen and two Carbon atoms. The polymer is cured by cross-linkings with amine or anhydride hardner, with or without heat, catalysts or both. Vinylester resin:

High performance corrosion-resistant epoxy based resin.

Lining: Integral internal reinforced lining of a GRP pipe, normally of high resin content consisting of a 'barrier layer' and a 'surface layer'. Roving: A collection of parallel glass strands or filaments with binder. Chopped fiber: Continuous fibers cut into short lengths (3-50mm). Resin-rich Lining: A corrosion resistant lining containing approximately 65-80% of resin by weight applied to the interior surface of GRP pipe to protect the structural wall from corrosion. Laminate:

A composite of cured resin and reinforcement.

Filament winding: General term for pipe manufacturing method using continuous rovings as the reinforcement. Helical winding: Filament winding manufacturing method where continuous rovings are applied at 60 - 70 degree to axis of pipe mould. Barrier-Layer: The resin -rich anti penetrant layer forming part of the internal corrosion resistant pipe lining applied behind the interior liner of pipe. Inner surface layer: Resin-rich layer forming part of the internal corrosion resistant pipe lining. Exterior surface layer: A filled or unfilled resin-rich layer (reinforced or non reinforced) applied to the exterior surface of the pipe wall. Barcol hardness: Measure of surface resin hardness, used to check the degree of cure. Cure: Conversion of liquid resin into solid. Air inhibition: Failure of surface layer of resin cure because of contact with atmosphere. Stress: The force per unit cross section area. Vol 3, Section3 – Civil Specifications

Page E-13 of 115


Specifications

Strain: Dimentional change per unit of length resulted from applied force or load measured in ( mm/mm). Strain corrosion: Brittle failure mode caused by exposure of a strained laminate to a corrosive environment. Stiffness: The resistance of a pipe to circumferential deflection in response to external loading applied along one diametrical plane. Pressure class: Maximum sustained pressure for which the pipe is designed. Pipe stiffness: A measure of the force required to deflect the diameter of a pipe ring a unit amount. Stiffness class: The nominal stiffness of a specified pipe. Creep: Deformation or strain that occurs over time when a material under sustained stress. GRP is subject to creep at all temperatures when subjected to stress. Hydrostatic Design Basis (HDB): The long -term hydrostatic hoop strength of a specific fibre glass pipe material as determined by hydrostatic pressure test and the data extrapolated to 50 years to use the data in pipe design calculation. Long-term strain corrosion (SCV): The long-term strain corrosion strength of a specific fibre glass pipe in acidic & under strained condition determined by deflection test and the data extrapolated to 50 years to use in pipe design calculation. Long-term Stiffness (Creep): The long term stiffness retention and creep factor of a GRP pipe(under wet condition) determined by constant failure strain (deflection) test and the test data analysed and extrapolated to 50 years. Long-term Ring bending strain: The long term bending strength (in normal water under immersed condition) of a GRP pipe determined by constant failure strain (deflection test) and the test data analysed and extrapolated to 50 years strain to use the data in pipe design calculation. Design factor (FS): A number equal or greater than 1.0 which takes into consideration the variables and degree of safety involved in a design. Test data are divided by the design factor to obtain design allowable values. Also called safety factor. E1.16.2

GRP Pipe and Fittings for use in Gravity and Pressure flowsystems conveying Sanitary Sewage Pipe manufacturers must be members of, or affiliated with, a quality control or certification authority relevant to the pipes or fittings proposed for incorporation in the works. ISO 9001 certification is required for pipe/fittings manufacturers. The following specifications are referenced as applicable: REFERENCE BS 5480: 1990


:

DESCRIPTION British standard specification for glass reinforced plastic (GRP) pipes, joints, and fittings for use for water supply or Page E-14 of 115


Specifications

sewerage. ASTM D3262:2004

:

Specification for fibreglass sewer pipes for use in gravity flow systems for conveying sanitary sewage

ASTM D3754:2004

:

Specification for fibreglass sewer and industrial pressure pipes for use in pressure systems for conveying sanitary sewerage and industrial wastes

ASTM D3517:2004

:

Specification for fibreglass pressure pipes for conveying water system.

AWWA C950:2001

:

Standard for fibreglass pressure pipes

AWWA M45

:

Fibreglass pipe design manual

The GRP pipes & fittings shall be certified in accordance to BS 5480, ASTM D-3262 & D 3754 (Certificate to be submitted for Engineer’s approval). Certification must include the diameters of pipe to be supplied. Evidence of diameter range is necessary. GRP Pipe and fittings shall be manufactured in accordance with BS 5480 and ASTM D-3262 for gravity application and BS 5480 and ASTM D-3754 for pressure application. GRP pipe and fittings shall be at least adequate to achieve a minimum working life of 50 years under all applicable loading, local environmental and installation conditions. The pipes and fittings shall be designed to withstand up to 5% long term deflection in the installed conditions. Both gravity & Pressure Pipes shall have a 50 years strain corrosion design performance as per the latest editions of ASTM D3262/ASTM D 3754, AWWA C 950 for sewer pipes, but the mean value of the regression line at 50 years shall not be less than 1 % strain. Evidence of third party approved regression test date must be submitted. The GRP pipes used for gravity applications shall comply with the minimum requirements for 6 Bar pressure pipes as the pipe lines may be intended to operate under surcharged conditions and not as gravity pipe lines. The pipe shall also comply with the additional requirements to suit the prevailing Local temperature and corrosive environment conditions specified. Materials Specification  Resin The resin used for the internal liner of the pipes and fittings shall be of an epoxy based vinylester resin complying with BS 5480 and shall have a minimum elongation to break of 5% when fully cured. The resin in the structural wall of the pipes and fittings shall be of unsaturated Isophtalic polyester type incorporating styrene as the monomer and meeting the requirements of BS 3532 Type B. The use of vinylester resin in the structural layer is also permitted. * No pigments in the liner or structure shall be added. Glass The internal and external layer shall be of "C" glass veil produced from a chemically resistant glass durable in both acid and alkaline environment and shall have a surface treatment compatible with the resin. All fiber reinforcement used shall be of high acid resistant type "ECR/Advantex" ' comply with BS 5480 and shall have a surface treatment




Page E-15 of 115


Specifications

compatible with the resin. The reinforcements shall generally comply with the standards listed below as appropriate. BS 3691 "Glass fiber roving for the reinforcement of polyester resin systems". BS 3496 "Glass fiber chopped strand mat for the reinforcement of polyester resin systems". BS 3396 "Woven glass fiber fabrics for plastic reinforcement". BS 3749 "Woven glass fiber roving fabrics for the reinforcement of polyester resin systems". Glass rovings used in the structural wall shall not exceed 2400 Tex. Aggregates and Fillers Aggregates if used, shall be minimum 98% pure Silica Sand as defined in BS 5480:1990 and AWWA C950 and shall contain no impurities. The aggregates shall only be used in the stiffening layer of the pipe wall, where it is designed as part of the composite structure.



The final product shall meet the requirements of the specifications. Silica sand aggregates as defined in BS 5480 shall contain no impurities. Fillers as defined in BS 5480 shall not be used. The silica sand content in the pipe wall shall not exceed 50%. The resin shall be cured to reach hardness not less than 90% of the resin manufacturer's recommended hardness. A manufacturer's tolerance of ± 1 % shall be allowed on the nominal diameter of the pipe. The pipes shall be supplied in standard lengths of 3, 6, 10 or 12 metres with a tolerance of ± 25 mm. The deviation from straightness of the bore of the pipe shall not exceed 0.3% of the effective length or 15.00 mm whichever is smaller and shall apply when measured on site. Up to 10% of the pipes will be allowed in random lengths. The ellipticity of any pipe when measured resting freely on the ground shall not be more than 2% of the mean diameter at any point. No pipe known to have undergone a deflection greater than 7% shall be incorporated into the Works. The Stiffness shall be minimum 5000 N/m2 for all pipes but for pipes to be used in Pumping Station and valve chambers and for Irrigation &Water application the stiffness shall be minimum 10,000 N/m2 and pipes for use in microtunnelling or similar jacking operations the stiffness shall be minimum 50,000 N/m2 unless surrounded in concrete. GRP Pipes shall also be used inplace of A.C. Pipes wherever applicable in storm water drainage and Irrigation Pipes. The pipe laying procedures & the deflection checks at Site etc. shall be the same as for sewer pipe. Pipe installation & Pipe surround material shall be the same as specified for GRP Pipes & Fittings. The minimum / maximum burial depth shall be as recommended by the Pipe manufacturer. Supporting design calculation shall be provided to the Engineer to satisfy the installation condition. The specific tangential initial stiffness shall be demonstrated by application of the following equation: Stiffness of the pipe = is defined as EI/D3 (STIS) Where: E


=

bending modulus of pipe wall circumferentially

Page E-16 of 115


E1.16.3

Specifications

I

=

D

=

(in N/m2). second moment of area of pipe wall per Unit length (in m4/m) mean diameter of the pipe in metres

Compulsory Requirements Particular to Sewer Pipes, Couplers and Joints The Inner Layer All pipes and fittings shall have a resin- rich liner internal to protect the glass in structural laminate from long term degradation having a minimum thickness of 1.5mm and maximum thickness of 2.5mm consisting of an inner most 0.25mm surface layer reinforced with chemical resistant "C" glass impregnated with 90% resin. The remainder of the 1.25 mm backup barrier layer shall consist of acid resistant (ECR/ ADVANTEX) chopped glass strands or powder bound chop strand mat and having a glass content between 25 and 30% by weight. The lining materials selected should provide a good impact and corrosion resistance.



The Structural Layer The structural wall of the pipe shall be reinforced with closely spaced continuous fiber glass (ECR/ADVANTEX) filament winding, chopped roving, Silica Sand all impregnated with Isophtalic polyester resin. No dark pigments or resin fillers such as Calcium Carbonate shall be used in the pipes or fittings. Fine Silica Sand. Containing no impurities and complying with the requirements of BS 5480 may be added in a core layer sandwich, between the pipe structural layers.



The Exterior Layer The exterior resin rich layer of the pipe shall have a maximum thickness of 1 mm reinforced with corrosion resistant glass (ECR/ ADVANTEX) and "C" glass veil impregnated with isophthalic resin/vinyl ester resin. For protection against ultra violet light degradation a translucent "uv" inhibitor should be included in the resin mix. A black colouring pigment to suit the service identification of Storm water drain pipe shall be added on external resin rich layer.



Fittings All fittings such as bends, tees, junctions, reducers and the like shall conform to BS 5480: 1990. The construction of bends shall be swept or mitered. The laminated joints used in the fabrication of fittings shall meet or exceed the required design requirements of the piping system. All hand laminations or windings shall utilize only one type of resin throughout.



Flanges GRP flanges shall be flat faced and drilled to BS 4504 PN 10 or PN 16 drilling pattern. Flanges shall be filament wound up to 1800mm and may be contact moulded for larger sizes. GRP flange gasket shall be of a design, material and thickness as recommended by the GRP fitting manufacturer. The use of epoxy resin in a flange manufacture is permitted.



Joints (For buried pipes) Except where otherwise detailed on the drawings, all pipes and joints shall be of flexible type. Joints shall be of loose GRP machine made coupling having two rubber rings gaskets. All joints shall be capable of withstanding the various tests specified for the appropriate class of pipe.



Joints shall withstand while maintaining the specified test pressure at a deflection of not less than the values specified in the BS5480: 1990/ ASTM D3262/ ASTM D4161.


Page E-17 of 115


Specifications

Pipes used for adjustment and short length shall be ordered from the manufacturer. Cutting and rejoining is only allowed when butt joints are used or a calibration machine is available and approved by the manufacturer. No cutting on site is allowed without manufacturer’s recommendation. The Rubber rings shall be kitemarked meeting the requirements of the appropriate parts of BS EN 681-1 and be of the EPDM formulation. Joint Lubricants For lubricants, use only a vegetable based soap available from the pipe manufacturer. Never use petroleum product or automotive oils to lubricate the joint, as they will damage the rubber rings.



Pipes shall have a resistance to longitudinal tensile force per unit circumference as under: Nominal Diameter (mm) InitialUltimate Resistance (N/mm) Up to 700 100 700 to 1,000 120 1, 000 to 1, 600 160 1,600 to 2,400 250 2,400 to 4,000 300 and when subjected to a parallel plate loading test shall show no evidence of crazing or cracking and no structural failure with the deflection levels specified in AWWA C 950-Table 9. The deflection criteria presented are based on a Maximum installed long term deflection of 5%. If the pipe sample fails to meet either or both requirements, the long term allowable deflection must be reduced proportionally for the pipes represented by the sample. The jointing system shall be an approved coupling system. Where the system involves separate reinforced plastic couplings of sockets formed by a lay-up process subsequent to pipe production, the resins used shall be clear and non-pigmented to permit visual examination within the laminate. Where GRP laminate is cut, exposed ends shall be sealed with a suitable resin and approved prior to incorporation into the Works. Where such cutting and sealing takes place at site the resins used and the methods of storage, mixing, application and curing shall be strictly to the manufacturer's recommendation. Before any such work takes place the manufacturer's representative shall visit the site to demonstrate and give clear procedural advice to the Contractor in the presence of the Engineer. GRP pipe and fittings shall be as uniform as commercially practicable in colour, opacity, density, and other physical properties. GRP pipe and fittings shall be smooth and both the internal and external surfaces shall be clean and free from delaminations, cracks, bubbles, pinholes, pits, blisters, foreign inclusions and resin-starved areas that due to their nature, degree or extent detrimentally affect the strength and serviceability of the pipe. Unless authorized by the Engineer, repair will not be permitted on any pipes with defects, as listed below and such pipes shall not be incorporated into the works:(1) A scratch of greater depth than 0.30 mm. (2) Cracks of any type on the inside of the pipe. (3) Cracks on the outside, longer than 200 mm circumferentially or 6mm longitudinally. (4) Delaminations. (5) Damaged ends including bubbles, cracks, voids, exposed reinforcement or extraneous matter. Vol 3, Section3 – Civil Specifications

Page E-18 of 115


(6)

Internal protruding fibres.

(7) (8)

More than 25% of the external area with protrusions of any sort. Air voids and blisters exceeding 5 mm diameter or 1 mm in depth, greater in area than 0.50% of internal or 1.00% of external surfaces. Pitting to more than 5% of the internal or 10% of the external surface area and individual pits more than 1 mm diameter or 0.5 mm in depth. Wrinkles more than 3% of the surface area and individual wrinkles more than 2 mm deep

(9) (10)

E1.16.4

Specifications

Type Tests for GRP Pipes and Joints Type tests shall be carried out on locally produced representative pipe products in accordance with Table E.1 to pre-qualify the products and to verify the design input data given in the design calculations. The tests will be witnessed by a Ministry of Housing approved, NAMAS accredited, independent third party materials testing laboratory. Table E.1: Pre-qualification Tests Qualification or Type Tests 1) Long term (10,000 hrs) Chemical test ( strain corrosion resistance)

Test Method BS 5480 OR ASTM D3681

Minimum Requirements Extrapolated predicted failure strain at 50 yrs. shall not be less than 1%.

ASTM D2992 / OR BS 5480 BS 5480 Appendix L

Hydrostatic strain at 50 yrs. shall not be less than 0.66%

5)

Long term hydrostatic or pressure design basis 10,000 hrs test. (for Pressure Pipe) Long term specific ring stiffness (creep factor) under ring deflection (10,000 hrs test) Long term ring bending strain (sb) Impact resistance

6)

Joint water tightness.

ASTM 4161/BS 5480

7)

UV exposure on GRP Pipe (1 Year).

8)

Short time Hydraulic failure pressure of pipes and fittings (After the first production).

Manufacturers Recommended test Method. ASTM D 1598 / D 1599

2) 3) 4)

Note:

ASTM D 5365 BS 5480 Appendix J

50 years-extrapolated stiffness value shall not be lower than 70% of the initial stiffness. 50 years strain shall not be less than 1.35%. As specified in relevant standard. Requirements as specified in relevant standard. Not to show surface Deterioration due to UV effect. (a) Withstand 3.5 times the rated working pressure with no sign of leakage or weep. (b) Determine the failure pressure by pipe bursting.

(1) The above tests are to be repeated on locally made pipes when the material type & compositions are changed during the production from the original type test of the product.

Quality control tests on raw materials and final products shall be carried out as listed below:

A. Quality Control Tests & Records

The manufacturer shall have maintained a record of all quality control tests for a period of not less than 2 years and if requested, shall submit the data to the Engineer.


Page E-19 of 115


Specifications

1. General Requirements The pipe manufacturer must demonstrate the capability to produce pipes of consistent properties and quality meeting the requirements of these specifications. A detailed quality control/quality assurance program must be implemented at the manufacturing facilities and all necessary test equipment to be operated by skilled technicians. Calibration of test equipment shall be performed at least once a year. Details of the pipe manufacturers QC/QA program, testing equipment, testing program shall be presented to the Engineer for review and approval prior to commencement of pipe manufacture. The manufacturer's quality control scheme shall be certified by a recognized independent authority to meet the requirements of ISO 9001. 2. Reconfirmation of Strain Corrosion Regression Line When a GRP piping product has an existing strain corrosion regression line, any change in material, manufacturing process, construction or liner will necessitate a Screening evaluation as described in CL 10.2, 10.3, 10.4, 10.6 & 11 of ASTM D3681:96. The pipe samples for screening test shall be selected by the Engineer’s representatives from locally produced pipes only. Table E.2: Minimum Design Parameters, Installation Conditions and the Mandatory Requirements for Sanitary Sewer Pipe Intended to Carry Septic Sewage Details

Requirements

Minimum working pressure class of pipe for gravity applications.

..

6 Bar

Ground water (assumed)

level

..

Minimum surface.

Minimum working Pressure class pipe Category for Pressure applications.

..

12 Bar

Service operating temperature

..

50 Degree C

table

Installation depth ('H' Min.& 'H' Max.)

1

metre

below

Not less than 1.5 M Not less than 10 M

Stiffness Class Pipe (for gravity & pressure)

..

Minimum 5000 N/M2

50 Years extrapolated stiffness retention value (end stiffness) of pipe..

..

(a) Not less than 3500 N/M2 for 5000 STIS class pipe (b) Not less than 7000 N/M2 for 10,000 STIS class pipe.

50 Years extrapolated strain value established by long-term strain corrosion type test conducted on local made pipe (G & P) and witnessed by 3rd party independent lab.

..

Minimum 1 % safety factor = 1.5


Page E-20 of 115

ground


Specifications

Required minimum strain value by 1000 hrs control test on local made production pipe.

..

Strain percentage achieved shall not be lower than the type test result of GRP.

50 Yrs extrapolated 'HDB' value established by long term type test conducted on local made pipe (G& P) and witnessed by 3 rd party independent lab.

..

Minimum 0.66% safety factor = 1.8

Permitted maximum long-term deflection at 50 years service life of pipe.

..

Not greater than 5%

Shape factor input data (Df) for pipe design.

..

Back fill modulus E'b for pipe zone embedment.

..

Live load assumption to use in pipe design.

..

Impact factor to use in pipe design.. Water hammer calculation

..

Minimum 4.5 as given in A WW A M45 manual. for pipe zone embedment material as gravel with compaction moderate to light. Minimum 20.7 Mpa as given in AWWA M45.manual..Crushed rock as pipe zone embedment with moderate proctor Four-lane road with truck centered in each 3.7Mwide lane as given in AWW A M45 manual. As per A WW A M45 manual recommendation. Ditto

..

B. M aterials in P ipe Lam inate Structure (A) (B)

Type of glass throughout the pipe wall Type of resin to be used in structural wall.

: :

(C)

Type of resin to be used on resin-rich liner internal & external of pipe wall.

:

(D)

Aggregate & fillers

:

ECR/ Advantex only Isophthalic polyester Resin type ‘B’ having minimum 3.0% elongation property. Epoxy based vinyl ester resin having minimum 5% resin elongation property. Silica sand SiO2 > 98%

(E)

'C' Glass (for the internal liner and liner external of pipe)

:

Chemical resistant ECR Type only.

C. Corrosion Resistant Lining I nside the P ipe W all (a) Surface layer internal

..

(b) Barrier layer behind the surface layer of pipe.

..


Nominal thickness 0.25mm Glass content upto 10%. Minimum thickness 1.25mm Maximum thickness 2.25mm Epoxy based V.E.Resin 60- 80% ECR / Advantex Glass 20-40%

Page E-21 of 115


Specifications

(c) Overall liner thickness internal

..

Minimum 1.5mm Maximum 2.5 mm

(d) Overall liner thickness external

..

Minimum 0.5mm Maximum 1.00 mm

(e) Glass fiber reinforcement & sand content minimum/max limitations

..

(a) Hoop glass % minimum 55% in structural layer(s) of pipe wall. (b) Chopped rovings in pipe wall minimum 7%. (c)Sand content in gravity pipe wall shall not be greater than 50% and 30% in pressure pipe.

The manufacturer shall carry out the quality control test listed below using the pipe production sample selected and witnessed by the Engineer at the frequency stated. The manufacturer shall maintain records of all tests and inspections and two copies of all test certificates and reports shall be forwarded to the Engineer. Raw Materials Checks shall be made on all raw materials to ensure that they comply with the manufacturers stated values. All deliveries of resin shall be checked for consistency of Viscosity and reactivity. Any resin deviation from the manufacturers published figures shall not be used. Glass samples shall be checked for yield/tex, moisture and size content. All deliveries of aggregate shall be checked for consistency of grading, moisture content and purity. The pipe manufacturer should provide a copy of the materials certificate of analysis for the material supplied together with in-house Q.C. test reports stating that the material used in the pipe wall construction is conforming in all respects to the relevant specification. Table E.3: Quality Control Tests on Final Product 1.

2.

Pipes & Fittings

Test Method

Minimum

Hydrostatic – Pressure Test (Pressure & Gravity) (1) 100% of pipes and couplers. (2) 1% of the pipes and couplers Stiffness (for Gravity & Pressure) 1 in every 100 pipes manufactured (minimum).

BS 5480 / ASTM D 3262 / ASTM 3754 / AWWA C 950

(1) 2 x Rated working pressure for 5 minutes.

(a) At 5% deflection.

ASTM D2412 / BS 5480 ASTM D3262 / D3754

a) 5000 / 10000 N / m2 (minimum). b) No liner crack

(b) At level “A” (12% / 9%) Deflection. For 5000 / 10000 STIS pipe. (c) At level “B” (20% / 15% ) Deflection for 5000 / 10000 STIS pipe.


Page E-22 of 115

Requirements

(2) 2 x Rated working pressure for 4 hours.

c) No structural failure


Specifications

(d) After level “A”. 3 4.

Wall Thickness (On 100% Pipes, Couplers and Fittings) Hardness (On 100% of pipes, Couplers and fittings) using Barcol impressor 934 – 1, on liner.

5.

Loss on Ignition every 100 pipes)

6.

7.

8.

(1 in

•

BS 4549:PI Appendix A or ASTM D2583.

ASTM D2584

+ / -5% of manufactures specified resin / glass sand ratio.

Hoop Tensile Strength 1 in 100 pipes.

ASTM D2290 / BS 5480

Longitudinal Tensile Strength (1 in 100 pipes) in axial direction. Fittings (a) Visual inspection (b) Dimension (c) Pressure tests

BS 5480 : 1990 Appendix A

Requirements specified in table 10 of ASTM D 3754 as appropriate for the pressure class or AWWA C950 Table 10. BS 5480 : 1990 Table 2 / Table 13 of ASTM D3754.

(d) Barcol hardness (Resin cure) •9.

ASTM D3567

d) Continue to deflect to the point of liner cracking and record. Manufactures minimum quoted thickness given in the calculation for the pipe design. Minimum 90% of the hardness value declared by the resin manufacturer but not less than 33 barcol readings using barcol impressor 934 – 1.

ASTM D2563 ASTM D3567 BS 5480 / AWWA C 950 ASTM D2583

Chemical Control Tests (100 & 1000 hours tests) on samples of manufactured pipes during pipes supply for each contract.

ASTM D3681 ASTM D3262 BS 5480

(a) Every items (b) Every items (c) 1 in 10flanged items 2 x WP for 60s. (d) Every item minimum. Barcol reading 33. Strain level shall be above 1%.

Evidence from the manufacturer shall be provided of the satisfactory completion of the ‘Strain Corrosion Control test’ on samples of pipe representative of those to be supplied together with an assurance that the test result are in full compliance with the requirements stated in Table above.

D. Visual I nspection

Each pipe and fittings shall be subjected to a complete schedule of inspection before shipment and after offloading at site. All pipes and fittings shall be commercially free of defects such as delaminations, bubbles, exposed or protruding fibre, cracks, air voids, pits, or resin-starved areas that due to their nature, degree of extent detrimentally affects the strength and serviceability of the pipe. The maximum allowable visual defects of GRP pipe laminate parts shall be classified to type and level as given in ASTM D2563: Table 1. The acceptable quality level for the pipes internal and external shall be the level 2 as specified in CL. 3.3 of the above standard. Visual inspection report of the pipes, couplers and fittings in accordance with the above standard are to be provided by the manufacturer. Joints surface shall be free of dent and other surface irregularities that will affect the integrity of the joints. Any repairs at site if approved by the Engineer shall be carried out by qualified and skilled staff of the pipe manufacturer.


Page E-23 of 115


Specifications

E. Design Calculations

The manufacturer shall design the pipes for a life of not less than 50 years and shall submit calculations for initial and long term deflection with truck loads, buckling, vacuum, pressure, class, and strain in accordance AWWA M45. (Chapter V) For the purpose of design calculations only the bedding and back fill for pipes shall be considered as crushed stones/gravel with slight compaction and the modulus of soil reaction value shall be 20.7 Mpa as given in Table 5.5 of AWAWA M45. The maximum calculated long term deflection shall not exceed 5%. Copies of the design calculations shall be submitted to the Engineer for review and approval at the time of material submission.

F. Shape Factor

The shape factor input data to be used in the design calculation shall be based on dumped gravel with slight compaction and its appropriate value shall choose as given in Table 5.1 of AWWA M45 Manual.

G. Safety Factor

The following safety factor shall apply: AWWA M 45 Design Procedure Pressure Rating > = 1.8 Ring Bending Strain or stress > = 1.5 Combined Strain or stress > = 1.5 and 1.8 Buckling> = 2.5

H. I nspection and Testing 1.

The manufacturer shall take adequate measures in the production of products covered by this specification to assure compliance with the requirements herein. An inspection and testing plan should be forwarded to the Engineer for approval prior to start of manufacturer.

2.

Production and testing notice: When plant inspection is required by the Engineer the manufacturer shall provide adequate advance notice of when and where production and testing of ordered products will commence.

3.

The Engineer shall have free access with reasonable advance notice to the manufacturer's plant areas that are necessary to assure that the products comply with all requirements herein.

I . W orkm anship

GRP Pipes, fittings and joints shall be free from delaminations, bubbles and pinholes, pits, blisters, dry spots, pimples, resin pockets, deep scratches, wormholes and deep wrinkles. All GRP Fittings shall be fabricated in the factory to ensure quality control (under no circumstances fabrication of fittings be allowed on site by the contractor). Complex fittings arrangements may be pre-assembled by the pipe manufacturer on the factory such that the field joints are kept to a minimum.

J. M arking

Each pipe and fittings shall be legibly marked with the following information: Manufacturers name or trademark • Manufacturing date and the applicable standard • Manufacturing number • Nominal diameter in mm • Operating pressure in bar • Pipe stiffness class • Nominal laying length (for pipe only) •


Page E-24 of 115


Specifications

Manufacturer's inspection mark Contract name and number Identificationmark & the colour distinguishing the gravity & pressure pipe.

• • •

K . Subm ittal/ Draw ings

The following information shall be submitted to the engineer by the manufacturer. (1) Resin, Glass reinforcement, aggregate, joint and gasket data, with material manufacturers certificate of analysis. (2) Pipe supply specifications & installation manuals. (3) GRP manufacturers Pre-qualification (4) GRP Manufacturers Quality Control and Assurance Manual. (5) GRP pipe data sheet in the standard format shown below. In addition to the above information, the following information shall be submitted during the mobilisation period. 1) 2) 3)

4) 5) 6) 7)

Detailed Manufacturing process for pipe, joints and fittings. Detailed drawing of pipe end and couplers including pipe spigot OD, home line length, allowable tolerance, and allowable gap between pipes. Complete design calculations and design requirements including pressure class from HDB, working pressure and surge pressure using pressure class, calculation of allowable deflection from ring bending, external loads, WC & WL based on Burrial depth, predicted deflection, buckling etc. Quality procedure Type test results and reports specified Safety factor Proposed inspection and testing programme.

Prior to start production the manufacturer shall submit to the Engineer dimensional drawings of each fittings required for approval. The Engineer may require design calculations, and samples for approval at no extra cost. GRP PIPE DATA SHEET (FOR EACH DIAMETER / PRESSURE/SERVICE) (TO BE PROVIDED TO THE ENGINEER PRIOR TO START OF PIPE MANUFACTURING) Design parameters Service (sewer/storm water) Nominal Diameter (DN) Pipe Manufacturing process Installation service (minimum/maximum depth adopted) Rated working pressure (PN) Joint type Maximum allowable vacuum Factory hydrotest pressure Length of each pipe

: : : : : : : : : :

Pipe Wall Structure Nominal Wall Thickness a) Liner thickness b) Structure Wall thickness c) Outer Layer thickness Resin /glass type


Page E-25 of 115

: : : :

Units


Specifications

Mechanical Properties Design specific Tangential initial stiffness (STIS) Design initial Longitudinal tensile strength Design initial hoop tensile strength Internal Pressure & External Load Flexural Modulus Allowance design stress

: : : : : :

Calculation Method Internal Pressure & External Load

E1.16.5

:

GRP Pipe and Fittings for Pumping Stations and Valve Chambers The design of GRP pipe and fittings for pumping stations and valve chambers shall incorporate all the requirements of these specifications except for the following over-riding or supplemental stipulations. GRP pipe and fittings inside pumping stations and chambers shall be designed for use above ground with no thrust blocks and shall have sufficient axial strength to resist end thrust, temperature and bending stresses. GRP pipe and fittings shall have a minimum pipe stiffness of 10,000 N/m2 and a minimum wall thickness of 10 mm. The design working pressure for pipes and fittings shall be minimum 12 bar unless otherwise specified and the service temperature shall be 50°C. A minimum surge allowance of 40% above the working pressure shall be included in the design of pipes and fittings. Copies of the design calculations shall be submitted to the Engineer for approval. The basis of design shall be checked by conducting 'type' tests on representative sample(s) of manufactured materials, in accordance with the requirements of BS 5480 or ASTM D-2992. The wall of the pipes and fittings shall be made up of: 1.

A resin-rich inner liner of 1.5 mm minimum thickness, consisting of ‘C’ glass veil, and 'ECR/ADVANTEX' glass and impregnated with vinylester or epoxy resin.

2.

The structural layer consisting of ‘ECR/ADVANTEX’ glass reinforcements impregnated with vinylester or epoxy resin. Silica sand shall not be used.

3.

An exterior resin-rich layer of 1.0 mm minimum thickness, reinforced with a ‘C’ glass veil and impregnated with vinylester or epoxy resin. No dark pigments, sand or aggregate fillers shall be used for pipes and fittings. Ultra Violet stabilizers shall be incorporated in the pipe and fitting construction. GRP pipe and fittings for pumping station and valve chamber pipework shall have a suitably designed restrained joint capable of withstanding the design operating pressure with no leaks and without the use of thrust blocks. The acceptable jointing system shall be GRP flanges. GRP flanges shall be machine filament wound using 'ECR/ADVANTEX' glass fibre reinforcements and vinylester or epoxy resin. Hand layed up flanges shall not be permitted. Flanges shall be drilled to BS 4504 (metric units) type PN 10.


Page E-26 of 115


Specifications

A. Factory Testing

The following tests shall be carried out on manufactured GRP pipe and fittings at the intervals specified. Test methods shall be in accordance with BS 5480 or ASTM equivalent. Witnessing of factory testing by the Engineer’s Representative will be required prior to delivery of the material. Copies of the Manufacturer's test reports shall be submitted to the Engineer after each consignment of pipe or fittings delivered to the site. All GRP standard pipe and pipe used for fitting fabrication shall be factory pressure tested to 24 bar for pressure pipes and 12 bar for non-pressure pipes.

The following tests shall be conducted on all GRP pipe and fittings: -

Dimension measurements (Wall thickness, Diameter, Length) Visual inspection Barcol Hardness (Resin Cure)

Stiffness and resistance to structural damage as per Tensile strength by strip for GRP pipes as per BS 5480: App: #, 1990. Mechanical property testing shall be conducted on 1% of GRP pipe and fittings produced. Other tests for quality assurance shall be carried out on representative sample(s) as required by BS 5480 or ASTM equivalent.  

Initial longitudinal unit tensile strength by a tensile strip test as per BS5480 Appx A. Initial specific stiffness under ring deflection BS 5480 Appx H.

B. I nstallation

GRP pipe and fittings shall be installed in accordance with the manufacturer's written instruction. A field representative of the manufacturer shall be made available as and when required during the installation of the GRP pipe and fittings. All flanges shall be tightened in accordance with the Manufacturer's written instructions using a torque wrench.

E1.16.6

GRP Pipes and Fittings for Irrigation and Potable Water Distribution and Transmission

A. Scope

This specification covers the minimum requirements for the GRP piping for aboveground and underground installations, intended to be used for potable and raw water applications. The Manufacturer's design shall satisfy the minimum requirements set herein. This specification includes the minimum requirements for design, manufacture, workmanship, testing, inspection and installation of standard GRP pipe systems.

B. M anufacturers P re-Qualification

All Pipes and fittings shall be certified in accordance with BS5480 / ASTM D3517. For the diameters intended for the supply, evidence of the certified range to be submitted.

GRP pipe and fittings shall be manufactured by an established pipe Manufacturer in a purpose-built facility for the production of such materials. The Manufacturer shall have an approved Quality Management System complying with ISO 9001 for all activities being undertaken during pipe design, manufacture and supply. Manufacturer's Scope of Work The GRP pipe system Manufacturer will be responsible for the following:


Page E-27 of 115


Specifications

a)

Manufacture and Supply of the GRP pipe, fittings, flanges, saddles for instrumentation tapping and pipe closing (make-up) pieces. Manufacturer to also supply the gaskets for use in flange connections and provide general recommendations on associated equipment such as valves, expansion bellows, nuts and bolts and other accessories.

b)

Design of the GRP pipe system including Stress Analysis (Surge and Flexibility), Support Location / Function Analysis and the Conceptual Support Design for the given design and routing for all above ground applications. These Engineering / Design analysis are to be implemented by the pipe manufacturer.

c)

Inspection and testing at the Manufacturer's works in accordance with specified requirements herein.

d)

Marking of pipe for identification shall be as per specification

e)

Provision of a Site Staff (s) to assist during pipe installation.

Applicable Codes and Standards The following internationally accepted standards are the minimum requirements for the manufacture of GRP Pipe Systems and should be referenced throughout the Project Specification where appropriate.

AWWA C950

Glass Fiber Reinforced Thermosetting Resin Pressure (Latest Edition)

AWWA M45

Fiberglass Pipe Design

BS 5480

Glass Fiber Reinforced Plastic GRP pipes and Fittings for use for Water Supply or Sewerage

ASTM D3517

Specification for Glass Fiber Reinforced Thermosetting Resin Pressure Pipe for conveying water system

C. P roduct Description 1. General

Pipe shall be designed and manufactured by the glass filament winding process as described by AWWA M45, ASTM D3517 and BS 5480. Accepted manufacturing processes are the continuous filament winding or the helical filament winding process. The filament wound pipe shall be made using a straight steel mandrel. The pipe shall be constructed so as to include internal and external corrosion barriers of a composition suitable to resist the corrosive effects of the contained and surrounding environments. The inside diameter (ID) of the finished pipe is fixed by the mandrel outside diameter. The outside diameter (OD) of the finished pipe is determined by the amount of material that is wound on the mandrel. The pipe shall be produced in one continuous piece with no joints. The resins to be used shall be:


Page E-28 of 115


Specifications

Polyester: Isophthalic Acid Grade (at least equal to the requirements of BS 3532 Type ‘B’). a. Liner Pipe and Fittings shall have a smooth resin rich internal liner of 1 mm thickness with a resin to glass ratio of 70 : 30. This liner will be reinforced with "C" Glass. No dark pigment or resin fillers, such as calcium carbonate shall be used. b. Structural Wall The structural wall of the pipe shall be reinforced with closely spaced continuous fiberglass filament winding, chopped roving, all impregnated in thermosetting resin. No dark pigments or resin fillers such as calcium carbonate shall be used.

c. External Layer A resin-rich post-coat, identically constructed as the inner liner, must be applied to the external surfaces of all of the GRP pipes. All external surfaces shall be able to resist the anticipated corrosion imposed by the service and ambient conditions. Approximate thickness of the external surface, shall be 0.5 mm. No dark pigments or resin fillers such as calcium carbonate shall be used. d. Reinforcing ribs Where stiffener ribs are used to structurally reinforce the pipe wall, they must be protected in the same manner as specified for the external surface, above. 2. Raw Materials All materials and the manner and degree to which they are used during the construction of all components required for the GRP pipe system described by this specification shall be selected so they will resist the corrosive effects of both the contained and surrounding environments. All structural materials shall be new and free from all deleterious defects and imperfections and only be used for production after having been controlled and approved by the Manufacturer's Quality Department. Testing and controlling shall be done according to the relevant methods Glass Reinforcements shall be compatible with the impregnating resin used and should be suitable for the service intended. Resins used shall be a commercial high grade thermosetting isophtalic, resin as specified No dark pigments shall be used in the GRP pipe or joints. No additives shall be used except when required for viscosity control. Pipes used for Potable Water Service: All GRP pipes and fittings conveying potable water shall be certified and listed for potable water use by the Water Regulations Advisory Scheme "WRAS" United Kingdom, in accordance with BS 6920.


Page E-29 of 115


Specifications

D. Requirem ents 1.

Wall Thickness

The wall thickness required for each size/pressure class shall be established by the manufacturer to meet the design requirements but in no case shall the wall thickness be less than (0.010 x DN); where DN is the nominal pipe inside diameter. For ribbed pipe, the minimum shell wall thickness shall be (0.005 x DN); where DN is the nominal pipe inside diameter. The pipe working pressure class shall be based on the Hydrostatic design basis (HDB) of the pipe with a design (service) factor of 0.5. 2.

Length

GRP pipe shall be manufactured in standard laying lengths of not greater than 12 meters. Random short lengths, if supplied, shall not exceed 5% of the quantity supplied of each size. The tolerance on the Manufacturer's declared laying length shall not exceed ± 25 mm. 3.

Diameters

Pipe shall be manufactured in standard metric sizes based on the pipe nominal diameter in sizes 25 mm and larger. The actual inside diameter shall not vary from the nominal inside diameter by, more than 1 % or 4 mm whichever is greater. 4.

Stiffness

The pipe stiffness shall be determined by the Manufacturer to meet the design requirement with particular regard to installation method, burial depths, deflection limits, buckling and vacuum requirements, in accordance with AWWA M45. The pipe initial specific stiffness (EI/D3) shall, in no case, be less than 10,000 N/m2, when tested in accordance with ASTM D2412 or BS 5480. 5.

Beam Strength

GRP pipe shall meet the minimum longitudinal tensile strength requirements specified in AWWA C950 for the appropriate operating pressure class. The above requirements are intended to provide adequate strength for normal handling and under ground conditions. Pipe intended to withstand the end load resulting from internal pressure at changes of direction or the beam load resulting from above ground installation shall require higher longitudinal strengths and a suitably designed, fully restrained, jointing system. 6.

Hoop Tensile Strength

GRP pipe systems shall meet the minimum hoop tensile strength requirements specified in AWWA C950 standard for the appropriate operating pressure class. However, the structural wall hoop tensile stress for pressure pipe shall not be less than 12 kN/m2 when tested in accordance with A WW A C950 or BS 5480. 7.

Hardness - Barcol (ASTM D 2583)

The laminated surface shall have Barcol hardness of at least 90% of resin manufacturer's minimum specified hardness for the cured resin.


Page E-30 of 115


8.

Joints

a)

Flexible Joints

Specifications

Standard buried pipe with unrestrained joints shall be filament wound GRP coupling, with confined rubber ring gaskets. Rubber rings shall be of natural rubber conforming to BSEN 681–1 or ASTM F 477 for seawater service, and synthetic rubber for other services. Neoprene rubber shall be used for oil contaminated services. Joints shall allow for at least 0.75° deviation while remaining watertight at 1.5 times the pipe operating pressure. The rubber rings shall be the sole element depended upon for water tightness. This system will require thrust blocks at changes in direction to accommodate thrust loads, b)

Rigid Joints Flanges: GRP flanges where used shall be machine filament wound upto 1800mmø. Contact moulded flanges may be used for sizes 2000mm and larger. Flanges shall be manufactured with epoxy or Vinylester resin. Flanges shall be flat faced with full or '0' Ring type gaskets. Gasket material and design shall be as per the Manufacturer's recommendations. The pipe Manufacturer shall provide the torqueing sequence and maximum tightening torque as appropriate for each flange size and design and should at least be present in a supervisory role during the torqueing of all flange connections. Washers shall be used under all nuts and bolts heads with special spacers to be used at flange to valve connections as required. Flange drilling and rating shall be as specified on the drawings. Flanged joints shall be tensile resistant for above ground service.

c)

Reinforced Overlay Joints (butt & wrap) Butt & Wrap joint where used only for site modification or repair shall consist of layers of Glass fiber reinforcement impregnated with resin. The wall thickness, tensile and axial strength of the reinforced overlay shall meet or exceed the design strength of the adjoining pipe sections. Butt & Wrap joints on site shall be performed only by or under the supervision of the pipe Manufacturer. All of the joint types shall be designed to remain watertight when tested after installation to 1.5 times the pipe line pressure for a minimum of one (1) hour.

9.

Workmanship

GRP pipe, fittings and joints shall be free from de-laminations, cracks, bubbles, pinholes, pits, blisters, foreign inclusions and resin-starved areas that due to their nature, degree or extent detrimentally affect the strength and serviceability of the pipe. No glass fiber reinforcements shall penetrate the interior surface of the pipe wall. Joint sealing surfaces shall be free of dents, gouges, de-laminations, or other surface irregularities that will affect the integrity of the joints. GRP pipe, fittings and joints shall be as uniform as commercially practicable in colour, capacity, density and other physical properties.


Page E-31 of 115


10.

Specifications

Fittings

GRP fittings such as bends, tees, junctions and reducers shall be equal or superior in performance to the GRP pipe of the same diameter and pressure. All fittings shall have a smooth internal surface with similar wall construction. Standard fittings shall be filament wound or mode by mitered construction from filament wound GRP pipes. For GRP fittings, the deviation from the stated value of the angle of change of direction of a bend, tee, junction etc. shall not exceed ± 1 degree. The tolerance on the Manufacturer's declared length of fitting shall be ± 10 mm taken from the point of intersection to the end of the fitting or ± 10 mm on a straight fittings. All GRP fittings shall be fabricated in the factory, by the pipe manufacturer, to ensure Quality Control (Under no circumstance shall fabrication of fittings be allowed on site by Contractor). Complex fittings arrangements may be pre-assembled by the pipe Manufacturer in the factory such that field joints are kept to a minimum.

E. Design P aram eters Pipe shall meet the following minimum design requirements: Operating Pressure (Pw)

Minimum 12 bar or as specified

Surge Pressure (Ps)

40% of ‘Pw' unless otherwise specified. As specified. 1 .0 m or as shown on drawings for buried pipe. 2.0% Min

Vacuum (Pv) Minimum Earth Cover Initial Installed Deflection for buried pipe Long term Installed Deflection for Buried Pipe

5.0% Max. (3.0% max for ribbed pipe and 5% for solid wall pipe).

Service temperature Safety Factors Pressure Rating Ring Bending Strain (stress) Combined Strain (stress) Buckling

As specified > = 1.8 > = 1.5 > = 1.5 > = 2.5

The Contractor shall be responsible for implementing / installing the correct design for each GRP pipe system. Buried GRP pipe design shall be established in accordance with A WW A M45. Support requirements for complex above ground piping systems shall be based on computer flexibility analysis (static and dynamic) of the piping systems. Pipe manufacturer’s Design calculations shall be submitted to the Engineer for review and approval.

F. I nspection & Testing

The Manufacturer shall take adequate measures in the production of the products covered by this specification to assure compliance with the requirements herein. An Inspection and Testing plan (ITP) should be forwarded to the Engineer for approval. Plant inspection by the Contractor’s or Engineers qualified personnel or the omission of such inspections shall


Page E-32 of 115


Specifications

not relieve the Manufacturer of the responsibility to furnish products complying with the requirements of the minimum manufacturing requirements given herein. Production and Testing Notice - When plant inspection is required by the Contractor or Client the Manufacturer shall provide adequate advance notice of when and where production and testing of ordered products will commence. The Contractor and / or Client Inspector (s) shall have free access with reasonable advance notice to the Manufacturer's plant areas that are necessary to assure that products comply with all requirements herein. As a minimum the following tests shall be performed at the indicated intervals unless otherwise agreed-upon, and shall form a part of the Manufacturers overall quality control program. The following test shall be conducted on every pipe; -

Visual Inspection Dimension Measurements Resin cure (Barcol Hardness)

The following tests shall be conducted on pipe samples at a frequency of not less than one per 50 pipes (one lot) of the same Diameter and Pressure. -

Stiffness Hoop Tensile Strength Longitudinal Tensile Strength Loss on ignition (composition)

However, this sampling is not applicable for GRP pipe manufactured thru helical winding process. The determination of strength properties may be treated as qualification testing, provided the manufacturer declares the winding angle and submits qualification test reports duly authenticated by third party. Pipe hydrostatic pressure test shall be carried out on 100% of Pipes. Test methods shall be in accordance with AWWA C950 and BS 5480. Copies of all test reports shall be submitted to the Client for each lot delivered to Site.

G. M arking

Each pipe and fitting shall be indelibly marked with the following information. -


Manufacturers Name or trademark Manufacturing date Manufacturing number Nominal diameter in mm Operating pressure in bar Nominal laying length in meter (for pipe only) Manufacturers Inspection mark Applicable standard complying the product.

Page E-33 of 115


Specifications

H. Subm ittals

The following information shall be submitted by the manufacturer. 1. 2. 3. 4. 5. 6. 7.

Pipe Data Sheet (s) Detailed Resin Data Detailed Glass Reinforcement Data Detailed Pipe Aggregate Data Detailed Joint & Gasket Data GRP Pipe Manufacturer's Pre-Qualification Manufacturer's ISO 9001 Certification

In addition to the above information, the following shall be submitted during the mobilization period: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

Detailed manufacturing process for pipe, joints and fittings. Detailed drawings for pipe ends, joints and fittings. Complete pipe design calculations for each Diameter/Pressure. Friction loss factors of pipes and fittings Manufacturers Quality Control and Assurance Manual. Proposed Inspection and Testing Program (ITP). Pipe Manufacturers written handling, storage and installation instructions. Proposed Hydrotest method statement Proposed pipe transport procedures. Qualification (Type) Test results and report for: - Long term stiffness (Aging factors); for buried pipe only - Long term hydrostatic Design Basis (HDB); for pressure pipe only

I . I nstallation (General Requirem ents) -

-

-

The Contractor shall submit the pipe Manufacturer's Installation Manual and associated Data for engineer’s review. A site meeting to include the engineer, the Contractor and Manufacturer is to occur within two weeks from Contract Award to clarify any outstanding issues / questions on the given installation procedures. GRP pipe shall be handled, stored, transported and installed in strict accordance to the Manufacturer written instructions. The pipe installation procedures and practices chosen shall meet the design requirements specified. No stacking of pipe larger than 1.8 m in diameter shall be allowed on site or during transport. Reinforced concrete thrust blocks shall be used at all changes in direction, size reduction / expansion, and other thrust locations under ground for unrestrained pressure systems. Thrust blocks shall encase the entire GRP fitting at the directional change and should be constructed to fully absorb all thrust loads. Thrust block sizes may be reduced or eliminated by using an axially restrained piping system utilising high axial strength GRP pipe and fittings and a suitable restrained pipe joint design. Pipe deflection readings shall be taken and recorded on all buried pipe at three meter intervals. Initial deflections shall not show a reduction in internal vertical. The Contractor shall employ on a full-time basis the services of field representatives from the pipe manufacturer throughout the pipe off loading, storage, installation and testing period. For standard buried unrestrained pipeline sections, a flexibly jointed short pipe shall be incorporated outside rigid structures to provide pipeline flexibility against differential settlement. A minimum of two (2) flexible joints on either side of a rigid structure is required. The length of the short pipe shall be in accordance with the


Page E-34 of 115


Specifications

manufacturer’s recommendation.

J. Onshore Buoyancy Considerations

Where the pipe is to be installed on-shore within water table level, proper considerations have to be taken to prevent pipe flotation. In general, a minimum soil cover equal to one pipe diameter should be kept above the, pipe crown to prevent flotation. GRP PIPE DATA SHEET (FOR EACH DIAMETER/PRESSURE/SERVICE) (TO BE PROVIDED PRIOR TO START OF PIPE MANUFACTURING) Design Parameters

Units

Nominal Diameter

:

mm

Pipe Manufacturing Process Service

: :

Rated Working Pressure Joint Type Maximum Allowable Vacuum

: : :

Barg

Laying Length

:

m

Nominal Wall Thickness Inner Layer Thickness Resin Type Glass Type

: : : :

mm mm

Structural Wall

: : :

mm

: : :

mm

:

Pa

Barg

Pipe Wall structure

Outer Liner

Thickness Resin Type Glass Type Thickness Resin Type Glass Type

Mechanical Properties Design Specific Tangential Initial Stiffness

E1.17

Design Initial Longitudinal Tensile Strength :

MPa

Design Initial Hoop Tensile Strength

Mpa

:

Ductile Iron Pipes Ductile iron pipes shall comply with the following requirements: (i)

Materials: Ductile iron pipes shall be manufactured from cast spheroidal graphite iron, having mechanical properties not less than the values in the following table:


Page E-35 of 115


Specifications

CentrifugallyCas t

Not CentrifugallyCast

Tensile Strength (MPa)

420

400

0.2% proof stress (MPa)

300

300

Modulus of rupture (MPa)

550

500

10

5

7

5

Elongation at break (%) (units up to DN 1000) Elongation at break (%) (units over DN 1000)

Note: DN = Nominal Internal Diameter in Millimetres (ii)

Manufacture: Straight Pipes shall be manufactured by centrifugal casting, and bends and fittings shall be cast in sand or metal moulds. Wall thickness of pipes and fittings shall be calculated from the formula: Thickness = K(0.5 +0.001 DN) - in which, unless otherwise specified, the value of K shall be as follows: For centrifugally cast pipes, For bends and tapers, For tees and branches,

(iii)

K=9 K = 12 K = 14

Joints: Unless otherwise specified, pipes and fittings shall be provided with push fit integrally cast socket and spigot joints, capable of accepting the following angular deviations and axial movements, at the specified pressure rating, without leakage: Nominal Diameter (mm)

(iv)

up to 300

300600

700- 1200

1400-2000

Deflection Angle

5o

4o

2½ o

1½ o

Axial Movement (mm)

25

40

50

60

Dimensions: Unless otherwise specified, socket and spigot pipes having diameters up to and including 600 millimetres may be supplied with individual lengths of from 4 to 6 metres, and pipes having larger diameters with individual lengths of from 5.5 to 8 metres. The tolerances on finished internal diameter of pipes shall be as follows: Diameter up to and including 250mm, + or - 5mm Diameter exceeding 250mm, +0.02DN and -0.005DN


Page E-36 of 115


Specifications

The tolerance on wall thickness shall be calculated from the following formula: Tolerance = -(1.3 + 0.001DN) In no case shall the wall thickness be less than 4.8 millimetres. The barrels of nominally straight pipes shall not show curvature or other departure from straightness, greater than the values given in, and determined in accordance with the following procedure: A true straight edge shall be placed against the outside of the pipe barrel, along a side showing concave curvature, so as to contact the barrel at points separated by at least two thirds of the length of the barrel. The maximum radial distance between any other point on the pipe barrel, and the straight edge, shall not exceed 0.125% of the length of the pipe. (v)

Performance: The superficial hardness of the iron in finished pipes shall not exceed 230 Brinell, and that of the iron in fittings shall not exceed 250 Brinell. The performance of pipes shall be verified by the testing of random samples, selected in accordance with Clause E2.1, and subjected to the tests specified in Clause E2.4.

(vi)

Corrosion protection: All pipes of sizes up to and including DN800 shall be coated externally with metallic zinc. The Zinc coating shall contain not less than 99.9% zinc, and shall be applied at a rate of not less than 130 grams per square metre of surface. Pipes of sizes greater than DN800 shall be coated externally, either with metallic zinc, as above, or with zinc rich paint, containing not less than 85% zinc, so that the mass of zinc is not less than 150 grams per square metre. Unless otherwise specified, the internal surfaces of the barrels of pipes and fittings shall be lined with cement mortar. The thickness of the lining of units of various diameters shall comply with the following: Nominal Size of Unit, mm dia

Minimum average thickness, mm

Minimum individual thickness value, mm

80 - 300

3.0

2.5

350 - 600

4.5

3.5

700 - 1200

5.5

4.5

1300 - 2000

8.0

6.5

over 2000

12.0

10.0

All surfaces of pipes and fittings, other than mortar lined surfaces, shall be coated with bitumen, to a minimum average thickness of 70 microns, and with an absolute minimum thickness at any individual point, of 50 microns. Where pipes and fittings are required to be protected additionally with polyethylene sheet wrapping, this may, unless otherwise instructed, be applied either in the factory, or on Site. Factory applied polyethylene wrapping shall comply with the following requirements:


Page E-37 of 115


Specifications

Polyethylene sheet wrapping may be unbonded, or bonded to the pipe surface. If unbonded, it shall be closely wrapped around the pipe barrel, and secured along the seam so as to provide a tensile strength across the seam not less than that of the material itself. If bonded, the peel strength shall be not less than 20 newtons per centimetre of strip width. The thickness of the material shall be between 0.2 and 0.25 millimetres, if the tensile strength is in excess of 15MPa, and at least 1.8 millimetres if the tensile strength is less than 15MPa, or is unspecified. The wrapping shall be free from "holidays" when spark tested at 25kV. E1.18

Steel Pipes General Unless fabrication on Site has been specifically approved in writing, steel pipes and fittings shall be factory made. Site fabrication of specials will be permitted, subject to the detailed provisions of this clause. Factory welding of longitudinal and spiral seams shall be by an automatic submerged arc welding process, except for smaller diameter pipes as detailed under 'Manufacture' in this clause. The ends of pipes, fittings and specials shall be fully prepared for jointing by the specified method, prior to delivery to Site. Internal and external corrosion protection systems shall normally be applied at the factory, and pipes and fittings shall be supplied to the Site with adequate quantities of materials to permit the completion of the protection systems at welded joints on Site. Materials Steel shall be manufactured by an open hearth, electric or basic oxygen process. For welded pipes, Grades 32 and 36 steel may be supplied rimmed, otherwise all steel shall be fully or semi-killed. Unless otherwise specified, steel shall comply with the chemical composition, and mechanical properties, for the appropriate grade, as follows: Maximum Content of Non-Ferrous Elements %

Minimum Yield Stress

Minimum Elongation

Grade

C

Si

Mn

P

S

MPa

%

32

0.16

-

0.70

0.05

0.05

195

25

36

0.17

0.35

0.80

0.05

0.05

215

24

40

0.25

0.35

1.20

0.05

0.05

227.5

22

43

0.25

0.50

1.50

0.04

0.04

270

20

50

0.20

0.50

1.60

0.04

0.04

345

18

Full details of chemical composition and recommended welding procedures shall be provided. Manufacture Seamless manufacture will not be permitted for Light Duty Class L pipes of any diameter nor for any class of pipe exceeding 50mm nominal bore.


Page E-38 of 115


Specifications

Butt welding may be used for longitudinal seams in pipes up to and including 100mm nominal diameter, manufactured from rolled steel strip having a thickness not exceeding 5.4mm. Electric resistance and induction welding may be used for longitudinal seams in pipes up to and including 500mm nominal diameter, manufactured from rolled steel strip having a thickness not exceeding 10mm. Submerged arc welding, using an automatic process, may be used for longitudinal or spiral seam welds for pipes of nominal diameters exceeding 100mm, using sheet steel having a thickness not exceeding 32mm. There shall be at least two weld runs, one of which shall be on the inside of the pipe. Heat treatment shall be applied to all cold finished pipes, and to the weld zones of electric resistance or inducation welded pipes with diameters of 200mm or more. Sheet and plate steel shall be shaped by rolling or pressing only. Special fittings may be fabricated on Site using, to the greatest possible extent, components cut from factory made and tested pipes. Fabrication shall use qualified welders and procedures, following the steel supplier's recommendations. All units, whether factory or Site fabricated, shall have a workmanlike finish, free from visual defects, and shall pass all specified tests. Butt welded, electric resistance and induction welded units shall not include welds used for joining lengths of strip steel. Dimensions Steel pipes with nominal diameters up to and including 150mm shall have average wall thicknesses not less than those given in the following table for the appropriate class. Individual thickness measurements less than the tabulated values will be accepted if within the stated tolerance.

Nominal Diameter Mm 6 8 10 15 20 25 32 40 50 65 80 100 125 150 Tolerance

Thickness mm Light Duty Class L 1.8 1.8 1.8 2.0 2.3 2.65 2.65 2.90 2.90 3.25 3.25 3.65 4.5 4.5 -8%

Medium Duty Class M 2.0 2.35 2.35 2.65 2.65 3.25 3.25 3.25 3.65 3.65 4.05 4.5 4.85 4.85 -10%

Heavy Duty Class H 2.65 2.9 2.9 3.25 3.25 4.05 4.05 4.05 4.5 4.5 4.85 5.4 5.4 5.4 -12.5%

Steel pipes with nominal diameters greater than 150 and not exceeding 480mm shall have average wall thicknesses not less than those given in the following table for the


Page E-39 of 115


Specifications

appropriate class. Individual thickness measurements shall be not more than 15% above or 12.5% below the tabulated value. Nominal Diameter mm

Thickness mm Schedule 20

Schedule 30

Schedule 40

Schedule 60

200

6.35

7.04

8.18

10.31

250

6.35

7.80

9.27

12.70

300

6.35

8.38

10.31

14.27

350

7.92

9.52

11.13

15.09

400

7.92

9.52

12.70

16.64

450

7.92

11.13

14.27

19.05

Note: Schedule numbers are as used in API 5L Steel pipes with nominal diameters greater than 480mm, unless otherwise specified, shall have minimum wall thicknesses such that the ratio of internal pipe diameter to minimum wall thickness does not exceed the value given in the following table for the appropriate steel grade and pipe pressure rating.

Steel Grade

Diameter: Thickness Ratio for Stated Pressure Rating

6 bar

10 bar

16 bar

25 bar

40 bar

32

130

130

122

78

48

36

130

130

130

86

53

40

130

130

130

91

56

43

130

130

130

108

67

50

130

130

130

130

86

Steel pipes with nominal diameters up to and including 150mm shall be supplied in lengths of between 4 and 7 metres. Pipes of larger diameters shall have individual lengths of between 6 and 10 metres. Jointing Provisions Steel pipes with nominal diameters up to and including 150mm shall be threaded at both ends and provided with a detachable screwed coupling attached to one end. Couplings shall have a minimum length of 44% of the pipe diameter, plus 30mm, and shall have parallel threads. Pipe ends shall be provided with taper threads. Couplings shall be made from similar material to that of the pipes. Steel pipes with nominal diameters exceeding 150mm, and not exceeding 650mm shall be provided with sleeve or socket type joints providing a double seal. The inner seal shall be provided by a rubber 0-ring, positively located by a groove in a raised portion of the pipe spigot end, and the outer seal by an externally Site welded joint between the end of the Vol 3, Section3 – Civil Specifications

Page E-40 of 115


Specifications

pipe socket and the periphery of a steel flange to be located at least 250mm back from the rubber 0-ring on the pipe spigot end. Steel pipes of diameters exceeding 650mm shall be provided with ends bevelled for butt welding, or with sleeved, collared or shaped ends providing socket and spigot assembly. Pipes for jointing by the latter method shall be suitable for the making of internal and external welds on Site, and shall be drilled, and fitted with a nipple to permit air testing between the internal and external welds. Pipes for butt welding shall have their ends square to the axis of the pipe within 1.5 millimetre, or 1 millimetre per 300 millimetres of pipe outside diameter, whichever is the greater. Corrosion Protection Unless otherwise specified, steel pipes shall be provided with internal and external corrosion protection systems as follows. Pipes and fittings up to and including 150mm nominal diameter shall be hot dip galvanised. Prior to galvanising, units shall be thoroughly descaled and cleaned. Galvanising shall be carried out by dipping in a bath containing not less than 98.5% by weight of molten zinc. The whole surface of the unit coated with uniformly adherent zinc, capable of passing an approved copper sulphate solution immersion test. Galvanising shall be carried out prior to threading of jointing surfaces. Pipes and fittings of nominal diameters greater than 150mm shall be protected externally by reinforced bitumen enamel wrapping, or coal tar enamel wrapping, and internally by cement mortar lining. Where in contact with sewage, the cement mortar lining shall have an additional coating of bitumen. Surfaces to be protected shall be thoroughly cleaned to remove all scale, rust, grease or other extraneous matter, by acid pickling, abrasive, mechanical or flame descaling. Reinforced bitumen or coal tar enamel wrapping shall comprise hot applied, mineral filled, bitumen, or coal tar, giving a minimum finished thickness of 3mm. Reinforcement shall comprise an inner layer of 40 grams/square metre glass tissue, spirally wound with overlap, separated from the pipe surface by at least 1mm thickness of enamel, and an outer sheathing of bitumen or coal tar impregnated, longitudinally reinforced, glass fabric spirally wound onto the pipe with overlap, and separated by at least 1mm of enamel from the inner glass reinforcement. Cement mortar lining shall be a centrifugally applied mortar containing not less than 1000kg per cubic metre of Portland or Sulphate Resisting cement, and suitably graded silica sand. The water cement ratio shall be between 0.30 and 0.45:1 by mass. The minimum thickness of lining shall be 6mm for pipes up to and including 325mm diameter, 7mm for pipes exceeding 325 and not exceeding 610mm diameter, 9mm for pipes exceeding 610mm and not exceeding 1220mm diameter, and 12mm for pipes exceeding 1220mm diameter. The lining thickness shall not exceed the specified value by more than 3mm. Where coatings other than those described above are specified, the requirements are given in Section G, or elsewhere in this Specification.


Page E-41 of 115


Specifications

Factory Testing Tensile tests on the steel used for pipe manufacture shall show compliance with the yield strength and elongation properties specified for the appropriate grade of steel. Tensile tests on samples cut to include a weld shall show strengths not less than specified for the base metal. Bend tests shall be carried out on complete tubes of nominal bore up to and including 50mm. Ungalvanised tubes shall be bent through 180 degrees around a former having a radius equal to six times the pipe outside diameter without signs of fracture or failure. Galvanised tubes shall be bent through 90 degrees around a former having a radius of eight times the pipe outside diameter, without signs of fracture or failure of the steel. Destructive weld tests shall be carried out on samples obtained from each batch of pipes. A batch shall be defined as the number of pipes manufactured during a single run. When more than one hundred pipes are manufactured during a single run sampling shall be at the rate of one pipe per hundred, or part thereof. Pipes of nominal diameter exceeding 50mm and not exceeding 150mm shall have test rings not less than 38mm cut from them and flattened between parallel plates. Any weld in the sample shall be positioned at the point of maximum bending, and shall show no sign of fracturing until the distance between the plates is less than 75% of the original outside pipe diameter. No sign of fracture in the base metal shall occur until the distance between the plates is less than 60% of the original outside diameter. Pipes greater than 150mm nominal diameter shall have samples cut from their ends and subjected to a weld bend test, by bending the sample through 180 degrees around a former having a radius equal to twice the pipe wall thickness. After bending, the sample shall show no crack in the weld metal, or between weld metal and base metal, with a dimension exceeding 3mm. Alternatively, if cracking or fracture does occur, the sample shall be opened and the fracture surfaces examined. The sample will be regarded as having passed the test if the fracture surfaces show no gas pockets or slag inclusions having any dimension exceeding 2mm. In the event that any test piece should fail any of the specified tests, then two further tests pieces shall be taken from the same pipe, and subjected to the same test. If both these additional test pieces pass the required test, then the pipe and the batch of 100 pipes which it represents will be regarded as having satisfied the requirements of the Specification in respect of the particular test. If either of the additional test pieces fails the test, then the pipe and the batch which it represents, will be rejected. The manufacturer will, however, retain the option of testing all the remaining pipes in the batch, at his own expense, and each pipe which then passes all the specified tests will be regarded as acceptable. In addition to the destructive tests specified above, all welded steel pipes shall be subject to non-destructive testing of the welds, as follows: Within an axial distance of 200mm of the pipe ends all welds shall be subject to radiographic examination. The acceptance limits for slag inclusions and gas pockets shall be as agreed with the Engineer. The remainder of all welds shall be subject to either radiographic or ultrasonic examination. Acceptance criteria for the assessment of imperfections identified by either method shall be as agreed with the Engineer’s Representative. Every complete pipe shall be hydrostatically tested to a pressure corresponding to a circumferential tensile stress in the pipe wall equal to 75% of the specified yield strength Vol 3, Section3 – Civil Specifications

Page E-42 of 115


Specifications

of the steel. The test pressure shall be held for sufficient time to permit inspection of all weld seams, which shall show no signs of leakage. Galvanised coatings of small diameter pipes shall be tested by dipping sample lengths of pipe in a copper sulphate solution containing 33 grams of crystalline copper sulphate per 100ml of distilled water. Samples shall have a length of 200mm for diameters up to and including 32mm, 150mm for diameters exceeding 32mm and not exceeding 65mm, and 100mm for diameters exceeding 65mm, and shall be prepared by dipping in a 2% solution of sulphuric acid for 15 seconds, and then rinsing and drying. The sample shall then be tested by dipping four times for a duration of one minute in the copper sulphate solution at a temperature between 15 and 20 degrees centigrade. Between dips the sample shall be rinsed, cleaned and dried. After the dips, the sample shall show no red deposit of metallic copper on the base metal, after rinsing and wiping dry, other than within 25mm of the ends. If any such red deposit of copper remains after rinsing and wiping, and it can be removed by rubbing, peeling or scrubbing after immersion in 1:10 hydrochloric acid solution for 15 seconds, then the sample will be regarded as having passed the test if continuous zinc coating is found beneath the removed copper. Bituminous and coal tar based coatings shall be tested for continuity of coverage by the use of holiday detectors. All pinholes or other discontinuities shall be made good. Adhesion of coatings shall be checked by cutting through the coating and peeling off a 50mm wide strip. Inspection during and after peeling shall show adhesion between coating and pipe to have been obtained over the whole area. E1.19

Stainless Steel Pipe General A.

Scope: 1 Stainless steel pipe, fittings and appurtenances.

B.

Reference standards: 1. AWWA MIL 11 : Steel Pipe – A Guide for Design and Installation 2. AWWA C200, C203 3. ANSI B1.1, B 36.19, B 18.2 4. ASTM A167, A182, A193, A194, A234, A240, A269, A304, A312, A325, 403,A 774,A 778. 5. AWS D1.1

C.

Source 1. 2. 3. 4.

D.

Quality Control Shop test fabricated pipe, fittings and specials after fabrication. Hydrostatically test fabricated pipe Test all welds of fittings and specials which are assembled from Hydrostatically tested fabricated pipe by non destructive means such as dye-penetration test. Follow requirements of AWWA C200.

Quality Control: 1. All welders certified per AWS D1.1.

Submittals Shop drawings and product data 1. Detailed drawings showing fabrication and weld locations; and the 2. Complete data of material proposed. Vol 3, Section3 – Civil Specifications

Page E-43 of 115


3. 4. 5. 6. Test Reports: 1. 2.

Specifications

Do not manufacture until approved. Show where each numbered pipe, fitting or special is to be installed. Numbers correspond to those tagged on pipe. Prepare drawings to scale. Submit certified copies of shop test on fabricated pipe, fittings and specials. Reports of field tests.

Product Delivery, Storage and Handling A.

B.

C.

Handling and storage: 1. Ensure undamaged condition. 2. Follow AWWA C203, Section 2.14. 3. Use wide canvas slings and wide padded skids. 4. Do not use bare cables, chains, hooks metal bars, or narrow skids. 5. Do not store directly on ground, provide proper blocking. Shipment: 1. Support on padded saddles not less then 300 mm. 2. Laterally support pipe ends, fittings, and specials to maintain shape. 3. Separate materials so they are protected from contact damage 4. Securely fasten load to prevent movement in transit. Delivery: 1. Reject products with dents, kinks, abrupt changes of curvature or other damage. 2. Reject any products dropped from truck or crane. 3. Replace or recondition rejected items at contractor’s expense. 4. Reconditioning subject to Engineer’s approval.

Material A.

Pipe: 1.

2.

3.

B.

Low Pressure Air (LPA) service: a. ASTM A778. b. Plate: ASTM A240, Type 316L. c. Diameters and wall thickness: ANSI B36.19. d. Min. Wall thickness: Sch.10 (interior or exposed) Sch.40 (buried) liquid service per these Specification documents: a. ASTM A312, welded b. Diameters and wall thickness : ANSI B36.19 c. Grade : Type 316L d. Min. Wall thickness : Sch.40 High Pressure Air service: a. ASTM A269 b. Grade : Type 316L c. Min. Wall thickness : 0.5mm

Fittings and Specials: 1. Low Pressure Air (LPA) Service: a. ASTM A774. b. Plate: Same as for Pipe. c. Diameter and wall thickness: ANSI B36.19. d. Diameter: ANSI B 16.9 , ASTM A234


Page E-44 of 115


Specifications

e. Wall thickness: Same as Pipe 2. Liquid Service: a. ASTM A403, WP-W b. Grade: Type 316L c. Dimensions : ANSI B 16.9 d. Rating: Standard weight, Class D, High Pressure, Class E. e. Use class E flanges for all service categories with test pressures in excess of 15 Bar, as defined in these Specification documents. 3. High Pressure Air: a. Type : Compression b. Grade : Type 316L C.

Flanged Joints: 1. Flanges: a. Face ring type on pipe b. Stub end on fittings. c. Material same as for pipe. d. Backing flanges standard (150 lb.) or high pressure (300 lb), flat face, stainless steel to match pipe. e. Forged stainless steel, ASTM A182, Grade 316L, or slip-on raised face machined when mating with flat faced flange in submerged service and designated hazardous environment. 2. Flange bolting: a. Material : Type 316L b. Type: Bolt and nut: bolt-stud and 2 nuts permitted for 25 mm and larger. c. Bolts and bolts-studs: 1. Length: Ends project 6 mm to 12 mm beyond nuts. 2. Ends: Chamfered or rounded. 3. Threading: ANSI B1.1 Coarse thread series class 2A fit. Bolt studs may be threaded full length. Studs for tapped holes. 4. ASTM A193, Grade B8M hex head bolts. d. Nuts: 1. Dimensions : ANSI B18.2, heavy, semi- finished Pattern 2. Threading: ANSI B 1.1, coarse thread series, class 1 B fit. 3. ASTM A 194, Grade 8M hex head nuts. 3. Mechanical Couplings 1. Couplings: a. Insulating: Dresser “Style 39” Rockwell “416W or equal. b. Reducing: Dresser “ Style 62”, Rockwell “ 415”, or equal. c. Transition coupling: Dresser “62”, Rockwell “413”, or equal. d. Others: Dresser “ Style 38”, Rockwell “411 flexible Coupling”, or equal. e. Flange coupling adapters: 1. 150 mm through 300 mm Rockwell 2912”, Dresser “127”, or equal. 2. 350 mm: Rockwell “ 913”, Dresser”128”. 3. Provide anchor studs at locations indicated or as directed by Engineer. f. Grooved –end, conforming to ASTM A743. 1. Style 77S Victaulic, flexible, or equal 2. Style 07 Victualic, rigid, or equal.


Page E-45 of 115


Specifications

3. Material: 316L S.S. 4. Gasket Type: EPDM 4. Joint harness: a.

Bolts: ASTM A193, Grade B7, or Ryerson Stress-Proof, minimum yield point 690 N/mm2. 1. Threading : ANSI B1.1, Class 2A fit, coarse thread series for 25mm and smaller and 8 thread series for 30 mm and larger, 2. Ends: Chamfered or rounded.

b.

Nuts: Hexagonal, ASTM A 194, Grade 2H, or better. 1. Threading: As specified for bolts except Class 2B fit. 2. Dimensions: ANSI B 18.2, heavy, semi-finished pattern.

c.

Washers: Hardened steel, ASTM A 325.

5. Gaskets: a. EPDM D. Expansion Joints: 1.

Flanged with stainless steel bellows.

2.

Flexonics “ Free Flexing Expansion Joint” or equal.

E. Small branch connections: 1. 2.

Pipe nipples: Seamless type 316L stainless steel pipe, ASTM A240 standard weight (Schedule 40). Thread lubricant: Teflon tape.

F.. Wall sleeves: Stainless steel, ASTM A304, Schedule 40S. Water stop material: ASTM A167, Type 304L. Fabrication and Manufacture A. Basis of design: Pipe, fittings and specials. 1. Use fabricated or seamless pipe conforming to ASTM A 778 or ASTM A312 as specified. 2. Use fittings and specials fabricated from hydrostatically tested pipe or welded seamless pipe conforming to ASTM A774 or ASTM A403 as specified. 3. Provide special sizes, dimensions and shapes per drawings. 4. Specified pipe size indicates the nominal inside diameter where 300 mm or smaller, and the actual outside diameter where 350 mm or larger. 5. Strength design criteria: a. Reinforce or increase shell thickness to maintain combined stress due to internal pressure and bending below 50% of yield strength. b. Internal pressure is the specified test pressure. c. For pipes with no specified test pressure, base design on an internal pressure of 14 Bar. d. Dead load is equal to pipe full of water.


Page E-46 of 115


e.

Specifications

Where pipe is installed in trench; design sheet thickness for external load of 5000 kg per lineal meter.

B. Ends of Sections: 1. 2. 3.

Use outside bevelled for field butt welding. Make welded bell and spigot per AWWA C200. For bell and spigot with rubber gasket. a. Provide gasket for watertight joint under all service conditions, including expansion, contraction and earth settlement. b. Groove spigot ends to retain gasket. c. Make pipe ends self –centering.

4.

For mechanical couplings: a. b. c. d.

make plain type ends per AWWA C200. Grind welds flush on ends without pipe stops to permit slipping the coupling in at least one direction to clear pipe joint. Make outside diameter and out-of-round tolerances within limits per manufacturer’s recommendation. Grooving shall confirm to rigid grooving dimensions.

5. Length tolerance: 1. Make space between pipe ends at least 12 mm or the length recommended by the manufacturer. 6. Special sections: 1.

Provide with ends as required and fabricate to shape, size and dimensions indicated on Drawings.

6. Small branch connections: 1.

Use welded fittings and threaded outlets for connections 60mm and smaller.

2.

Use 25 mm outlet and reducers for connections known to be less than 25 mm. Use pipe nipples or fittings welded to pipe shell and reinforced as required for connections 75mm through 300mm. Locate connections to avoid interference with joints, supports, or other details.

3.

7. Field joints: 1. 2. 3.

Provide flanged, welded and compression sleeve coupled joints in exposed locations as shown on Drawings. Additional field welded and mechanically coupled joints may be provided to facilitate installation. Keep additional field joints to minimum. Location of additional field joints subject to Engineer’s approval

8. Flanged Joints: 1. 2.


Finish flange faces to a Flat to a plane surface within a 0.25 mm maximum tolerance. Maximum tolerance of 0.40 mm/m of flange diameter for flange faces from the normal with respect to axis of pipe. Page E-47 of 115


Specifications

3. 4. 5.

Test flanges for true plane after welding and reface if necessary. Coordinate flange dimensions and drillings between piping, valves and equipment. Blind flanges: a. Conform in diameter, drilling and thickness with flanges to which they attach. b. Reinforce as required.

9. Mechanical Couplings: 1.

Couplings: a. b. c.

2.

Middle ring length not less than 175 mm. Omit pipe stop from inner surface of middle rings where couplings are used for closures or where union connections are requires. Clean couplings and shop prime with manufacturer’s standard rust inhibitive primer.

Joint harnesses. a. Provide joint harnesses on all couplings under pressure. b. Design harnesses per Section 19.8, Table 19.7, of AWWA M11, Steel Pipe Manual except. Lug plate thickness increased 1/3. Fabricate lugs from 3 pieces of plate; single bent plate not acceptable. c. Shop weld lugs to pipe; except where drawings require a sleeve be welded to the pipe and lugs welded to the sleeve. d. Place harness lugs and use bolts of sufficient length so coupling can be slipped clear of joint in at least 1 direction. e. Use at least two bolts per harness. f. Double nut bolts. g. Design bolts based on 276 n/mm2 max stress at hydrostatic test pressure after installation. h. Design harness on couplings not subject to hydrostatic test on basis of 10 Bar hydraulic pressure and above requirements.

3.

Flanged coupling adapters: a. Use per coupling manufacturer’s recommendations. b. After pipe placement determine location and drill anchor stud holes if required by Engineer. c. Hole diameter: Not mote than 3 mm larger than diameter of stud projection. d. Use only at direction and approval of Engineer.

10.

Size grooved coupling joints for proper installation on ends provided.

11.

Shop welded joints: 1. 2.


Make sound and free from embedded scale and slag. Ensure tensile strength across weld is not less than that of the Page E-48 of 115


Specifications

3. 4. 12.

thinner of connected sections. Make watertight. Use butt welds for all joints in line pipe assemblies and in fabrication of fittings and other specials.

Pipe supports, anchors blocking and hangers: 1. 2. 3. 4.

13.

Per requirements of pipe support specification and drawings Install complete with concrete bases, anchor bolts and nuts, plates, rods, and other accessories. Modifications for fit subject to Engineer’s approval. Shop weld lugs required for lateral or longitudinal anchorage.

Type of protective coatings: All pipe, fittings, specials and wall fittings: Exterior exposed: Standard No. 4 polish finish. Buried: Same as steel pipe, E1.18, p.E-42

Installation A.

General: 1. Install as shown on Drawings. 2. All piping beneath concrete slabs and footings to be concrete encased. 3. Buried piping shall be installed in trench in accordance with Section 02700.

B.

Flanged joints: 1. Take care in bolting to avoid restraint on opposite end that would prevent uniform pressure application on gasket. 2. Ensure that stresses are not transmitted to equipment flanges by connecting piping. 3. Gradually tighten bolts, in turn, at uniform rate. 4. Permanently support pipe at equipment to obtain accurate matching of bolt holes and uniform contact over surface of flange, before installing bolts. 5. Ensure pump connection piping is free to move longitudinally while bolts are tightened. 6. Level, align and wedge equipment into position to fit connecting piping. 7. Do not grout equipment until connecting piping properly aligned. 8. Test pump connections by loosening flange bolts. There should be no movement of piping relative to equipment or opening of equipment connection joints.

C.

Field welded joints. By certified welders Furnish test specimens as required by Engineer.

D.

Grooved coupling joints: 1. Arrange piping so the clear space between pipe ends inside each grooved coupling is not more than 1 times, or less than ½ times the maximum recommended by manufacturer. 2. Couplings shall not be used to connect valves, equipment, or structures. 3. Grooved flanges shall not be used without prior written approval of the Engineer.

E.

Coupling: 1. Remove dirt or foreign material from pipe ends and couplings. 2. Keep gaskets clean. 3. Use wrenches recommended by coupling manufacturer.


Page E-49 of 115


4.

Specifications

Tighten all bolts the same amount with parts square and symmetrical.

F.

Anchorage: whether indicated on Drawings or not. 1. Anchor or harness piping with mechanically couplings or similar joints to prevent separation of joints in all exposed locations where coupling is subject to internal pressure.

G.

Closures: 1. Make length adjustments as necessary by making cuts or by use of wrapper plates. 2. Make wrapper plates the same thickness and material as pipe, full-fillet double welded, and lapped no less than 65 mm. Make the lap no less than 75 mm between pipe ends. 3. Make closures after backfilling as near a practical and after pipe temperature has had time to stabilize. 4. Make closures in early morning when air and pipe are coolest.

H.

Mitre cutting: 1. For bends up to 4-½ degrees, mitre by cutting one end. 2. For bends up to 22-½ degrees, mitre by cutting two adjacent ends. 3. For bends greater than 22-½ degrees, use fabricated bends.

I. Alignment: Make horizontal and vertical deviation not more than 150 mm from lines shown on Drawings, at any point. No tolerance at manholes, valves or connections to existing pipelines. J. Insulation of dissimilar piping material: Electrically insulate connections between stainless steel and ductile iron, steel, copper and other dissimilar piping materials for corrosion protection. Make connections using non-conductive gaskets and bolt spacers/sleeves. Use One piece sleeves and washers for bolt isolation. K.Provide expansion joint for Low Pressure Air (LPA) pipe at maximum 30 meter intervals. Cleaning A.

Remove dirt, rocks, debris and other foreign material from all pipelines. For low pressure air remove all material greater than 1 micron in diameter. Keep interior of pipe and fittings thoroughly clean before installation and until work is accepted. Take precautions to prevent entrance of foreign material during jointing, lining repair and inspection operation.

B. C.

Field Quality Control Leaks:

1. 2. 3. 4. 5. 6. 7.


Make all joints and seams watertight and airtight whether tested or not. Inspect all exposed shop and field welded seams. Mark leaks clearly. Do not remove marks until leak corrected. Repair welded joints by grinding or chipping out defective parts and rewelding. Do not hammer welds. Repair leaks discovered within 1 year after Taking- Over of Works at Contractor’s expense.

Page E-50 of 115


E1.20

Specifications

Carbon Steel Pipe This Section includes the specification of carbon steel pipe and applicable fittings identified in the Pipe Schedule and within these Specifications documents Quality Assurance A. Reference Standards American Society for Testing and Materials: a. ASTM A53 - Specification for Pipe, Steel, Black and Hot-Dipped, ZincCoatedWelded and Seamless b. ASTM A 47 - Ferritic Malleable Iron Castings c. ASTM A 105 - Standard Specification for Forgings, Carbon Steel, for Piping Components. d. ASTM A 106 - Standard Specification for Seamless Carbon Steel Pipe for High-Temperature Service. e. ASTM A 181 - Standard Specification for Forgings, Carbon Steel, for General Purpose Piping. f. ASTM A 183 - Standard Specification for Carbon Steel Track Bolts and Nuts g. ASTM A 193 - Standard Specification for Alloy-Steel and Stainless Steel Bolting Materials for High-Temperature Service. h. ASTM A 194 - Standard Specification for Carbon and Alloy Steel Nuts for Bolts for High-Pressure and High-Temperature Service. i. ASTM A 197 - Standard Specification for Cupola Malleable Iron. J. ASTM A 307 - Standard Specification for Carbon Steel Externally Threaded Standard Fasteners. k. ASTM A 536 - Standard Specification for Ductile Iron Castings. I. ASTM A 563 - Standard Specification for Carbon and Alloy Steel Nuts 2.

American Society of Mechanical Engineers a. ASME-17 Boiler and Pressure Vessel Code, Section Ix – Welding and Brazing Qualifications.

3.

American a. b. c. d. e. f. g. h. i. j. k.

National Standards Institute ANSI B21 Pipe Threads. ANSI B16.3 Malleable Iron Threaded Fittings. ANSI B16.5 Pipe Flanges and Flanged Fittings. ANSI B16.9 Factory-Made Wrought Steel Butt Welding Fittings. ANSI B 16.11 Forged Fittings, Socket-welding and Threaded. ANSI B16.25 Butt- welding Ends. ANSI B16.39 Malleable Iron Threaded Pipe Unions. ANSI B31.1 Power Piping. ANSI B31.2 Fuel Gas Piping. ANSI B31.3 Chemical Plant and Refinery Piping. ANSI B36.1 0 Wrought Steel and Iron Pipe

4. American Water Works Association a. AWWA C207-78 Steel Pipe Flanges for Water Works Service - Size 4 in through 144 in. b. AWWA C209-84-Cold Applied Tape Coatings for the Exterior of Special Sections, Connections, and Fittings for Steel Water Pipelines 5. Chlorine Institute a. Comply with Chlorine Institute recommendations for all chlorine pipelines operating under pressure.


Page E-51 of 115


B. Source 1. 2. 3.

Specifications

Quality Control: All products shall be new. Shop test pipe, in accordance with ASTM A312. Hydrostatically test fabricated pipe.

C. Quality Control: 1. All welders certified per ASME-17, Section IX. Pipe: A. Pipe, 50 mm and smaller 1. 2. 3. 4.

Material: Carbon Steel, ASTM A 106. Type: Seamless. Grade: B. Wall Thickness: Schedule 80, ANSI B36.10.

B Pipe, 65mm and larger 1. Material: Carbon Steel, ASTM A53. 2. Type: Seamless or Electric Resistance Welded. Use only Seamless piping for chlorine gas 3. Grade: B, Type S. 4. Wall Thickness: Schedule 40. Use Schedule 80 for Chlorine pipelines operating under pressure. C. Joints 1. Pipe. 50mm and smaller a. Threaded: ANSI B2.1. 2. Pipe, 65mm and larger a. Flanged: ANSI B16.5, Class 150, and ASTM 105 b. Butt-welded. D. Fittings 1.

50mm and smaller a. Joint: Threaded. b. Rating: Class 150 for Malleable Iron; Class 125 for Cast Iron. Use 1364 kg CWP forged steel fittings for chlorine gas (pressure). c. Material: Malleable iron ASTM A 197 or cast iron ASTM A 126. d. Dimensions: ANSI B16.3

2. 65mm and a. b. c. d. e.

larger Joint: Butt-welded. Rating: Standard weight, Class D, High Pressure, Class E Material: Carbon steel, ASTM A234, Grade WPB. Dimensions: ANSI B16.9. Use Class E Flanges for all service categories with test pressures in excess of 15 Bar.

3. 65mm and larger a. Joint: Grooved End. b. Material: Malleable iron ASTM A47 or ductile iron ASTM A536. c. Grooved or shouldered ends to accept mechanical couplings without field preparation. Vol 3, Section3 – Civil Specifications

Page E-52 of 115


d.

Specifications

Manufacturer: Victualic, Gustin-Bacon, or equal.

4. Unions, 50mm and smaller a. Rating: Class 150 or equivalent to fittings b. Material: Malleable iron, black, ASTM A 197, brass to iron seat. Use Ammonia type union with lead washers for chlorine gas (pressure). c. Dimensions: ANSI B16.39. E.

Flanges 1. Type: Weld-neck or slip-on. a. Material: Forged carbon steel, ASTM A 105. b. Raised-face. c. Rated: Standard Weight, Class D 1.03 N/mm2 (150 psi), High Pressure Class E,1.9 N/mm2 (275 psi) d. Dimensioned: ANSI B16.5. e. Use Class E Flanges for all service categories with test of 15 Bar. 2.

When mating with a cast iron flat faced flange, machine off steel flange raised face or provide suitable spacer plate designed for full contact with the flat faced flange.

3.

Grooved –end pipe adapter flange: a. Material: 1. 2. b.

Malleable iron, ASTM A47, or Ductile Iron, ASTM A536.

Rated: Standard Weight, ANSI Class125, High Pressure,ANSI Class 300.

F.

Grooved- end Couplings 1. Type : Rigid 2. Material: a. Malleable iron, ASTM A47, or b. Ductile Iron, ASTM A536 3. Rated: Standard Weight, ANSI Class 125, High Pressure, ANSI Class 300.

G.

Gaskets 1. Flanged Joints: a. Material: Cloth insert rubber b. Thickness: 3.2 mm 2. Grooved – end Joints: Material: EPDM or Chlorinated butyl; ASTM D2000. Dimensions: AWWA C606.

Galvanised Steel Pipe A.

Pipe. 1. 2. 3.


Material: Galvanized Carbon Steel, ASTM A120. Type: Welded or Seamless. Wall Thickness: Schedule 40.

Page E-53 of 115


B.

Joints 1.

C.

Specifications

Threaded: ASTM A – 120

Fittings 1. 2. 3.

Joint: Threaded Material: Malleable iron ASTM A47 Galvanizing to ASTM A –153 Dimensions: ANSI B16.3

Couplings A.

Screwed Coupling 1. 2.

Material Malleable iron, ASTM A197 or A47. Dimensions: ANSI B16.3.

B. Grooved-end Pipe Couplings 1.

Material: a. Malleable iron, ASTM A47, Federal Specification QQ-1-666C, Grade 11. b. Ductile iron, ASTM A536.

Bolting A. Class 150 and 300 Raised-Face Flanges. 1. Bolts: Carbon Steel, ASTM A307, Grade A, hex head. 2. Nuts: Carbon Steel, ASTM A563, Grade A, hex head. B. Grooved-end Joints. 1. Bolts: Heat-treated carbon steel, ASTM A 183. 2. Nuts: Heat-treated carbon steel, ASTM A 183. 3. Tensile strength: 758 N/mm2, minimum. C. Insulating Flanges (steel). 1. 3.2 mm undersize bolting material. 2. Bolts: ASTM A 193, Grade B7 Alloy stud. 3. Nuts: Carbon Steel, heavy hex, ASTM A 194, Grade 2H. Thread Lubricant Teflon Tape. Welding A. General: In accordance with the latest editions of API 1104, ASME-17 and ANSI 831.1 and 831.3. B. Performance Qualifications: 1.


Qualify all welders and welding operators before performing welding under this section. Perform welder qualification tests in accordance with Article III of ASME17.2. Qualify welders and operators in the performance of making groove welds in carbon steel pipe.

Page E-54 of 115


Specifications

C Identification of Welds: Mark each weld with a symbol identifying the person who made the weld. D. Procedure: 1.

2. 3.

No welding shall be performed if there is any rain, high wind or other inclement weather in contact with the weld area or if the ambient temperature is below Design Operating Conditions. If the ambient temperature is less than Design Operating Conditions, local preheating to a temperature warm to the hand is required. Tack weld piping into position. a. b. c.

Remove tack welds if not made by a qualified welder using the same procedure as for the completed weld. If not removed, make tack weld with an electrode the same as, or equivalent to, the electrode to be used for the first weld pass. Remove cracked tack welds.

4.

Clean each layer of deposited weld metal with a power-driven wire brush, prior to depositing each subsequent layer of weld metal, including the final pass. 5. Chip or grind out surface defects which will affect the soundness of the weld. 6. Weld Passes: a. 150mm and Larger Pipe: Minimum of three weld passes using the specified covered electrode. b. 100mm and Under Pipe: Minimum of a full root and second pass. 7.

8.

Welds: Free of cracks, incomplete penetration, weld undercutting, excessive weld reinforcement, porosity, slag inclusions, and other defects in excess of the limits prescribed in Chapter V of ANSI 831.3. Branch Connections: Fit and groove-weld in accordance with the details described and shown in Chapter V of ANSI 831.3.

Fabrication A.

End Preparation: 1. Machine shaping of pipe ends is the preferred method. 2. Oxygen or arc cutting is acceptable only if the cut is made smooth and true with all slag removed either by chipping or grinding. 3. Bevelled Ends for Butt Welding: Meet the requirements of ANSI B16.25.

B. Cleaning: Clean surfaces free of paint, oil, rust, scale, slag, or detrimental to welding. C. Alignment and Spacing: 1. 2.

Align ends to be joined within existing commercial tolerances on diameters, wall thicknesses, and out-of-roundness. Root Opening of the Joint: As stated in the welding procedure specification as specified in Article II of ASME-17.

Flanged Joints A. Take care in bolting to avoid restraint on opposite end that would prevent uniform pressure application on gasket. Vol 3, Section3 – Civil Specifications

Page E-55 of 115


Specifications

B. Pipe or fitting free to move in any direction while bolting. C. Gradually tighten bolts, in turn, at uniform rate. Follow manufacturer's recommendations. D. Ensure that stresses are not transmitted to equipment or valve flanges by connecting piping. E. Permanently support pipe to equipment to obtain accurate matching of bolt holes and uniform contact over surface of flange, before installing bolts. E1.21

Mechanical Joints - General Other than in cases where welding is used, or where detachable mechanical couplings (Clause E1.24) are used, all pipes shall be provided with a complete mechanical jointing system by the pipe manufacturer. All components of the jointing system shall be mutually compatible, and shall be capable of providing a lasting watertight seal under the specified operating conditions, and in the specified tests. The design and assembly of the joint shall be such that the stresses developed in the pipes, and joint components, do not cause harm. Unless otherwise specified, pipes shall be provided with an appropriate mechanical jointing system as specified.

E1.22

Flanged Joints for Iron and Steel Pipework Flanges for grey and ductile iron pipes and fittings shall have at least a 16 bar pressure rating and be drilled accordingly. Where an item to which a flange is to be jointed is drilled differently then the flange shall have a thickness appropriate to a 16 bar pressure rating but shall be drilled to suit.

E1.23

Flange Gaskets Gaskets for use on water supply pipelines shall be manufactured from ethylene propylene rubber (EPDM or EPM) and shall comply with the requirements of Clause E1.3. Gaskets shall be 3.2mm thick and dimensioned to the full face of the flange to suit the flange bolting. The rubber hardness (measured in International Rubber Hardness Degrees - IRHD) shall be in the range 66 to 75. Gaskets shall be stored in a clean, cool condition out of direct sunlight and without being deformed.

E1.24

Flexible Mechanical Couplings and Flange Adapters Flexible mechanical couplings and flange adaptors shall be of an approved type and design and shall be compatible in all respects with the pipes or fittings to which they are connected. They shall be designed to withstand the maximum hydraulic works test pressure specified for the pipeline. Couplings shall consist of a central sleeve and two end rings retaining elastomeric sealing rings; the end rings shall be tightened by an adequate symmetrical bolting system or, for sizes up to 60mm outside diameter only, screw threaded to the central sleeve. Unless otherwise specified, central sleeves of couplings shall be provided without integral registers or locating plugs. All nuts, bolts, and washers shall be galvanised unless otherwise specified.


Page E-56 of 115


Specifications

Anchored, harnessed or other special couplings or flange adapters shall be provided as detailed on the drawings, or otherwise indicated Couplings shall be capable of accepting the minimum angular and axial movements shown in the following table whilst subjected to the internal Site test pressure without leakage, without direct contact between pipe and coupling at any point, and without inducing stresses or strains in the pipe that exceeds safe working limits: Deflection Criteria for Couplings and Flange Adaptors Nominal Diameter

Up to 600

601750

751900

9011200

12011800

greater than 1800

Deflection Angle

6o

5o

4o

3o

2o

1o

Axial Movement (mm)

9

9

9

9

9

9

The minimum deflection angles and axial movements accepted by flange adapters shall be fifty per cent of the values specified above for couplings. Axial movement shall be achieved by deformation of the elastomeric sealing ring. Protective coatings shall be as specified elsewhere and applied in accordance with the requirements of Section G of this Specification. If not specified elsewhere, couplings and flange adapters shall be shop painted with one coat of red pigmented chlorinated rubber primer paint for protection in transit. E1.25

Flexible Joints - Sleeve and Integral Socket Types This clause applies to sleeve-type joints and integral spigot and socket joints with or without a detachable mechanical (bolted) gland ring assembly. Unless specified elsewhere for particular pipe materials, or pipeline duties the completed joints shall be capable of accepting the following ranges of deflection and load whilst subjected to the internal Site test pressure without leakage, without direct contact between socket (or sleeve) and spigot, and without inducing stresses or strains in the pipe that exceed safe working limits: Angular Deflection: (all materials) Nominal Pipe Diameter (mm)

Minimum Angle (degrees)

up to 200

3.0

201 to 500

1.5

501 to 1350

1.0

greater than 1350

0.5

Axial Movement: Not less than 10mm or the following proportions of the length of the longest pipe or rigidly jointed pipeline unit at any joint:


Page E-57 of 115


Specifications

Pressure Pipelines

Non-Pressure Pipelines

Steel, ductile and grey iron, asbestos cement, cement and concrete

0.2%

0.1%

Polyethylene

2.3%

1.0%

uPVC and RTR

0.7%

0.3%

ABS

1.2%

0.5%

Shear: Joints for rigid pipes shall be capable of accepting a shear load equivalent to 20N per mm of pipe diameter. Joints for flexible pipes shall be capable of accepting a shear load induced by a 5% elliptical deflection of the spigot end forming part of the joint. If the approved Standard does not include a shear test for the jointing system, the test shall be as instructed by the Engineer. E1.26

Elastomeric Joint Sealing Rings Elastomeric sealing rings for water supply pipelines shall be manufactured from ethylene propylene rubber (EPDM or EPM) and shall comply with the requirements of Clause E1.3. Sealing rings for use on sewage pipelines may alternatively be manufactured from styrene butadiene rubber (SBR). All sealing rings shall have physical and chemical properties, including hardness (measured in International Rubber Hardness Degrees - IRHD), compatible with the pipe material. Sealing rings shall be stored in a clean, cool condition out of direct sunlight and without being deformed. Rings for use with thermoplastic pipes shall contain no component which can react with the material of the pipes.

E1.27

Lubricants for Joint Assembly Lubricants for the assembly of pipeline joints shall be inert so as not to damage the pipes or joint components and, for water supply pipelines, shall comply with the requirements of Clause E1.3. Lubricants other than those recommended by the pipe or joint supplier shall not be used without the Engineer's approval.

E1.28

Granular Materials for Pipe Bedding and Surrounds Granular material for pipe bedding and surrounds shall be sand, gravel or crushed rock as indicated in the following table. Selected excavated material (see Clause E1.29) may be used only in the cases indicated.


Page E-58 of 115


Specifications

Suitability of Bedding Materials for Various Group A and B Pipeline Installations Pipe Material Group

A

B

Installation Characteristics

Suitability of Bedding Material

Gravel or Crushed Rock

Sand

Selected Excavated

“Granular bedding”

BB

Yes

Yes

No

“Granular surround”

SO

Yes

No

No

SO

Yes

No

No

SO

Yes

Yes

No

SO

Yes

Yes

Yes

Non-pressure pipes under 50000N/sq.m stiffness and pressure pipes under 5000 N/sq.m stiffness Non pressure pipes over 50 000 N/sq.m and under 100 000 N/sq.m stiffness and pressure pipes over 5000 N/sq.m and under 100 000 N/sq.m stiffness Non-pressure pipes over 100 000 N/sq.m stiffness and pressure pipes over 10 000 N/sq,m stiffness

*

Bed Type*

As depicted on the Drawings

Material for gravel beds shall be free- draining, hard, clean, chemically stable natural gravel, crushed stone or crushed slag, graded in accordance with the following table: Granular Material Gradings for Pipe Bedding and Surround Percentage by Mass Passing Test Sieve

For Pipes of Diameter 400mm and above

For Pipes of Diameter 600mm and below

63 mm

-

-

37.5 mm

100

-


Page E-59 of 115


Specifications

20 mm

85-100

-

14 mm

-

100

10 mm

0-50

85-100

5 mm

0-10

0-25

2.36 mm

-

0-5

The material for sand beds shall contain not less than 90% passing a 5mm sieve and not more than 10% passing a 0.2mm sieve, and shall have a compaction fraction value not exceeding 0.2 when determined in accordance with the following test: A sample of the material proposed for use shall be submitted to the Engineer for his testing and written approval well in advance of the time when it will be needed on Site; in the event that the sample material is not satisfactory, the Contractor shall adjust the proportions of the constituents of the material, or obtain alternative materials, until a satisfactory material is obtained, and this shall be used in all relevant parts of the Works unless the Engineer gives written approval for an alternative material. The Engineer may from time to time require the Contractor to submit further samples for routine testing and the Contractor shall have available on the Site at all times throughout pipelaying the apparatus necessary to carry out the tests required. Pipe bedding material to concrete pipes shall not contain more than 0.3 per cent sulphate, expressed as sulphur trioxide. For all thermoplastic and polythene wrapped DI pipes only rounded aggregates will be permitted but for all other pipe materials crushed aggregates may also be used. Beds and surrounds for small diameter service pipelines of 100mm diameter and less which are for pipe protection only and are not required for structural support shall be approved sands free from particles larger than 5mm. A sample of the material proposed for use shall be submitted to the Engineer’s for his testing and written approval well in advance of the time when it will be needed on Site; in the event that the sample material is not satisfactory, the Contractor shall adjust the proportions of the constituents of the material, or obtain alternative materials, until a satisfactory material is obtained, and this shall be used in all relevant parts of the Works unless the Engineer gives written approval for an alternative material. The Engineer may from time to time require the Contractor to submit further samples for routine testing, and the Contractor shall have available on the Site at all times throughout pipelaying the apparatus necessary to carry out the tests required. E1.29

Selected Excavated Material for Pipe Bedding and Surrounds This material shall be a consistent quality, well graded, inert and free from roots or other vegetable matter, building rubbish or debris, any clay lumps or stones retained on a 25mm mesh sieve, minerals that may be dissolved in groundwater or other deleterious materials.

E1.30

Maintenance of Quality The requirements of the Specification relating to the quality, performance and finish of pipes and pipeline components, will apply to their condition as installed. The certification or approval of items at the manufacturers works, at a stockyard, or at any other temporary location, will in no way relieve the Contractor of his responsibilities for the condition of the items when installed.


Page E-60 of 115


Specifications

Any damage, or circumstances capable of giving rise to damage, shall be reported immediately to the Engineer, who will give instructions regarding the testing and/or repair of the suspect items. Any protective lining, coating or wrapping damaged during construction shall be repaired as soon as is practicable after the damage occurs in order to limit the extent of any resulting corrosion. Any such damage which cannot, in the opinion of the Engineer, be satisfactorily repaired in-situ shall render the item or items concerned liable to rejection and they shall be replaced by the Contractor at his own expense. Where pipes and pipeline components have been purchased separately by the Employer, and are handed over to the Contractor for installation, the Contractor shall, before moving or using any of the items, visually inspect them, and immediately notify the Engineer of any damage, deterioration, or suspicious circumstances. Failure to do this will result in the Contractor being held responsible for any damage coming to light after he has taken over the materials. Unless otherwise instructed by the Engineer, the Contractor will not be required to carry out tests, or examinations other than visual, at the time of taking over, and will not be held responsible for any not visually apparent defects originating prior to the time of taking over. The Contractor will, however, be responsible for insuring the items against all normal risks, from the time of taking them over.


Page E-61 of 115


Specifications

E2

TYPE TESTING, ROUTINE TESTING, AND VISUAL INSPECTION OF PIPES

E2.1

General Requirements Pipes shall be subjected to "Type" and "Routine" testing in accordance with the frequencies stipulated below and in the following clauses. This requirement is additional to any further requirements of the approved Standard to which the pipes are manufactured. where specified test requirements differ from those given in the approved Standard, the more stringent requirement shall apply. Pipes to be coated at the place of manufacture shall have all hydraulic and pressure testing completed prior to application of the coating. Test certificates for all pipes shall be submitted to the Engineer for approval. The Engineer or his appointed Inspecting Engineer may require to witness any of the stages of manufacture or any of the tests and free access shall be provided by the manufacturer during all working hours for such purposes. Adequate notice of the time and place of all prescribed testing shall be given. (i)

"Type" Tests are required to prove the design of a component or assembly and shall be carried out whenever there is a change of design, of type of material or method of manufacture. The number of tests performed shall be sufficient to demonstrate consistent performance within the prescribed range. For long term tests and/or provided consistency of material quality and dimensions of construction can be demonstrated, certified manufacturer's test results may be accepted.

(ii)

"Routine" Tests are required as a means of quality control to demonstrate consistency and adequacy of materials and production techniques. Testing shall be carried out at the sampling frequency described below in which the number of units in a batch shall be taken as the number of joints, and batches shall be distinguished by diameter and manufacturing group. (a)

For all pipes: No. of Units in Batch

up to 50 51 to 150 151 to 250 251 to 500 501 to 1000 over 1000

No. of Units in First Sample

No. of Units in Second Sample

2 4% 3% 2% 1.5% 1%

5 8 10 14 20 2%

Limiting Failures for Acceptance of Second Sample 1 2 2 3 4 20% of sample

Samples shall be selected on a random basis. Any failure in the first sample shall necessitate the testing of a separate second sample. Provided the number of failures in the second sample is less than or equal to the limiting number quoted, then the batch will be accepted, excluding those sample pipes which have failed.


Page E-62 of 115


Specifications

If a batch fails the manufacturer may request either:

(b)

(1)

Having the batch passed for a lower pipe class if a lower class is required and if the sample test results permit acceptance for that class in which case the pipe shall be marked as "derated to Class ...".

(2)

The testing of all pipes in the batch for those tests which have failed the sampling criteria to enable pipes to be passed individually. In such a case the manufacturer will accept all costs of the Employer’s Representative’s Inspector.

For Pressure Pipes: In addition to the prescribed sample testing, the internal pressure test only shall be carried out on every pipe and joint to be supplied and pipes and/or joints will be accepted or rejected individually. Satisfactory pressure test certificates shall be provided for every pressure pipe and joint supplied.

In addition to the prescribed testing, pipes shall be subjected to visual inspection at the place of manufacture and at Site and may be rejected if pipes are incorrectly marked or have defects outside the ranges permitted. E2.2

Visual Inspection Requirements for Group A (Rigid) Pipe & Pipeline Components All pipes and pipeline components will be subject to visual inspection at any time and, if found unsatisfactory may be rejected or, where permitted, repaired. Cutting of pipes to permit use of undamaged or unaffected sections may be permitted provided the distance from the unacceptable defect to the cut is not less than one metre. TABLE D5 Visual Inspection Requirements for Group A (Rigid) Pipes Condition

Requirements Concrete

Vitrified Clay

Ellipticity

+ 3% on mean dia for diameters up to 500. + 1% on mean dia for diameters over 500

+ 2% on mean diameter.

Variation in wall thickness

+ 5% of mean thickness at any pipe cross section.

y+ 5% of mean thickness at any pipe cross section

Cracks

Unreinforced pipes shall contain no cracks.

There shall be no cracks running in a longitudinal direction, and no cracks of length 25mm running in a circumferential direction.


Page E-63 of 115


Specifications

Condition

Requirements Concrete

Vitrified Clay

Voids, chips and cavities.

There shall be no honey combing or open texture.

There shall be no broken blisters and no chips or other cavities measuring more than 25mm in a longitudinal or 50mm in a circumferential direction or 0.25 times the pipe wall thickness in depth.

Protruberances

There shall be no protruding aggregates. There shall be no protruberances of any sort extending more than 2mm from the normal surface.

There shall be no blisters of diameter 50mm or height 2mm There shall be no protuberances extending more than 2mm from the normal internal surface.

Other

Where glazing is specified not more than 5% of the surface area (excluding pipe ends) shall be free from glaze.

E2.3

Not Used

E2.4

Type and Routine Tests for Metal Pipes The tests required in respect of steel and ductile iron pipes are indicated in the following table:

Steel

Ductile Iron

Burst pressure

-

-

Joint watertightness

-

Yes

Yes

Yes

Chemical analysis

Yes

-

Tensile test

Yes

Yes

Modulus of rupture

-

Yes

Charpy impact

-

Yes

Flattening test

Yes

Yes

Type Tests

Deflection test (for mortar lined pipes) Routine Tests


Page E-64 of 115


Specifications

Ductile Iron

Steel Weld bend test

Yes

-

Brinell hardness

-

Yes

Hydrostative test

Yes

Yes

Weld inspection

Yes

-

Note:

Additional tests for small diameter steel pipes are specified in Clause E1.18. The flattening, and weld bend tests for steel pipes are alternatived tests, and it will not normally be required to perform both tests.

E2.5

Visual Inspection Requirements for Metal Pipes All steel, ductile iron, and grey iron pipes and pipeline components will be subject to visual inspection at any time, and, if found unsatisfactory shall be rejected, or, where permitted, repaired. Cutting of pipes to permit use of undamaged or unaffected sections may be permitted provided the distance from any unacceptable defect to the cut is not less than one metre. Condition

Steel

Requirements Ductile Iron

Elipticity

+ or - 1%

+ or - 1%

Dents and Buckles

None

None

Laces and Laps

-

None exceeding 30% wall thickness

Cracks and Tears

None deeper than one third wall thickness or one eighth wall thickness over a length of one quarter pipe diameter. Defects deeper than one eighth wall thickness, but not exceeding above criteria, shall be made good by welding.

None

Pits and Voids

Ditto

None

Mortar Lining

The maximum crack width, or radial displacement, in all types of iron and steel pipe shall not exceed the following values: Pipe Diameter (mm)

Maximum Dimension (mm)

80

0.8

100-600

1.2

700-1200

1.5

over 1200


Page E-65 of 115

2.0


E2.6

Specifications

Type and Routine Tests for Thermoplastic and RTR/GRP Pipes The tests required in respect of pipes manufactured from thermoplastic and RTR materials are indicated in following table: Type and Routine Tests for Thermoplastic and RTR Pipes PE

ABS PVC

RTR/ GRP

Type Tests Deflection Stress rupture (pressure pipes) Strain corrosion Environmental stress cracking Creep Joint watertightness

Yes Yes Yes Yes -

Yes Yes Yes Yes

Yes Yes Yes Yes Yes

Routine Tests Stiffness Heater reversion Watertightness (gravity pipes) Pressure (pressure pipes) Water bath Acetone immersion Barcol hardness Fracture toughness

Yes Yes Yes Yes Yes -

Yes Yes Yes Yes Yes (1) Yes

Yes Yes Yes Yes -

Note: (1) PVC only (i)

Deflection Test: Short sections of sample pipe shall be vertically compressed between rigid parallel flat plates for periods of one minute, and the pipe inspected for damage at various deflections. Deflection shall be measured as percentage shortening of the vertical diameter. For thermoplastic pipes, the test deflections are as follows: Minimum Crack and Failure Deflections for Thermoplastic Pipes Pipe SDR (1)

10 20 30 40 50 60 or more


% Deflection No Crazing or Cracking

No Failure of Wall

1.75 3.50 5.25 7.00 8.75 10.00

20 20 20 20 20 20

Page E-66 of 115


Specifications

Note: SDR (standard dimension rates) is included as the mean pipe diameter measured at the midpoint of the wall divided by the wall thickness In addition the deflections at which crazing and/or cracking of the inner and outer surfaces of the pipe first occur shall be noted, and also the deflection at which failure occurs. The pipe deflection shall be progressively increased to the extent which is necessary to enable these points to be established. For the purpose of this test wall failure shall be defined as the formation of any discontinuity extending throughout the thickness of the pipe wall. (ii)

Stress Rupture Test: Two representative pipes for each combination of class and pipe diameter shall be tested for each material. The tests shall consist of maintaining the sample pipe at constant temperature and effective internal pressure for a specific period as indicated below: (a)

For thermoplastic pipes:

Stress Rupture Tests for Thermoplastic Pipes Test 1 Stress Mpa

Test 2

Time & Temperature

Stress MPa

Time & Temperature

Test 3 Stress MPa

Time & Temperature

PVC-U

42.0

1 hour @ 20°C

35.0

100 hours @ 20°C

12.5

1000 hours @ 60°C

PE/MRS 100

12.4

100 hours @ 20°C

5.5

165 hours @ 80°C

5.0

1000 hours @ 80°C

PE/MRS 80

10.0

100 hours @ 20°C

4.6

165 hours @ 80°C

4.0

1000 hours @ 80°C

PE/MRS 63

8.0

100 hours @ 20°C

3.5

165 hours @ 80°C

3.2

1000 hours @ 80°C

PE/MRS 40

7.0

100 hours @ 20°C

2.5

165 hours @ 80°C

2.0

1000 hours @ 80°C

PE/MRS 32

6.5

100 hours @ 20°C

2.0

165 hours @ 80°C

1.5

1000 hours @ 80°C

Note: The effective internal pressure for each test shall be that pressure which produces a stress in the pipe wall of magnitude not less than the indicated value. (b) For thermosetting pipes (RTR/GRP) the test pressures shall be related to thepressure rating (PR) of the pipe as follows:


Page E-67 of 115


Specifications

Test No.

Temperature

Pressure

Duration

1

20 C

6 x PR

1 hour

2

80 C

4 x PR

1 hour

3

80 C

2.7 x PR

170 hours

4

80 C

2.3 x PR

1000 hours

No pipe shall fail in a time less than that stated for the particular test. Stress rupture testing carried out at temperatures, pressures and durations other than those indicated may be accepted as indicating compliance provided that at least two samples for each combination of class, diameter and material have been tested for a duration of not less than 1000 hours and that the test data indicates a regression not inferior to that indicated by the tabulated requirements. (iii)

Strain Corrosion Test: A programme of strain corrosion testing shall be carried out for each design of RTR pipe. Provided that the materials employed in the pipe construction, the gelcoat thickness, the laminate design, and all other relevant aspects, remain effectively similar then tests will not be required for all pipe diameters. For each design a minimum of 18 samples shall be tested by measuring the time to failure at various levels of pipe wall bending strain in the presence of 0.1 normal sulphuric acid. The sample pipe rings shall be strained, by vertical deflection, to various levels such that the number of failures occurring within various periods shall comply with the following: Time to Failure (Hours)

No. of Failure Points

10 to 1000

At least 4

1000 to 6000

At least 3

More than 6000

At least 3

More than 10000

At least 1

The performance of the samples tested shall be such as to indicate a minimum time to failure at 0.9% strain of 50 years. In addition, the tests shall indicate that the pipe can sustain the strains associated with the deflections stipulated in Clause D3.1.16 for at least 50 years, if these strains exceed 0.9%. Any of the following shall constitute failure of the sample: fracture of the pipe wall; passage of liquid through the pipe wall; evidence of delamination; lifting and cracking of resin surface; blistering of more than 25% of the wetted surface area.


Page E-68 of 115


(iv)

Specifications

Environmental Stress Cracking Resistance Tests of Polyethylene: The resistance of polyethylene materials to environmental stress cracking shall be tested by measuring the time to failure of notched specimens subjected to flexural stress and immersed in an appropriate surfactant which is not absorbed by the material.

(v)

Flexural Creep Test: For each thermoplastic material, or for each laminate design of RTR, three sample pipe sections shall be tested as follows: The samples shall be subjected to a parallel-plate or two-edge line loading, applied uniformly along the length of the sample, such as to produce an immediate deflection of 1% of the pipe diameter. For each sample the deflection shall then be remeasured after elapsed times of 0.1 hours and 100 hours under continuous constant load. For each sample the ratio which the deflection at 100 hours bears to the deflection at 0.1 hours shall be calculated. The resulting ratios shall not exceed the values shown in the following table. Creep Deflection Tests for Thermoplastic Pipes Average Creep Deflection Ratio of Three Samples

Maximum Creep Deflection Ratio of Any One Sample

Polyethylene

2.5

3.0

PVC and ABS

1.75

2.0

RTR/GRP

1.4

1.5

Pipe Material

The tests shall be carried out at a temperature of 20oC + 1oC, and the samples shall have a length of 1/5 pipe diameter, or 300mm for pipe diameters less than 1 500mm. (vi)

Stiffness Test: Pipe stiffness shall be determined by parallel plate loading on sample pipe sections having lengths of 1/5 pipe diameter or 300mm for pipe diameters less than 1 500mm, at a temperature of 20oC + 1oC. The total load on the sample shall be measured at deflections of 3% and 5%. The pipe stiffness shall be calculated as EI/D3 = K x load/deflection where the load is measured in newtons per linear metre and the deflection in metres. K shall have a value of 0.01935 at 3% deflection and 0.0199 at 5% deflection.

(vii)

Heat Reversion Test: Heat reversion testing of thermoplastic pipes shall be carried out at the rate of one sample pipe per production machine per 8 hours operation. The tests shall be carried out by measuring the change in dimension, parallel to the pipe axis, between two points in the pipe barrel after the pipe as been heated


Page E-69 of 115


Specifications

to, and maintained at, a temperature of 120oC for a period of 30 minutes and then allowed to return to room temperature. The change in length shall not exceed 2% for polypropylene plastics, and 5% for other thermoplastics. (viii)

Watertightness Testing: Pipes for non pressure applications shall be subject to watertightness testing at the place of manufacture. Wherever possible the testing of pipes and joints shall be carried out simultaneously. Sample pipes shall be subjected to an internal hydrostatic pressure of 1 bar, and shall withstand this pressure for a period of one minute without distress and without the appearance of water on the outside of the pipe.

(ix)

Internal Pressure Testing: In addition to the internal hydrostatic pressure tests carried out in accordance with the stress-rupture test requirements, pipes for pressure applications shall be subjected to following internal pressure testing at the place of manufacture. Wherever possible the testing of pipes and joints shall be carried out simultaneously. The sample pipes shall be subjected to an internal hydraulic pressure equal to the pressure rating of the pipe, and shall withstand this pressure for a period of 30 minutes without distress and without the appearance of water on the outside of the pipe.

(x)

Water-bath Test for Polyethylene Pipes: Polyethylene pipes shall be tested to ensure that oxidation of the material has not occurred during extrusion or otherwise during manufacture. Testing shall consist of cutting a sample ring from the pipe, the ring being a complete cylindrical section of pipe having a length of approximately 50mm, and immersing this sample in water at a temperature of 80oC (+2o) for a period of 24 hours. The sample shall then be removed from the water-bath and allowed to dry in air without wiping or other intervention. The appearance of any form of coating on the surface of the pipe shall constitute failure of the test.

(xi)

Acetone Immersion Test for uPVC Pipes: Suitably sized samples shall be cut from uPVC pipes such that a substantial proportion of the surface area of the sample is comprised of material from the interior of the pipe wall. The sample shall then be immersed in acetone completely free from water in a sealed container for 30 minutes at 20oC + 3oC. At the end of this period there shall have occurred no flaking, delamination or disintegration. Swelling of the sample, provided it is not associated with other deterioration, shall not constitute failure.

(xii)

Barcol Hardness Test of Reinforced Thermosetting Resin: Barcol hardness shall be measured by means of an indentor consisting of a hardened steel truncated cone having an angle of 26o with a flat tip of diameter 0.157mm. Hardness tests shall be carried out on the cured pipe at the rate of at least two tests per curing operation; thus the testing rate may only be less than two tests per pipe if two or more similar pipes are simultaneously cured under


Page E-70 of 115


Specifications

identical conditions. The two test measurements shall be conducted one on the outside surface and one on the inside surface of the pipe. The pipe surface shall be adequately supported during testing so as to prevent flexure of the specimen. Measurements shall not be taken within 10mm of the ends of the pipe or within 5mm of previous test compressions. E2.7

Visual Inspection Requirements for Thermoplastic and RTR/GRP Pipes and Pipeline Components All thermoplastic and RTR/GRP pipes and pipeline components will be subject to visual inspection at any time and, if found unsatisfactory shall be rejected or, where permitted, repaired. Cutting of pipes to permit use of undamaged or unaffected sections may be permitted provided the distance from the unacceptable defect to the cut is not less than one metre. These visual inspection requirements also apply to RTR/GRP joints and fittings which have otherwise been manufactured in accordance with Section H of this Specification. Visual Inspection Requirements for Thermoplastic and RTR/GRP Pipes

Condition

Requirements Thermoplastics

Thermosets

Elipticity

+1% on mean diameter

+1% on mean diameter

Eccentricity

Pipe wall thickness measured at any point must be such that the Standard Dimension Ratio calculated on that thickness is within the stipulated range.

Pipe wall thickness must be within +10% of design value at any point and within +5% when the average thickness is measured along any single straight axial line the length of the pipe.

Surface Finish

There shall be no crazing, flaking or indication of disintegration.

There shall be no crazing of external gel-coats or resin-rich layers.

There shall be no evidence of extrusion dye-marks or ’spiderlines’.

Resin-dry areas not exceeding 6mm dia externally may be accepted if made good.

Scratches

None on internal surface. External surfaces shall be free from longitudinal scratches and from circumferential scratches longer than 5% of the pipe wall thickness.

Scratches not exceeding 0.3mm deep may be accepted without repair. Scratches exceeding 0.3mm deep but not exceeding 1mm deep may be accepted if satisfactorily made good.

Cracks

All pipes shall be completely free from cracks.

Longitudinal cracks: There shall be none on internal surfaces. External cracks may be accepted after repair if less than 200mm long. Circumferential cracks: No cracks shall be of sufficient depth to expose glass fibres. Cracks not exceeding 200mm length may


Page E-71 of 115


Specifications

Requirements

Condition

Thermoplastics

Thermosets be accepted after repair. "Star cracks" may be accepted after repair if all cracks are contained within a circle of 100mm diameter.

E2.8

Voids

No visible voids will be accepted.

Voids (or blisters) may be accepted after repair if not greater than 2mm diameter and 1mm depth provided that not more than 0.5% of surface area of pipe is affected.

Protuberances

Ridges or ripples shall not exceed 0.5mm in height.

There shall be no protruding fibres from the internal surface of the pipe. Wrinkles, ridges and nipples shall not exceed 3mm in height.

Inclusions

There shall be visible inclusions of extraneous matter.

There shall be no visible inclusions of extraneous matter other than permitted fillers or aggregates.

Delamination

Not applicable.

There shall be no visible delamination.

Holiday Detection Test Coatings and linings which are required in the Specification to be subject to holiday detection testing, shall be tested in accordance with the following procedure: Factory applied coatings shall be tested at works. Site applied coatings and areas of factory applied coatings which have been completed or repaired on Site or which may, in the opinion of the Employer’s Representative, have suffered damage or have deteriorated in any way which warrants a retest shall be tested on Site. Unless otherwise permitted in writing by the Employer’s Representative, all coatings which are to be tested in accordance with this clause (in whole or in part) shall be tested in the presence of the Employer’s Representative or his appointed representative. The apparatus for testing pipeline coatings shall consist of: (i)

a low amperage, adjustable voltage, full wave rectified direct current output detector;

(ii)

an exploring electrode of the wire brush, coil spring, conductive rubber or silicon electrode, or other approved type capable of being moved in a controlled manner across the surface of the coating under test;

(iii)

an audible alarm signal which shall be activated whenever the exploring electrode passes over a defect in the pipeline coating under test;

(iv) (v)


a "ground wire" to provide a low resistance connection between the apparatus and the coating substrate; a kilovoltmeter capable of detecting a single pulse and holding the reading for sufficient time for the meter circuits and alarm to indicate the fault.

Page E-72 of 115


Specifications

The apparatus shall have a power rating of no more than 20 watts and an output voltage variable up to 20 kilovolts. The operating voltage of the equipment shall be selected to suit the type and thickness of the coating to be tested and shall be determined from either: (i)

the dielectric breakdown voltage per millimetre of coating thickness quoted by the manufacturer; The operating voltage for test purposes shall be the product of the above voltage and the minimum allowable thickness of the coating in millimetres;

or: (ii)

by using the apparatus to apply a steadily increasing voltage to an approved sample area of the coating (the sample area shall be free of holidays and other weaknesses) until sparking occurs due to breakdown of the coating. The voltage shall then be steadily reduced until sparking ceases; The operating voltage for test purposes shall be mid-way between the above two voltage limits.

If the second method is used and the sample area forms part of the coating of an item to be incorporated into the Works, the sample area shall be repaired to the satisfaction of the Employer’s Representative upon completion of the test to determine the operating voltage. Holiday detection testing shall only be carried out when: (a)

the surface of the coating to be tested is completely dry;

(b)

the ambient air temperature exceeds 4oC;

(c)

the relative humidity of the ambient air is less than 85%.

Each coating to be tested for holidays shall be thoroughly and completely explored. The electrode shall, insofar as is practicable, remain in contact with the coating surface throughout the test and shall travel steadily across the surface at a speed within the limitations recommended by the manufacturer of the testing apparatus or, in the absence of such recommendation, at no more than 0.3 metres per second. All flaws, pinholes, holidays and other defects discovered by the test shall be marked and shall be recorded and reported to the Employer’s Representative or his representative. Repairs to coatings shall be carried out only with specific permission from theEmployer’s Representative and to his entire satisfaction. Items with coatings which include flaws, pinholes, holidays or other defects shall not be incorporated into the works. Coatings which are repaired as aforesaid shall be retested as described above. All retesting and repairs to coatings shall be carried out at the Contractor's expense.


Page E-73 of 115


Specifications

E3

PIPELINE CONSTRUCTION

E3.1

Storage and Handling of Pipes Method Statements must be approved for the transportation, handling and storage of pipes before any pipes are delivered to site. All pipes shall be handled and stored in compliance with the manufacturer's recommendations subject to the following limitations: Pipes shall be transported, handled and stored with such packing and in such a manner that damage does not occur and that contact is avoided with sharp edges which may cause damage. During transit, pipes and fittings shall be well secured and adequately supported along their length. At every point of loading or unloading, all pipes or castings must be handled by approved lifting tackle unless specified elsewhere. Unloading by rolling down planks or any other form of inclined ramp will not be allowed. Pipes shall not be tipped or dropped. Pliable straps, slings or rope shall be used to lift pipes, and steel cables or chains will not be used without written permission. Nesting of pipes for transportation will be permitted provided method statements demonstrate that effective precautions will be taken to protect inner surfaces from damage. All pipes and fittings shall be thoroughly inspected on arrival at site after off-loading and prior to installation for detection of any damages. Damages to coatings, if any, shall be made good in an approved manner. For other damages, proposals for repairs shall be submitted in writing for the Engineer's approval. If in the Engineer's opinion the nature of any damage is such that the condition of a pipe has been impaired and cannot be repaired, the pipe concerned shall not be incorporated in the Works. Suitably smooth and level storage areas shall be provided at or near the site and made secure to prevent unauthorised access. Pipes of different sizes and thickness shall be stocked separately. Glass Reinforced Plastic Pipes (GRP) When pipes are transported or stacked they shall be supported on cradles at least 100 mm wide, conforming to the shape of the pipe placed at not more than 3 metres centres. Pipes must on no account be stacked directly on the ground but if individual pipes are placed on the ground prior to laying care shall be taken to remove all rocks and any potentially damaging debris. The number of layers in a stack shall not exceed the following: Internal Diameter of Pipe (mm) Up to 500 500 to 700


Maximum Number of Layers 5 3

Page E-74 of 115


Specifications

The end pipes in each row shall be strapped to the battens. Pipes shall not rest on their sockets. Thermoplastic Pipes (uPVC) Pipes and fittings of plastic materials smaller than 300 mm diameter may be handled manually and those equal or larger than 300 mm diameter shall be lifted using a single fabric or large diameter rope sling. There shall be enough slack in the sling to keep the hook at least 600 mm over the pipe. Use of wire rope chains and fork lifts shall not be permitted. Care shall be taken to prevent distortion of the pipes during transportation, handling and storage. They shall be stacked either on bearing timbers on a level surface staked to prevent movement, or in suitable racks. Not more than two layers shall rest on the bottom layer, and for spigot and socket pipes, sockets shall be at alternate ends so that no pressure comes on a socket. Bearing timbers shall be spaced at not more than 1 metre and shall be wide enough to prevent denting of the pipe wall. Sharp edges (e.g. of metal) shall be avoided. Similar care shall be taken with pipes in transit. Where shaped battens are used, they shall be at least 100 mm wide and not more than 1.5 meters apart. The end pipes in each row shall be strapped to the battens. The pipe shall not be stacked any higher than five (5) layers. All thermoplastic pipes shall be shaded/protected from direct sunlight during handling, transportation, storage and laying. The Contractor shall ensure that thermoplastic pipes do not come into contact with bituminous or other hydrocarbon based materials.. E3.2

Trench Widths for Pipelines - General Requirements The Contractor will be responsible for selection of actual trench width. In so selecting, the Contractor shall take proper account of the needs to: (i)

provide sufficient width to permit safe working and proper pipelaying procedures;

(ii)

minimise disruption of vehicular, pedestrian or other traffic;

(iii)

minimise the risk of damage to adjacent buildings, services or other installations;

(iv)

minimise possible loss of crops or other surface vegetation or amenity.

When no limitations on trench width are stipulated, the trench widths defined below shall be used for measurement purposes. For single pipelines, the nominal trench width shall be defined as 1.5 times the nominal pipe diameter plus 300mm subject to a minimum trench width of 750mm. For two or more pipes in the same trench, the nominal trench width shall be defined as the sum of the nominal pipe diameters plus 450mm between the pipes plus 450mm. The pipe bedding provided shall completely fill the whole width of the trench excavated, and any additional material necessary to fill regions of overexcavation shall be provided entirely at the Contractor's expense. Where the actual trench width exceeds a specified maximum, then unless otherwise agreed by the Employer’s Representative the volume produced by the additional width Vol 3, Section3 – Civil Specifications

Page E-75 of 115


Specifications

between the trench bottom and a plane 1000mm above the crown of the pipe shall be filled with concrete at the Contractor's expense (minimum Grade ‘blinding’). E3.3

Trench Widths for Flexible Pipes - Additional Requirements Because flexible pipes (Group B) rely in part on the surrounding soil to resist the development of excessive deflections it may be necessary, where trenches pass through soft ground, to increase the trench width and replace the soft native soil with imported material, or to introduce other measures to limit the pipe deflection. All such measures shall be carried out according to the Employer’s Representative’s instructions issued as work proceeds. In order that delays to construction arising from the above considerations may be minimised the Contractor may be required to carry out in-situ measurements to establish the deformation modulus of the native soil at the installation level of the pipe. Such measurements shall normally be made using a Static Cone Penetrometer in advance of the trench excavation. Where such penetrometer tests indicate a modulus of less than 9kg per sq.cm for the native soil then one of the following forms of construction shall be employed as instructed by the Engineer: (i)

concrete haunching shall be provided between the pipe and the trench walls;

(ii)

trench sheeting shall be left in below a level of 300mm above the top of the pipe, or such higher level as theEmployer’s Representativemay direct;

(iii)

precast concrete (or other approved material) slabs, having a height of 500mm or one pipe diameter, whichever is greater, shall be placed vertically in the granular bedding material at the sides of the pipe midway between the sides of the pipe and of the trench;

(iv)

as an alternative to any of the above measures where considerations of available space, practicality and economics permit, the trench width may be increased to at least the minimum value obtained from the following table. Trench Width Criteria for Flexible Pipes Static Cone Penetrometer Modulus (kg/cm²)

Minimum Trench Width

less than 9 less than 8 less than 7 less than 6 less than 5 less than 4

2.5 x Pipe Diameter 3 x Pipe Diameter 3.5 x Pipe Diameter 4 x Pipe Diameter 4.5 x Pipe Diameter 5 x Pipe Diameter

Notes: (a)

Where the static cone penetrometer test value is less than 3kg/cm2 a construction method other than wide trench will normally be required.

(b)

For pipelines of small diameter (less than 100mm) little or no increase in trench width, beyond the minimum required for safe construction, may be necessary in order to obtain the required structural width.


Page E-76 of 115


E3.4

Specifications

Pipelaying - General Pipes shall be laid and jointed in accordance with all relevant recommendations of the manufacturer. Any variations between the manufacturer's recommendations and this specification shall be notified to the Engineer and installation of pipes shall not commence until the conflict has been resolved. All pipelaying shall be performed by experienced and competent pipelayers. The joints and interiors of all pipes and fittings shall, if necessary, be carefully cleaned before installation and any damage to coatings shall be rectified. Particular care shall be taken to prevent sewage or polluted water of any kind from coming into contact with pipes for water supply. Whenever pipelaying is interrupted for any reason, the open end of the pipeline shall be sealed with a suitable expanding stopper. The line of the pipe shall be set out and agreed with the Engineer well in advance of the excavation. Surface stripping, excavation, pipelaying, backfilling and reinstatement shall follow each other without undue delay or distance between them. Pipes shall be laid to true inverts and, except when using rigid joints, each pipe shall be separately set by laser or boned between sighting rails. Any pipe which is outside the permissible tolerances shall be unjointed and removed; the bedding shall be adjusted, and the pipe relayed and rechecked for line and level. After the laying of a length of a pipeline but before preliminary testing, the crown of the pipeline shall be checked for level and alignment and any necessary adjustment shall be carried out by unjointing and removing the pipes concerned, adjusting the bedding, relaying the pipes and rechecking for line and level. The permissible tolerances for pipelines in trench and heading shall be 6mm in level and 25mm in line between manholes or changes in direction or gradient. In addition, where a gravity pipeline is shown on the drawings as being straight between manholes it will not be accepted unless a light can be sighted through the length concerned. Pipelines shall not be laid to a curved alignment, achieved either by angular deflection at the joints or by curvature of flexible pipe except where expressly indicated on the drawings, specified or instructed by the Engineer. For pipeline jointing systems incorporating flexible jointing rings, pipes shall be laid with a gap between the end of the spigot and the base of the socket, or between spigots. This gap shall be not less than 6mm or greater than one third of the axial deflection test dimension specified for the pipe joint and it shall be achieved by positive means, such as marking the outside of the pipe or using removable metal or hardwood feelers. After the joint has been made and the preliminary testing completed, the annular gap at a socket or collar outside the flexible jointing ring shall be closed with fine grained clayey soil or cotton waste to prevent the entry of granular material. Where flexibly jointed pipes are laid to curves the angular displacement at any joint as laid shall not exceed three quarters of the maximum allowed by the manufacturer. Pressure pipelines shall be secured at all changes in direction by concrete anchor blocks. All bends and junctions on gravity pipelines shall be made inside a chamber unless otherwise specified. For pipelines laid in headings the individual pipes shall not exceed 2.5m in length, where the heading is to be backfilled manually, and the heading shall be driven complete from shaft to shaft before pipelaying is commenced.


Page E-77 of 115


Specifications

E3.5

Not Used

E3.6

Welded Joints for Thermoplastic Pipes The most widely used forms of welding for polyethylene (and other polyolefin) pipes, are butt fusion, and, increasingly, electrofusion sleeve jointing. Butt fusion, which, for obvious reasons, is normally the only acceptable method where polyethylene pipes are to be inserted into old pipelines as liners, requires careful control to maintain quality. Electrofusion sleeve jointing, on the other hand, is a largely automated process, and therefore more likely to be consistent in quality where control and supervision are suspect or difficult. (i)

General Requirements Solvent welded joints for uPVC and ABS pipes will not be permitted unless specifically ordered or permitted in writing by the Engineer. Thermal fusion welded joints for PE, PP and PB pipes shall comply with the following requirements: The type of welded joint and all plant, personnel, materials and procedures shall be in accordance with the pipe manufacturer's recommendations. Pipe manufacturers will be required to provide suitably qualified technical representatives on Site to assist in such matters as the establishment of procedures, training of welders and the resolution of technical problems. Subject to the above, the following table indicates the acceptability of various jointing systems relying wholly, or in part, on thermal fusion welding. Welded Joints for Thermoplastic Pipes Type of Welded Joint

Acceptability for Various Pipe Diameters Less than 750mm dia

750mm dia and over

No

No

Socket and spigot with sealing ring and external extrusion weld

Yes (1) (2)

No

Heated tool socket fusion

Yes

-

Socket and spigot with internal and external welds

No

Electrofusion of spigot and socket or sleeve joints

Yes

Yes

Butt fusion

Yes

Yes

Friction Welding

Notes: (1)


Acceptable for non-pressure pipelines only.

Page E-78 of 115

No

(Filter rod welding)

Yes

(Extrusion welding)


(2)

Specifications

Sealing rings may be omitted for joints between small diameter lateral sewers or house connections and main sewers (or compatible plastic manholes).

Welding shall be carried out in such a manner that the weld can sustain any stresses arising from subsequent laying operations without damage or loss of efficiency. Any evidence of oxidation of the weld material or pipe material will constitute cause for rejection of the joint. Welds must be continuous across the whole available weld surface. Where butt fusion welding is employed accurate alignment around the full circumference shall be ensured by the use of positive mechanical support around the whole of the circumferences of both pipe ends. The completed welded joint shall be free from projections into the bore of the pipe except in the base of butt fusion welds where weld "beads" not exceeding 2mm projection will not be required to be removed unless specifically ordered by the Engineer. Joints on pressure pipelines shall provide a weld factor of not less than 1.0 and on non-pressure pipelines of not less than 0.7. (ii)

Testing of Welded Joints The ability of each type of welded joint proposed for use in construction to provide the specified weld factor shall be proved by a Type Test carried out at the pipe manufacturer's works (or other agreed location). The type test shall consist of making three representative welded joints, each of which shall be formed between two sections of pipe having lengths of at least two pipe diameters. Each of the three assembled samples shall then be subjected to a tensile test by clamping around the full circumference at each ends, and loading until failure occurs. Where welded joints are proposed for pressure pipelines, a further type test shall be performed to prove the ability of the weld to withstand the internal pressure. The test shall consist of taking three representative sections of pipe containing a welded joint, and subjecting each to the 170 hour duration stress-rupture test specified for the appropriate pipe material. The welded joint shall withstand the specified test pressure for at least 170 hours without sign of distress. The tensile and stress-rupture type tests will be regarded as satisfactory if all three samples for each test meet the specified requirements. If two samples pass the test and the third fails then one further sample shall be taken and tested. If this sample meets the specified requirements then the whole test shall be regarded as satisfactory, if this sample fails to meet the specified requirements then the whole test shall be regarded as having been failed. Where the whole test has failed to meet the above requirements, the method of welding will not be accepted for use without modification. A suitably modified, or alternative, method or procedure shall then be proposed, and shall be subjected to the appropriate type tests. Site tests of welded joints shall be made according to the following procedures:


(a)

All joints will be subject to inspection for lack of continuity, oxidisation of materials, excessive projections or other faults.

(b)

All joints will be subject to the specified pressure tests for the pipeline. Page E-79 of 115


(c)

Specifications

Periodically the Engineer will order selected joints to be removed from the pipeline by cutting the pipe not less than 300mm on each side of the joint. Tensile test samples shall then be cut from the removed section of pipe and shall be tested to show compliance with the specified weld factor. The normal rate of carrying out such tests shall be 2% of the joints made by each method being employed. In the event of any such sample failing to meet the specified weld factor, then the subsequent rate of testing for that type of joint shall be increased to 10%, until such time as 20 successive joints have been successfully tested, when the testing rate shall revert to 2%. In the event of two successive tests on a particular type of welded joint failing to provide the specified weld factor then approval of the method of jointing employed will be withdrawn until the appropriate type test procedures have been repeated and satisfied. In addition, if two successive tests of joints made by a particular individual welder should fail to meet the specified weld factor, then approval of the employment of the welder concerned on permanent work will be withdrawn. Any such welders from whom approval has been withdrawn will not be permitted to be re-employed on permanent work until they have completed a representative sample weld in the presence of the Engineer and the sample weld has then been satisfactorily tested.

E3.7

Pipelines with Concrete Beds and Surrounds Concreting shall be carried out in accordance with Section D of this Specification. Where pipes are laid with a plain concrete cradle, a reinforced concrete cradle, or a full concrete surround, any vertical faces, or faces sloping more steeply than 1 vertical to 2 horizontally, shall be properly shuttered, (unless, with the approval of the Engineer, they are cast directly in contact with the side of the trench). A transverse expansion/movement joint shall be provided at each pipe joint of compressible expansion joint filler shaped exactly to the shape of the pipe and the full extent of the concrete. Unless detailed otherwise on the drawings the thickness of this expansion/movement joint shall be a minimum of 25mm except in the case of full concrete surrounds, where the minimum thickness shall be as follows: Pipes up to 300mm nominal diameter

-

25mm

Pipes 301 - 600mm nominal diameter

-

50mm

Pipes 601 - 1200mm nominal diameter

-

75mm

Pipes greater than 1200mm nominal diameter

-

100mm or as otherwise specified

For spigot and socket type pipes, the expansion joint in the concrete shall be aligned with the face of the socket, and for asbestos cement sleeve type joints, with the face of one end of the sleeve. For flexible detachable/sleeve type joints, the expansion joint filler material shall be positioned on one side of the coupling but the filler and concrete bed or surround shall only be placed after the application of the specified corrosion prevention system has been applied to the pipe ends and joint. No steel reinforcement shall pass through the concrete expansion joint. At the Contractor's option he may use rectangular concrete blocks (two per pipe) made of Grade C45/20 concrete, cast at least 7 days before use, together with pairs of approved hardwood folding wedges of the same width as the blocks in order to align and support the pipe before concreting. The blocks and wedges shall be of sufficient size and suitably Vol 3, Section3 – Civil Specifications

Page E-80 of 115


Specifications

founded on the bottom of the trench to support the pipe adequately without settlement or movement at any stage. The blocks and wedges should be placed near the ends of each pipe length and should be left undisturbed during jointing of subsequent pipes and during construction, although the wedges should be removed during placing of the concrete. Alternatively the pipe may be bedded direct onto the concrete cradle or base of the surround, provided care is taken to ensure uniform support along the length of the pipe and that the alignment of the pipe is correct; the bedding-down of the pipe must be done whilst the concrete is fresh and workable. The concrete shall be placed carefully and uniformly (to ensure that the pipeline is not displaced), and shall be properly compacted by mechanical vibration, with particular attention to ensuring that no cavities are left underneath the pipe. The whole of the concrete for each length of pipe shall be placed in the same concreting operation and suitable measures shall be adopted to ensure that the pipeline is not displaced by differential side pressure or by flotation. All shuttering used for forming the concrete bedding shall be removed, unless the written approval of the Engineer is given to leave it in place for safety or similar reasons. The bedding and surround shall be completed by the careful placing of selected excavated material in layers not exceeding 150mm thick, thoroughly compacted on both sides of the pipeline to a level at least 300mm above the crown of the pipes. As this material is placed and compacted in the trench, the supports to the sides of the trench shall be concurrently partly withdrawn so that there are no voids or uncompacted zones. Except where instructed by the Engineer, no traffic load may be imposed upon the trench within 72 hours of the placing of the concrete cradle or surround. If the Contractor wishes to use any other method of laying pipes in concrete cradle or surround, he must submit his proposals in writing to and obtain the approval in writing from the Engineer well in advance of the date when he wishes to perform the work. E3.8

Pipelines with Granular Beds or Surrounds Where pipes are laid with a granular bed or surround the appropriate granular bedding material shall be placed in the trench bottom, carefully so as to avoid segregation, and spread and thoroughly compacted by approved mechanical means in successive uniform layers each not exceeding 150mm compacted thickness to produce a uniform bed true to gradient. Where plate vibrators are used, there shall be a minimum of one pass for gravels and two passes for sands. Hand tamping or punning will only be permitted where insufficient space is available to allow the use of mechanical plant. The minimum thickness of compacted granular material over even bottoms and peaks of irregular bottoms shall be as follows: 150mm (minimum 100mm under sockets) for pipes not exceeding 300mm nominal diameter; 200mm (minimum 100mm under sockets) for pipes greater than 300mm nominal diameter. The pipes shall then be bedded evenly on the bed with great care being taken to ensure uniform support for the entire length of the pipe. Pockets in the bedding shall be formed at each pipe joint to permit jointing to be carried out without the sleeve or socket of the pipe joint bearing on the bedding material and without bedding material entering the joint.


Page E-81 of 115


Specifications

After the pipeline alignment and joints have been inspected and approved by the Engineer, after satisfactory completion of the preliminary air testing of the pipeline and where appropriate after the sealing of the annular gap at each pipe joint to prevent entry of stones, each joint pocket shall be carefully filled with granular material and thoroughly compacted up to the same level as the top of the bedding. Granular bedding material of the same type shall be placed on both sides of the pipeline in successive uniform layers not exceeding 150mm thick and compacted as specified, care being taken to ensure that no cavities remain under the pipe, and that the pipes are not displaced by differential pressure from either side. When placing surround material the Contractor shall take care not to displace or damage the pipes - tipping surround material from ground level directly onto the pipes shall not be permitted. Unless otherwise detailed on the drawings, for pipes with a full granular surround the granular material shall extend up to a minimum height of 300mm over the crown of the pipes. For rigid pipes with granular bedding, unless otherwise detailed, the granular material shall extend up to the springing level of the pipe, and the surround shall be completed by the careful placing of selected excavated material in layers not exceeding 150mm thick, thoroughly compacted on both sides of the pipeline to a level at least 300mm above the crown of the pipes. If the Contractor wishes to use any other method of laying pipes in granular bedding or surround he must submit his proposals in writing to and obtain the approval in writing from the Engineer well in advance of the date when he wishes to perform the work. E3.9

Compaction of Granular Pipe Surrounds Granular surround material shall be carefully laid and compacted below and at the sides of pipes in accordance with one of the procedures shown in the following table: Granular Surrounds - Compaction Requirements Surround Material (Clause E1.28)

Maximum Layer Thickness mm

Alternative Methods (Number of Passes of Compaction Plant) Hand Rammer

Vibrating Plate

100kg Power Rammer (Group A pipes only)

Gravel

200

2

1

2

Sand

150

3

2

4

In no circumstances will the use of heavy power rammers be permitted in the vicinity of Group B, flexible pipes. In all cases, special attention shall be given to ensuring that bedding material is fully brought into contact with the haunches of the pipes. This shall be achieved by carefully shovel slicing the material beneath the pipe's horizontal diameter or by other approved methods. Great care shall be taken not to damage or displace the pipes while compaction of the surround is carried out.


Page E-82 of 115


Specifications

As bedding and surround material is placed and compacted in the trench, the supports to the sides of the trench shall be concurrently partly withdrawn so that there are no voids or uncompacted zones in the bedding and surround. Once the surround material has been brought up to the level of the crown of the pipe, compaction equipment shall only be used for the portions of the subsequently placed surround material at the sides of the trench. The portion of surround material immediately above the pipe shall be lightly compacted by foot only. E3.10

Pipelines Bedded on Trench Bottom Where pipes are to be bedded directly on the trench bottom the formation shall be trimmed to provide even bedding for the pipeline and to be free of extraneous matter that may damage the pipe or its coating. A recess shall be formed by hand excavation at each joint to permit making the joint and to prevent loads from bearing at this point. After the pipeline alignment and joints have been inspected and approved by the Engineer, after satisfactory completion of the preliminary air test and where appropriate after the sealing of the annular gap at each pipe joint, the recesses shall be carefully packed with selected fine material. The bedding and surround shall be completed by the careful placing of selected excavated material in layers not exceeding 150mm thick, thoroughly compacted on both sides of the pipeline to a level at least 300mm above the crown of the pipes. As this material is placed and compacted in the trench, the supports to the sides of the trench shall be concurrently partly withdrawn so that there are no voids or uncompacted zones.

E3.11

Stanks to Pipelines with Granular Bedding Where pipes are laid with granular bedding or back fill a stank (which is an impermeable barrier designed to prevent groundwater flow along the trench) shall be provided across the full width of the trench and for the complete depth of the bedding and fill at intervals not exceeding 50m and generally midway between manholes or thrust blocks. Stanks shall also be provided at any points where pipe trenches pass through or into impermeable strata or strata whose permeability is lower than that of the adjacent ground so as to form a restriction to the flow of groundwater. In these cases, the stank shall be so formed as to restore the continuity of the impermeable, or low permeability, stratum where it has been intersected by the trench excavation. Stanks may be dispensed with where the pipeline will always be above groundwater level. The frequency of stanks may need to be increased, or other measures undertaken, in locations where the groundwater is already highly mobile. The stank shall consist of either: (i)

a 300mm long plug of clay, clayey soil or other approved impermeable soil, or of a mixture of sand and bitumen, consolidated in an approved manner;

or (ii)

a layer of plastic sheeting, minimum thickness 1mm, cut to fit around the pipe across the full width of the trench and laid on the granular bedding or fill material at the natural repose angle.

All methods must form an impermeable barrier. Vol 3, Section3 – Civil Specifications

Page E-83 of 115


Specifications

Bitumen shall not be used for trenches containing thermoplastic pipes. E3.12

Backfilling of Pipe Trenches After completion of placement and compaction of the surrounds to the pipelines backfilling shall proceed using selected excavated materials in accordance with the specifications for earthworks, (Section C). The use of power rammers will not be permitted over any pipe until the depth of fill above the crown of the pipe is at least 500mm.

E3.13

Deformation Measurements on Flexible Pipes Deformations of the cross sections of buried pipes shall be measured in accordance with, and shall conform to the limits specified in, this clause, for the following categories of pipes: (a)

all thermoplastics pipes;

(b)

reinforced thermosetting resin pipes having initial stiffnesses less than 100,000 Newtons per square metre;

(c)

ductile iron pipes having a standard dimension ratio greater than 60. Thus, class K9 ductile iron pipes of DN600 and smaller, will not be subject to this clause;

(d)

steel pipes having a standard dimension ratio greater than 65.

The procedures for measuring deformation, and the acceptance criteria, depend on whether the pipes have a nominal diameter greater than 600 millimetres or not. (i)

Pipes of DN600 and less: The deformation of pipes of DN600 and less will be checked by passing a mandrel throughout the length of the pipeline. The mandrel shall have a cylindrical cross section, of diameter not smaller than 1 millimetre less than the minimum acceptable pipe diameter, calculated by applying the deflection limits given in the following table to the reference diameter of the pipe. The reference diameter of the pipes shall be calculated according to the following formula: Reference diameter = (External circumference of pipe -2T) 3.14159 where T is the wall thickness of the pipes. Deflection Limits for Flexible Pipes DN600 and smaller Maximum Limits for Flexible Pipes DN600 and Smaller Type of Pipe

UPVC,


Pipe Acceptance (See Note 1)

Bedding Acceptance (See Note 2)

Installation Acceptance (See Note 3)

2.25 3.75 5.00 7.00

1.0 1.5 2.0 2.5

1.0 2.0 2.5 3.0

SDR less than 16 SDR 16 to 25.9 SDR 26 to 34.9 SDR 35 and over Page E-84 of 115


Specifications

Maximum Limits for Flexible Pipes DN600 and Smaller Pipe Acceptance (See Note 1)



PE, SDR 10 and over

7.00

2.5

3.0

PP, SDR 15 and over

7.00

2.5

3.0

RTR/GRP

SDR 30 to 40.9 SDR 41 to 49.9 SDR 50 and over

5.00 6.00 7.00

1.5 2.0 2.5

2.0 2.5 3.0

Steel

CM lined Bitumen lined

See Note 4 5.00

2.0 3.0

2.5 4.0

Type of Pipe

Notes:

(ii)

(1)

Pipes whose deflection at any time has exceeded this value will not be accepted for incorporation into the work.

(2)

To be measured after placing of the surround material, and after withdrawal of trench sheeting to above the crown of the pipe, but before backfilling. For non-pressure pipes, the permissible percentage deflection will be accepted only as an elongation of the vertical diameter, and no reduction will be acceptable at this stage. For pressure pipes, the permissible deflection will be acceptable as either an increase or decrease of the vertical diameter.

(3)

To be measured not less than two weeks after completion of backfilling. If the deflection of non-pressure pipes exceeds the permissible value within less than two weeks of the completion of backfilling, the installation will be rejected without additional measurement after two weeks. If the deflection of pressure pipes exceeds the permissible value at any time prior to pressure testing, but does not also exceed the "pipe acceptance" value, then the installation acceptance criteria may also be regarded as having been satisfied if the deflection measured not less than two weeks after pressure testing of the pipeline is less than the permissible value. This latter provision will only apply, however, if pressure testing is carried out within 6 months of the completion of backfilling.

(4)

Pipes will be accepted provided their deflection has at no time exceeded 5%, and also provided they have not sustained bends, buckles or damage to the mortar lining in excess of the limits stipulated in Clause E2.5.

(5)

'SDR'is the Standard Dimension Ratio which is defined as the ratio of pipe diameter (measured at midpoint of wall) to pipe wall thickness.

Pipes larger than DN600: For pipelines of more than 600mm diameter, internal measurements of deflection shall be made in the vertical and horizontal planes and readings shall be recorded at each pipe joint, at the midpoint of each pipe length, at any point where the limiting deflections appear to be exceeded and at any other point directed by the Engineer.


Page E-85 of 115


Specifications

The deformations of the pipe cross section, at every point measured, shall be within the limits indicated in the following table. Attention is drawn to the fact that, for pipes in this size range, not only must the separate measurements of vertical and horizontal diameters, at any one cross section, comply with a more stringent limit but Deflection Limits for Flexible Pipes Larger than DN600 (Notes as for previous table) Maximum Limits for Flexible Pies DN600 and Smaller Pipe Acceptance (See Note 1)



PE, SDR 10 and over

1.75

0.625

0.750

RTR/GRP SDR 30 to 40.9 SDR 41 to 49.9 SDR 50 to 64.9 SDR 65 to 89.9 SDR 90 and over

1.25 1.50 1.75 2.00 2.25

0.375 0.500 0.625 0.750 0.875

0.500 0.625 0.750 0.875 1.000

See Note 4 1.25

0.50 0.75

0.625 1.00

0.500 0.625 0.750

0.000 0.500 0.625

0.750 0.875 1.000

Type of Pipe

Steel

CM lined Bitumen lined

DI

SDR 55 yo 69.9 SDR 70 to 89.9 SDR 90 and over

Individual measurements of either the vertical or horizontal diameter may show deflections, by comparison with the reference diameter, of FOUR TIMES the value listed above. E3.14

Thrust and Anchor Blocks in Pressure Pipelines Underground pressure pipelines shall be provided with thrust and anchor blocks where necessary or instructed by the Engineer. Thrust blocks will normally be required at bends, tee branches, angle branches, tapers, stop ends and similar fittings; anchor blocks will normally be required on pipelines laid to gradients steeper than 1:20 as follows: •

up to 1:15

anchor block every third pipe;

•

up to 1:10

anchor block every second pipe;

•

greater than 1:10

anchor block every pipe.

Concrete shall extend to undisturbed ground on thrust faces of thrust blocks and on both side faces of anchor blocks; any additional costs arising from over excavation shall be borne entirely by the Contractor. Additional requirements for both location and details of thrust and anchor blocks may be instructed as work proceeds to suit the actual Site conditions encountered.


Page E-86 of 115


E3.15

Specifications

Pipes Protruding from Structures (i)

General Requirements Where pipes are built into structures the joint between the pipe and the structure shall be watertight. The Contractor's attention is drawn to the importance of providing flexibility in pipelines protruding from structures so that differential settlement between a structure and pipeline will not lead to pipe failure. The Contractor will be responsible for ensuring that pipes, joints and supports are provided and placed in accordance with the Specification and drawings. Unless otherwise detailed on the drawings, pipelines (other than those constructed from PE,PP and PB) at or below ground level protruding from a structure shall have two flexible joints adjacent to the structure located according to the pipeline material and diameter as shown in the following table:

Location of Pipe Joints at Structures for Different Pipe Materials DISTANCE FROM STRUCTURE TO FIRST JOINT Pipe Dia. (mm) Rigid Pipes

DI and Steel Pipes

uPVC, ABS and RTR Pipes

* Note:

DISTANCE BETWEEN FIRST AND SECOND JOINTS

up to 225

226450

451900

901 and over

up to 225

226450

451900

901 and over

Max.

200

1D

1D

1D

450

750

1300

2500

Min.

*

*

*

*

300

600

1000

2000

Max.

400

2D

2D

2D

1500

2500

5000

8000

Min.

*

*

*

*

1000

1500

3000

5000

Max.

200

1D

1D

1D

3D

3D

3D

3D

Min.

*

*

*

*

2D

2D

2D

2D

Unless specifically detailed on the drawings, the first joint shall be constructed as close to the face of the structure as is practicable. For key to pipe groups, see Clause E1.5. If during construction a void arises below a built-in pipe protruding from a structure, the Contractor shall clear the void of all extraneous and uncompacted materials and then fill it with Grade C20 concrete in the form of a cradle under the protruding pipe. This cradle must not extend beyond the first flexible joint. If the void extends beyond the first flexible joint the formation of the pipeline beyond that joint shall be restored with compacted structural fill material.

(ii)

Requirements for Concrete, Clay, AC, PF, CI (grey) Pipelines Where additional support to the length of pipe between the structure and first joint is necessary, details will be shown on the drawings or issued as work proceeds.


Page E-87 of 115


(iii)

Specifications

Requirements for uPVC, ABS, RTR Pipelines Where a flexible pipe passes through a rigid concrete face to a structure, the pipe shall be protected from stress concentration and possible fracture of the pipe at the concrete face as follows. A 10mm thick neoprene or other approved synthetic rubber strip shall be wrapped around and cemented to the pipe and, where the neoprene strip is exposed to liquid, a sealant groove shall be formed and filled with an appropriate, approved sealant. The precise configuration is detailed on the drawings. Care shall be taken to ensure that the neoprene strip is not displaced during concreting.

(iv)

Requirements for Steel and Ductile Iron Pipelines Except where otherwise detailed, the two flexible joints shall not be provided for steel and ductile iron pipelines less than 75mm in diameter.

E3.16

Plastic Pressure Pipes Encased in Concrete Where plastic (including RTR/GRP) pressure pipes are encased in concrete, for instance where they pass through anchor or thrust blocks, they shall be wrapped with an approved compressible material such as building felt of minimum thickness 2mm.

E3.17

Marker Posts for Water Mains and other Pressure Pipelines Precast concrete marker posts of approved type shall be installed at all changes of direction, valves, air valves, washout and hydrant positions, road crossings, land boundaries and otherwise at approximately 150-200m intervals as directed by the Engineer. Marker posts shall be installed in a foundation block of Grade C45/20 concrete (0.1 m3 concrete per post). The type, depth, location and diameter of the main or fittings shall be detailed in Arabic and English to an approved design on an approved type of indicator plate, which shall be attached to the indicator post. Details of indicator posts and plates are to be found in Section 7.3 of the Code of Practice for Service Installation prepared by the Ministry of Works, Power and Water.

E3.18

Cutting Pipes Where pipes are required to be cut for any reason the cutting shall be done by the Contractor in accordance with the recommendations of the manufacturer and in a manner approved by the Engineer. Care shall be taken not to damage either section of the cut pipe, and the Contractor shall be responsible for the accuracy of the measurement of the cut pipe as well as the actual cutting. The Contractor shall take all necessary safety precautions. In particular, all personnel involved in cutting or turning asbestos cement pipes must be warned that inhalation of asbestos cement dust is dangerous to health. When cutting or turning pipes by any process which creates dust, all personnel shall be provided with, and instructed to wear or use appropriate clothing and equipment including where necessary suitable face masks or respirators.


Page E-88 of 115


E3.19

Specifications

Flanged and Flexible Mechanical Joints Flanged joints shall be made with great care, and with special attention to the accurate alignment of pipes and flanges. Jointing materials shall be cleaned before assembly and bolts shall be tightened up in sequence, diametrically opposed bolts being tightened a small amount in turn. Any specified torque limitations shall be strictly adhered to. Proprietary flexible mechanical joints shall be assembled in accordance with the manufacturer's instructions.

E3.20

Pipework within Structures - General Requirements Pipework shall be supplied complete with all joint rings, gaskets, washers to each side of a bolted joint, nuts, bolts, grease and any other components necessary for the complete installation. The layout and design of the pipework shall be such as to facilitate its erection and the dismantling of any section for maintenance of associated plant by inclusion of approved mechanical couplings or flange adaptors. Where a common delivery pipe is used, individual pump delivery branches shall be jointed to it in a horizontal plane and angled to minimise turbulence in the flow. Adequate supporting and anchoring arrangements for all pipes shall be included which may take the form of straps, stays, tie bars, concrete cradles and puddle flanges. Steel and cast grey and ductile iron pipes shall be provided with puddle flanges where they pass through the walls of underground or water retaining structures. Where thrusts will be transmitted from the pipework to the wall, the puddle flanges shall be integrally cast in the case of cast iron pipes or welded in the case of steel pipes. All pipes connected to pressure vessels, pumps and similar equipment shall have flanged connections. All pipes shall be checked for alignment and mating of flanges and connections before being secured. Pipes shall not be sprung into position.


Page E-89 of 115


Specifications

E4

STRUCTURAL DESIGN OF PIPELINES

E4.1

General All pipelines to be constructed or installed as part of this contract shall be satisfactorily structurally designed so as to facilitate their construction, and to ensure a service life of not less than 50 years. Full structural design calculations shall be submitted for approval in respect of all pipelines of size DN100 or larger. For pipelines of smaller size, the Contractor shall submit details of the type of pipes proposed, and of the installation details, and the Engineer will then decide whether design calculations are also required. The design calculations and/or installation details described in this Clause are to be accompanied by construction method statements, which must be fully compatible with the design, and must show how the assumptions of the design will be fulfilled on Site. The structural design must verify that the criteria set out below, or such additional criteria or more stringent criteria, as may be stipulated by the pipe or coupling manufacturer, are satisfied.

E4.2

Polyethylene Pipes (a)

Criteria to be satisfied by both non-pressure and pressure pipelines: Long-term deflection: Buckling stability:

Not more than 6% of reduction in vertical diameter. The factor of safety against buckling collapse shall not be less than the following: 1.5 2.0 2.5 3.0

(b)

for pipes with less than 1.5m cover, calculated without soil support. for pipes embedded in gravel. for pipes embedded in sand. for pipes embedded in other soils.

Criteria to be satisfied by pressure pipelines only: The combined stress due to ring bending (external loads) and hoop tension (internal water pressure) shall not exceed the following values: Material Grade

Combined Stress

PE/MRS PE/MRS PE/MRS PE/MRS PE/MRS

7.0 6.3 5.0 3.2 2.5

100 80 63 40 32

Mpa Mpa Mpa Mpa Mpa

E4.3 & E4.4 Not Used E4.5

Steel Pipes (a)

Criteria to be satisfied by both non-pressure and pressure pipelines: Long-term deflection:


The long-term deflection, measured as reduction of the vertical diameter shall not exceed the following:

Page E-90 of 115


Specifications

2% for pipes with cement mortar lining and cement mortar (or concrete) coating. 3% for pipes with cement mortar lining, and polymeric, bitumen, coal-tar or similar coating. 5% for pipes with polymeric or bitumen lining and coating. Buckling stability:

The factor of safety against buckling collapse shall be not less than the following: 1.5 for pipes with less than 1.5m cover, calculated without soil support. 2.0 for pipes embedded in gravel. 2.5 for pipes embedded in sand.

E4.6

Ductile Iron Pipes (a)

Criteria to be satisfied by both non-pressure and pressure pipelines: Long-term deflection

The long-term deflection, measured as reduction of the vertical diameter, shall not exceed the following: Pipe Size (DN)

Class K7

Class K9

100

1.6

1.00

150

2.1

1.45

200

2.4

1.85

250

2.7

2.20

300

3.0

2.45

350

3.1

2.65

400

3.2

2.90

450

3.3

3.05

500

3.4

3.25

600

3.6

3.50

700

3.8

3.75

4.0

4.00

800 and over Bending Stress:

(b)

Criteria to be satisfied by pressure pipelines only: Hoop tensile stress:


The bending stress in the ductile iron pipe walls shall not exceed the guaranteed minimum bending strength divided by 1.5.

The hoop tensile stress caused by internal water pressure shall not exceed 140 Mpa.

Page E-91 of 115


Specifications

E4.7 to E4.9 Not Used E4.10

Design Requirements The structural design calculations to be submitted by the Contractor to verify that the above criteria, as appropriate for the pipe material, will be satisfied, shall take account of the following:

E4.11

(a)

The loading and environmental criteria specified in this clause, elsewhere in the specification, or stated by the contractor in respect to temporary construction loadings.

(b)

The depths of cover at which the pipelines will be installed.

(c)

The detailed method of construction which will be employed by the Contractor for the installation of the pipeline.

(d)

Any temporary loadings to which the pipeline will be subjected by the contractor’s operations on Site.

Loading Criteria Backfill density: Unless otherwise specified or indicated, the backfill density shall be taken as 20kN per cubic metre. Backfill loading: The design backfill loading (as vertical pressure, or load per unit length of pipeline) shall be not less than that resulting from an average vertical pressure, acting on the full width of the pipe, equal to the product of the backfill density and the depth from ground level to the top of the pipe. Where the pipe: soil stiffness ratio is such as to cause a concentration of load (pressure) then the increased value shall be used in design. Where pipelines are installed in sufficiently narrow trenches, the backfill loading may be reduced to take account of the silo-effect, provided that in no case is it reduced below the value obtained as the product of soil density and depth of cover. Surcharge loading:

E4.12

The design shall include for the effect of surcharge pressures due to a single wheel load of 100kN, applied with an impact factor of 1.5.

Environmental Criteria Temperature: Ground Conditions:

E4.13

See environmental and climatic data See Site investigation information

Loading Combinations to be Considered The pipeline structural design shall satisfy the criteria specified above for each of the following loading combinations relevant to the pipe material.

(a)

Pressure pipelines: PE, PVC and RTR/GRP pipes:


Page E-92 of 115


Specifications

Each of the following simultaneous loadings shall be considered: (i) (ii) (iii)

Backfill load, vehicle surcharge, working pressure. Backfill load, minimum negative surge pressure (for buckling) Backfill load, maximum positive surge pressure.

Steel pipes Simultaneous action of backfill loading and minimum negative surge pressure (for buckling). E4.14

Approved Calculation Procedures The following design codes are approved in respect of their calculation procedures, though not necessarily in respect of the loadings which they include. (The actual loadings used in the design calculations for this contract shall be not less than those specified in this Clause). Pipe Material

Design Code

PE and PVC

‘Pipe Materials Selection Manual’, WRc, 1988

Steel

American Water Works Association, M11, 1986 ‘Pipe Materials Selection Manual’, WRc, 1988

Ductile Iron

American Water Works Association, C150, 1981 International Standards Organisation, CD 1083 (Third Edition, 1994) ‘Ductile Iron Pipelines, Embedment Design’, Stanton, 1979

Pipeline structural design in accordance with other codes or procedures may be permitted, but only if a full English language version of the code has been submitted to the Engineer and approved in advance. E4.15

Additional Structural Design Requirements The pipeline structural designs shall not be limited to coverage of the requirements referred to above, or in the approved codes, but shall also include the following: (a)

Provisions to resist the thrusts generated at changes of direction or cross-Section Gn pressure pipelines, and to avoid joint dislocation, excessive pipeline movement, overstressing or overstraining of pipes, or other harmful effects.

(b)

Provision of pipeline foundations which will ensure that the pipeline remains within the specified tolerances on level for the design lifetime.

(c)

Provision of arrangements to accommodate differential settlements at any point along the pipelines, including their approach to structures, such that the pipes will not be overstressed or overstrained, and so that the movements at pipe joints will not exceed their stated or specified capabilities.

(a)

Provision of anchorages to pipelines constructed in ground sloping as per Clause E3.14, p E-88.


Page E-93 of 115


Specifications

E5

NON DISRUPTIVE METHOD (NDM) FOR PIPELINE CONSTRUCTION

E5.1

Scope of Work Furnish all labour, materials and equipment and perform all the work necessary to design and construct pipelines crossing under paved roads using non-disruptive methods, as specified herein and indicated on the drawings. Construction shall be by using trenchless techniques that are appropriate for the intended installation and which can be demonstrated to the satisfaction of the Engineer to meet the contents of these specifications. Where a pipeline is to be constructed by microtunnelling, the Contractor shall confine his surface operations to working shafts and the area immediately adjacent to such shafts. Such working area shall be kept to the minimum practicable for the proper construction of the works. The Contractor shall propose the location of all working shafts, having due regard to existing services, minimising disruption to traffic and pedestrian movements and achieving the required system layouts, as shown on the Drawings. Locations shall be approved by the Engineer prior to the commencement of construction. The Contractor shall obtain approval of his method statement from concerned Authorities. Where the Drawings show that a range of pipe diameters are to be constructed, the Contractor may propose to the Engineer for his approval that certain sections are constructed within larger diameter pipes and the annular space grouted. The difference between the external face of the inner pipe and the internal face of the outer pipe shall not be less than 150mm and not more than 250mm.

E5.2

E5.3

Related Work Earthworks

Section C

Concrete Works

Section D

Design The Contractor shall be responsible for the design of the pipes used for the non-disruptive method including all joints, for the design of the thrust and reception pits including support and thrust wall and for the design of the jacking system in general. His design shall have the Engineer’s approval.

E5.4

Submittals In addition to the applicable requirements of this Specification, the following shall be submitted by the Contractor and approved by the Engineer prior to commencement of any works: 1.

Programme of work with resource and equipment allocations.

2.

Additional Soil Investigations.

3.

Design Calculations for the non-disruptive method:


Page E-94 of 115


a)

Specifications

Pipes including jacking and friction forces in the axial direction and earth, traffic and surcharge loadings in the vertical direction and the pipes resistance to these loads. Also, allowable deflections at joints to limit damage to the joint from eccentric loading under thrust and sealing limits.

b)

Thrust and reception pits to resist external soil and water pressures and stresses resulting from jacking machine. Drawings showing on plan and sections the method of supporting excavations and equipment layout shall be included.

All calculations shall be certified / signed by a qualified Engineer.

E5.5

4.

Materials Specifications and product data.

5.

Method Statements which shall include : a)

List of equipment and resources.

b)

Detailed step by step procedure describing how work will be carried out including clear definition of responsibilities and authority.

c)

Support of existing services and adjacent structures.

d)

Safety arrangements for compliance with safety requirements.

e)

Arrangements for dealing with groundwater taking due regard to controlling the loss of material and preventing settlement around pits, pit / pipe interface and tunnel face.

f)

Dealing with different ground conditions.

g)

Locking pipe in position during insertion of next pipe.

h)

Sealing thrust and reception pits during exiting and entering of pipe.

i)

Control of overbreak.

j)

Grout mix design and method of grouting.

k)

Handling and fixing, of the inner pipe in the case of microtunnelling with larger diameter pipes.

Quality Assurance The non-disruptive method of pipeline installation shall be executed by firms having a record of at least five years of successful, trouble free execution of similar works.

E5.6

Delivery Storage and Handling All materials shall be properly protected so that no damage or deterioration shall occur during a prolonged delay.

E5.7

Site Investigation Soil conditions and ground conditions shall constitute the Contractor’s risk.


Page E-95 of 115


Specifications

After award of the Contract, the Contractor shall be responsible for carrying out all geotechnical site investigations, including ground water level monitoring, which he considers necessary but as a minimum at the proposed access pit locations, and central median. The Contractor’s site investigation programme shall be submitted to the Engineer for review. The results of such investigations shall be submitted to the Engineer and shall include recommendations for pipelaying, excavation support and soil stabilisation if required. The Contractor shall be responsible for obtaining existing utility information and executing trial pits to locate and confirm services at pit locations, etc., as required. E5.8

Health and Safety The Contractor shall adopt safe working practices for tunnelling in accordance with BS 6164. Only authorised personnel shall be allowed access to the site. The Contractor shall provide a Safety Officer, suitably experienced in tunnelling operations and with adequate authority to control and implement safe working practices. The Contractor shall make suitable arrangements for accommodating his personnel at the site including the following as a minimum : 1.

Air-conditioned mobile office at the thrust pit with space, desk and chair for one inspector.

2.

Telephone service.

3.

Telecommunication between the control room and the work crews.

4.

Cool air-conditioning in summer for work crews engaged in operations at the thrust and the reception pits.

5.

Approved gas detectors.

6.

First aid kit.

7.

One vehicle.

8.

Emergency escape or BA sets.

The excavated pits shall have a separate cage type ladder bay complete with ladder in addition to any other bay or bays required for the construction of the works. The pits shall be fenced off on all sides with close steel panels at least 1.8m in height and equipped with safety warning lights. The panels (maximum space between 100mm) shall be joined by steel rods supported on concrete blocks. Adequate lighting and ventilation shall be provided to the pits and electricity shall be supplied at no greater than 110/220 volts. E5.9

Skilled Operators and Supervision All operators in the employment of the Contractor shall be skilled and experienced in their respective trades and in particular shall be fully skilled in shaft sinking and tunnelling microtunnelling.


Page E-96 of 115


Specifications

The operators who will perform the Work shall have a minimum of 1 year experience in the performance of tunnelling/ microtunnelling subject to performance with 3 months probation. Curriculum Vitae of key personnel and operators shall be submitted for approval. Interviews may be undertaken at the discretion of the Engineer/Department. E5.10

Pipe Materials Pipe materials shall comply with the specifications. Microtunnel pipes shall be designed to withstand the maximum axial thrust with a factor of safety of 4 based on the full effective area and the ultimate compressive strength of the pipe material. For reinforced concrete pipes the full effective area at the joint shall be used. Where GRP or similar materials pipes with concrete surround are proposed for microtunnelling, the concrete shall be regarded as sacrificial. The concrete surround shall be designed to withstand the maximum jacking force. Joints in pipes used in microtunnelling shall be designed to avoid projections which could obstruct the travel of the pipe and they shall be watertight under axial loading and at the permissible deflection of the pipes. Quality control tests at the factory should include subjecting the pipe joints, at a maximum permissible deflection, to an external hydrostatic pressure of 2 bars. The Contractor’s submittals shall describe the measures to be taken to avoid the development and transfer of grout shrinkage or expansion stresses to the pipe and to avoid any adverse chemical reaction between the pipe and concrete, grout or other materials comprising the pipeline. The pipe manufacturer has to guarantee that this pipe and its material are suitable for its intended use. Standard pipes shall be a minimum in length subject to the installation method used. Where required, pipes shall incorporate lubricant injection holes spaced equally around the circumference. Concrete pipes with a liner shall only be permitted to have lubricant injection holes in the concrete. Lubrication holes shall be clear of joints and shall be plugged on completion of the work. The liner shall be made good and continuous. Pipes may incorporate lifting holes and fixing holes for securing temporary apparatus. All such holes shall be threaded to enable plugs to be screwed into the sockets to withstand any external water pressures. Joints which shall be used in conjunction with a resilient packing, shall be capable of accepting repeated annular deflections of up to 10 without : i)

damage to pipe or loss of structural strength.

ii)

the ingress or egress of water or lubricant under the maximum operational or test pressures.

iii)

the ingress of soil / groundwater onto the bearing surfaces.

The joint design for concrete pipes shall be such that the areas available for transmitting the maximum permitted thrust force will be sufficient to ensure that with an annular deflection of 1º and with resilient packing material in place the maximum pressure applied to the joint bearing surface will not exceed 23.5 N/mm2 for drives up to 100 metres in length and 21.0 N/mm2 for drives in excess of 100 metres and up to 150 metres in length. Vol 3, Section3 – Civil Specifications

Page E-97 of 115


Specifications

Unless independently authenticated test results acceptable to the Engineer are available, two consecutive axial loading tests incorporating a 1º angular deflection with the application of double the maximum permissible thrust force (or, if greater, of the greatest thrust force that the proposed thrust equipment can apply) shall have been successfully conducted without any visible crushing, cracking or spalling of the pipe being evident, before any pipes will be accepted for use. The tests shall be extended to record the loading at which any visible signs of failure become evident, and shall be carried out in an approved manner to simulate actual working conditions. Pipes which have been submitted to the proof load test will not be permitted in the Works. Where the Contractor elects to construct certain sections within larger diameter pipes and grout the annular space, the external pipe may be of steel with full circumferential weld. The steel pipe and the grout shall be regarded as sacrificial and the inner pipe shall be designed as a stand alone pipe, capable of withstanding installation and grouting forces and soil, traffic and groundwater loads subject to the method. Where the Contractor elects to construct sections not within larger diameter pipes, pipe installation shall continue until at least one additional length of pipe beyond the limit of construction is exposed. Where the pipe has failed, a second pipe shall be jacked through and inspected. The condition of the exposed pipe and its exterior coating shall be inspected by the Engineer. Where in the opinion of the Engineer the pipe or coating has been damaged during installation, the Contractor shall submit a proposal, for review by the Engineer, for demonstrating the adequacy of the pipeline installed. The external coating to reinforced concrete pipes shall be pure epoxy 500 microns minimum thickness. E5.11

Joint Packing The material used for joint packing shall have under dry conditions when subjected to the maximum permitted bearing pressure : i)

a restoration after 1 hour of at least 65% of the original thickness, and

ii)

a compression of at least 50% of the original thickness.

Independently authenticated test results to demonstrate that the packing complies with the Specification shall be submitted and shall include a graph of the stress / strain relationship over the range of conditions which will be encountered during the Works. The material used for packing shall withstand all imposed loadings applied during the installation of all pipes for each completed length without showing signs of deterioration or distress. The packing material is to be cut to dimensions that ensure the full bearing width of the joint is protected. The initial thickness of the packing shall be such that the final joint gaps achieved upon completion of the pipeline are a nominal 8mm in width. Packing shall not be fixed over the full face of the pipe but stopped approximately 1cm from free edges. The joint gap shall have a tolerance of between 6mm and 15mm depending on jacking forces. Outside gaps in the joints between pipes shall be sealed. E5.12

Lubricant Lubricant shall always be used when microtunnelling.


Page E-98 of 115


Specifications

The material used for lubrication shall be a polymer or bentonite based slurry approved by the Engineer. It shall be stored and mixed in a manner recommended by the supplier and tested prior to use. Lubricant injection overpressure shall be avoided. It shall be sufficient to fill the annular overbore voids around the outside of the pipe to avoid collapse and upward migration of the void prior to permanent grouting. A certificate shall be obtained by the Contractor from the manufacturer of the bentonite powder showing the properties of each consignment delivered to the Site. This certificate shall be made available to the Engineer on request. The properties to be given by the manufacturer are the apparent viscosity range (in pascal seconds) and the gel strength range (in pascals) for solids in water. Bentonite shall be mixed thoroughly with clean fresh water to make a slurry 24 hours before its usage. The temperature of this water used in mixing the bentonite suspension, and of the suspension when supplied to the drilling machine, shall be not lower than 50C. Where saline or chemically contaminated groundwater exists, special precautions shall be taken to modify the bentonite suspension or prehydrate the bentonite in fresh water so as to render it suitable in all respects for the intended purpose. Control tests shall be carried out on the bentonite suspension, using suitable apparatus. The density of freshly mixed bentonite suspension shall be measured daily as a check on the quality of the suspension being formed. The measuring device shall be calibrated to read to within 0.005 g/ml. Tests to determine density, viscosity, shear strength and pH value shall be applied to bentonite supplied to the pipe bore. For average soil conditions the results shall Generally be within the ranges in the following Table. Tests on Bentonite Property to be measured

Range of results at 200C

Test method

Density

Less than 1.10 g/ml

Mud density balance

Viscosity

30 - 90s

Marsh cone method

or less than 0.020 Pa-s

Fann viscometer *

Shear Strength

1.4 - 10 Pa

Shearometer

(10 minute gel strength)

or

pH

*

4 - 40 Pa

Fann viscometer

9.5 - 12

pH indicator paper strips electrical pH meter

Where the Fann viscometer is specified, the fluid sample should be screened by a number 52 sieve (300 gm) before testing.

The frequency of testing bentonite slurry and the method and procedure of sampling shall be proposed by the Contractor for approval before the commencement of work. The frequency may subsequently be varied as required, depending on the consistency of the results obtained, subject to approval.


Page E-99 of 115


Specifications

The tests shall be carried out until a consistent working pattern has been established, account being taken of the mixing process, any blending, of freshly mixed bentonite suspension and previously used bentonite suspension, and any process which may be used to remove impurities from previously used bentonite suspension. When the results show consistent behaviour, the tests for shear strength and pH value may be discontinued, and tests to determine density and viscosity shall be carried out as agreed with the Engineer. In the event of a change in the established working pattern, tests for shear strength and pH value shall be reintroduced for a period if required. E5.13

Joint Sealant The joint sealant shall be an elastomeric ring complying with BS 2494:1990.

E5.14

Grout As Slurry replacement: The grout shall consist of Portland cement and water as determined by geotechnical data and directed by the Engineer. It’s normal strength shall be at least 20 N/mm2. Admixtures shall be used only if tests have shown to the satisfaction of the Engineer that their use improves the properties of the grout, e.g. by increasing workability or slightly expanding the grout. As Annular Space Filling: A low strength, non shrink grout or foam concrete shall be used and placed at low pressures. The density of the mix shall be in the range 900 - 1200 kg/m3 and the free water/cement water not greater than 0.6. The carrier pipe and joints shall be protected from the possible adverse physical or chemical-effect of grout. Compressible material shall be wrapped around pipe. The internal pipe shall be filled with water to avoid floatation forces, hydration temperatures and to resist forces during grouting. A 5m high free vented standpipe should be used. A free venting standpipe of not less than 100mm dia. shall be installed on the grout injection feed to restrict grouting pressures to a maximum of 1 bar.

E5.15

Thrust and Reception Pits The dimensions of thrust and reception pits shall be limited to the minimum required to construct the Works. Thrust and reception pits shall be constructed within a sheet pile cofferdam or caisson if the ground conditions dictate. The pit bottom shall be sealed with concrete. Entry and exit sealing rings shall be provided. The Contractor shall determine the excavated dimensions of the drive and reception shafts as required to suit the site conditions. Minimum shaft dimensions shall be used at all locations where utilities, roads or trees exist adjacent to the required shaft locations. Excavations shall be supported according to type of pit as specified below : Type ‘A Thrust and reception pits in all types of soils except rock, with high groundwater table and with the excavation secured by precast reinforced concrete caisson.


Page E-100 of 115


Specifications

The caisson bottom shall be sealed with a concrete plug which shall be placed underwater and designed to resist water uplift as well as forces from the jacking equipment to be installed in the pit. All the joints between caisson rings shall be sealed with the joint sealant and the caisson grouted from outside in order to make in water tight. A reinforced concrete wall shall be provided in the thrust pit to resist the jacking force. A properly braced concrete wall shall be provided in the thrust and reception pits in order to install the entry and the exit rings. Type ‘B’ Same as Type ‘A’ but the excavation is secured by inter-locked steel sheet piles. The sheet piles shall be braced by suitable steel framing welded to the sheet piles. No struts shall be used for bracing. The first set of bracing shall be at 0.5m from the ground surface. Type ‘C’ Same as Type ‘A’ but in dry conditions. Type ‘D’ Same as Type ‘B’ but in dry conditions. Type ‘E’ Same as Type ‘A’ except that the pit is partially in soil and partially in rock. The portion in soil is secured by caisson as in Type ‘A’ where as the portion in the rock can be unsupported. Special precautions shall be taken to seal the interface between the caisson and the rock so that it is water and soil tight. Type ‘F’ Same as Type ‘E’ except that excavation in soil is secured by sheet piles instead of a caisson. Type ‘G’ Same as Type ‘E’ but in dry conditions. Type ‘H’ Same as Type ‘F’ but in dry conditions. Type ‘I’ The thrust and reception pits are in rock in an area of high groundwater table. The excavation can be unsupported. A reinforced concrete wall shall be provided in the thrust pit to resist the jacking force. Properly braced concrete walls shall be provided in the thrust and reception pits in order to install the entry and exit rings. Type ‘J’ Same as Type ‘I’ except in dry conditions. The pits shall be completely dry prior to commencing and throughout tunnelling works. Dealing with groundwater where required shall be conducted in a slow manner. Standby facilities shall be provided.


Page E-101 of 115


Specifications

The thrust wall shall be perpendicular to the proposed line of thrust. The thrust wall shall be sufficient to accept repeatedly the maximum permitted thrust force without undue movement. It will not be permissible to thrust directly off any permanent part of any shaft, chamber or pumping station unless this is specifically designed to withstand the thrust reaction. Thrust wall shall not be joined to the jacking rig base concrete. Where it is proposed to use a tail tunnel as the reaction surface the maximum permitted thrust force shall not exceed the lesser of the following : i)

The maximum permissible thrust force.

ii)

a)

50% of the sum of the maximum forces recorded at the rigs used to construct the tail tunnel, or

b)

if the overbreak to the tail tunnel has been grouted up, 100% of the sum of the maximum forces recorded at the rigs used to construct the tail tunnel.

Any tail tunnel which has been used as a reaction surface shall pass the specified watertightness test at a time not less than 14 days after the load has been removed. The design of the thrust wall and any other associated Temporary Works shall be such as to prevent damage to any part of the Permanent Works or any immediately adjacent service or structure. Any void between the soil face used to provide a reaction to the thrust force and the thrust wall shall be filled completely with grout. The Contractor shall take any measures necessary to prevent damage or deterioration of the soil reaction face during the construction of the Temporary and Permanent Works from whatever possible cause, such as ingress of water, softening, corrosive soil or loss of fines from a granular soil. E5.16

Pipe Installation within Sleeves Pipe sections shall be placed and joined individually within the sleeve or mounted on guide rails or trolleys in such a manner as to transmit the pulling / pushing forces through the carriage and not through the pipe.

E5.17

Microtunnelling Unless otherwise agreed, the method to be employed for microtunnelling shall be mechanical earth-pressure counter balance tunnelling system incorporating, a polymer or bentonite based slurry system. The use of water alone shall not be permitted. The horizontal drive rate shall be maintained equal to the excavation rate throughout the operation. During all stages of the setting up, microtunnelling operation and dismantling both subsidence and heave shall be prevented. The microtunnelling system shall be manufactured and operated having regard to the provisions of BS 5228:Parts 1 and 2 and BS 6164. The slurry system shall have a dual purpose of removing excavated soil and balancing groundwater and face pressures. The slurry / excavated soil mixture shall be properly


Page E-102 of 115


Specifications

removed from the excavation, and removed from the site to a suitable location. Stock piling on site shall be avoided. Presure gauges shall be provided in the control room to measure the slurry and suction pressures. Face support shall be provided by full earth pressure balance. The tunnelling machine shall be steerable, incorporating hydraulic rams to move the articulated head. The line and level control shall be achieved by a laser beam transmitted from the jacking shaft to a target mounted in the tunnelling machine. The design of the tunnelling machine shall ensure no rotation or rolling during installation. The tunnelling operation shall be run continuously between thrust and reception pits. During short stoppages needed for pipe jointing, the slurry pressures / face pressures shall be maintained. Tailings removal and cutting face shall not be operated when the pipe thrust is not being carried out. A remote control tunnelling machine shall be used and it shall include a closed circuit television camera which transmits a picture of the laser beam on the target together with other machine information (such as jacking force, face pressure, length, roll, pitch, steering attitude, temperature valves open or closed) to a microprocessor console on the surface from where the system is operated. The tunnelling machine shall be capable of operating under groundwater conditions as necessary. The hydrostatic balance shall be not less than 3m head of water. E5.18

Line and Level A laser guidance system shall be used for the control of tunnel alignment. The laser shall be mounted independently of the thrust wall or machine jacking rig or anything else that may move during jacking. The shield / tunnel machine shall be fitted with a calibrated laser target, robustly constructed and rigidly secured to the shield / tunnel machine. Manual checking of line and level shall carried out by conventional theodolite and level techniques. The setting of the laser and target and the alignment of the tunnel relative to the laser beam shall be accurate and checked constantly. The lateral deviation of any part of the pipeline should not be more than ±50mm from that detailed in the Contract. The level of any part of the pipeline shall not deviate by more than ±20mm from that detailed in the Contract. The maximum lipping between the edges of adjacent pipes shall not be more than ±5mm. If the deviation exceeds the specified tolerance, work shall cease immediately and the Engineer informed forthwith. The Contractor shall submit proposals to rectify the deviation and work shall only recommence on the written instruction of the Engineer.


Page E-103 of 115


E5.19

Specifications

Thrust System The rig shall distribute the thrust to the pipes via a thrust ring and packing. The jacks shall apply the thrust to the thrust ring by means of a symmetrical distribution. Interjack stations shall be used where frictional resistance or other causes would otherwise result in unacceptable thrust forces. If used, spacer blocks shall be true and free from any distortions. All thrust rings shall be true and free from any distortions and sufficiently stiff so as to transfer the load from the jacks uniformly to the packing. Other than at the shield, each group of jacks shall be interconnected to ensure that an evenly distributed load is applied to the thrust ring. Each jack shall incorporate a load cell. At the rig and at intermediate stations automatic thrust recording equipment monitoring load cells incorporated in each jack is to be provided together with a pressure metering device. Other continuous records including cutter torque, rate of progress, slurry progress, pitch, roll, slurry flow, earth face pressure, etc. shall be provided. Copies of these records clearly stating the units measured shall be submitted daily to the Engineer. The thrust force shall not exceed the maximum permissible thrust force as determined by the Contractor, based on calculations submitted by the Contractor and approved by the Engineer and on consideration of the behaviour of the pipe joint at the maximum permitted angular deflection of 0.5’ with the maximum permissible bearing stress in conjunction with the stress / strain relationship obtained from the packing compression tests.

E5.20

Lubrication Holes Where lubrication holes are required, these shall be threaded to enable plugs to be screwed into the socket and withstand the external pressure. Non-return valves shall be fitted where opening a hole would permit ground loss. Lubrication holes shall be plugged watertight on completion, lining or coating shall be made good. The pressure of the lubricant shall be maintained until it is replaced by grout.

E5.21

Grouting Upon completion of a section, if grouting is required or specified, the grout shall be pumped through all lubrication holes. The pressure and quantity of grout injected shall be calculated by the Contractor and approved by the Engineer. Grouting shall commence at the lower holes and shall be carried out systematically working from one end of the pipejack to the other. Where injection holes can be opened without loss of ground, grout shall be pumped through the lower injection holes until it emerges from the upper holes. Grouting progress shall be continuously monitored to ensure no over pressurisation.

E5.22

Records The Contractor shall maintain and submit to the Engineer after each shift a log which records: •

Identification number of pipes installed during shift and name of operator Strata encountered.

•

Position and orientation of the lead ten pipes.


Page E-104 of 115


E5.23

Specifications

•

Forces used on both main and intejack rams during driving of each pipe.

•

Line and level.

•

Roll of pipe jacking shield.

•

Maximum rate of advance.

•

Thrust from ground on face of machine.

•

Volume of lubricant used, location of injection and pressure at point of injection.

•

Gas readings at the excavating face (oxygen, methane and hydrogen sulphide)

•

Volumes of material removed.

•

Volumes of grout used, the points of injection and pressure at the points of injection.

•

Cutter torque.

•

Slurry flow and pressure.

•

Supply pressure.

•

Pitch of TBM.

•

Gas readings in thrust pit.

•

Level records of around surface or road pavement.

•

Accident and stoppage, if any, with full explanation.

Testing Upon completion of the permanent construction of the tunnel, an infiltration test shall be conducted to verify that the joints are water tight. The infiltration test shall be carried out after dewatering has stopped and the groundwater has attained normal levels. In the case of lined concrete pipes the leakage tests shall be carried out after installation and before the liners of the successive pipes are joined and sealed. After joining and sealing of the liners, there shall be no evidence of a build-up of groundwater pressure at the joints of the concrete pipe. Man-entry pipelines shall be visually inspected only. Any leaks will be repaired / stopped. Infiltration or pipe deflection is not permitted in sections of pipelines underneath roads, paved areas and services. In the event of the Works failing the test, for whatever reason, the Contractor shall at no extra cost to the Employer, take such remedial action as is necessary, subject to the Engineer’s approval of any methods proposed. The Works shall then be re-tested until such time as the Works pass the test.

E5.24

Monitoring Ground Surface Movement The Contractor shall continuously monitor the ground surface, adjacent structures, and buried utilities and shall control activities such as excavation, tunnelling and dewatering to prevent movement and / or damage to existing structures.


Page E-105 of 115


Specifications

Settlement shall be held to within the following limits : 1.

Ground or roadway surface above the pipe centreline : 5mm

2.

Front face of adjacent structures : 3mm

Settlement points shall be installed and monitored prior to any excavation associated with the pipeline to be constructed by microtunnelling. The Contractor shall determine the optimum location for settlement points to monitor existing structures to approval of the Engineer. The Contractor shall provide settlement points on the road surface and within existing structures. Settlement points along the road surface shall be located along the pipe centreline and on lines parallel to the centreline at 2 metres and 4 metres away from the pipe centreline on each side. The distance between settlement points along the same line shall be 5 metres. Settlement points on existing structures shall be located approximately 0.5 metres above the ground surface. Location of settlement points in the vicinity of the shafts will be agreed with or at the direction of the Engineer. The Contractor shall monitor all settlement points with reference to benchmarks located outside the area of influence of the works. Monitoring shall demonstrate repeatedly to 3mm. The Contractor shall obtain the elevations of settlement points as described below: 1.

For settlement points within 20 metres of the heading, after each advance of 5 metres.

2.

For settlement points greater than 20 metres but less than 100 metres away from the heading, daily.

The settlement point elevations shall be reported to the Engineer within 24 hours during the course of construction of the pipeline and related shafts. Should settlement occur greater than the specified limits, at any location affected by the works, the Engineer may require modification of the method or sequence of the work or a shutdown of the work to make appropriate changes in the construction operation. Changes required to keep settlement within the specified acceptable limits shall be made solely at the Contractor’s expense. Upon completion of the pipeline, the Contractor shall continue to monitor the settlement point elevations regularly during the maintenance period and report to the Engineer on a monthly basis. If the specified limits are exceeded then the Contractor should report immediately and submit a proposal to rectify the road surface and prevent further settlement. E5.25

Tunnelling-General Requirements

E5.25.1

General (1)

The Contractor shall be responsible for all methods of working in underground works, including the design, provision and erection of all things necessary to safeguard the Works and the workmen. In particular, the Contractor shall be responsible for the support of all excavation in underground works during construction, which shall include making good after falls.


Page E-106 of 115


E5.25.2

Specifications

(2)

All procedures necessary to safeguard the Works and workmen, except for any emergency measures that may have to be taken by the Contractor to ensure safety, shall be subject to the prior consent of the Engineer, but such approval shall not relieve the Contractor of any of his responsibilities.

(3)

Except where otherwise required, tunnels in soft ground shall be straight or, in order to accomplish changes in alignment, shall lie on horizontal and vertical circular curves of minimum 50m radius. Curves may be omitted where a change in alignment occurs at a shaft.

Submissions For each pipeline the Contractor shall submit to the Engineer for his approval the following:

E5.25.3

(a)

particular site investigation;

(b)

calculations of design and tunnel linings;

(c)

method description including drainage, excavation, ventilation and illumination;

(d)

specifications of materials and equipment to be used;

(e)

pipe calculations and loading tests results;

(f)

design and calculations of Temporary Works for tunnelling shafts and receiving pits, shoring and drainage;

(g)

safety measures.

Safety (1)

The Contractor shall comply with the safety requirements specified in this Specification.

(2)

All tunnelling works shall be carried out in accordance with BS6164 Code of Practice for Safety in Tunnelling in the Construction Industry and other relevant construction and safety standards and regulations. The Contractor shall be fully conversant and comply with the relevant sections of all safety regulations relating to underground works enforceable by law.

(3)

The Contractor shall be responsible for the safety of all his employees and other persons entering or in the Works and shall, at his own cost, and with the approval of the Engineer, take all measures necessary to ensure their safety. In particular such measures shall include the following: (a)

Provision of proper safety and emergency regulations and fire, gas and electric shock precautions.

(b)

Provision of a first aid box and rescue facilities at each tunnel portal or shaft.

(c)

Provision of a first aid post. The first aid post shall be in telephone communication with portals and shafts in their areas and shall have a telephone on the public network.

(d)

Safe storage, handling and use of gases, fuels and other dangerous goods.

(e)

Safe supporting of all excavations.


Page E-107 of 115


E5.25.4

Specifications

(f)

Provision of efficient safety helmets for all personnel including authorized visitors to the site; provision where necessary of safety harnesses for personnel including the Engineer and his staff.

(g)

Control of water, including the provision of generating plant.

(h)

Provision of lighting to provide adequate illumination of the Works, including spares and standby equipment.

(I)

Provision and maintenance of safe, sound mechanical cranes, hoists and conveying facilities for the transport of materials, each item of plant having an up to date test certificate.

(j)

Provision and maintenance of safe, sound ropes, slings, blocks and other lifting tackle, each appliance having an up to date test certificate.

(k)

Provision of temporary ladders to all shafts, with landings at intervals not exceeding 3m. Protection shall be so provided that neither persons using the ladders nor the ladders and their supports are subject to danger or risk of damage by the passage of skips and/or materials in the shaft.

(l)

Provision and maintenance of safe, sound hoists and cages for conveying personnel where necessary, each item having an up to date test certificate.

(m)

Provision of competent operators for control of all lifting and hoisting equipment, with at least one banksman, the operators of shaft hoisting gear being in telephone communication with the bottom of the shaft.

(n)

Provision and maintenance of all temporary electrical installations to the standards prescribed in BS 6164.

(o)

Provision of notices, minimum 1.5m by 1.0m in size written in bold letters to be erected on existing footpaths where appropriate and at points of access likely to be used by the public to warn them of the existence of the Works. These notices shall be in addition to any statutory requirements demanded of the Contractor.

ample standby pumping and

(4)

The Contractor shall submit for the approval of the Engineer detailed proposals of safety and emergency regulations. After approval, copies of the safety regulations shall be produced by the Contractor and distributed to all of his employees and staff and to the Engineer and his staff. Notices shall be displayed at all portals and shafts detailing emergency and rescue procedures.

(5)

The Contractor shall ensure that all personnel are conversant with regulations.

Control of Water (1)

The Contractor shall be responsible for the control of water in underground works and shall keep these works well drained until the issue of the last Certificate of Completion in respect of underground works or until the written approval of the Engineer.

(2)

The Contractor shall ensure that all watercourses, whether they be natural or manmade, shall be trained away from shafts and tunnel entrances so that the Works are protected from flooding.


Page E-108 of 115


E5.25.5

Specifications

(3)

Where the levels of workings are such that drainage or accumulations of water do not flow away or cannot be piped away by natural gravitational means to existing points outside the underground workings, the Contractor shall install and operate all necessary pumping plant, pipework, tanks etc. including stage pumping where appropriate, and shall eject all accumulations of water from the underground workings. The Contractor shall, in locations agreed by the Engineer, provide and install meters or other approved means of flow measurement in all incoming and outgoing water pipes for monitoring the natural ingress of water.

(4)

Standby pumping plant with alternative motive power shall be provided by the Contractor.

(5)

The Contractor shall at all times be aware of the possibility of sudden inrushes of water if the excavation taps an underground source of water and shall take all necessary precautions to ensure the safety of all men working in the tunnel and to prevent delay in tunnel driving due to damage to plant. The precautions to be taken shall include pilot drilling ahead of the face at all places where there is reason to expect significant inflows of water, or there is a risk of interception known or suspected fault zones or similar hazards. When excavation is by drilling the pilot hole shall be drilled to at least twice the distance of the anticipated pull. The number of pilot holes and their positions shall be governed by the type of ground and available site investigation data. Radial pilot holes shall be utilized where necessary. The Contractor shall be deemed to have allowed for the effects of pilot holes on adjacent works and structures.

(6)

The Contractor shall ensure that all watercourses whether they be natural or manmade shall be trained away from shafts and portals so that the Works are protected from flooding. Where in the opinion of the Engineer there is a danger of flooding, he may order work to be discontinued and labour removed either until such danger had passed, or until the Contractor completes additional protective measures to the satisfaction of the Engineer.

(7)

Measures shall be taken by the Contractor, to the satisfaction of the Engineer, to prevent pollution of existing watercourses by impurities in water discharges from tunnels and shafts.

(8)

Water shall be kept clear of concreting work by grouting or by piping it away from behind the shutter. Water shall not be allowed to run over or through freshly placed concrete.

Testing and Records (1)

Notwithstanding which method of excavation is used, the Contractor shall keep a log in which shall be recorded the results of all examinations of the ground immediately after excavation. The log for each heading shall be available for inspection by the Engineer at a day’s notice at his office and on demand at the tunnel site. A copy of the log shall be provided for the Engineer’s retention.

(2)

Entries in the log shall give the precise locations of all visually distinguishable geological features. The log shall show the precise length and chainage excavated in each shift. The chainage shall be marked at 10m intervals by approved temporary marks concreted in place and maintained.

(3)

Records shall be kept of progress, ground conditions and where appropriate of the line, level, plumb, square and roll of the shield and the lining and of the wedge ram thrust at every tenth ring or such other interval as the Engineer may direct and a copy sent daily to the Engineer.


Page E-109 of 115


E5.26

Specifications

(4)

Where appropriate records shall also be kept of the type and amount of grout injected in each section of shaft or tunnel and a copy supplied to the Engineer daily.

(5)

Inspection and watertightness tests of completed tunnelling shall be performed in accordance with the requirements of this specification.

Undertaking The Contractor shall enclose with his request for approval (Notice of Intent) to carry out the works from the concerned Authorities, an undertaking in the form of Exhibit I formally executed by the Contractor, bearing the corporate seal and signed by the Contractors duly authorised signatory. EXHIBIT 1 UNDERTAKING

We undertake to inform the

*

in the event of collapse or settlement of a

*

road when we are carrying out excavation in, under or near to it. We hereby undertake to carry out the required reinstatement works exactly in accordance with

*

specifications and to pay all compensations / entitlements for any accidents that may occur due to this road collapse or settlement.

This is our undertaking in this respect.

CONTRACTOR

CORPORATE NAME

CHIEF EXECUTIVE OFFICER

Corporate Seal

*

Insert name of concerned Authority


Page E-110 of 115


Specifications

E6

INSPECTION AND TESTING OF PIPELINES

E6.1

Cleaning and Inspection of Pipelines For the purposes of cleaning and inspection, the term "pipelines" includes those laid in heading or by pipe-jacking techniques. During and after construction the Contractor shall take all reasonable measures, including the provision of plugs where appropriate, to prevent the ingress of deleterious matter into pipelines. After completion of manholes, chambers and similar features, the interior of pipelines shall be cleaned of silt and debris by approved methods for inspection by the Engineer as described below. In the case of pipelines laid in trench, this shall be carried out after trench backfilling but before surface reinstatement. Pipelines of 600 mm nominal internal diameter and smaller shall have a loose plug passed through them to show that they are clear of obstruction. This shall be in the form of a sphere or cylinder 25 mm smaller than the actual internal diameter of the pipeline. Pipelines greater than 600 mm nominal internal diameter will after cleaning be inspected from the inside and the Contractor shall provide a suitable trolley, ventilation and safety equipment, and any other plant and labour necessary for this purpose. Pipelines will be inspected again before commissioning or taking-over (whichever is sooner) and if required by the Engineer shall be cleaned again in whole or in part.

E6.2

Testing of Pipelines - General Requirements For the purposes of inspection and testing, the term "pipelines" includes those laid in heading or by pipe-jacking techniques. All pipelines and pipework shall be tested by the Contractor for watertightness and stability. All tests shall be carried out in the presence of the Engineer and the Contractor shall notify the Engineer or his Representative at least one full working day in advance of his intention to carry out any test. The Contractor shall provide all necessary plant and equipment, including struts and thrust blocks, as may be necessary for effectively testing the pipelines to the specified pressures, and shall be responsible for the supply and later disposal of all water necessary for testing purposes. The Contractor shall be responsible for sealing pipelines at the appropriate test pressures and any difficulties encountered for whatever reason shall be overcome at the Contractor's expense. Should any inspection be unsatisfactory or any test fail the Contractor shall at his own expense replace defective pipes, leaking joints or otherwise re-execute defective work following which cleaning and testing will be repeated until the Engineer certifies the pipeline as satisfactory.

E6.3

Testing of Non-Pressure Pipelines Non-pressure pipelines of 750 mm and smaller nominal internal diameter laid in trench shall be given a preliminary test when the pipeline is bedded and jointed but before backfilling, and a final test after backfilling. Pipelines laid in heading or by pipejacking shall be given a final test after completion of pipeline construction.


Page E-111 of 115


Specifications

Unless otherwise instructed, pipelines shall be tested in sections between manholes/chambers/pumping station wet wells. In addition pipelines shown as straight lines on the drawings shall be subjected to a light test as detailed in the pipelaying specification, and all pipelines other than those with ogee joints shall be subjected to an infiltration test. Preliminary and final tests will not normally be applied to pipelines greater than 750 mm nominal internal diameter and acceptance of these pipelines will be dependent on satisfactory infiltration testing and visual inspection of the pipes and joints. (i)

Preliminary Test Air shall be pumped into the pipeline to a pressure of 100 mm head of water and the pressure shall not fall to less than 75 mm during a period of 5 minutes. Adequate precautions shall be taken to ensure that the accuracy of the test is not impaired by fluctuations in the temperature of the air inside the pipeline. If necessary, the hours during which testing is carried out shall be restricted as directed by the Engineer's Representative.

(ii)

Final Test The part of the pipeline under test shall be filled with fresh water to give an effective minimum internal water pressure of 1.2 m at the highest point and a maximum of 6m at the lowest point. Due allowance shall be made for any external groundwater pressure. After standing for 30 minutes the water shall be topped up if necessary and in the following 60 minutes the loss of water shall not exceed 0.25 litres per metre of diameter per metre of length of pipeline under test. In addition there shall be no identifiable leak at any point in the pipeline. This test will not be required where, in the opinion of the Engineer, it is not appropriate due to the presence of a high groundwater table.

(iii)

Infiltration Test After completion of backfilling and restoration of normal sub-soil conditions all pipelines and their associated manholes shall be examined for infiltration. There shall be no discernible inflow of water at any point and there shall be no flow of water at any manhole or pipeline outlet.

E6.4

Testing of Pressure Pipelines Unless otherwise specified, site testing for pressure pipelines shall be to 1.5 times their maximum working pressure. (i)

Preliminary Test Pressure pipelines laid in trench shall be given a preliminary test after pipelaying and bedding but before backfilling as follows: Pipelines of 675 mm or more internal diameter shall have each joint individually water tested by means of an approved joint testing apparatus at a pressure of 100 kN per square metre. The test will not be considered satisfactory if the loss of pressure during a test period of 30 minutes exceeds 10 kN per square metre as indicated by an approved pressure gauge having a range of 0-150 kN per square metre.


Page E-112 of 115


Specifications

Pipelines of lesser diameter shall be air tested in convenient lengths as short as is practicable. Air shall be pumped into the pipeline by suitable means until a pressure of 300 mm head of water is indicated on a water manometer and the test will not be considered satisfactory if the air pressure falls to less than 275 mm during a period of 5 minutes. Adequate precautions shall be taken to ensure that the accuracy of the test is not impaired by fluctuations in the temperature of the air inside the pipeline. If necessary, the hours during which testing is carried out shall be restricted as directed by the Engineer. (ii)

Final Test After they have been cleaned and inspected all pressure pipelines shall be given a final test using fresh water as described below. In the case of pipelines laid in trench this shall be carried our after trench backfilling. Pipelines shall be tested in convenient lengths of up to 400 m by filling with water under pressure. In addition to tests on separate sections, the whole pipeline shall be tested by the same procedure as described below for individual sections. The section under test shall be filled with water so that all air is expelled. In the case of absorbent pipe materials or linings such as cement lined ductile iron, the pipeline may be left to stand for a suitable period, normally 24 hours, at a pressure less than the test pressure. The pressure in the pipeline shall then be steadily raised to the specified test pressure in accordance with the pipe manufacturer’s recommendations and maintained at that level for a period of one hour. The pump shall then be disconnected, and no further water shall be permitted to enter the pipeline for a test period of a further one hour. At the end of this period the original pressure shall be restored by pumping and the loss measured by drawing off water from the pipeline until the pressure as at the end of the test is again reached. The loss of water shall not exceed 2 litres per metre nominal diameter per kilometre length per metre pressure head (average head applied to the section) per 24 hours. In addition, there shall be no visible leak or pipeline movement at any point in the pipeline. Care must be taken where appropriate to isolate air valves and other fittings, not to apply a higher pressure than specified at any point in the pipelines, and to ensure that the pipelines are adequately anchored before any test is carried out. Testing against valves which are themselves connected to an existing public water supply is prohibited because of the danger of contamination. Testing against other closed valves (including air valves) not so connected may be attempted if the Contractor so wishes but at his own risk, provided that the valves are of adequate pressure rating and are anchored against thrust and on condition that any consequent damage is rectified by the Contractor as his own expense.

After testing, suitable plugs shall be provided and maintained in all open ends of the pipelines in order to exclude silt or any other deleterious matter until the pipelines are commissioned.


Page E-113 of 115


Specifications

TABLE OF CONTENTS Page No. SECTION F - BRICKWORK AND BLOCKWORK

1

F1

GENERAL

1

F2

DESIGN

1

F3

MATERIALS

1

F3.1

Clay Engineering Bricks

1

F3.2

Concrete Blocks

1

F4

F3.2.1

Cement

1

F3.2.2

Aggregates

1

F3.2.3

Sand for Mortar

2

F3.2.4

Lime for Mortar

2

F3.2.5

Water

2

F3.2.6

Plasticisers for Mortar

2

F3.2.7

Pigments

2

F3.2.8

Concrete Block Manufacture

3

CONSTRUCTION

4

F4.1

Brickwork and Blockwork General

4

F4.2

Clay Engineering Brickwork

4

F4.3

Jointing and Pointing

4

F4.4

Mortars Generally

4

F4.5

External Rendering

5


Page i of i


Specifications

SECTION F - BRICKWORK AND BLOCKWORK F1

GENERAL This section gives the general requirements for brickwork and blockwork. Further details of the requirements for brickwork and blockwork in buildings are given in Section L of the General Technical Specification.

F2

DESIGN Brickwork and blockwork shall be designed to BS 5628 or other approved design code with reinforcement designed and fixed accordingly. Jointing arrangements shall be in accordance with the guidance given in BS 6093. Design calculations shall be submitted to the Engineer for approval and no laying of brickwork and blockwork shall commence before the designed is approved. Building designs shall be in accordance with local building regulations and Ministry standards.

F3

MATERIALS

F3.1

Clay Engineering Bricks Bricks for all sewerage and drainage work shall be clay engineering bricks to BS 3921, Class A or Class B as detailed. Special purpose bricks (e.g. bull nosed, coping or radial bricks for circular work) shall be to the shapes and dimensions specified in BS 4729. Faces of engineering bricks to be exposed to the weather shall not be wire cut. Bricks for oversail corbelling shall be solid. Before any bricks are ordered samples shall be submitted to the Engineer for approval.

F3.2

Concrete Blocks

F3.2.1

Cement Cement for concrete blocks required for work below ground level shall be sulphate resisting Portland cement complying with BS 4027. Cement shall be “low alkali” having a total acid soluble alkali content (Na20 + 0.685K20) of less than 0.6 percent when tested in accordance with BS 4550. Cement for mortars shall be compatible with the cements specified for concrete blocks.

F3.2.2

Aggregates Aggregates used for the manufacture of concrete blocks shall comply with the requirements for aggregates for concrete stated in Clause D1.4. The grading shall comply with Table 4 of BS 882 for 10mm nominal size of single-sized aggregates as follows:


Page F-1 of 6


F3.2.3

Specifications

Sieve Size (mm)

Percentage by mass passing BS sieve

14 10.0 5.0 2.36

100 85 - 100 0 - 20 0-5

Sand for Mortar Sand for mortar for brickwork, blockwork and general purposes shall comply with Table I of BS 1200, as follows: Sieve Size (mm)

Percentage By Mass Passing BS sieve

5.00 2.36 1.18 microns 600 300 150 75

100 90 - 100 70 - 100 40 5 0 0

-

100 70 15 5*

* May be increased to 10% for crushed stone sands. The clay/silt content when determined in accordance with BS 812 shall not exceed 3 percent. The chloride and sulphate contents for sands and mortar shall not exceed the limits given for aggregates for concrete stated in Clause D1.4 and sands shall not contain harmful matter such as iron pyrites, salts or laminated material such as mica, shale or organic or other impurities in sufficient quantity to adversely affect the hardening strength or durability of the mortar. F3.2.4

Lime for Mortar Lime for mortar shall be non-hydraulic (calcium) or semi-hydraulic (calcium and magnesium) and shall comply with BS 890.

F3.2.5

Water Water for block making or mortar shall be as specified for concrete in Clause D1.2.

F3.2.6

Plasticisers for Mortar Mortar plasticisers shall comply with the requirements of BS 4887.

F3.2.7

Pigments Pigments for use in blocks or mortar shall comply with BS 1014. The pigment content shall not exceed the weight of cement by more than 10 percent and if carbon black is used the proportion shall be not more than 3 percent by weight of cement.


Page F-2 of 6


F3.2.8

Specifications

Concrete Block Manufacture Concrete blocks shall be manufactured generally in accordance with BS 6073 and shall be solid, hollow or cellular and to the dimensions as shown on the Drawings. For hollow blocks the hollow area shall not exceed 50 percent of the overall plan area of the block. The minimum compressive strength when sampled and tested in accordance with BS 6073 shall be not less than 7N/sq.mm. Where blocks of moderately sulphate resisting Portland cements and sulphate resisting cements are required on the same site the Engineer may require the latter to be pigmented in accordance with Clause F1.7 if, in his opinion, the two categories of blocks might otherwise be confused on site.


Page F-3 of 6


Specifications

F4

CONSTRUCTION

F4.1

Brickwork and Blockwork General Bricks and blocks shall be carefully handled during unloading, properly stacked on clean level hard-standing, and adequately protected from inclement weather. Broken bricks and blocks shall be removed from the site. During hot and dry weather, bricks and blocks shall be wetted before laying as necessary and the tops of walls shall be wetted to reduce excessive suction before any work commences. Completed work shall be protected to avoid excessive drying out. No brickwork or blockwork shall be carried out when the shade temperature is greater than 35ºC. Bricks and blocks in each course shall break joint correctly with the course underneath. The courses shall be laid parallel with joints of uniform thickness and shall be kept straight or regularly curved as required. Vertical joints shall be in alignment as required by the bond and shall, unless otherwise shown on the drawings, have an average thickness of 8mm. Bricks forming reveals and internal and external angles shall be selected for squareness and built plumb. Bricks with single frogs shall be laid frog upwards. All joints shall be bedded solid in mortar as the work proceeds. Walls shall rise uniformly; corners and other advanced work shall be raked back and not raised above the general level more than 1 metre. No brickwork shall be carried up higher than 1.5 metres in one day. For brickwork, oversail corbelling shall not exceed 30 mm on each course. All faces of blockwork shall be kept clean and no rubbing down will be permitted. Exposed faces of finished brickwork and blockwork and joints shall be protected in accordance with Clause G4

F4.2

Clay Engineering Brickwork Unless otherwise specified or ordered all engineering brickwork shall be built in alternate header and stretcher courses In all engineering brickwork the overall dimensions of four bricks laid in mortar shall not exceed by more than 25mm overall dimensions of the same bricks laid dry.

F4.3

Jointing and Pointing Bricks and blocks shall be laid in mortar properly bedded and jointed and all joints filled with mortar on every course. Unless otherwise stated all joints are to be finished flush pointed. Where walls are to receive rendering joints are to be raked out not exceeding 5 mm deep.

F4.4

Mortars Generally Mixing of mortar will normally be carried out with a machine driven roller pan mixer of approved type and size. Mortar which has begun to set shall not be revived or re-used. Proportions of Mortar: Cement Mortar


1 part cement 3 parts sand Page F-4 of 6


Cement/Lime Mortar

Specifications

1 part cement 1 part lime 6 parts sand

Unless otherwise specified cement mortar shall be used for brickwork and blockwork below ground level and cement/lime mortar shall be used for work above ground level. F4.5

External Rendering The following applies to below ground external rendering. Refer to Section L for building wall rendering. Where external renders are detailed on the drawings they shall be applied to various backgrounds as follows: Concrete, Concrete Blocks and Bricks and Engineering Bricks: The render shall be three coat work comprising of a stipple coat, undercoat and finishing coat giving a maximum thickness of 15mm. The mix shall be in the proportions shown on the schedule of mixes. (i)

The stipple coat shall consist of 1:1½ cement/sand mixed with 50% water/50% PVA bonding agent to form a thick slurry. The mixture shall be vigorously brushed onto the background and stippled to give a close textured key. The resulting finish shall be kept damp to prevent rapid drying out and allowed to harden for seven days minimum before subsequent coats are applied. Prior to rendering, surfaces are to be damped sufficiently to ensure uniform absorption.

(ii)

The undercoat shall be level, true and of nominal thickness 9 mm but always of sufficient thickness to prevent the joints in the background showing through. A key for the final coat shall be provided by combing the undercoat prior to setting with wavy lines 20 mm apart and 5 mm deep. In hot weather the undercoat shall be protected to avoid rapid drying out and if necessary polythene sheet shall be held against the surface to prevent evaporation and retained in place for 3 - 4 days to achieve satisfactory curing. This shall be followed by a further period to allow the surface to dry out before the final coat is applied.

(iii)


Before application of the final coat the surface shall be damped down to control and provide an even suction. The final coat shall be applied approximately 6 mm thick and to achieve the overall thickness of the render required. The surface shall be worked to a level and smooth finish with a wooden float. The whole shall be protected from rapid drying out and surface kept damp to obtain even drying.

Page F-5 of 6


Specifications

Schedule of Mixes to External Render Mix Type

Cement:Lime:Sand


Concrete, Concrete Blocks, Concrete Bricks, Engineering Bricks Undercoat

Finish

1:½:4

1:1:5

Page F-6 of 6


Specifications

TABLE OF CONTENTS Page No. SECTION G - CORROSION PROTECTION AND SURFACE COATINGS

1

G.1 MATERIALS G.1.1 Corrosive Environment and Corrosion Protection System G.1.2 Paint G.1.3 Impervious Tanking Membrane G.1.4 PVC Sheet Lining Materials G.1.5 Glass Reinforced Plastic Liners G.1.6 In-situ GRP Laminations G.1.7 Epoxy Mortar for Stormwater Manholes G.1.8 Rubberised Bitumen Emulsion G.1.9 Waterproof Paper G.1.10 Protective Materials for Wrapping Pipeline Components G.1.11 High Density Polyethylene Protection Sheet G.1.12 Protective Coating with Cementitious Water Proof Coating G.1.13 Approved Paint Suppliers G.1.14 In-situ GRP Lamination with Grit bonding on final finish coat

1 1 1 2 2 2 5 16 17 17 17 17 18 18 19

G.2 INSTALLATION OF PROTECTIVE COATINGS AND LINERS TO CONCRETE G.2.1 General G.2.2 Water Proof Membranes/Liners/Roof Waterproofing and Protective Coatings G.2.3 GRP Prefabricated benching unit for Sewer Inspection Chambers G.2.4 Cutting and Sealing of Reinforced Liners G.2.5 Protective Coatings to Concrete Works

20 20 20 31 31 31

G.3 COATING SYSTEM FOR FERROUS, NON FERROUS METALS AND PLASTICS G.3.1 General G.3.2 Products G.3.3 Execution G.3.4 Testing and Inspection

40 40 47 48 51


Page i of i


Specifications

SECTION G - CORROSION PROTECTION AND SURFACE COATINGS G.1

MATERIALS

G.1.1 Corrosive Environment and Corrosion Protection System Systems and surface coatings for protection against corrosion and for decorative purposes shall in all cases be suitable for-exposure to their contact with environmental conditions which may include any or all of the following: 1. The average climatic conditions detailed in Section A of the Specification, with particular emphasis, where appropriate, on the consequential effects of UV light, temperature variations, high surface temperatures and high humidity. Under certain combinations of the climatic conditions considerable condensation may take place. A considerable amount of salt is contained in the atmosphere, which together with the extremely high ambient humidity, can produce severe corrosion problems. Distribution of rainfall is irregular, and the precipitation amounts are normally of no significance, but attention should be paid to the fact that sudden heavy rainfalls over a very short period of time can occur. 2. Septic sewage with a pH value of less than 1. 3. Sulfuric acid solution in sewage slimes in concentrations up to 15 % by weight. 4. Hydrogen sulphide and other gases (Ammonia, methane and carbon dioxide) emanating from sewage, septic sewage and sewage sludges. 5. Saline groundwater with high chloride or sulphate contents both below the water table and in soil zones above the water table where capillary action and the presence of oxygen may cause extremely severe conditions. 6. Wind blown chlorides 7. Wind blown abrasive sands For raw and treated potable water schemes the protective systems and coatings shall be approved by a recognised certifying authority as being suitable for water systems without imparting odour or taste, nor causing discolouration, and all materials shall be non-toxic and non carcinogenic. The Contractor shall ensure that suppliers and manufacturers of materials for protective systems are made aware of the above conditions and the conditions described elsewhere in the Specification G.1.2 Paint Protective and decorative paint systems including primers and undercoats shall be obtained ready mixed for use. All containers of paints and other coating systems shall show date of


Page G-1 of 68


Specifications

manufacture, shelf life and pot life where applicable. Paint shall be applied as per Clauses in section G.2. The Contractor shall only be allowed to use paints which are delivered to the site in sealed cans or drums bearing the name of the manufacturer and properly labeled. Tints and shades of final coats shall be advised by the Engineer or his Representative. G.1.3 Impervious Tanking Membrane Membrane used for tanking to concrete structures shall be impervious, self-adhesive and covered with a release agent. G.1.4 PVC Sheet Lining Materials PVC sheet materials to be used for lining concrete structures and pipelines internally shall be manufactured from polyvinyl chloride, plasticisers and pigments to make permanently flexible sheets. The colour of the sheet shall be approved on site. The PVC sheet shall have a minimum thickness of 1.5 mm and shall be formed by extrusion to have on one side locking keys or ribs of either 'T' or diamond section at centers not greater than 75 mm. It shall be capable of forming a continuous 100% effective seal with the use of welding strips or other approved method and shall be supplied with all materials and tools for making the joints. The tensile strength of the material shall be not less than 17000 kN/m2. All weld strips, patches and other sheets used in the permanent fixing of the ribbed sheet shall be of a material having the same composition as the ribbed sheet. G.1.5 Glass Reinforced Plastic Liners Glass Reinforced plastic liners to be used for lining pumping stations and manholes shall be manufactured to the dimensions given on the Drawings, within the following tolerances : (1) The work size, which is defined as internal diameter as specified by the manufacturer, shall be declared and shall not differ from the normal diameter by more than ±1%. A manufacturing tolerance on the work size of 10 mm will be allowed provided that a tight fit is achieved between the liner and the slab liner. (2) Liners shall be supplied in lengths to suit requirements with a resin rich finish to internal surfaces. (3) Maximum thickness shall be 7 mm for sewerage work and 5 mm where approved for drainage work. Liners larger than 2000 mm in diameter shall have a minimum wall thickness of 9 mm. (4) The out of squareness shall not be greater than 10 mm. (5) The deviation from straightness of the bore of the liner shall not exceed 20 mm. Although the liners are not designed to be structural, they shall have a sufficient stiffness to withstand: a. Buckling or distortion in transit or storage. b. A hydrostatic head of 8 metres without distortion damage, leakage or permeation.


Page G-2 of 68


c.

Specifications

Grouting pressures.

Prior to grouting of the manhole liner at least 24 hours shall be allowed for temperature equalization between the manhole structure and the reinforced plastic liner. The manufacturer shall provide shop drawings of the proposed top slab liners prior to manufacture for approval. The manufacturer shall stipulate the maximum deflection of the slab liner permitted without causing surface cracking to the gel coat. The Contractor must take care not to exceed this limit, and any surface cracking that occurs will be repaired. The construction methods employed shall be so as to ensure that a completely water and gas tight seal is made preventing any exposure of the concrete surround to the corrosive liquids and gases present, in the sewage. In particular: Glass Reinforced plastic liners shall be handled in the same manner as glass reinforced plastic pipes. In addition, extra care shall be taken to avoid damage to the liners which are not designed to carry loads. The manufacturer shall visit the site to demonstrate to the Contractor in the presence of the Engineer's Representative the methods of handling and lifting, including formation of the joints between the chamber liner. The Contractor is reminded that these liners are not designed to withstand pressure exerted by the concrete during construction. The design of GRP liners to provide a permanent internal shutter, to the concrete structures shall be the responsibility of the liner manufacturer. The design should however incorporate all the requirements of these Specification. The liner shall be designed to provide protection for concrete for 50 years from the corrosive effects of raw sewage in temperature up to 50°C. The GRP liners shall be machine made filament wound and of similar material (except sand filler) construction and manufacturing process as for the GRP pipe. Chemical Requirements The liner design shall qualify the chemical requirements specified in ASTM D3753. 1. Testing shall be performed in accordance with the chemical test method. 2. The log percentage property retention versus log of time data graph should be extrapolated by a linear plot beyond the 12 months result to 10,000 hours. The extrapolated data must assure retention of at least 50% of the initial properties. Chemical Test Method Testing procedures for measuring chemical resistance shall conform to ASTM C581 with the exceptions as noted below: 1. Test Laminate Construction: The basic test coupon shall be cut from a laminate made in a manner consistent in every way with manhole construction. 2. Test Intervals: Coupons shall be drawn and tested after 1 month, 3 months, 6 months, and 12 months immersion in each test medium. It may be advisable to include extra


Page G-3 of 68


Specifications

coupons at the time of the initial immersion in the event it is necessary to extend the test interval beyond 1 year to 10,000 hours. 3. Test Media: The test media shall represent as completely as equal to the actual environment in the manhole service. In that respect, test medium shall be the material as specified for chemical resistance for sewer manholes. 4. Test Temperature: The test temperature of test medium used in corrosion resistance verification of manhole containing that medium (normally this shall be 50ºC). 5. Interpretation of Results: Laminate properties to be determined initially and after each test period are flexural strength, flexural modulus (both as per ASTM D790) and the Barcol hardness as per ASTM D2583) of both interior and exterior lamination. The laminate should be fully cured before initial properties are obtained. Any effect up on the immersion medium or laminate observed during visual inspection shall be noted. The log percentage retention after immersion testing (verses initial) is to be plotted against the log of immersion time in hours. Quality Control Testing The following test shall be carried out as detailed below: 1. Composition Test: A loss on ignition test shall be carried out once every 100m of shaft produced. Conduct the test as per ASTM D2584 and determine the glass/resin ratio. Controls on glass and resin content must be maintained for all manufacturing process and for each portion of manhole fabrication. Record shall be maintained of these control checks. 2. Barcol Hardness: Each manhole component part shall be tested in accordance with ASTM D2583, standard method of test for Indentation Hardness of plastics by means of a Barcol Impressor. The minimum acceptable value of cure shall not be less than 90 percent of the resin manufacturers minimum value for the cured resin. 3. Thickness: Wall thickness of each manhole component part shall be checked with a micrometer caliper gauge, or other suitable instrument to establish the actual thickness. 4. Appearance (Interior and Exterior Surfaces): The following defects are not permitted. (a) Crazing (b) Delamination (c) Blisters (d) Fiber show (e) Surface pits and voids directly beneath the surface of the laminate and on the surfaces (f) Dry spots (g) Pimples (h) Pit or pinhole (i) Resin pocket (j) Deep scratches (k) Impact cracks (l) Fish eye (m) Worm holes (n) Deep wrinkles. Certification When requested, a certification shall be made on the basis of acceptance. This shall consist of manufacturers test report accompanied by copy of test results, that the GRP liner has been sampled, tested and inspected, in accordance with the previsions of this specification and meets all requirements. Each certification shall be signed by the manufacturer. Cutting and Sealing of Reinforced Liners Where the Contractor is required for any reason to cut reinforced plastic liners, he shall seal the exposed ends with an approved resin before incorporating the cut reinforced plastic in the work. No cut reinforced plastic shall be used until the resin has cured. The resin shall be as recommended by the manufacturer of the reinforced plastic item and shall be pigmented so that the areas where it has been applied are easily identifiable. It shall be delivered to site in sealed containers bearing the name of the manufacturer and properly labelled as to its content and shelf life.


Page G-4 of 68


Specifications

For flexible pipe materials a rubber protection strip shall be inserted between the pipe barrel and the steel band. G.1.6 In-situ GRP Laminations General This Clause shall cover all in-situ GRP lamination work to be carried out under the Contract as corrosion protection. It shall include site work related to jointing of prefabricated reinforced plastic components eg. manhole liners, GRP pipe sleeves, lamination work to benchings and channels, sealing of pipe entries, lamination work to internal concrete faces of major concrete structures, pumping stations, valve chambers, air valves and washout chambers etc as shown in the approved drawings.


Page G-5 of 68


Specifications

Table G1- PROPOSED CORROSION PROTECTION SYSTEM WITH 7mm THICK IN SITU GRP LAMINATION ON MAJOR CONCRETE STRUCTURES INTERNAL Unit Process

Fluid Type

Covered

Corrossive environment

Proposed Corrosion Protection System

1

TLPS Wet Well

Septic sewage

Yes

Very high H2S levels, high corrosion risk

System ‘A’

2

Tanker Reception Sump

Septic sewage

Yes


System ‘A’

3

Inlet Works (Screen Channels)

Septic sewage

Yes


System ‘A’

4

Aerated Grit Channels

Septic sewage

Yes


System ‘A’

5

Flow Splitter Chamber

Septic sewage

Yes


System ‘A’

6

Digested Sludge Sump & Pump House

Digested sludge

Yes


System ‘A’

7

Ferric bund area

Ferric Chloride

No

PH=1, very acidic

System ‘A’

8

Liquor Return Sump & Pump House

Filter dirty backwash, permeate from GBT, Belt press/centrifuge & site drainage

Yes

PH = 1, very acidic, pH = very alkaline

System ‘A’

9

Diesel Storage Tank Bund

Diesel /oil

No


Page G-6 of 68

-

System ‘A’


Specifications

Site Operatives for GRP Work The In-situ GRP lamination work shall be carried out only by the Client approved laminators. All lamination work must be carried out by skilled operators under the supervision of a worker with a minimum of 10 years experience in in-situ lamination. The Contractor shall only employ personnel who have received suitable training and possess relevant experience in the execution of any in-situ GRP work, including lamination work and the cutting, sealing and jointing of reinforced plastic. Site operatives for employment on this work shall be certified in writing by the supplier or Contractor as trained to a satisfactory standard in application techniques. Such personnel will be subject to approval by the Engineer prior to the commencement of such work. Approval will include site trials to demonstrate competence to undertake the work. GRP Applicator’s Special Requirements 1. The company doing the GRP lamination work should have: a. a Safety Manual ‘For Guide to Making a Laminate, Planning and Maintaining the Work area’ b. an automatic master and batch mixer with agitator c. a mobile storage (fire-proof) vehicle with steel container having AC, exhaust fan inside for storing the resin and glass and the master batch resin mixer. d. automatic resin discharge pump system and spray facilities to feed the resin from master batch mixer into the laminated work area to achieve a uniform resin mixing and dispensing during lamination period. e. in-situ testing apparatus to carry out the following quality control tests. 1. 2. 3. 4. 5.

Barcol impressor Nr. 934-1 with sufficient numbers of calibrating shim. Digital elcometer thickness gauge with calibration shim Pull off adhesion tester with sufficient numbers of dolly. Holiday detection spark tester recommended by the resin manufacturer Relevant hammer for hammer test

f. Safety arrangements to keep inflammable catalysts with fire hydrant in working condition. g. services of an efficient technician at site to mix the resin in desired proportion to suit the variable working temperature condition at site. h. AC room facilities for bulk storage of resin drums and glass mat rolls in an isolated place. i. first aid facilities and the services of a safety engineer at site. j. Sufficient numbers of powerful exhaust fan at working area to clear out the styrene gas. k. Breathable air inlet facilities for the workers at site l. Safety harness for each labourer working on site. Method Statement All in-situ lamination must be carried out in accordance with an approved detailed method statement. This shall include details of all materials to be used together with the manufacturers names, addresses and specification sheets. Particular details of procedures relative to separate categories of work as given above shall be itemised separately. If materials are to be stored on site then details shall be provided of the store in which the materials are to be kept, the environmental controls which will be used to ensure materials are stored in accordance with manufacturers recommendations and the control and security arrangements necessary to prevent unauthorised tampering with materials.


Page G-7 of 68


Specifications

If materials are to be brought to site on a daily basis from the supplier’s central store in site containers then details shall be provided of the type, size and identification markings on each container to be used for this purpose. The Contractor shall indicate the controls to be set-up to ensure that different resins and materials are clearly identifiable at site. The method statement shall include forms to be submitted to the Engineer which will be necessary to record the decanting of materials from manufacturers containers to site. Materials in GRP Lamination Table G2– Materials in GRP Lamination a. Type of resin to prime the concrete surface b. Type of glass (csm) throughout the lamination

: :

c.

Type of ‘C’ glass tissue for final layer

:

d.

Recommended catalysts to prepare resin at site Type of resin throughout the lamination

:

e.

:

Epoxy based vinyl ester resin having minimum 8% elongation property Powder bound ECR/Advantex fiber glass ‘csm’ having excellent corrosion resistance to acids ‘C’ glass of ECR type having excellent corrosion resistant to acids 1. BUTANOX LPT 2. MEKP LA 3 Epoxy based vinyl ester

Table G3-Typical Room Temperature Clear Casting properties of VE Resin Tests Tensile Strength MPa Tensile elongation at yield% Tensile modulus GPa Flexural strength MPa Flexural modulus GPa Compressive Strength MPa Compressive Modulus GPa Compressive deformation at yield% Specific Gravity Average coefficient of expansion between 25 and 100ºC X10-6 cm cmºC Izod impact J/m Heat distortion temp ºC Barcol Hardness

Epoxy Resin 81 5 3.3 124 3.1 114 2.4 6 1.12

Epoxy Resin Primer 70 8

Method of Analysis ASTM D-638 ,, D-638

3.1 135 3.2 86

,, ,, ,, ,,

D-638 D-790 D-790 D-695

2.2

,,

D-695

6

,,

D-695

,, ,,

D-256 D-648

1.13

65 22

70 250

102 35

80 40

Table G4- Typical Properties of Liquid Resins Property Epoxy Resin Epoxy Resin Primer Styrene Level % 45 40 Brook field Viscosity MPa at 25ºC 500 350 Flash point ºC Tag open cup 34 32


Page G-8 of 68

Barcol impresser model 934 - 1


Property Specific Gravity uncured at 25ºC Acid number maximum Storage stability (months)

Specifications

Epoxy Resin

Epoxy Resin Primer

1.04

1.04

8.5

10

6

3

Table G5- Physical Properties of ECR / Advantex Glass Fibres Property Density Refractive index Thermal linear expansion 0 - 300ºC Softening point Annealing point Strain point

Test Method ASTM D1505 Oil Immersion ASTM D696

Unit g/cc ppm/C

ECR/Advantex 2.62 1.560-1.562 6

ASTM C338 Parallel Plate Viscometry Parallel Plate Viscometry

ºC

916

ºC

736

ºC

691

Table G6- ECR/Advantex Single Filament Tensile Properties Property Tensile Strength @23ºC Elastic Modulus Elongation at the Breaking Load

Test Method ASTM D2101 Sonic Method ASTM D2101

Unit MPa Kpsi GPa MPsi

ECR/Advantex 3100-3800 450-550 80-81 11.6 – 11.8

%

4.6

The method statement shall also provide details of the material build up or lay up. It shall state the number and type of layers of glass fibre reinforcement together with the resin used to impregnate it. Proposed lay up shall be not less than the requirements detailed in this Clause. The method statement shall also detail the Contractor’s safety proposals with respect to this work to demonstrate compliance with his obligations under the Contract, for each type of work location. Surface preparation The concrete surface must be fully cured and older than 4 weeks. Before commencing work surfaces must be cleaned down, suitably prepared and allowed to dry. Under no circumstances must the laminate be applied in dirty, damp or wet conditions. Once dry, no water should be allowed into the structure except that required for safety reasons. Concrete surfaces must be clean, sound, dry and dust free. Any surface laitance, loose or unsound concrete etc shall be removed. Surfaces must be entirely free of oil, grease, paint, detergents, rust, biological or other surface contaminants. Surfaces shall preferably be prepared by high pressure water jetting, pneumatic scabbling, grinding or steel grit blasting, followed by thorough brushing with a clean paint brush (used only for this purpose) or by washing to remove dust and remaining particles and to provide an exposed aggregate finish


Page G-9 of 68


Specifications

to ensure a mechanical key to the laminate. Diesel, oil and grease contaminants shall be removed and rinsed thoroughly with water by steam cleaning, detergent scrubbing or the use of proprietary degreaser. Effectiveness of decontamination may, on the instructions of the Engineer, require to be assessed by a pull-off test. The hardened condition of the concrete substrate is to be subjected to hammer test by tapping on concrete and make sure any hollow sound is not produced. The defective concrete is to be removed and make good and allow the surface to dry condition. Prior to application, all active hydrostatic leaks must be stopped by the use of an appropriate approved material specifically formulated to stop the ingress of water. Where the laminate will be in contact with the surface or edges of uPVC pipes or existing GRP laminates, liners, pipe or fittings the contact surface shall first be roughened by grinding or wire brushing. The contact surface for benching lamination extending within GRP pipes shall be accurately feather ground from 0 to 7 mm over a length of 150 mm. All dust shall be removed as above. Grinding shall be carried out to limits neatly defined by masking tape or other approved means. Measures shall be taken to prevent damage to surfaces outside such limits by the use of appropriate masking devices etc. On concrete surfaces of major structures, base slab wall and roof slab: After completed two layers of GRP lamination work, SS 316 grade HILTI nails are to be shot into the concrete by the help of a shotgun at 60 cm intervals to achieve a proper key in interlock between the concrete surface and the GRP lamination work. Further layers of lamination work shall be continued after the nail fixing. Particular care is needed in preparation to ensure that the correct laminate thickness will be maintained over nosings to the arris between horizontal and vertical parts of the benching, including removal of concrete as necessary. Following after obtaining engineer’s approval for the GRP materials a trial lamination work to a size of 1.2M x 1.2M shall be carried out on concrete surfaces of any one of the structures and conduct the followings Pre qualification test. These trials shall be carried out using the approved type of materials, mixing procedures and applications as will be used on the Contract. Table G7- Trial Sample and Pre qualification Test on GRP Lamination Work Sr.

Test 1. 100 days acid immersion test @10% concentrated sulphuric acid at 50ºC 2. Flexural strength of GRP laminate sample 3. Tensile strength of GRP laminate sample 4. Pull off adhesion strength of lamination 5. Resin / Glass ratio 6. Resin cure

Test method ASTM C581

7. Thickness of Lamination 8. Holiday Detection Test

Digital Elcometer 105 DC high voltage 0-


ASTM D790

Minimum Test Requirements Test sample shall not show any defects as mentioned in relevant standard 193 MPa

ASTM D639

138 MPa

ASTM D 4541

Pulling strength shall be greater than concrete 60:40 Minimum : 33 Barcol reading in accordance with the manufacturer’s test procedure specified. Not less than the specified thickness Air bubble / voids free surface on

ASTM D 2584 Barcol Impressor 934-1

Page G-10 of 68


Sr.

Test 9. Surface Quality 10 Acetone Sensitivity test 11 Hollow sound detection

Specifications

Test method 10 to 20 kV Holiday Detector ASTM D 2563 Resin manufacturer’s recommended test Hammer test

Minimum Test Requirements final lamination Quality level ‘2’ as specified in relevant standard Tack free surface on GRP lamination No hollow sound on completed lamination work.

Note: 1. All relevant samples of GRP lamination test coupons are to be taken from the test patch area and identified by the Engineer. 2. The tests are to be witnessed by the Engineer. 3. Testing apparatus required for in-situ tests is to be provided by the GRP applicator. The acid immersion test will take 100 days duration and hence the applicator shall provide a guarantee for the work until they get the relevant test results for the GRP lamination work. The lamination work shall start at site on written confirmation with the guarantee. Table G8- Minimum Quality Control Test on Final GRP Lamination work Sr.

Test 1. Barcol Hardness

Test method Resin manufacturer’s recommended test method

2. Thickness

Digital elcometer

3. Alarm type Spark test

As stated in Spark tester catalogue

4. Pull off adhesion test 5. Resin glass ratio

Pull off test in accordance with ASTM D4541 ASTM D 2584

6. Visual inspection

ADTM D 2563

Minimum Test Requirements Average 33 reading on Barcol Impressor @ 100% of laminate area in accordance with test procedure specified Min. 3 tests on each structure and shall achieve the minimum thickness specified. Full surface area of each structure. Locate the defects if any & repair in good condition Minimum one test on each major structure. Pull off strength shall be greater than the concrete strength One test on a sample taken from any one of the structure. The proportion shall be ±5% of the specified value 100% of the GRP laminated area. Required Level-2 as specified in the standard.

Test Procedure for Barcol Hardness Test Recommended by the Resin Manufacturer    

Use Barcol impresser apparatus Nr. 934-1 Take 10 – 12 readings on test patch area Reject the highest and lowest readings Take the average of the remaining 10 readings to get the Barcol hardness value

Final approval for the GRP lamination work will be given by the Engineer only after comply with the pre-qualification test specified. Final approval for GRP work to proceed on site shall be subject to satisfactory compliance test results observed at site. Vol 3, Section3 – Civil Specifications

Page G-11 of 68


Specifications

Site Lamination The following details of lamination apply to all work required under the Contract. Application shall be carried out in the cooler times of the day ie. early morning or late evening. Application shall not be carried out to surfaces exposed to direct sunlight and high surface temperatures. Shade structures shall be provided as necessary. Application shall not be carried out in conditions of windblown dust and sand or during periods of high humidity. Before entering any chamber or standing on any surface which is to receive lamination workers shall check their footwear to ensure that it is clean and will not transfer contamination. Care shall be taken when passing materials down into chambers etc. to avoid entry of contaminating materials. Upon completion of mixing, materials shall be used immediately. During lamination, work must cease immediately if the resin starts to gel and the work completed to that point shall be allowed to cure before restarting. No standing on or application of pressure to uncured laminates will be permitted as this will result in squeezing out of resin producing defective areas of laminate where the glass has not been fully wetted out. All surfaces to receive lamination shall be prepared as detailed above. Lamination shall not be carried out to concrete surfaces until they have cured for at least the minimum number of days recommended by the resin manufacturer since casting of the concrete. All lamination to surfaces of prefabricated components shall be gradually feathered away to a defined limit using masking tape or similar so that the final appearance is neat without a sudden change in thickness or of appearance to the completed job. Lamination Build-up A Primer coat of 75 to 125 micron catalysed vinyl ester resin shall be painted over the area to be laminated. Whilst still wet one layer of ECR/Advantex glass shall be applied over the area. Where it is necessary to make a joint in the reinforcement then the reinforcement must overlap by a minimum of 25 mm. The reinforcement shall then be rolled with a metal roller and then wet out with further resin until fully wet. It shall then be carefully finally rolled with a metal roller to remove all air and consolidate the laminate. Successive layers of ECR/Advantex glass shall be added and fully wetted-out with epoxy based vinyl ester resin. Between applying each layer the laminate shall be fully rolled using the metal roller to ensure that all the air is removed from all the layers. Joints in reinforcement layers shall not lie directly above joints in layers below. This layer shall be allowed to fully cure. When fully dry the whole surface shall be lightly abraded using a grinder with a 120 grit disc. A coat of vinyl ester resin shall be applied over the area. Whilst still wet one layer of ECR/Advantex glass chopped strand mat shall be applied. Further layers of ECR/ Advantex glass chopped strand mat shall be applied and fully wet out with epoxy based vinyl-ester resin and rolled with a metal roller. The final two layers of 'c' glass tissue shall then be applied and wet out with vinyl-ester resin. These layers shall not be rolled with a metal roller.


Page G-12 of 68


Specifications

When the last layer has dried it shall be lightly sanded using 120 grade wet and dry abrasive paper to remove any lumps or loose fibres. Any resin runs shall also be removed making sure not to de-laminate the previous layers. A final layer of epoxy based vinyl ester resin incorporating a sealing agent (paraffin wax) to ensure final and full cure shall then be applied over the whole laminate and allowed to dry. In situ GRP lamination to concrete surfaces shall have the following composition, as a minimum requirement. Final finished GRP surface ---------------------------

Minimum 7 mm thick GRP Laminated Composite

-------------------------============ ==== xxxxxxxxxxxxx XXXXXXXXXXXX XXXXXXXXXXXX XXXXXXXXXXXX XXXXXXXXXXXX

Concrete surface

-----------------------

Finished GRP Surface with Paraffinated vinyl-ester resin flowcoat 2 x ECR, ‘C’ glass tissue impregnated with Epoxy based vinyl ester resin 300 g/m2 ECR glass CSM impregnated with Epoxy based vinyl ester resin 600 g/m2 ECR glass CSM impregnated with Epoxy based vinyl ester resin 600 g/m2 ECR glass CSM impregnated with Epoxy based vinyl ester resin 600 g/m2 ECR glass CSM impregnated with Epoxy based vinyl ester resin 600 g/m2 ECR glass CSM impregnated with Epoxy based vinyl ester resin Vinyl ester Resin Prime Surface coat

In situ GRP lamination to the internal faces of brickwork corebelling shall have a lesser composition as a minimum requirement as follows. Final finished GRP Finished GRP Surface with Paraffinated surface ------------------------- vinyl ester resin flowcoat --------------------------============ 2 x ECR, ‘C’ glass tissue CSM impregnated with Epoxy based vinyl ester resin Minimum 3 mm thick xxxxxxxxxxxxxxxxxx 300 g/m2 ECR glass CSM impregnated with Epoxy based vinyl ester resin GRP Laminated xxxxxxxxxxxxxxxxxx 300 g/m2 ECR glass CSM impregnated Composite with Epoxy based vinyl ester resin xxxxxxxxxxxxxxxxxx 300 g/m2 ECR glass CSM impregnated with Epoxy based vinyl ester resin ------------------------- Vinyl ester Resin Prime Surface coat Concrete surface Surface coat Pipe Entries The position of the centre of the required hole shall be accurately marked. This includes holes to liners only where a box-out has been provided through the structural wall. The prefabricated component and/or concrete wall shall be neatly cut by means of a hole saw or diamond drill coring machine. The radius of the hole shall be not less than the outer pipe radius plus 5 mm nor more than the outer pipe radius plus 15 mm. The surface of the liner shall be abraded to a distance of 100 mm from the cut hole. The pipe to be fitted shall have its end and final 75 mm of barrel prepared to receive lamination. The pipe shall be-fitted and securely fixed in position in accordance with an approved Method


Page G-13 of 68


Specifications

Statement. It shall protrude at least 50 mm and not more than 100 mm past the face of the liner. The annular gap shall be filled with vinyl ester putty which shall be neatly trimmed and allowed to cure. Lamination shall then be carried out to seal the pipe entry to the liner using ECR' glass buildup to a minimum of 7 mm thickness but using vinyl ester resin only throughout. Lamination shall be turned over the pipe end. These requirements apply to all pipe entries including house connections, cable ducts, air release pipe work from pump casings, sump pump discharges, penstock spindle sleeves, etc. These requirements apply to pipes built through both walls above benching level and to pipes through walls into the benching. Sealing requirements where the pipes penetrate the main structural wall are identical in both cases irrespective of whether the pipe will later be covered by benching concrete. Should the material of the pipe built through the walls into the benching be incompatible with in situ GRP lamination materials then the joint between the pipe and liner shall incorporate a prefabricated GRP pipe sleeve which shall be bonded to the pipe outer diameter with a solvent free epoxy adhesive putty. In-situ GRP benching lamination shall be bonded to the inner faces of the GRP pipe sleeve in accordance with the above. Cutting and Sealing of Reinforced Plastic Where the manufacturer or Contractor is required for any reason to cut or drill prefabricated reinforced plastic (GRP), including pipes, he shall completely seal the exposed ends and edges with a coat of approved vinyl ester resin, before incorporating the cut reinforced plastic into the Works. No cut reinforced plastic shall be used until the sealing resin has fully cured. Resin used for sealing shall be delivered to site in sealed containers bearing the name of the manufacturer and properly labelled as to its contents, storage requirements and shelf life. Safety Precautions Proper ventilation and/or breathing apparatus shall be provided and all necessary precautions shall be taken to ensure the safety of workers when in situ GRP lamination materials are being used. Applicators shall also be made aware of the health risks involved in working with these materials. Skin and eye contact should be prevented by the use of plastic or rubber gloves, barrier creams, eye protection and protective clothing. Smoking will not be permitted. Nothing in this Clause shall be deemed to limit the Contractor's more general obligations under the Contract. In-Situ GRP Lamination Requirements Following Lamination Procedures and tests are to be conducted by the G.R.P applicator. 1. To reduce air bubbles in the laminate relevant catalysts recommended by the resin manufacturers only to be used. Catalyst manufacturer's technical catalogue to be provided along with the material submission. 2. Samples of all materials to be used on sites are to be provided prior to start of lamination work on site.


Page G-14 of 68


Specifications

3. Resin and glass mat brought to the site are to be supplied in manufacturers sealed drums, in packets with manufacturing date, compliance certificate and the allowable pot life. 4. Details of each constituent material and proof of supply through out the work period on site from the manufacturer is to be provided. Also provide test certificates from the relevant material manufacturers for the materials used on site. 5. The lamination work is to be guaranteed for material and workmanship for a period of 10 years from completion by the applicator and countersigned by the manufacturer. 6. A Trial lamination is to be carried out in the presence of Engineer's Representatives using proposed materials and the procedure, as specified, on a concrete surface and arrange to conduct an initial pull off test, barcol hardness, thickness and resin/glass ratio tests. 7. Lining of a concrete surface is to be carried out as per the manufacturers recommended procedure. 8. Care must be exercised to ensure the correct balance of catalyst and accelerator for optimum curing. Checking for complete cure to be carried out as per the procedure recommended by the manufacturer. 9. The resin/glass ratio in the laminate, type of resin and glass and the sequence of layers proposed are to be reported. 10. Final laminate thickness, loss on ignition, pull off adhesion, hardness tests etc are to be conducted to prove compliance of the laminate with the contract requirement and specification. 11. 100 days acid immersion test in 10 percent concentrated sulphuric acid solution at 50 degree centigrade using final laminate samples selected by the Consultant is to be carried out. In-situ tests on the resin will be conducted during lamination work. 12. 2 layers of 'c' glass tissue of ECR type to be used on the final laminate. 13. Final wax topcoat resin formulation to be as per the procedure recommended by the manufacturer. 14. Provide full details of safety measures that will be instituted during lamination works for separate approval before starting any in-situ work. A full time supervisor from the applicator's side must be on site. 15. Provide technical catalogue for all the type of resin, glass and surface tissue proposed. 16. Minimum thickness of lamination shall be 7 mm and use only ECR glass epoxy based vinyl ester resin approved by the Engineer. 17. No hollow sound on final laminate will be permitted. 18. Lamination work is to be carried out in layer by layer and not to apply more than 3 layers in a day and allow the styrene gas to come out and enough curing time for curing each layer. 19. Final approval shall be given following the acceptance of quality of the finished works.


Page G-15 of 68


Specifications

Material samples, safety procedures, material details, guarantee letter, name of skilled workers and supervisors etc. are to be provided prior to starting the lamination work on site. G.1.7 Epoxy Mortar for Stormwater Manholes Where indicated on the drawings or specified to use epoxy mortar for benching and channels in any manhole or any other structure such as chambers, pump station wet-well, etc., they shall be formed to have a min. of 10 mm thickness of an approved epoxy-resin mortar system. The epoxy mortar system shall be a trowellable, two component epoxy resin system consisting of a prefilled base and unfilled reactor which when mixed shall produce a high strength, impermeable and chemically resistant mortar. The epoxy mortar system shall have excellent chemical resistance to sodium chloride and sulphuric acid (shall pass the relevant chemical resistance test), and shall have high impact resistance. Typical properties are given in the following table: Table G9- Properties of Two Component Epoxy Mortar Property

Test Method

Limit

Sag at 10 mm thickness

-

None

Working Time

ASTM C308

> 90 min. at 25°C

Full Cure at 25°C

-

3 to 7 days

Setting Time at 25°C

-

30 to 45 min.

Water Absorption

ASTM C413

< 0.07 %

Compressive Strength

BS 6319:Part 2

> 40 N/mm2 at 25°C, 7 days cure

Flexural Strength

BS 6319:Part 3

> 3 N/mm2 at 25°C,

Tensile Strength

BS 6319:Part 7

7 days cure > 8 N/mm2

Bond Strength

BS 6319:Part 4

> 30 N/mm2

Density

BS 6319:Part 1

1750 kg/m3

When placed on a concrete substrate the epoxy mortar system shall have an adhesive strength of not less than the internal cohesive strength of concrete. To achieve the necessary adhesion to the substrate an epoxy primer compatible for use with the mortar and the substrate shall be applied. The epoxy mortar, or the primer where required, shall be suitable for application onto a substrate with a moisture content of 4% or less as measured by the "wet-check" Moisture Meter or other instruments approved by the Engineer. The pot-life of the mixed mortar shall not be less than one hour at the temperature at the place of application at the time of mixing. The Engineer may restrict application to such time as the ambient temperature is sufficiently low for the specified pot-life to be ensured. There shall be strict control of surface cleanliness between primer and epoxy mortar and between coats of the same. Vacuum removal of dust and sand shall be employed and water soluble contamination shall be removed as specified above. Where dirt or dust has become trapped in the primed surface it shall be removed with suitable abrasive paper. The surface


Page G-16 of 68


Specifications

being primed shall be free of visible moisture throughout these operations. The mortar manufacturer shall stipulate primer and epoxy re-coat intervals for all curing temperatures likely to be encountered and these shall be adopted with a maximum tolerance of +4 hours. Where this is exceeded the surfaces to be re-coated shall be suitably abraded to remove gloss. Mixing of the components shall be strictly in accordance with the Manufacturer's recommendations and care shall be taken to avoid the entrainment of air in the mixes. Wet thickness gauge shall be used by the mortar applicators continually to check that sufficient mortar is being applied to achieve the required dry thickness. G.1.8 Rubberised Bitumen Emulsion The bitumen emulsion shall be a cold applied thixotropic coating incorporating a liquid latex in the bitumen emulsion conforming to BS 8102. The latex content will be a minimum 10% on the dried film and the solid content Min. 60%. The coating shall be applied in two coats with a priming coat which will be made by diluting the bitumen emulsion with max. 10% clean potable water or as manufacturer’s recommendations. Two undiluted coats of the bitumen paint shall be applied @ 1.1 lit/m2 in two coats. The total dry film thickness of the coating shall be Min. 0.50 mm. The second coat will be applied at right angles of the first coat and only after the coat has dried completely. For concrete haunching at manhole and chamber covers and for 300 mm height of concrete of structures above ground level, two coats of rubberised bituminous emulsion system shall be applied. The second coat shall not be the same colour as with the first. The brush applied bituminous emulsion shall be used on location as given in the approved drawings. The surface shall first be wire brushed and all dust and loose scale removed. Both methods of protection shall totally enclose the substructure within a water proof membrane of either polyethylene sheet or a waterproof building paper as applicable to the limits shown on the drawings. G.1.9 Waterproof Paper Waterproof building paper shall be to the approved standard. For road works it shall be Class ‘B’. G.1.10 Protective Materials for Wrapping Pipeline Components The protective materials for wrapping pipeline components shall comprise a rust inhibiting compound for the bolts, a mastic or comparable filler which will not harden for moulding over the assembly, and a waterproof tape for wrapping. G.1.11 High Density Polyethylene Protection Sheet The polyethylene sheet shall be of 1000 gauge (heavy duty) minimum thickness 250 microns.


Page G-17 of 68


Specifications

G.1.12 Protective Coating with Cementitious Water Proof Coating Concrete surface shall be protected with an approved elastomeric cementitious waterproof coating as follows: –

On the concrete blinding below perimeter and dividing wall base slabs.

The materials are required to provide excellent waterproofing and crack-bridging properties, whilst providing protection against water abrasion. The system shall be a high performance, elastomeric, cementitious coating system specifically formulated to provide excellent resistance against aggressive elements whilst retaining its chemical and physical properties through long term water immersion. The coating shall exhibit the following typical properties. Table G10- Typical Properties of Coatings % Elongation Minimum 120% Water vapour diffusion resistance SD 0.11 m @ 200 microns dft Resistance to positive water pressure 7 bar DIN BSEN 12390 Resistance to negative water pressure 3 bar – DittoReduction in chloride ion penetration >99% (no penetration after 10 months continuous testing) Dynamic crack accommodation 1.8 mm Abrasive resistance Wear index The mixing and application of the elastomeric cementitious coating shall be strictly in accordance with the manufacturer's instructions. In preparation for the fairing coat and protective coating all existing surfaces shall be free from existing coatings, oil, grease, loose particles, decayed matter, moss or algae growth and general curing compounds. All surface contamination and surface laitance must be removed through the use of high pressure water jetting or sweep blasting. Blow holes, prepared surface cracks and areas of substantial pitting shall' then be filled with a proprietary polymer modified cementitious fairing coat as recommended by the coating manufacturer. The protective coating system shall be spray applied by a specialised applicator approved and recommended by the coating manufacturer. Where required by the Engineer, trial areas not exposed in the finished work shall first be treated using the selected materials. These trial areas shall be carried out using the type of materials, mixing procedures and applications as will be used on the contract. These shall be approved by the Engineer before the Contractor commences with the general work. . G.1.13 Approved Paint Suppliers All paint suppliers shall be subject to approval. Suppliers shall demonstrate that their paint systems have been successfully used in sewage environments similar to conditions experienced and / or anticipated in Bahrain.


Page G-18 of 68


Specifications

G.1.14 In-situ GRP Lamination with Grit bonding on final finish coat This clause will cover all in-situ GRP Lamination work as specified in G.1.6 and an additional resin coat to be applied as final finish top coat sprinkled with non-metallic mineral abrasive grit or sand to achieve a non-slip, non-abrasive surface finish.


Page G-19 of 68


G.2

Specifications

INSTALLATION OF PROTECTIVE COATINGS AND LINERS TO CONCRETE

G.2.1 General Concrete structures shall be protected both internally and externally by the methods detailed. G.2.2 Water Proof Membranes/Liners/Roof Waterproofing and Protective Coatings All the protection systems shall be applied strictly in accordance with the manufacturer’s instructions, two copies of which shall be included with the Contractor’s application for the approval of the material, and when approved will be deemed to be part of this specification unless stated otherwise. The permissible rate of permeation of all protection systems shall not exceed 0.0027 per inch (ASTM, 1 per inch = 1 gram of water per hour per square foot (0.0929 m2) per mil (0.00254 mm) of thickness for a 1 inch (25.4 mm) difference in Hg vapour pressure on each side of a membrane. Coating shall not be applied at expansion, contraction or construction joints which incorporate a sealant. External and Internal Exposed Surfaces Where exposed surfaces of concrete structures are not protected by reinforced plastic liners, the following systems given in the ‘Schedule of Tanking Membranes and Protective Coating’ or as indicated on the drawings, where applicable, shall be applied. Table G11- Schedule of External Tanking Membrane on Concrete Surfaces of under ground Structures up to the Existing Finished Ground Level System Description & Generic Type of Material T1 Single coat solvented bitumen primer as recommended by the tanking membrane manufacturer T2 Pre-fabricated self-adhesive SBS modified bitumen membrane 1.5 mm thick sandwiched between two layers of silicon film having the specified properties T3 Impervious self adhesive bituminous water proofing membrane 2 mm thick tropical grade, non-perforated, cross laminated white polythene sheet top film with high impact and puncture and UV resistance having the specified properties. T4 Self-adhesive type 6 mm thick Asphaltic protection board impregnated with tough layer fibre glass reinforcement inside to use under all raft foundation floor slab on top of blinding layer. T5 Self-adhesive type 3 mm thick bituminous protection board with ‘UV’ resistant, 400 gm/m2 polyester fabric layer external having specified properties. T6 Termination end details of self-adhesive membrane 2 mm thick + 3mm thick selfadhesive protection board as shown in the approved drawing T7 Termination end details of composite 1.5 mm thick SBS modified membrane + 2mm thick cross laminated membrane + 6 mm thick self adhesive protection board as shown in the approved drawing T8 Termination details of membrane over protruded built in pipes from the structure as shown in the approved drawing. T9 Termination details of membrane at internal and external corners as shown in the drawing T10 Termination details of bitumen emulsion + P.E. sheet as shown in the drawing. Or alternatively T11 3 mm thick two component spray in place flexible 100% solid content Thermoplastic (Tpu) Polyurathene / Polyurea Coating System Note:

The Contractor can choose either the tanking membrane system T1 – T10 or the 3mm thick polyurea coating without any extra cost variation.


Page G-20 of 68


Specifications

External Buried Surfaces The external surfaces of major and minor concrete substructures shall be protected or ‘tanked’ by the following methods which will be indicated on the approved Drawings. a)

External Waterproofing for Major Buried Structures Water proofing for major structures shall be a three layer application.  Prime the concrete surface with solvent based bitumen primer as recommended by the membrane manufacturer.  The first layer shall be a 1.5 mm thick prefabricated layer of SBS modified bitumen sandwiched between two layers of silicon film. The layer shall have 1200 % elongation. The overlaps should be 15cm and should have 100% bitumen to bitumen adhesion to ensure a seamless layer of rubberized bitumen. The layer should have no reinforcements or top films which would affect the elongation and overlap adhesion.  The second layer shall be 2 mm thick an impervious bituminous waterproofing membrane. The membrane shall be tropical grade, non- perforated cross-laminated top film with high strength, puncture and impact resistance and shall be chemically resistant for protection against aggressive soils and contaminated ground water. The membrane shall be white in colour to reduce the effect of UV and for easy identification of damages if any on the membrane. The cross laminated self-adhesive membrane shall comply with the following: Table G12 – Properties of Self-adhesive Membrane Properties Test Method Typical Results Tensile strength of membrane ASTM D 638 Longitudinal 3.8 N/mm width Transverse 3.8 N/mm width Top Surface High Density Cross Laminated PE Film White Tensile strength (Film) ASTM D 882 Longitudinal 38 N/mm2 Transverse 38 N/mm2 Elongation of membrane ASTM D 638 Longitudinal 230% Transverse 180% Tear Resistance (film) Longitudinal Transverse

ASTM D 1004

Puncture Resistance

ASTM E154

220N /60mm deflection

Adhesion to primed substrate -Ditto- self Water absorption After 24 hours After 35 days

ASTM D 1000

2 N/mm width 2.4 N/mm width

280N/mm thickness 280N/mm thickness

ASTM D 570 0.14% 0.95%

Crack bridging ability Water resistance of Membrane Cross laminated Film (solvent extracted from membrane) Self-adhesive softening point


Page G-21 of 68

Min 1 mm BSEN 12390 5 bar pressure

No penetration

5 bar pressure ASTM D 36

No penetration 102°C


Specifications

The membrane shall be laid on the twin stick surface of the SBS bitumen layer with the sticky side downwards and laid strictly in accordance with the manufacturer’s instructions. The minimum overlap should be 150 mm side and end. The top silicon release film of the twin stick membrane to be removed before the application of the subsequent layer. The corners and pipe joints shall be sealed with a 1.5 mm thick two side adhesive bitumen tape. The tape shall comprise of a non-reinforced SBS modified bitumen layer sandwiched between two layers of plastic release film. The bitumen tape should have a minimum ultimate elongation of 1200%. The tape should be a minimum of 300 mm width. The silicon release film on the top side should be removed at the time of laying the waterproofing membrane. In the event adhesive side of the tape gets contaminated with dust or other debris, the tape should be removed with a heated scraper. The surface should then be primed again and the tape re-applied. If the contamination is very minor and localised, the tape can be repaired with heating it up with a hot air gun. A 40 mm x 40 mm corner fillet with polysulphide sealant shall be made for all corners around the pipes to allow movement. 

Protection Board (6 mm & 3 mm thick)

The membrane has to be protected as the third layer with a 6 mm thick self-adhesive asphaltic protection board impregnated with a tough layer of fibre glass and to be used under all the raft foundation and 3 mm thick protection board for walls and sides of raft foundation. The board should be weather, water and rot proof and should be completely devoid of organic material. The edges of the protection board to be sealed with a 50 mm self adhesive bitumen strips in order to avoid any back fill material from entering into the system. The protection board shall comply with the following properties. Table G13- Properties of Protection Board Property Test Method Thickness Chisel test BS 1142 Heat resistance Ueatc

Typical Results 6 mm & 3 mm pass Min 80°C

All products in the waterproofing system to be sourced from the same manufacturer who operates a certified ISO quality system. The membrane shall be applied strictly in accordance with the manufacturer’s method statements. Termination of the system shall be done at a height of 100 mm from the ground level. A 40mm x 40mm groove to be cut and the membrane neatly tucked into the groove. The groove to be sealed with a polysulphide sealant. The self-adhesive protection board should extend at least 50 mm above the groove and be sealed to the substrate with an epoxy adhesive or a suitable system recommended by the membrane manufacturer and approved by the Engineer. The cost of membrane is inclusive of fixing and termination with approved sealant. (b) External Waterproofing for Minor Buried Structures such as Manholes, Inspection Chambers etc. The external surfaces of minor concrete substructures shall be protected or tanked by the following method. The water proofing system shall be two layer application. The 1st layer waterproofing membrane shall be a 2 mm thick bitumen cross laminated self


Page G-22 of 68


Specifications

adhesive membrane and the 2nd layer shall be with a 3 mm thick self adhesive membrane protection board with a tough geo-textile surfacing. The membranes shall comply with the technical specifications as given in Clause 7.2.2.1 (a). The surface on which the waterproofing membrane is to be applied shall be smooth and free of any sharp edges or protrusions. The surface should be primed with an approved primer recommended by the membrane manufacturer. Once the primer is completely cured, the membrane shall be laid on the surface. The silicon release film is peeled off the sticky side and the membrane is to be carefully laid on the surface. Care should be taken to minimize the entrapped air. The minimum overlap should be 100 mm at side and end and minimum 200 mm at the corners. The corners and pipe joints shall be sealed with a 1.5 mm thick two side adhesive bitumen tape. The tape shall comprise of a non-reinforced SBS modified bitumen layer sandwiched between two layers of plastic release film. The bitumen tape should have a minimum ultimate elongation of 1500%. The tape shall be of minimum 300 mm width. The silicon release film on the top side shall be removed at the time of laying the waterproofing membrane. In the event adhesive side of the tape gets contaminated with dust or other debris, the tape should be removed with a heated scraper. The surface shall then be primed again and the tape re-applied. If the contamination is very minor and localised, the tape can be repaired with heating it up with a hot air gun. Protection Board (3 mm thick) The membrane shall be protected with a self-adhesive protection membrane board with a tough, UV resistant, polyester surface. Staggered overlaps to be ensured while application of protection membranes. The protection membrane shall comply with the following properties. Table G14 – Protection Membrane Properties Property Test Method Thickness Puncture resistance ASTM E 154 Tear resistance ASTM D 5147 Min: top surfacing weight of fabric Elongation of compound ASTM D 638

Typical Results 3 mm 1500 N 500 N 350 gm / m2 1500%

Any punctures on the membrane shall be repaired with an additional patch which would extend at least 5 cm from the edges of the damage. The waterproofing membrane shall be protected immediately with the protection membrane to avoid any damages to the system because of ongoing site activities. The end termination of the composite system shall be as shown in the approved drawings or as recommended by the membrane manufacturer and approved by the Engineer. (c ) Brush Applied Bituminous Emulsion The bitumen emulsion shall be cold applied thixotropic coating conforming to ASTM D 1227 Type III Class 1. The coating shall have a solid content of Min 50%. The coating shall be applied in two coats with a priming coat which will be made by diluting the bitumen emulsion with max 20% clean potable water or as per manufacturer’s recommendations. Two undiluted coats of the bitumen paint shall be


Page G-23 of 68


Specifications

applied @ 1.1 lit /m2 in two coats. The total Dry Film Thickness of the coating shall be a minimum 0.5 mm. The second coat shall be applied at right angles of the first coat and only after the coat has dried completely. The above coating system shall be protected with 1000 gauge polyethylene sheet or building paper as specified for each specific location and use.


Page G-24 of 68


Specifications

Table G15 Application Procedure for Impervious Bituminous Tanking Membrane System (Clause G.2.2 (1) (a) & (b) on Concrete Surfaces & Structures (External) up to the Ground Level (For Major Structures) Item

Description and/or Location of work

Application / location

1.

Buried concrete external surface in contact with soil and groundwater for major structures; blinding under the raft foundation

Blinding layer under raft foundation (a) under the blinding (b) over the blinding

2.

Ditto – Raft Foundation sides and tank walls and roof slab in contact with ground soil / water


(a) Raft foundation base slab sides and tank walls

Surface preparatio n

Levelled formation Sweep blast

Shop / site

– –

Sweep blast

Type of Coat

No. of coats

Description & generic type of material

Thickness Microns

PE sheet 1000 gauge as specified

250

Primer System T1 Membrane System T2

One layer One coat One layer

Rubberised bitumen emulsion

50 1.5 mm thick

Membrane System T3

One layer

Membrane System T4 Primer System T1

One layer One coat

Self-adhesive type SBS modified Bitumen non-reinforced membrane as specified Self-adhesive Bituminous membrane cross laminated with white PE at top as specified Self-adhesive type Bituminous Protection board. Solvented Bituminous Primer.

Membrane System T2

One layer

1.5 mm thick

By hand application

System T3

One layer

2 mm thick

System T5

One layer

Self adhesive type SBS modified bitumen membrane (non reinforced) as specified. Self adhesive type bituminous membrane cross laminated with white PE at top as specified. Self adhesive type bituminous protection board with UV & puncture resistant fabric layer on top.

Fix in staggered joints Fix in staggered joints.

1000 gauge Polyethylene sheet

2 mm thick 6 mm thick 50

Remarks

To be placed on the formation By brush application By hand application By Hand in staggered Joints -DittoBy brush application

–

Page G-25 of 68

3 mm thick


Specifications

Table G15 (Continued…) Item

Description and/or Location of work

Application / location

3.

Ditto – for Minor Structures like manholes, chambers, strip footing and its blinding layers.

Concrete blinding (a) under the blinding (b) over the blinding

4.

Ditto – for wall, roof slab, the buildings strip footing, and on chambers below ground


Manhole wall, roof slab

Surface preparati on

Levelled formation Sweep blast

Sho p/ site

– –

Sweep Blast

Type of Coat 1000 gauge Polyethylene sheet

No. of coats

Primer System T1 Membrane System T3

One layer One coat One layer

Membrane System T5

One layer

Primer System T1

One coat

Membrane System T3

One layer

System T5

One layer

Description & generic type of material

Thickness Micron s

Remarks

To be placed on the formation By brush application By hand application

PE sheet 1000 gauge as specified Solvented bitumen primer as specified Self-adhesive Bituminous membrane cross laminated with white P.E. at top as specified Self-adhesive type bituminous protection board with polyester fabric at top as specified Solvented Bituminous Primer as specified

250 50

Self adhesive type bituminous membrane with cross laminated at top with white PE as specified Self adhesive type bituminous protection board with polyester fabric at top as specified

2 mm thick

By hand application

3 mm thick

Fix in staggered joints

2 mm thick 3 mm thick 50

Fix in staggered joints By brush application

–

Page G-26 of 68


Specifications

Table G16 [System – I, J, K, L, M & N] TANKING MEMBRANE AND PROTECTIVE COATING TO CONCRETE Clause G.2.5 (1) [B & C] SCHEDULE OF IN-SITU BITUMINOUS MEMBRANE/GRP/ COATING SYSTEM (FOR MINOR STRUCTURES) STRUCTURE INTERNAL EXTERNAL FLOOR WALL CEILING Base Slab/Strip footing Base slab sides, /foundation Wall and Top of Cover Slab 1. Sewer Manholes (Internal)

In-situ GRP Lamination

Pre Fabricated GRP Liners

7mm thick system

Pre Fabricated GRP slab Liners

System ‘I’

System ‘J’

System ‘J’

5 mm Prefabricated GRP Benching Unit or in-situ GRP lamination System ‘N’

300 micron thick Epoxy Coating

300 micron thick Epoxy Coating

System ‘L’

System ‘L’

3. Building Strip footing, compound wall foundation etc.

N/A

N/A

N/A

4. Storm water MH’s, chambers & Similar

Epoxy Resin mortar as specified in CL 7.1.7

300 micron thick Epoxy coating system

300 micron thick Epoxy coating

System ‘K’

System ‘L’

System ‘L’

5. Anchor blocks Protection slab, concrete surround, & other similar burried concrete

N/A

N/A

N/A

6. Above ground structures like Panel plinth (Exposed Surfaces)

System ‘D’ as specified

System ‘D’ as specified

N/A

2. Sewer Inspection Chambers (Internal)


Page G-27 of 68

P.E sheet under the blinding

*System T1 +

*Rubberised Bitumen emulsion over the blinding + *System T1 + *System T3 + *System T5 System ‘M’ Rubberised bitumen emulsion + 1000guagePolyethylene sheet

*System T3 +

*System T1 + *System T3 + *System T5

*System T5 For each structure Rubberised emulsion + P.E Sheet System ‘M’ -

Same system given for sewer manholes & chambers as above

Same system given for sewer manholes & chamber as above

P.E. sheet at formation 2 Coats Rubberised Bitumen emulsion over concrete • 1 Layer P.E. sheet on top System ‘M’ Same as item 1 above

Ditto

• •


Specifications

(d) Alternative Proposal for Membrane Protection 3 mm thick two component spray in place flexible 100% solid content thermoplastic (Tpu) polyurethane /Polyurea Coating System. Table G17- Physical Data of Coating System Physical Properties Density (kg/m3) Permeability (more than 1 mm) Hardness (Shore ‘A’) Abrasion Resistance (Taber) Tensile Strength (kg/cm2) Elongation (%) Adhesion Tear Resistance (N) Colour

ASTM Test D - 1622 D - 2240 D - 4060 D - 2370 D - 2370 D - 4541 Absolute Load FED STD 595B

Value 1121.3 (kg/m3) 0.000 (metric/m2) 98 0.001/1000 Cycles 126.67 82.24% @ yield 77 (kg cm2) 123.56 (N) Black or other

Table G18- Resin Liquid Chemical Properties @24°C Properties Viscosity (cps) Specific Gravity (gr/cc)

ASTM Test Method D - 1638 Component ‘A’ Component ‘B’ D - 1638 Component ‘A’ Component ‘B’

Mixing Ratio (A:B) by volume

Value 600 + 100 1100 + 100 1.15 1.08 50:50

A Trial sample of the ‘Tpu’ coating is to be applied on any one of the concrete structures external surfaces and the relevant sample is to be subjected to 100 days acid immersion test in 10% concentrated sulphuric acid @ 50°C. This coating will be acceptable only, if the chemical resistance of the “coating” fully comply with the specification. The test shall be conducted in accordance ASTM C 581. (e) Waterproofing on Tanks Building’s Roof where thermal insulation is required. The roofing system shall incorporate the materials and methodology specified in Building Works - Section ‘L’. (f) Roof Water proofing on tanks where slope is required to drain rain water The roof water proofing system proposed shall include the following materials and works to be supplied and installed by an approved manufacturer 1. Materials 1st Layer


:

Sprayed high density polyurethane foam waterproofing Grade: Spray Average thickness: 20 mm Core Density: 55 kg/m3

Page G-28 of 68


Specifications

Comp. Strength: 2.5 kg/cm2 Tensile Strength: 3 kg/cm2 Closed cells: 98% Standards: BS 5241 – Part 1 2nd Layer

:

Liquid Elastomeric UV coating Grade: Spray Density: 1.2 gm/cc pH: 8-8.5 Solid content: 60% Elongation: 300% Standards: BS476-3

3rd Layer

:

Filter Membrane Grade: Filter Membrane Mass: 120 gm/m2 Thickness: 1.5 mm Elongation: 50% Colour: White

4th Layer

:

Shotcrete (Recommended fall 1:200) to a minimum thickness of 40mm. Grade: Pouring Mix Class: 350 OPC Slump: 100 ±25mm Density: 2.5 Kg/litre

5th Layer

:

Cementitious Waterproof coating as specified Grade: Brush / Spray Density: 1.8 gm/cc Elongation: 120% Water Penetration: Nil Standards: BS 1881 Part 5

Construction Joints:

Filler Board Grade: Impregnated Filler Board Thickness: 12 mm Density: 220 kg/m3 Standards: BS 1142

Construction Joints:

Poly sulphide Sealant Grade: Pouring Solid Content: 100% Temperature Resistance: 20°C to 120°C Elongation: 400% (at break) Standards: BS 6920-88

2. Installation a. Roof slab shall be inspected by a roofing specialist from the manufacturer and confirm acceptance of the roof for application of the waterproofing system. Surfaces to receive membrane roofing shall be free of projections, voids, depressions, scale, efflorescence, loose material, laitance, oil, grease


Page G-29 of 68


Specifications

and other foreign contaminants. Before start the work, inspect all surfaces to receive membrane and report in writing to the Engineer any surfaces that are not suitable for correct application of the membrane. For surfaces which are unsuitable to receive membrane, the Contractor shall see that same are corrected by the respective trade prior to application of his work. Relevant shop drawing shall be submitted to the Engineer prior to start of the work. b. Clean the roof using compressed air to make sure substrate is free of dust and debris. c.

Supply and spray polyurethane foam insulation complying with BS 5241 – Part 1 at an average thickness of 45mm of density 40-50 Kg/m3 over the entire roof area including the upstand to a height of max. 200 mm.

d. Supply and spray liquid elastomeric UV protection coating over the entire foam area and allow to dry for 48 hours. e. Flood test the roof for a minimum period of 24 hours with 25 mm head of water as specified in Cl.9.3 of BS 8007: 1987. Any area where leaks occur shall be drained, thoroughly dried, repaired and then retested. Installation of insulation board, separation layer and concrete, which are applied over the waterproofing, shall not start until such time as the membrane is leak free and has been accepted by the Engineer. f.

Supply and lay filter membrane protection layer over the entire roof area.

g. Supply and fix expansion joint filler boards in slope and in panels h. Supply and lay protective concrete screed in panels and cure as per standard procedures i. j. k. l.

Supply and apply PVA bonding agent to all corners and upstands in 1:3 Proportion. Prepare angle fillet all around parapet and upstands using sand cement mortar. Supply and apply polysulphide sealant to all construction joints including backing rod. Supply and spray apply cementitious water proof coating over the entire roof area including upstands and allow to dry for 48 hours.

m. Final inspection shall be carried out by the manufacturer n. Roof water proofing system shall be carried out only by Client’s approved applicator. 3. Inspection Inspection will be carried out as per Client’s approved inspection plan. 4. Guarantee


Page G-30 of 68


Specifications

a. Guarantee stating that the water roofing system installed will be waterproof and free from defects for a period not less than 25 years from the date of Taking Over of the Works. b. In the event any leaks occur within the period stipulated, the Contractor shall at the convenience of the Employer, effect all repairs and replacements necessary to remedy defects all to the complete satisfaction of the Engineer at no additional cost to the client. G.2.3 GRP Prefabricated benching unit for Sewer Inspection Chambers GRP prefabricated benching units shall be manufactured to the same process as specified in G.1.6 for in-situ lamination but the work shall be carried out in manufacturer’s yard with a wall thickness of 5 mm. G.2.4 Cutting and Sealing of Reinforced Liners Where the Contractor is required for any reason to cut reinforced plastic liners, he shall seal the exposed ends with an approved resin before incorporating the cut reinforced plastic in the work. No cut reinforced plastic shall be used until the resin has cured. The resin shall be as recommended by the manufacturer of the reinforced plastic item and shall be pigmented so that the areas where it has been applied are easily identifiable. It shall be delivered to site in sealed containers bearing the name of the manufacturer and properly labelled as to its content and shelf life. For flexible pipe materials a rubber protection strip shall be inserted between the pipe barrel and the steel band. G.2.5 Protective Coatings to Concrete Works Protective Coating on Concrete ( Internal & External) General Requirements 



The coating system and the surface preparation shall be to the approved standard and shall conform to the ‘schedule of surface preparation and protection systems’ given below for concrete work. The coating system proposed shall be applied by Client approved specialist applicator.

Table G19- Surface Preparation on Concrete Syste Description Surface Preparation m a) Sweep Blasting The surface shall be sweep blasted with non-metallic mineral abrasive to achieve a minimum surface roughness of 100 micron on concrete or as recommended by the paint manufacturer. b) Surface Cleaning The concrete surface shall be cleaned to remove dirt, oil, dust, laitance and all other surface contaminations. c) Epoxy binder / sealer One coat 100 micron D.F.T two component polyamide epoxy based transparent sealer coat shall be applied by spray application to seal the porous concrete substrate if any.


Page G-31 of 68


d)

Filler

Specifications

One coat of alkali resistant acrylic based filler 100 micron DFT shall be applied by steel trowel or hand application to fill the surface voids or as recommended by the paint manufacturer.

1. Application of Field Coatings: a. Coating shall be applied with spraying equipment recommended by the Manufacturer. 1. Areas inaccessible to spray coating or rolling shall be coated by brushing or other suitable means. o. Give special attention to ensure that edges, corners, crevices, welds, bolts, and other areas, as determined by the Engineer, receive a film thickness at least equivalent to that of adjacent coated surfaces. p. Protective coating materials shall be applied in strict accordance with the manufacturer’s printed instructions. q. Prime coat shall be applied to clean surfaces: 1. Within a 4-hour period of the cleaning. 2. Prior to deterioration or oxidation of the surface. 3. In accordance with the manufacturer’s recommendations. r.

Coatings shall be applied in dry and dust-free environment. 1. No coating shall be applied during following conditions: a.

2. 3.

f.

from

When the surrounding air temperature, measured in the shade, is below 17° C b. To wet or damp surfaces. c. In rain, fog or mist or when the relative humidity exceeds 85%. d. When it is expected that the relative humidity will exceed 85% or that the air temperature will drop below 5°C within 18 hours after the application of the coating or paint. e. Dew or moisture condensation shall be anticipated. f. The cement laitance is removed with non-metallic mineral abrasive blasting g. Minimum specified surface roughness is achieved. h. Specified primer /sealer coat is applied. i. Filling the surface voids/cracks/and imperfections with approved epoxy filler. If the above conditions are prevalent, coating shall be delayed until surfaces are dry. The day’s coating shall be completed in advance of the probable time of day when condensation will occur in order to permit the film a sufficient drying time prior to the formation of moisture.

Care shall be exercised to avoid lapping, coating on adjacent surfaces. 1. 2. 3. 4.


Coatings shall be sharply cut to lines. Finished coated surfaces shall be free from defects or blemishes. Drop cloths shall be used to protect floors, fixtures, and equipment. Care shall be exercised to prevent paint from being spattered onto surfaces

Page G-32 of 68


5. 6. g.

which such paint cannot be removed. Surfaces from which paint cannot be removed shall be painted or repainted as required to produce a finish satisfactory to the Engineer. Apply second coat at right angles to first coat, ensuring pinholes are covered.

Surfaces inaccessible after assembly shall be coated before erection.

h.

Touch-up of surfaces shall be performed after installation.

i.

Surfaces to be coated shall be clean and dry at the time of application.

j.

Time of Coating: a. Manufacturer’s recommended recoat time shall be complied with. b. Sufficient time shall be allowed to elapse between successive coats to permit satisfactory recoating, but once commenced, the entire coating operation shall be completed without delay. c. No additional coating of any structure, equipment, or either item designated to be painted shall be undertaken without specific permission of the Engineer until the previous coating has been completed for the entire structure, piece of equipment, or other item.

k.

Thickness of Coating: a.

[A]

Specifications

Dry film thickness specified shall be achieved for each coat.

l.

Clean up 1. Concrete surfaces shall be visually inspected to ensure proper and complete coverage has been attained. 2. Upon completion of the work, staging, scaffolding, and containers shall be removed from the site or destroyed in an approved manner. 3. Coating spots, oil, or stains upon adjacent surfaces shall be removed.

m.

Protective coating properties tests are to be conducted on the final coated surface and shall comply with the requirements specified in Table G21.

Schedule of Concrete Protection System For Major Structures Internal: System -

‘A’

7mm thick in-situ GRP lamination as specified in CL G.1.6.

System-

A-1

7 mm thick in-situ GRP lamination with grit bonding on top of final finish coat as specified in CL.G.1.14.

System -

‘B’

1mm thick heavy duty glass flake vinyl ester resin based coating 250 micron each. Total D.F.T 4 x 250 microns + Approved Primer recommended by the paint manufacturer.

System -

‘C’

1mm thick Polysulphide modified Epoxy resin coating system designed for superior adhesion, corrosion Protection, Chemical resistance & waterproof coating 250 micron for each coat. Total D.F.T (4 x 250 micron) = 1 mm + approved primer recommended by the paint manufacturer.

System -

‘D’

0.5 mm thick solvent free 100% solid content polyamine based Epoxy + Polyurethane resin coating.


Page G-33 of 68


Specifications

Epoxy = 300 microns thick Polyurethane = 200 microns thick Total DFT = 500 microns + Approved Primer recommended by the paint manufacturer. System -

‘E’

Aggregate dressed (3 component) heavy duty, hard wearing, solvent less Epoxy, anti slip deck coating minimum D.F.T = 3 mm. +75 micron high build epoxy finish top coat with anti-fungi and antibacterial agents.

System -

‘F’

Fibre reinforced acid resistant, mineral based alkaline silicate mortar minimum 6 mm thick with finish top coat for hard floor coating.

System -

‘G’

Double sided PVC lined membrane as specified in Section 4 Mechanical Specification.

For Major Structures External Surfaces above Ground Exposed to Sunlight System -

[B]

[C]

[D]

‘H’

Alkali Resistant Acrylic based anticarbonation coating + Sealer coat + filler Coat  Epoxy binder / Sealer Coat – 100 microns thick.  Alkali Resistant Acrylic based filler 100 microns thick.  Alkali Resistant acrylic based anticarbonation coating – 100 x 3 coats = 300 microns thick.

For minor Structures (Internal Surfaces) System -

‘I’

7mm thick in-situ GRP lamination over granolithic benching for sewer MH’s as specified in CL G.1.6.

System -

‘J’

7mm thick Prefabricated GRP liner as specified in CL G.1.5 for sewer manholes.

System -

‘K’

Two component Epoxy mortar 10mm thick over granolithic benching of storm water MH’s as specified in CL G.1.7

System -

‘L’

Solvent free 100% solid content Polyamine based pure Epoxy 300 micron thick + primer, for storm water MH’s and Inspection chambers (sewer) etc.

For Minor Structures (External surfaces) System -

‘M’

System -

‘N’

Rubberised bitumen emulsion + P.E sheet on top as specified in G.1.8. 5 mm thick GRP pre fabricated benching or in-situ lamination over benching of inspection chambers (sewer) as specified in Clause G.2.3.

Roof Water Proofing System on Roof Top Exposed To Sunlight System -

RWP - 1

Roof Water Proofing Systems on Roof top of Residential Buildings & Pump Rooms as specified in Building Specification.

System -

RWP - 2

1.5 mm thick Protective coating with Acrylic modified elastomeric


Page G-34 of 68


Specifications

cementitious coating on “Sloping Roof” Top where Insulation is not required Table: G20- Schedule of Concrete Protection Details

S.N.

EXTERNAL PROTECTION FOR ALL MAJOR STRUCTURES Particular Protection Protection details System

1 a. b.

Below Ground Level Below Blinding Above Blinding (raft)

c.

Walls outer surface

2

Above Ground Level

A.N. 1 a.

P.E System T1,T2,T3 & T4 System T1,T2,T3 & T5 System ‘H’

INTERNAL PROTECTION AND ROOFING DETAILS Unit Details Protection Protection details System Tanker Reception Tanker Discharge Sump, Spill System ‘A’ GRP Liner (7mm thick) as specified in CL G.1.6 Collection channel, Pump Sump

2 a.

Coarse and Screen Channels Walls, Floors (top of benching if System ‘A’ any), columns, beams and roof slab (internal)

3 a. b.

Ferric Storage system Ferric storage and dosing area bund System ‘A’ Ferric chemical unloading area System ‘A-1’ Aerated Grit Channels Channel between coarse and fine System ‘A’ screen and aerated grit channels Feed channels, grit channels, Scum System ‘A’ channels and outlet channel

4 a. b.

5

Bio-reactor

5.1

Flow Splitting Cham ber

a.

Floor, walls, ceiling

5.2

Anaerobic/Anoxic/ Aeration, Membrane tank & RAS Sump Floors, Walls & Ceiling, inlet/ outlet channels

a.

1000 gauge PE Sheet (250 micron thick) Approved bituminous primer + 2 layers bituminous membrane 1.5 mm and 2mm thick each & 6 mm thick protection board as specified. Approved bituminous primer + 2 layers bituminous membrane 1.5 mm and 2mm thick each with 3 mm thick protection board on top as specified. Approved sealer coat and filler coat and Alkali resistant acrylic based anticarbonation coating (300 micron) thick


GRP Liner (7mm thick) as specified in Cl.G.1.6

GRP Liner (7mm thick) as specified in CL.G.1.6 Grit bonded GRP liner (7mm thick) as specified in Cl.G.1.14 GRP Liner (7mm thick) as specified in Cl.G.1.6 GRP Liner (7mm thick) as specified in Cl.G.1.6

System ‘B’

Approved primer recommended by the Paint manufacturer +1 mm thick heavy duty glass flake vinyl ester resin based coating

System ‘B’

Approved primer recommended by the Paint manufacturer +1 mm thick heavy duty glass

Page G-35 of 68


Specifications

flake vinyl ester resin based coating b.

Membrane Tank pipe gallery floor

System ‘E’

c.

Membrane Tank pipe gallery walls

System ‘L’

b.

Valve Chamber (RAS/SAS)

System ‘L’

6 a.

CCT and TSE Storage Tank Floors, Walls, Columns, ceiling

System L

b.

Inspection Manholes

System ‘L’

7 a.

TSE Pump House Wet Well

System ‘L’

b.

Valve Chamber

System ‘L’

8

Chemical Storage & Dosing

3 mm thick heavy duty (3 component) non-slip epoxy abrasion resistant deck coating + high build 75 micron finish coat on top with anti fungi and anti bacterial agents. Approved primer recommended by the paint manufacturer +300 micron epoxy paint Approved primer recommended by the paint manufacturer +300 micron epoxy paint

Approved primer recommended by the paint manufacturer +300 micron epoxy paint (polyamine based) Approved primer recommended by the paint manufacturer +300 micron pure epoxy paint (polyamine based)

Approved primer recommended by the paint manufacturer +300 micron pure epoxy paint (polyamine based) Approved primer recommended by the paint manufacturer +300 micron pure epoxy paint

P olym er Storage and Dosing a.

Polymer storage and dosing area bund

9

Aerobic Digesters

a.

Walls and Floors (top of benching if System ‘B’ any)

b.

Walkways

10

Digested Sludge Pump and Sump

a. b.

Walls, floors, ceiling Valve Chamber

11

Liquor Return Sump and Pump House Wet Well Walls, Floors and Ceiling Dry Well/ Valve chamber floor and Roof top

a. b.

12

System ‘A’

GRP Liner (7mm thick)as specified in CL G.1.6

System ‘E’

Approved primer recommended by the Paint manufacturer +1 mm thick heavy duty glass flake vinyl ester resin based coating 3mm thick, heavy duty, non slip abrasion resistant deck coating + high build 75 micron finish coat on top with anti-fungi and anti bacterial agents.

System ‘A’

GRP Liner (7mm thick)as specified in CL G.1.6

System ‘L’

Approved primer recommended by the paint manufacturer + 300 micron pure epoxy paint (Polyamine based)

System ‘A’

GRP Liner (7mm thick)

System ‘L’

Approved primer recommended by the paint manufacturer + 300 micron pure epoxy paint (Polyamine based)

Diesel Storage


Page G-36 of 68


Specifications

Diesel Tank Concrete Bund

System ‘A’

GRP Liner (7mm thick)

Concrete protection of any major and minor units not including under Table G20 shall be provided to suit the purpose as specified in this section. Table G21- Test on Protective Coating of Concrete Sr.

Properties

Test Method

Minimum Requirements

1

Dry film thickness

BS 3900

Specified thickness for each coat

2

Discontinuity (holiday) detection

National Association of Corrosion Engineer’s standard recommended practice

100% pin hole free

3

Pull of adhesion strength

ASTM D4541/ISO 4624

3.00 N/mm2 for epoxy coating 2.00 N/mm2 for anti carbonation coating

Notes: (1) (2)

Freedom from pinhole shall be established by the use of a spark tester. Coating system should be resistant to: (a) Sulphate and chloride ion penetration (b) CO 2 diffusion (c) Bacterial and fungus growth (d) Atmospheric temperature resistant (e) Acids and alkalis of PH2 -14 (f) To accommodate shrinkage cracks appearing on concrete substrate.

TABLE G22- BUILDING FINISHES DETAILS Sr. 1

2

Building Type MCC Room, Transformer room, RMU/ Battery Room

Flooring

Blower Houses

3mm thick heavy duty non slip (3 component) epoxy abrasion resistant deck coating + finish coat with anti-fungi and anti-bacterial


Walls (internal)

Power floated Plaster and plastic concrete paint with anti- fungi structural slab and anti- bacterial agent Primer - 1 coat No Coating On Intermediate coat - 1 Finish coat - 1 Floors

Plaster and plastic paint with anti fungi and anti bacterial agent Primer - 1 coat Intermediate coat - 1 Finish coat - 1

Page G-37 of 68

Walls (external)

Ceiling

Skirting

Cement plastered or fair- faced concrete and weather shield (water resistant, UV resistant, Crack Bridging and flame retardant) acrylic emulsion coating Primer -1 coat Paint - 2 coats -----do-----

Plaster and plastic paint with anti- fungi and antibacterial agent Prime - 1 coat Intermediate coat - 1 Finish coat - 1

100mm high ceramic skirting with chamfere d/ rounded edge

-----do-----

N/A


Sr.

Building Type

Flooring

Specifications

Walls (internal)

Walls (external)

Ceiling

Skirting

agents

3

Ventilation fan Room

4

TSE Pumping Station- Dry Well (concrete walls/floor/ro of)

5

Residual Chlorination Building (delivery and storage area)

6

Residual Chlorination Building (chlorinator, motive water and compressor room)


3mm thick heavy duty non slip (3 component) epoxy abrasion resistant deck coating + finish coat with anti-fungi and anti-bacterial agents 6mm (min) thick fibre reinforced alkaline silicate mineral based mortar flooring with paint manufacturers recommended finish coat (System F) 6mm (min) thick fibre reinforced acid resistant alkaline silicate mineral based mortar flooring with paint manufacturers recommended finish coat (System F) 3mm thick heavy duty non slip (3 component) epoxy abrasion resistant deck coating + finish coat with anti-fungi and anti-bacterial agents

Plaster and plastic paint with anti- fungi and anti- bacterial agent Primer - 1 coat Intermediate coat - 1 Finish coat - 1

-----do-----

-----do-----

--

Cement plastered or fair- faced concrete and epoxy, primer + two coats paint

-----do-----

-----do-----

--


-----do-----

-----do-----

--


-----do-----

-----do-----

--

Page G-38 of 68


Sr. 7

8

9

10

11

Building Type Sludge Dewatering and Drying

Flooring

Specifications

Walls (internal)

Walls (external)

Ceiling

Skirting

3mm thick Cement plastered or -----do---------do----heavy duty fair- faced concrete non slip (3 and epoxy, primer + component) two coats paint epoxy abrasion resistant deck coating + finish coat with anti-fungi and anti-bacterial agents Polymer 3mm thick Cement plastered or -----do---------do----preparation heavy duty fair- faced concrete and dosing non slip (3 and epoxy, primer + room component) two coats paint epoxy abrasion (including resistant deck polymer coating + storage finish coat with room) anti-fungi and anti-bacterial agents Emergency 3mm thick Plaster and plastic -----do---------do----Generator heavy duty paint with anti- fungi Building non slip (3 and anti- bacterial component) agent epoxy abrasion Primer - 1 coat resistant deck Intermediate coat - 1 Finish coat - 1 coating + finish coat with anti-fungi and anti-bacterial agents Diesel Pump 3mm thick Plaster and plastic -----do---------do----Room heavy duty paint with anti- fungi non slip (3 and anti- bacterial component) agent epoxy abrasion Primer - 1 coat resistant deck Intermediate coat - 1 Finish coat - 1 coating + finish coat with anti-fungi and anti-bacterial agents Building Roof min 50mm thick light weight concrete (for slope) + bituminous waterproofing Top Water membrane + 50mm thick extruded polystyrene insulation board + geotextile Proofing protection layer + 400x400x 40mm white aggregate concrete tiles. Details


Page G-39 of 68

--

--

--

--


G.3

Specifications

COATING SYSTEM FOR FERROUS, NON FERROUS METALS AND PLASTICS

G.3.1 General DESCRIPTION A. Provide all labour, materials, equipment, services and accessories necessary to furnish and install the coating system work of this Section, complete and functional as indicated in Contract Documents and as specified herein. 1. Coatings for all ferrous, Non-ferrous surfaces, interior and exterior. 2. Submerged ferrous metal surfaces. 3. Structural and miscellaneous steel including tanks, hoppers and similar equipment. 4. Equipment furnished without factory finished surfaces. 5. Exposed galvanized metal except handrails, grating, piping and checkered plate. SUBMITTALS. A. Manufacturer’s Data 1. Manufacturers current printed product description, materials safety and technical data sheets for coating systems. 2. Detailed mixing, thinning and application instructions, minimum and maximum application temperature, curing and drying times between coatings. 3.

Instructions for surface preparation requirements, number and types of coats required for each surface.

4. 5.

Colour charts for each coating system. Certifications from manufacturer verifying factory applied prime coatings are compatible with the specified finish coatings.

6.

Detailed maintenance manual including the following information: a.

Product name and number.

b.

Name, address and telephone number of manufacturer and local distributor.

7.

c.

Detailed procedures for routine maintenance and cleaning.

d.

Detailed procedures for light repairs such as scratches and staining.

Abrasive: a.

Certified information of: 1. Particle size distribution. 2. Dust generation at proposed operating pressure and distance. 3. pH value. 4. Soluble chloride content. 5. Analysis for free silica. 6. Trace toxic contaminants.

B.

Sample Panels 1. Apply a complete coating system to a panel of the same material as that on


Page G-40 of 68


Specifications

C.

which the coating will be applied and submit for approval for each colour specified. 2. Approved sample panels will be used for quality control in applying coating systems. Certificates of Compliance.

D.

Inspection Reports.

E.

Test Reports.

DELIVERY, STORAGE AND HANDLING A Delivery 1. Deliver materials in original, unopened packages and containers bearing manufacturer's name and label including the following information: a.

B.

Name or title of material.

b.

Manufacturer's stock number and date of manufacture.

c.

Manufacturer's name.

d.

Contents by volume for major pigment and vehicle constituents.

e.

Thinning instructions where recommended.

f.

Application instructions.

g.

Colour code and name.

Storage 1. Store materials on site in a suitable location, protected from exposure to extreme weather. 2. Keep area clean and accessible. 3. Restrict storage of coating materials and related equipment. 4. Keep temperature of storage area between 18°C and 32°C. 5. Comply with Local Laws and Regulations. 6. Cloth and Cotton wastes that might constitute of fire hazard shall be placed in closed metal containers or destroyed at the end of each workday. 7. Provide approved fire extinguishers in material storage area.

QUALITY ASSURANCE A. Applicator Qualifications 1. Submit name and experience record of manufacturers recommended coating applicator. 2. Include list of utility or industrial installations painted, responsible officials, architects, or engineers concerned with the project and the approximate contract price. B.

Inspect surface and correct defects prior to application of each coat.

C.

The protective coating systems specification, report on paint work progress and the final report on corrosion protection should be provided by the applicator in the formats (A), (B) and (C) given in this clause.


Page G-41 of 68


Specifications

Form A – Form for a Protective Paint System Specification for New Work (To be filled in for each constituent element of the structure by the applicator) Project: Name of Client: Project:

Protective paint system:

Location:

ISO 12944-5 paint system No.

Constituent element:

Environment:

Drawing No. / area:

Required durability:

Position No.:

Sheet No:

Shop Application Surface Preparation Grade: Type of Prefabrication Primer (if used): Area:………..m2

Paint manufacturer: Protective Paint System

Nominal dry

Overcoating interval

Drying time at ….°C (h)

film thickness µm Minimum (h)

Maximum (h)

st

1 Coat 2nd Coat 3rd Coat 4th Coat Total: Site Application Surface Preparation Grade: Touch up: Complete: Area: ………..m2

Paint Manufacturer: Protective Paint System

Nominal dry

Overcoating interval

at ….°C (h)

film thickness µm Minimum (h) st

1 Coat 2nd Coat 3rd Coat 4th Coat Total:


Drying time

Page G-42 of 68

Maximum (h)


Specifications

Form B – Form for a Report on Paint Work Progress and Application Conditions (To be filled in by the coating applicator during the progress of work) Project:

Drawing No:

Location:

Corrosion Protection Plan No:

Constituent Element:

Position No:

Inspected by:

Comments:

Area: 1

2

Date

Time

3

4

5

6

7

8

9

10

Type of work

Method

General

Temp

Temp

Rel.

Dew

(i.e. surface

used

weather

Air

Structural /

air

point

preparation,

conditio

°C

Constituent

humidity

°C

application of

ns

element °C

%

priming coats,

11

12

13

Blast

Paint

Colour

Remarks (eg.

Signature/

cleaning

batch

ISO standard,

initials

abrasive

no.

surface

(material

prepar,

no.)

grade, irregularities

intermediate coats, top coats)

_______________

__________________

_______________ (Place) Vol 3, Section3 – Civil Specifications

(Date)

___________________________

________________________

___ (1st Signature) Page G-43 of 68

(2nd Signature)

(3rd Signature)

14


Specifications

Form C – Form for Final Report on Corrosion Protection Work (To be filled in by the applicator after the completion of the paint works) Name of structure:

Project No:

Drawing No:

Protective paint system: ISO 12944-5 paint system No. (if applicable) 1st Coat

2nd Coat

3rd Coat

4th Coat

Paint work contractor: New work Rust grade of steel surface (ISO 8501-1) .A

.B

.C

.D



Milling imperfections found



Sharp edges and burrs removed



Welding residues, including weld spatter, not removed

Specified surface preparation grade (ISO 8501 –1 or ISO 8501-2): Blast-cleaning



Sa2



Sa 2½



Sa 3



PSa 2



PSa 2½



PSa 3

Flame cleaning



FI

Hand and power tool



St2



St3

Cleaning



PSt2



PSt3

Machine abrading



Pma

Specified surface profile (ISO 8503-1): Comparator G ·

Fine ·

Medium ·

Coarse ·

Comparator S ·

Fine ·

Medium ·

Coarse ·


Page G-44 of 68

5th Coat



Specifications

Page G-45 of 68


Specifications

ENVIRONMENTAL CONDITIONS A.

Unless otherwise recommended by coating manufacturer, the ambient temperature shall be between 7°C and 35°C when applying coatings other than water-thinned epoxy.

D.

Water-thinned coatings shall be applied only when ambient temperature is between 10°C and 32°C.

C.

Epoxy coatings will be applied only within the minimum and maximum temperatures recommended by the coating manufacturer.

D.

Coatings, except water-thinned types shall be applied only to' surfaces that are completely free of moisture as determined by sight or touch.


Page G-46 of 68


E.

Specifications

Do not apply to surfaces which have visible frost or ice.

G.3.2 Products MANUFACTURER A. Products and manufacturers specified hereinafter are specified for the purpose of establishing minimum quality standards. Products equal in quality to, or better than those specified will be considered acceptable. Decision of acceptability will rest with the Engineer. Paint shall be from the approved supplier’s list. GENERAL A. No substitutions shall be considered that decrease: 1. Film thickness. 2. Number of coats. 3. Surface preparation. 4. Performance criteria of the generic type of coating specified. B.

Furnish coatings and coating products under this Section from a single manufacturer unless otherwise specified.

C.

Compatibility 1. Compatible materials shall be used as primer and finish coats of systems. 3. Compatible barrier coats may be used between factory-applied prime coats, or finish coats on existing surfaces to be refinished and subsequent field coats with the Engineer's approval.

D.

Colours 1. Colours shall be as scheduled or selected by the Engineer. 2. Prime and intermediate coats shall be tinted as approved by the Engineer to facilitate inspection of coverage for each coat

HAZARDOUS MATERIALS RESTRICTIONS A.

Paints and painting practices shall comply with all applicable state and local requirements limiting the emission of volatile organic compounds.

MATERIALS A. Abrasive 1. Chose particle size, shape, and specific gravity to produce desired surface profile for coating adhesion recommended by coating manufacturer. a. If not listed in manufacturer's literature, provide for a 50 to 75 microns average profile. 2. pH value : Not less than 4 nor greater than 10 when mixed in neutral water


Page G-47 of 68


3. 4. 5. B.

Specifications

Soluble Chloride Free Silica Trace Toxic Contaminants

: : :

None. To meet government regulations To meet government regulations

Colours as selected by Engineer from manufacturer's standards.

G.3.3 Execution WORKMANSHIP A. Paint and coatings shall be applied so as to produce an even film of specified thickness. B. Edges, corners, crevices and joints shall receive special attention to ensure that they have been thoroughly cleaned and that they receive an adequate thickness of paint. C. Finished surfaces shall be free from runs, drips. ridges, waves. laps. brush marks and variations in colour, texture and finish. D. Coverage shall be complete so that the addition of another coat of paint would not increase the coverage. E. Adjacent surfaces shall be protected by the use of drop cloths or other approved precautionary measures. ITEMS NOT TO BE COATED A. Hardware, hardware accessories, nameplate data tags, machined surfaces and similar items shall not be coated. Such items in contact with coated surfaces shall be removed or masked prior to the commencement of the surface preparation and painting operations. B. Following completion of coating of each piece, removed items shall be reinstalled. C. Removal and installation shall be done by workmen skilled in the trades involved. PREPARATION A. Surfaces to receive paint and protective coatings shall be cleaned as specified prior to application of coating materials. B. C. D.

Examine surfaces to be finished and correct surface defects before application of any coating material. Beginning the work of this section without reporting unsuitable conditions to the Engineer constitutes acceptance of conditions. Marred or abraded areas on shop-primed 'and factory-finished surfaces shall receive touch-up restoration prior to any other coating applications.

SANDBLASTING A. All sandblasting shall be done in strict accordance with the referenced specifications of the Steel Structures Painting Council. B.

When items to be shop primed or shop primed and finish coated in the shop, surface preparation shall be as specified in this Section.

C.

The Engineer shall have the right to witness, inspect and reject any sandblasting done in the shop.

D.

When sandblasting is done in the field, care shall be taken to prevent damage to structures and equipment. 1.


Pumps, motors and other equipment shall be shielded, covered or otherwise

Page G-48 of 68


2.

E.

protected to prevent the entrance of sand. No sandblasting may begin before the Engineer inspects and approves the protective measures.

Following surface preparations for metal surfaces to be painted or given protective coatings shall form part of this Section: 1.

White Metal Blast Cleaning (For very corrosive atmosphere). a.

2.

3.

Blast cleaning of all except tightly adhering residues of mill scale rust and coatings, exposing numerous evenly distributed flecks of underlying metal.

Solvent Cleaning a.

Removal of oil, grease, dirt, soil, salts and other contaminants by cleaning with solvent, vapour alkali, emulsion or steam.

Surface preparations shall be done to the satisfaction of the Engineer. 1.

G.

Blast cleaning until at least 67 percent of each element of surface area is free of all visible residues.

Brush- off Blast Cleaning a.

5.

Blast Cleaning nearly to White Metal Cleanliness, until at least 95 percent of each element of surface area is free of all visible residues.

Commercial Blast a.

4.

Removal of all visible rust, will scale, paint and foreign matter by blast cleaning by wheel or nozzle (dry) using sand, grit or shot.

Near-White Blast Cleaning (For high humidity, chemical atmosphere, marine or other corrosive environment). a.

F.

Specifications

No painting or protective coating shall be applied before the Engineer has inspected and approved the preparation.

After sandblasting, dust and spent sand shall be removed from the surfaces by brushing or vacuum cleaning.

APPLICATION OF PROTECTIVE COATINGS A.

Shop Coating 1. 2.


Fabricated metalwork and equipment which requires coating may be shop primed with specified primer. Any such work delivered to the job site with any other shop coat shall have this coating removed and the specified coating applied in the field. Manufactured equipment with approved corrosion-resistant factory finishes and galvanized finishes shall be exempt from this requirement of stripping.

Page G-49 of 68


B.

Specifications

Field Coating 1.

Except where in conflict with the manufacturer's printed instructions or where otherwise specified herein, use choice of brush, roller, spray or airless spray application. a. b.

2.

3. 4.

5. 6.

Any spray painting must first have the approval of the Engineer. Areas inaccessible to spray coating or rolling shall be coated by brushing or other suitable means.

Give special attention to ensure that edges, comers, crevices, welds, bolts and other areas as determined by the Engineer, receive a film thickness at least equivalent to that of adjacent coated surfaces. All protective coating materials shall be applied in strict accordance with the manufacturer's printed instructions. Prime coat shall be applied to clean surfaces within a 4-hour period of the cleaning and prior to deterioration or oxidation of the surface and in accordance with the manufacturer's recommendations. Coatings shall be applied in dry and dust-free environment: No coating or paint shall be applied during following conditions: a.

When the surrounding air temperature, measured in the shade is below 15°C.

b.

To wet or damp surfaces.

c.

In rain, fog or mist, or when the relative humidity exceeds 85%.

d.

When it is expected that the relative humidity will exceed 85% or that the air temperature will drop below 5°C within 18 hours after the application of the coating or paint.

e.

Dew or moisture condensation shall be anticipated.

7.

If above conditions are prevalent, painting shall be delayed until surfaces are dry.

8.

The day's coating shall be completed in advance of the probable time of day when condensation will occur in order to permit the film a sufficient drying time prior to the formation of moisture. Care shall be exercised to avoid lapping paint on adjacent surfaces:

9.

a. b. c. d. e. f.

Coatings shall be sharply cut to lines. Finished coated surfaces shall be 'free from defects or blemishes. Drop cloths shall be used to protect floors, fixtures, and equipment. Care shall be exercised to prevent paint from being spattered onto surfaces from which such paint cannot be removed. Surfaces from which paint cannot be removed shall be painted or repainted as required to produce a finish satisfactory to the Engineer. Whenever two coats of a dark coloured paint are specified, the first coat shall contain sufficient powdered Aluminium to act as an indicator of proper coverage, or the second coating shall be of a contrasting colour.


Page G-50 of 68


10.

Surfaces inaccessible after assembly shall be coated before erection: a. b.

C.

No structural friction connections, high-strength bolts and nuts shall be painted before erection. Areas damaged during erection shall be hand or power-tool cleaned and recoated with prime coat.

11.

Touch up of surfaces shall be performed after installation.

12.

All surfaces to be coated shall be clean and dry at the time of application.

Time of Coating 1.

Manufacturer's recommended recoat time shall be complied with. a.

b.

2. D.

Specifications

Sufficient time shall be allowed to elapse between successive coats to permit satisfactory recoating, but once commenced, the entire coating operation shall be completed without delay. No additional coating of any structure, equipment or other item designated to be painted shall be undertaken without specific permission of the Engineer until the previous coating has been completed for the entire structure, piece of equipment or other item.

Piping shall not be finish coated until it has been pressure tested and approved.

Thickness of Coating 1.

Dry film thickness specified shall be achieved and verified for each coat.

G.3.4 Testing and Inspection A.

Inspection Devices 1.

Provide, until final acceptance of coating and' painting, inspection devices in good working condition for detection of holidays and measurement of DFT of coatings and paints. .

2.

Furnish U.S. Department of Commerce, National Bureau of Standards or equivalent certified thickness calibration plates to test accuracy of DFT gauge and certified instrumentation to test accuracy. Dry film thickness gauges shall be made available for the Engineer's use until final acceptance of application. Holiday detection devices shall be operated in the presence of the Engineer. Inspection devices shall be operated in accordance with the manufacturer's instructions and when directed by the Engineer's representative.

3.

B.

Conduct DFT measurements and electrical inspection of the coated surfaces.

C.

Recoat and repair as necessary for compliance with the specifications.


Page G-51 of 68


D.

Specifications

After repaired and recoated ferrous metals areas have cured, final inspection tests shall be conducted by the Engineer. 1.

Coating thickness specified in mils on ferrous substrates shall be measured with a non destructive magnetic or digital type dry-film thickness gauge

2.

Discontinuities, voids and pinholes in the coatings will be determined with

non-destructive type electrical holiday detector. 3. Epoxy coatings and thin film coatings shall be checked for discontinuities and voids with a low-voltage detector of the wet-sponge type, 4. Use a non-suding type wetting agent, which shall be added to the water prior to wetting the sponge. 5. A high-voltage, low-current, spark type detector shall be used for electrical inspection of coal tar enamel only. 6. Tape-type coatings shall be inspected for holidays using a device designed for use in detecting such flaws. 7. Pinholes shall be marked, repaired in accordance with the manufacturer's printed recommendations and retested. 8. No pinholes or other irregularities will be permitted. 9. Coatings not in compliance with the specifications will not be acceptable and shall be replaced and re-inspected at Contractor's expense until the requirements of the specifications are met. All gauges and detectors shall be provided with calibration by the Contractor facilities subject to the approval of the Engineer. Paint Properties tests are to be conducted on final coated surface and shall comply with the following test. Test on protective coating to metal works shall be as given in Table G23 Table G23 -TEST ON PROTECTIVE COATINGS OF METAL WORKS Properties

Test Method

Minimum Test Requirements

1.

Dry film thickness

BS 3900

2.

Pull of adhesion strength Discontinuity (Holiday detection)

ASTM D 4541 / ISO 4624

Specified thickness for each coat 6N/mm2

3. 4.

Abrasion resistance

5.

Coating resistance to cracking (bend test)

National Association of corrosion Engineering standard recommended practice ASTM D 4060 BS 3900 : PG8 RG5

100% pin hole free 0.22gm weight loss in 1000 cycles Permeability–Nil Visible defects - Nil

CLEANUP A.

Upon completion of the work staging, scaffolding and containers shall be removed


Page G-52 of 68

from


Specifications

the site or destroyed in an approved manner. B.

Paint spots, oil or stains upon adjacent surfaces shall be removed.

PAINT AND COATING SCHEDULE A.

General 1.

The schedule here-in shall indicate the surface preparation and practice coating system to be used.

2.

The list shall not be construed as a complete list of surfaces to be coated, but

3. 4.

B.

rather as a guide as to the application of the various coating systems. All surfaces shall be painted except those specifically deleted herein. Where reference is made to ferrous metal in this schedule, it shall not include stainless steel or galvanized metals except as specified in paragraph C - Paint Schedule.

Painting Systems 1.

a.

On ferrous metal subject to corrosive moisture or atmosphere and condensation. Typical examples include the screening facility and grit dewatering facility.

b.

Surface Preparation: 1. All metal surfaces shall be sandblasted near White Blast Cleaning using proper abrasive size to achieve 35 to 40 micron anchor pattern. 2. Weld surface, edges and sharp corners shall be ground to a curve and all weld splatter removed.

c.

Coating: 1.

Shall be applied by airless spray or by brush for small areas.

2.

Coating Thickness:

Minimum Dry Film Thickness 50 microns

Primer

Intermediate Coat Finish Coat d.


Component or

as specified in Table 7-25

200 microns or


50 microns

or


Time Between Coatings: 1. A minimum of 12 hours time is required before additional coats are applied to the prime coat. 2. Two hours for the intermediate coat 3. Two hours for the finish coat

Page G-53 of 68


2.

Specifications

a.

On ferrous metals subject to normal indoor or outdoor exposure, except as specified for buildings and not subject to chemical attack.

b.

Surface Preparation: 1.

All surfaces shall be free of dirt, dust, grease or other foreign matter before coating. Surfaces shall be cleaned and, Brush off Blast Cleaning. Weld surfaces and rough edges shall be ground and weld splatter removed.

2. 3.

c.

Coating: 1. 2.

3.

Application shall be in strict conformance with the manufacturer's recommendations. All sharp edges, nuts, bolts or other items difficult to coat shall receive a brush-applied coat of the specified coating prior to application each coat.

Coating Thickness: Minimum Dry Film Thickness

d.

a.

b.

Primer Intermediate Coat

50 micro

or as specified in Table 7 – 25 200 microns or as specified in Table 7 – 25

Finish Coat

50 microns or as specified in Table 7 - 25

Time Between Coatings 1.

3.

Component

As stated in B1 (d) above

On ferrous metals submerged or intermittently submerged in water or corrosive liquid. Typical examples include the primary settling tanks and aeration tanks. Surface Preparation: 1.

c.

All metal surfaces shall be sandblasted with near White Blast Cleaning using proper abrasive to achieve 50 to 75 microns anchor pattern. 2. Weld surface, edges and sharp comers shall be ground to a curve and all weld splatter removed and welds neutralized with thinner. Coating: 1.


Application shall be in strict conformance with the manufacturer's recommendations.

Page G-54 of 68


Specifications

2.

3.

All sharp edges, nuts, bolts or other items difficult to coat shall receive a brush-applied coat of the specified coating prior to application of each coat. Coating Thickness: Minimum Dry Film Thickness Primer Finish Coat

d.

Component

50 microns

or as specified in Table 7 – 25 250 microns or as specified in Table 7 - 25

Time between Coatings: 3. As stated in B1 (d) above

4.

a.

For exterior galvanized steel including the operating platform, handrail, piping etc. Surface Preparation:

b.

1. 2. c.

Coating: 1.

d.

Given in schedule of protection system for metal surface.

Time Between Coatings: 1.

C.

Galvanized surfaces shall be washed with solvent thinner as recommended by the paint manufacturer. Use power tool cleaning to remove insoluble contaminants.

As stated in B1 (d) above

Paint Schedule 1.

General a.

The coating system to be used is specified here-in the schedule of protection system for metal surface.

b.

All surfaces shall be painted except those specified in paragraph 1.01.

c. The Engineer shall select the colours. 2.

Process Piping Colour Code a.

3.

As specified in “Mechanical Identification".

Equipment Colour Code a. All plant and equipment shall be painted to the colours detailed below or equivalent RAL colours unless otherwise instructed by the Engineer.


Page G-55 of 68


Specifications

Item

D.

BS 4800

Colour Description

Base-plates and mounting stools handrails, walkways & steel supporting structures

} } }

00 A 05

Light Grey

Screw pumps Non Potable Water Tanks

} }

00 E 53

Black Light Green

Coupling & Fly wheels Drive Shafting Valve hand-wheels Lifting equipment, including rails beams, Bogies, gantry girders crab, block and control cabin

} } } } } }

04 E 53

Red

Pumps Gearboxes

} }

08 E 51

Mid Yellow

Transformers Control, switchgear, distribution & mimic panels

} } }

18 E 51

Sky Blue

Motors Alternators All other exposed metalwork

} } }

Shafts and coupling guards Aluminium or GRP hand railing

} }

18 E 53

Mid Blue

Self Colour

General Coating System 1. The following list shall indicate the coating system. 2.

Piping shall be defined as all pipe, valves, fittings, supports, operating systems

3.

and guides. Mechanical equipment shall include all drives, motor control panels, and all other electrical equipment requiring a protective coating.

4

The colours of other surface shall be selected by the Engineer. Item

System

•

aPump Station Wet Wells and Sewage and .Sludge Treatment Equipment:

As specified in schedule of protective coating on metal works

•

All exposed mechanical equipment

• • •


All submerged mechanical equipment and piping b Pump Station Dry Wells and Motor Rooms: . All mechanical equipment and piping

Page G-56 of 68

Colour

* ..

Black

..

*


Specifications

•

c Offices/Store/Workshops: .

..

•

All exposed metal

..

*

..

*

• • •

d Miscellaneous: . All miscellaneous interior exposed metal surfaces All miscellaneous exterior exposed

..

*

metal surfaces •

All submerged metal surfaces

..

Black

* 5.

Colour per equipment or pipe color code schedules. All structural steel shall be hot-dip Galvanised in accordance with BS729 and to be painted as per the schedule of protection system after applied paint manufacturer’s particulars recommended wash primer.

SCHEDULE OF SURFACE PREPARATIONS ON FERROUS & NONFERROUS METALS & PLASTICS System

Description

Surface Preparation

(a)

Degreasing

Shop cleaning to remove group 1 contaminants in accordance with the approved standard.

(b)

Blast Cleaning

The surface shall be shot or grit blasted to remove all rust, mill scale, in accordance with the approved standard first quality finish for steel, second quality finish for cast iron. Blasting materials shall be free of deleterious substances.

(c)

Fettling

The surface shall be cleaned to remove all scale, rust, etc., by hand cleaning using a powered wire brush or other approved method.

(d)

Site cleaning

Immediately before site painting all dirt, oil or grease shall be removed from the surface with white spirit or other approved solvent.

(e)

Wire wool or Abrasive cloth

On site preparation to provide key for primers and undercoats.

(f)

Polish and /or Anodise

Shop treatment for aluminium.

Sweep Blast

Site preparation for galvanized areas.

(g)


Page G-57 of 68


(h)

Specifications

Spot Blast cleaning

Welded spot shall be spot blast cleaned to Sa 2½ to remove the accumulated dirt & welding resounds.

(i)

Pickling (stainless steel)

The passive layer on the welded parts of stainless steel shall be removed & restored by pickling prickling the metal in a tank and then treating it with passivating solution.

(j)

Electro Chemical Polishing (Stainless steel)

Electrolyte bath to produce a homogeneously polished surface with a dirt repelling effect.

SCHEDULE OF PROTECTIVE COATINGS ON FERROUS & NONFERROUS METALS System

Description

P1

Zinc metallisation or zinc spray to the approved standard. Or thicker metallic zinc coating

P2

Sealer primer to follow hot dip galvanising.

P3

Etch primer or wash Primer to follow zinc spray.

P4

Micaceous Iron Oxide Paint containing not less than 80% iron oxide and not more than 5% anti-settling agent.

P5

Alkyd Resin base undercoat

P6

Alkyd Resin base gloss finish paint

P7

Zinc Chromate primer with 85% zinc on dry film

P8

Epoxy or Polyester prefabrication primer

P9

Epoxy Zinc phosphate submersible primer

P10

High build Polyamine based Epoxy or Polyester airless spray coating

P11

Approved nylon, PVC or other synthetic dip or spray applied coating.

P12

Hand wrapping with hydrocarbon paste, mastic, Denso PVC tape and Insulation

P13

Polyurethane tie coat for non ferrous substrate

P14

Polyurethane based coating for ferrous and non-ferrous metal

P15

Acrylic urethane based finish coat

P16

High alumina fibre cement mortar lining to specified thickness.

P17

Air drying modified polysiloxane resin based coating to withstand 250°C. temperature


Page G-58 of 68


Specifications

P18

Fusion bonded Epoxy

P19

High build Epoxy aluminium primer/build coat.

P20

Vinyl ester based primer

P21

Glass flake vinyl ester

P22

Zinc Phosphate Primer Epoxy for ferrous substrate

P23

Modified Epoxy

P24

Epoxy high build MIO (for Galvanized)

P25

Special Red oxide Primer for non-ferrous areas.

P26

Polyethylene Sleeve / Thermal Insulation

P27

Anti Slip Deck Coat (3mm thick)

P28

Sprayed aluminium

P29

High build Epoxy for Potable water resistant

Notes: (1)

For manufactured items all cutting and drilling shall be completed before application of any of the surface treatment specified.

(2)

All paint systems shall achieve a minimum dry film thickness (dft) of 300 and a maximum of 500 micron unless otherwise stated separately. The number of coatings to achieve this thickness may vary according to method and time of application.

(3)

Epoxy/polyester coatings must be applied by airless spray of electrostatic charging of particles and stoving.

(4)

Freedom from pin holes shall be established by a spark tester or such other means recommended by the coating applicators/manufacturer. Such equipment shall be provided and maintained by the contractor and be available at all times for the sole use of the engineer.

(5)

Hot dip Galvanizing shall be as specified.


Page G-59 of 68


Table G24-

SCHEDULE OF PROTECTION SYSTEMS ON FERROUS & NON- FERROUS METALS [A]

No.

1.

Specifications

Substrate

INTERNAL SURFACES Environment

Ductile Iron



Cast Iron



Carbon Steel

Ditto



Mild Steel

Ditto



Ductile Iron

 

Cast Iron Carbon Steel

Ditto Ditto

Ditto Ditto



Mild Steel

Ditto

Ditto

(b) Partially submerged in sewage or in contact with sewage vapours



Pipes & fittings

Preparation in Shop




(a) Fully submerged in Sewage or in contact with Sewage vapours

Typical Application

Ditto



(a) & (b)

Shop Coatings 1st,2nd,3rd,4th,5th

P1, P16, P10, P10

Shop coating thickness in microns

Preparation on Site

1st 100

2nd 4mm*

3rd 100

4th 100

5th (d) & (e)

Site Coating System

1st P10

2nd P10

P10

P10

3rd

Total Coating thickness including Primer microns 4300

Ditto

P1,P9,P10,P10

100

50

100

100

"

Ditto

P1,P9,P10,P10

100

50

100

100

"

Ditto

P1,P9,P10,P10

100

50

100

100

"

P10 P10

P10 P10

350

P1,P16,P10,P15

100

4mm*

150

50

"

P10

P15

4300

P1,P3, P10,P15

100

50

150

50

"

P10

P15

350

P1,P3, P10,P15 P1,P3, P10,P15

100 100

50 50

150 150

50 50

" "

P10 P10

P15 P15

350 350

Pipes & Fittings

Page G-60 of 68

350

350


No.

2.

Substrate

Specifications

Environment

Typical Application

(c) Submerged Potable /effluent water





(a) & (b)

P1,P16,P10,P10

100

4mm*

100

100

"

4300

P1,P9,P29,P29

50

50

125

125

"

350

P1,P9,P29,P29 P1,P9,P29,P29

50 50

50 50

125 125

125 125

"

350 350

(a) & (b)

P22,P16,P10

50

4mm*

125

P22,P29,P29

50

125

125

P22,P29,P29 P22,P29,P29

50 50

125 125

125 125

P22,P16,P10,P2 9

100

4mm*

100

P9,P29,P29

50

125

P9,P29,P29 P9,P29,P29

50 50

125 125



Ductile Iron

 


Ditto Ditto

Ditto Ditto



Mild Steel

Ditto

Ditto



Ductile Iron

 


Ditto Ditto

Ditto Ditto



Mild Steel

Ditto

Ditto



Ductile Iron

 


Ditto Ditto

Ditto Ditto



Mild Steel

Ditto

Ditto

Stainless Steel GR: 316L/GR304

(d) Exposed to ambient conditions

(e) Buried under the ground






Exposed to ambient conditions Buried under the ground



Pipes & Fitting

Preparation in Shop

Pipes & fitting

Pipes & Fittings



Hot water pipes

(a) & (b)

No Coating Internal No Coating Internal

Page G-61 of 68

Preparation on Site

"

Site Coating System

Total Coating thickness including Primer

P10

P10

4175

P29

P29

300

" "

P29 P29

P29 P29

300 300

(d) & (e)

P29

4300

125

Ditto

P29

300

125 125

Ditto Ditto

P29 P29

300 300

100


Specifications

No.

Substrate

Environment

Typical Application

3.

Galvanised Metals

(a) Exposed to ambient conditions



Ductile Iron

Ditto

 


Ditto Ditto

 

Mild Steel Galvanised Iron

Ditto Ditto (b) Buried under Ground

Ductile Iron Cast Iron Carbon Steel

Ditto Ditto Ditto

Mild Steel Galvanised Iron Thermo Plastics & Thermo Set Plastics in uPVC/GRP/ GRE

Ditto Ditto

  4.





P3,P22,P16, P10, P15 P3,P22,P24,P15

10

50

10

P3,P22,P24,P15 P3,P22,P24,P15

Pipes & fittings

150

50

4m m* 150

10 10

50 50

150 150

100 100

P3,P22,P24,P15

10

50

150

100

P3,P22,P23,P23 P3,P22,P23,P23

10 10

75 75

125 125

100 100

P3,P22,P23,P23 P3,P22,P23,P23

10 10

75 75

125 125

100 100

P3,P22,P23,P23 No Coating required Internal

10

75

125

100

* 4 mm thick cement mortar lining


Preparation on Site

Site Coating System

Total Coating thickness including Primer

(g)

P15

4310

" "

P15

310

P15 P15

310 310

P15

310

P23 P23

310 310

"

P23 P23

310 310

"

P23

310

Pipes & fittings



  

Preparation in Shop

Page G-62 of 68

100

100

" "

" " "


Table G25-

SCHEDULE OF PROTECTION SYSTEMS ON FERROUS, NON- FERROUS METALS & PLASTICS [B]

No.

1.

Substrate

Ferrous Metals  Ductile Iron

Specifications

EXTERNAL SURFACES

Environment

(a) Fully submerged in sewage or in contact with sewage vapours

Typical Application

 

Mechanical Equipment Pipe work **

Preparation in Shop

Shop Coatings 1st,2nd,3rd,4th,5t h

Preparation on site Shop coating thickness Unit (microns) 1st 2nd 3rd 4th

Preparation on Site

Site Coating System 1st

2nd

3rd

Total Coating thickness

(a) (b) & h

P20,P21,P21

50

750

750

(d)

(e)

(g)

P20

P21

1550micro ns

(a) (b) & h

P20,P21,P21

50

750

750

(d)

(e)

(g)

P20

P21

1550micro ns 1550micro ns 1550micro ns 1550micro ns



Carbon Steel



Ditto

P20,P21,P21

50

750

750

(d)

(e)

(g)

P20

P21



Structural Steel Mild Steel

Ditto

P20,P21,P21

50

750

750

(d)

(e)

(g)

P20

P21



Cast Iron

Ditto

P20,P21,P21

50

750

750

(d)

(e)

(g)

P20

P21



Ditto

P22,P4,P15, P15

75

125

50

50

(d)

(e)

(g)

P4

P15

300 microns

P22,P4,P15, P15 P22,P4,P15, P15

75

125

50

50

(d)

(e)

(g)

P4

P15

75

125

50

50

(d)

(e)

(g)

P4

P15

300 microns 300 microns

(d)

(e)

(g)

P14

P14

(d)

(e)

(g)

P4

P15

(b) Exposed to Ambient Conditions


*Mechanical equipments ** Pipe works

(a) (b) & h "



Valves

"



Gratings

"

P22,P14,P14

75

250

250



Handrails

"

P22,P4,P15,P1 5

75

125

50

Page G-63 of 68

50

575 microns 300microns


No. * **

Substrate

Environment

Specifications

Typical Application

Preparation on site Shop Preparation on Site coating thickness h Unit (microns) Mechanical equipment shall include all drives, motor control Panel and all other electrical equipment requiring a Protective Coating. Pipe work shall include all Pipes, Valves, fittings, supports operating system and guides  M.S.Pipe " P7,P3,P5,P6 100 10 100 100 (e) (g) Protection Barrier  Plat forms " P22,P14,P14 75 250 250 (d) (e) (g)  

 2.

3

Ditto Ditto

Galvanised Metals

(c) Buried under the ground



Fully submerged in effluent /Potable water








MH & PSTN Covers Pipe work to with stand temperature up to 250°C Pipe works

"

Mechanical equipment Pipe works Galvanised steel gratings

 G.I multispan covers  G.I Panel support frames  Galvanised electric light poles  G. I. Pipes


Preparation in Shop

Shop Coatings 1st,2nd,3rd,4th,5t

75

200

200

"

P9,P10,P10, P15 P7,P17,P17

25

75

"

P22,P23,P23

75

(a) (b) & h

P9,P29,P29

Ditto

P5

P6

310microns

P14

P14

P10

P15

575 microns 525microns

(e)

50

(d)

(e)

125

125

(d)

(e)

(g)

P23

P23

125

125

125

(d)

(e)

(g)

P29

P29

P9,P29,P29

125

125

125

(d)

(e)

(g)

P29

P29

(g)

P3,P24,P14, P14

10

100

250

250

(d)

(e)

(g)

P14

P14

(g)

P3,P24,P24, P14 P3,P24,P5,24 P15

10

100

250

250

(d)

(e)

(g)

P14

P14

10

100

100

100

P15

P15

P3,P24,P24,P1 5, P15 (clear) P3,P24,P24, P15,P15

10

100

100

50, 50

(d)

(e)

(g)

P15

P15

310 micron

10

100

100

50, 50

(d)

(e)

(g)

P12

P12 Insula tion

310 microns

(g) (g)

Page G-64 of 68

(g)


(d)

(g)

50

Site Coating System

P17

150 microns P12

325 microns 375 microns 375 microns 610 microns



No.

4.

Substrate

Non- Ferrous metal. Stainless steel GR 316L/304

Ditto

Environment

Specifications

Typical Application

(b) Buried under the ground

G. I. pipes

(a) Fully submerged in sewage or in contact with sewage vapours



Pipe works

(b) Exposed to ambient conditions



Pipe works carrying hot water up to 50°C Ditto above 50°C to 120°C



 

Ditto

Ditto 5.

Aluminium


P3,P24,P23, P23

Preparation on Site (d)

(e)

(g)

Site Coating System P23

P23

50

500

500

(e)

(g)

P21

P21

"

P25,P15,P15

50

50

100

(e)

(g)

P15

P15

"

P25,P28

50

100

(e)

(g)

Covers & platforms Handrails

"

P25,P14,P14

50

250

250

(e)

(g)

P14

P14

"

"

No coating external & internal (Natural Finish) P25,P29,P29

50

125

125

(e)

(g)

P29

P29

"

P25,P29,P29

50

125

125

"

"

P29

P29

"

P25,P23,P23

50

125

125

"

"

P23

P23

(g) & (f)

P25,P15,P15

50

50

50

(d)

(e)

P15

P15

 

Mechanical equipment Pipe works

(d) Buried under the ground



Pipe works

Exposed to ambient conditions



covers

(e) & g , (h) (i)(j)

Preparation on site Shop coating thickness Unit (microns) 10 100 100 100

P25,P21,P21

(c) Fully submersed in effluent/Pota ble water


Preparation in Shop

Page G-65 of 68

Total Coating thickness 310 microns

1050 microns

P12 Insul ation

200 microns

P12 Insul ation


300 microns 300 microns 300 microns P12 Insul ation

150 microns


No.

6.

Substrate

Thermo Plastics UPVC/P.P/ HDPE

Environment


Specifications

Typical Application



pipe works

Preparation in Shop (d) & (e)

(b) Buried under the ground 7

Thermo Setting Plastics (GRP/GRE)


Preparation on site Shop coating thickness Unit (microns)

Preparation on Site

Site Coating System

P25,P15,P15

50

50

50

(d)

(e)

P15

P15

150 microns

h


No Coating Required 

Odour Control GRP Duct Pipes & fittings

(d) & (e)

P25,P15,P15

50

50

50

(d)

(e)

P15

P15

150 microns

GRP Pipes and fittings for water distribution Type ‘A’ covers on Odour Control units

(d) & (e)

P25,P15,P15

50

50

50

(d)

(e)

P15

P15

150 microns

(d) & (e)

Type ‘B’ cover on Odour Control Unit

(d) & (e)

Cover manufacturer’s recommended protective coating system resistant to corrosion & U.V Cover manufacturers recommended protective coating system resistant to corrosion , Non slip and U.V resistant

GRP

"



GRP

(b) GRP Dome shaped smooth finish non pedestrian trafficable covers



GRP



GRP Non Slip pedestrian trafficable covers




Shop Coatings 1st,2nd,3rd,4th,5t

Page G-66 of 68


No.

Substrate GRP

GRP

GRE

Environment GRP Non Slip Pedestrian trafficable covers with chequer plate wearing surface  GRP Chemical Storage tanks / GRP potable water storage tanks (c) Potable Water Pipes exposed to ambient conditions for fire fighting 

Specifications

Typical Application

Preparation in Shop


Preparation on site Shop coating thickness Unit (microns)

Preparation on Site

Site Coating System




Type ‘C’ covers on odour Control Units

(d) & (e)

Cover manufacturer’s recommended protective coating



Tanks external & related fittings

(d) & (e)

P25,P15,P15

50

50

50

(d)

(e)

P15

P15

150 microns



Tanks pipes & Fittings external surfaces

(d) & (e)

P25,P15,P15 P25,P15,P15

50 50

50 50

50 50

(d) (d)

(e) (e)

P15 P15

P15 P15

150microns 150microns

Note: (1) Final Coat protective coating on exposed surfaces of all GRP, GRE items Multi Colour Shades for beautification purposes will be selected by Dubai Municipality Architect / Engineer at site. (2) All structural steel items are to be hot dip galvanised to a minimum thickness of 140 microns. (3) Colour shades of the metal works should match with relevant structures concrete paint system or as decided by the Engineer/Architect. (4) All buried ferrous and non ferrous metal painted pipes & fittings shall be protected further with any one of the Protection wrapping system specified in CL.7.2.5.4 on top of Protective Coating specified. (5) All S.S bolts, nuts & washers are to be removed from the fittings before to apply paints and rectified after painting. (6) All S.S bolted fitting, buried under the ground shall be protected with approved insulation system specified.


Page G-67 of 68


Specifications

G.3.5 Protective Wrapping Tapes and Sleeve on Buried Pipes and Fittings Buried ferrous and stainless steel pipelines, joints, valves and other fittings shall be protected either by wrapping with adhesive tape, synthetic resin or plastic tape or plastic sleeves. When applying wrapping tape an overlap of at least half the width of the tape for pipes up to 300 mm dia is required. Adhesive Tape Adhesive tape shall be either a synthetic fibre or glass cloth impregnated with a mixture of petroleum jelly and neutral mineral filler. When used for above ground pipes these tapes shall be protected by a bituminous tape. Synthetic Resin or Plastic Tape Synthetic Resin or Plastic Tape shall be PVC or black polyethylene strips 250 micron thick with fabric core coated one side with a compact adhesive normally of synthetic rubber base. Two-Pack Taping Two-pack taping system shall be woven glass tape or sheet form impregnated with a two pack solventless composition of polyester or epoxy. The surface to be protected should first be cleaned and primed to receive the with two pack epoxy. It should then be wrapped with glass cloth in tape form with polyester or epoxy. A thin coat of impregnating tape and then reinforcing substrate are applied. Several layers are be built up and the final layer shall be trowelled smooth. The coating should set to a hard glass like protective coating which is impermeable to water G.3.6 Plastic Sleeves Plastic sleeve shall be a black colour high density polyethylene 250 micron thick which shall be used as a protective sleeve on pipes. The sleeving is to be applied at the time of laying the pipe and joints are taped with adhesive tape. G.3.7 Hot Dip Galvanising Hot dip galvanised coating on iron and steel articles shall be carried out in accordance with the requirements of BS 729:1971. The minimum average coating thickness shall be 140 microns (equivalent to 720-1000g/m2).The coating operation shall consist of dipping the steel parts into a molten Zinc bath at a temperature of 450°C. After completion of the dipping further treatment comprising of degreasing, pickling, rinsing, fluxing and drying shall be carried out separately. G.3.8 Water Level Marking Paint The paint shall be a thermoplastic non-toxic ‘WRAS APPROVED’ product suitable for application by brush or airless spray, day light reflecting type acrylic paint with fluorescent pigments which give intense colour impression and high visibility. Suitable colour shades shall be as approved by the Engineer.


Page G-68 of 68


Specifications

CONTENTS Page No.

SECTION H - FITTINGS AND FABRICATED ITEMS H1

1

MATERIALS

1

H1.1

Aluminium Alloys

1

H1.2

Steel

1

H1.3

Stainless Steel

1

H1.4

RTR (Reinforced Thermosetting Resin)

2

H1.4.1

General RTR Requirements

2

H1.4.2

Manufacturing Standards

2

H1.4.3

Resins

2

H1.4.4

Curing

2

H1.4.5

Reinforcement

2

H1.4.6

Structural Design

3

H1.4.7

Moulds

3

H1.4.8

Fabrication

3

H1.4.9

Samples

4

H1.4.10

Tolerances for Moulded RTR

5

H1.4.11

Quality Control and Testing

5

H1.4.12

Visual Inspection

6

H1.4.13

Trial Erection

7

H1.5

RTR Liners for Pumping Stations and Manholes

7

H1.6

RTR Sealing Plates to Access Covers

8

H1.7

Valves and Penstocks - General Requirements

8

H1.8

Gate Valves for Water Supply

9

H1.9

Gate Valves for Sewage and Related Fluids

9

H1.10

Non Return Valves

10

H1.11

Valves for Gas Pipelines

10

H1.12

Cast Iron Butterfly (Disc) Valves

10

H1.13

Cast Iron Penstocks

11

H1.14

Plastic Composite Penstocks

11

H1.15

Cast Iron Flap Valves

11

H1.16

Plastic Flap Valves

12

H1.18

Underground Fire Hydrants

12

H1.19

Marking of Valves, Penstocks, and Hydrants

13

H1.20

Hydraulic or Pneumatic Actuators for Valves and Penstocks

13

H1.21

Electric Actuators for Valves and Penstocks

13

H1.22

Access Covers and Frames and Surface Boxes

14

H1.23

Access Gratings and Frames

14

H1.24

Ladders

15

H1.25

Staircases

15

H1.26

Open Mesh and Chequer Plate Flooring

16

H1.27

Hand railing

16


Page i of ii


H2

Specifications

H1.27.1

General

16

H1.27.2

Aluminium Alloy Hand railing

16

H1.27.3

RTR Hand railing

17

H1.28

Safety Chains, Safety Ropes and Fittings

17

H1.29

Nuts, Bolts, Screws, Washers and Grommets

17

H1.30

Fixing Bolts and Building-in Material

18

H1.31

Step Irons

18

H1.32

Hand Blocks

18

H1.33

Weirs

18

H1.34 Glass Reinforced, Hot Pressed, Sheet Moulding Compound Potable Water Tank

18

H1.35

GRP Baffles

23

H1.35

Glass Reinforced Plastic Tanks for Chemical Storage

23

INSTALLATION

29

H2.1

Installation of Access Covers and Surface Boxes

29

H2.2

Fixing Metalwork and Machinery

29

H2.3

Installation of RTR Manhole and Pumping Station Liners

30

H2.4

Cutting and Sealing of RTR (Reinforced Thermosetting Resin)

30

H2.5

Installation of Lifting Equipment

30

H2.6

Fixing of Weir Plates

31


Page ii of ii


Specifications

SECTION H - FITTINGS AND FABRICATED ITEMS H1

MATERIALS

H1.1

Aluminium Alloys Aluminium alloys shall be selected as having properties appropriate to the duty of the unit, the method of fabrication and the environmental conditions. Unless otherwise specified or detailed, alloys of the following ISO designations shall be used (ref. BS EN485 and 573): For Castings

For Wrought Items

A1 Si7 Mg

Al Mg 4.5 Mn

or

or

A1 Si12

Al Si1 Mg Mn

Alternative alloys may be proposed by the Contractor if the manufacturer considers its properties more appropriate to the application or the environmental or physical conditions. Construction in aluminium shall be to the recommendations of BS 8118. H1.2

Steel Steelwork shall comply with the approved international standard (refer to Section S and unless otherwise specified by reference to Section G shall be supplied by the manufacturer with a zinc dipped coating.

H1.3

Stainless Steel Unless otherwise specified or approved by the Engineer all supply items specified and manufactured in stainless steel shall be to BS 970 as follows: Percentage Chemical Composition Fabrication Technique:

Welded

Cold Fabrication

Classification:

316S12

316S16

Carbon Silicon Manganese Nickel Chromium Molybdenum Sulphur Phosphorous

% min. 0.2 0.5 11.0 16.5 2.25 -

% max. 0.03 1.0 2.0 14.0 18.5 3.0 0.03 0.045

% min. 0.2 0.5 10.0 16.5 2.25 -

% max. 0.07 1.0 2.0 13.0 18.5 3.0 0.03 0.045

Alternative higher grade stainless steel may be proposed by the Contractor if the manufacturer considers its properties more appropriate to the environmental or physical conditions.


Page H-1 of 31


Specifications

H1.4

RTR (Reinforced Thermosetting Resin)

H1.4.1

General RTR Requirements This clause applies to all RTR items except machine made pipes, the requirements for which are stated in Section E of this Specification. RTR (Reinforced Thermosetting Resin) shall be as follows:

H1.4.2

Manufacturing Standards The specification for design, materials, construction, inspection and testing of RTR laminates shall conform to the appropriate sections of the BS 4994.

H1.4.3

H1.4.4

Resins (a)

Isophthalic, Terephthalic and Bisphenol Polyester resins complying with BS 3532 or Vinyl Ester resins may be used. The resins used shall have a minimum strain to failure of fully cured cast resin of 3% and a minimum heat distortion temperature of 65°C.

(b)

Pigments or fire retardant resins (or fillers) shall only be used when specified or ordered in writing.

(c)

Additives shall not be included in the resins unless they are required for viscosity control.

(d)

Due attention must be paid to preclude the possibility of air inhibition occurring on the laminate surfaces. The inclusion of paraffin wax or similar additives must be in accordance with the resin supplier's recommendations.

(e)

Where protection against Ultra Violet light degradation is provided, it shall be achieved by including a translucent UV inhibitor in the outer layers of the laminate.

Curing Curing systems shall be in accordance with the resin manufacturer's recommendations. The manufacturer of the laminate shall demonstrate that the laminate has been adequately cured prior to its acceptance at the laminator's works.

H1.4.5

Reinforcement (a)

‘E’ type glass chopped strand mat reinforcement shall be to BS 3496 and shall be of 1st grade quality to a maximum unit weight of 600 gm/m2.

(b)

‘E’ type glass woven roving fabrics shall be to BS 3749 and shall be to a maximum unit weight of 800 gm/m2.

(c)

‘C’ type glass veil (or synthetic fabric veil where approved by the Engineer) shall be used to reinforce all internal and external surface resin layers on laminates.

(d)

Use of high acid resistant glass fibre reinforcement will also be permitted.


Page H-2 of 31


H1.4.6

Specifications

Structural Design (a)

The laminate shall be designed to withstand all the loadings normally carried by the laminates during service and any abnormal loads arising during handling and erection of the finished item. Full details of the proposed laminate construction shall be submitted to the Engineer for approval.

(b)

Under the worst combination of loading conditions, a maximum design strain of 0.2% shall be permitted in the laminate.

(c)

Except where otherwise specified for particular fabricated items, a minimum laminate thickness of 4 mm shall be maintained at all points including the facings over and under stiffener sections.

(d)

Stiffener sections may be used to increase the rigidity of a structure. The minimum glass reinforcement content shall be 1.8 kg/m2 in these areas. Stiffener sections may be manufactured from the following materials. (1)

Polyurethane Foam

(2)

Marine Plywood

(3)

Other material agreed to in writing by the Engineer.

Stiffener sections shall not be made from steel or other metal sections unless written consent has been previously obtained from the Engineer. H1.4.7

Moulds Moulds shall be of adequate rigidity to retain dimensional stability and permit a high level of laminate consolidation. The mould surfaces shall be of a quality which will ensure maintenance of the previously approved surface finish throughout the full extent of the Contract.

H1.4.8

Fabrication Manufacture shall be by approved mechanical methods or by hand lay-up processes. If deposition of resin by gun is used, this must be carried out by airless spray technique. (a)

Unless otherwise specified all laminate surfaces which may be exposed to chemical attack shall include a corrosion resistant finish which shall comprise a veil reinforced surface layer and a backing layer and shall have a minimum overall thickness of 1.5 mm. A veil reinforced surface layer shall be provided on all other surfaces. Veil reinforced surface layers shall be approximately 90% resin by weight and between 0.25 mm and 0.50 mm thick. Backing layers shall normally be reinforced with chopped strand mat and shall have a resin content of between 65% and 75% by weight.

(b)


Where un-reinforced gel coats to moulded surfaces are specified they shall have a maximum nominal thickness of 0.5 mm and shall be of a suitably resilient gel coat system.

Page H-3 of 31


Specifications

Where un-reinforced gel coats to non-moulded surfaces (top coats) are specified they shall be fully brushed out to remove resin rich areas. The top coat shall not exceed 0.3 mm in thickness.

H1.4.9

(c)

Chopped strand mat layers in the structural laminate shall have a resin content of between 55% and 70% by weight.

(d)

Woven roving glass fabric layers in the structural laminate shall have a resin content of between 40% and 50% by weight.

(e)

Where edges of laminates are cut or exposed they shall be sealed with a continuous layer of fully cured resin. The resin shall be the same as or superior to the resin used for the structural laminate.

(f)

Where protective bisphenol or vinyl ester internal linings are used in conjunction with isophthalic or terephthalic structural laminates, these linings shall be allowed to harden sufficiently before the structural laminate is applied to prevent movement of the lining layers.

Samples (a)

A sample measuring 500 mm square and typical of each different laminate proposed shall be submitted for approval together with a detailed descriptive specification at least 4 weeks prior to the commencement of manufacture.

(b)

Production samples measuring 300 mm square and typical of each different section of laminate shall be submitted to the Engineer or his duly authorised Inspecting Engineer throughout the period of manufacture for the purpose of testing. The rate of sampling shall be one sample per 20 square metres of production laminate unless otherwise agreed by the Engineer.

(c)

Samples of liquid and cast resin together with reinforcements and surfacing veils (or fabrics) required to manufacture the samples indicated in (b) above shall also be made available to the Engineer on request.


Page H-4 of 31


H1.4.10

Specifications

Tolerances for Moulded RTR Tolerances in thickness shall be in accordance with the following table (ref. BS 4549 Part 1): Nominal Thickness mm

H1.4.11

Open Mould mm

Closed Mould mm

Up to but not including 1.5

+0.50 -0.25

+0.20

Matched Metal Mouldings mm +0.18

1.5 to but not including 3

+0.75

+0.30

+0.20

3 to but not including 6

+1.1

+0.50

+0.30


+1.5

+0.75

+0.40


+2.0

+1.4

+0.50

25 and over

+3.0

+1.9

+0.65

Quality Control and Testing Testing, inspection and quality control shall be carried out generally in accordance with BS 2782. In particular: (a)

(1)

The laminate shall be fully cured and shall show full resistance to a commercial acetone sensitivity test.

(2)

The laminate shall give Barcol Hardness of at least 90% of the resin manufacturer’s recommendations. The measurement of hardness by means of a Barcol Impressor shall be carried out in accordance with the approved Standard.

(b)

Resin burn off tests shall be performed on cut-outs for man-ways or other apertures. Where no such cut-out exists the Engineer reserves the right to have 50 mm diameter cut-outs for checks to be made on local glass reinforcement content; the laminate shall then be repaired by the manufacturer. The tests shall be conducted in accordance with the BS 2782 Part 10 Method 1002, except that the result shall define glass content.

(c)

Where directed by the Engineer the following strengths of the laminate shall be determined:


(1)

Ultimate tensile unit strength, lap shear strength and extensibility in accordance with Appendix C6 BS 4994

(2)

Flexural strength in accordance with BS 2782 Part 10 Method 1005.

(3)

Where a laminate has been designed to take bolts in the make up of the structure, tests for bolt bearing strength shall be performed in accordance with BS 4549 Part I Appendix C.

(4)

Where a laminate is to be used in conjunction with electrical control equipment, electrical strength and insulation resistance tests in accordance with BS 2782 Part 2 may be called for.

Page H-5 of 31


(e)

Specifications

Additional tests may be called for at the discretion of the Engineer.

All the tests referenced in (a) to (f) above shall be witnessed unless waived in writing by the Engineer. Test Certificates shall be obtained from the resin supplier for the following properties of the resin when cured as proposed for the laminate manufacturing procedure:

H1.4.12

(i)

Heat distortion temperature.

(ii)

Barcol hardness.

(iii)

Extension to failure of fully cured un-reinforced resin.

(iv)

From the glass reinforcement manufacturer for all the different grades and types of glass employed in the fabrication of the laminate.

Visual Inspection All RTR items will be subject to visual inspection at any time and shall meet the following requirements. For the purpose of this sub-clause, a “corrosion resistant surface” is one with a corrosion resistant lining as described in H1.4.8 (a). (a)

Surface finish There shall be no crazing of gel coats or resin rich layers. Resin dry areas not exceeding 6mm diameter on moulded and corrosion resistant surfaces may be accepted if made good. Not more than 0.5% of the surface area shall be so affected. There shall be no resin dry areas on other surfaces after repair.

(b)

Scratches Scratches not exceeding 0.2 mm deep to moulded and corrosion resistant surfaces may be accepted without repair provided that no glass fibres are exposed. Scratches exceeding 0.2 mm deep but not exceeding 0.5 mm deep may be accepted if satisfactorily made good. The total extent of scratching shall not exceed 200 mm length per m2 surface area. Alternatively, where small scratches are grouped together, the affected area shall not exceed 1% of the surface area. Scratches to other surfaces may be repaired provided that the structural integrity of the laminate is not impaired.

(c)

Cracks For moulded and corrosion resistant surfaces there shall be no cracks of depth greater than 0.5 mm or of sufficient depth to expose glass fibres. Cracks up to 0.5 mm depth not exposing glass fibres and not exceeding 200 mm in length may be accepted after repair but such cracks shall not be present to an extent greater than 1 crack per 5 m2 of surface area. Cracks not exceeding 200 mm in length to other surfaces may be repaired provided that the structural integrity of the laminate is not impaired.


Page H-6 of 31


Specifications

“Star cracks” may be accepted after repair if the cracks are contained within a circle of 100 mm diameter and a maximum of 0.2% of the area of any one moulding is affected. (d)

Voids Voids (or blisters) at moulded and corrosion resistant surfaces may be repaired if not greater than 2 mm diameter and 1 mm depth provided that the voids occur in discrete clusters and the sum of the areas of discrete clusters does not exceed 0.5% of the total moulding area. Voids to other surfaces may be repaired if they do not extend to more than 20% of the laminate thickness and not more than 3% of the surface area is affected.

(e)

Protuberances There shall be no fibres protruding from the surface of laminates. Wrinkles and undulations shall be gradual and the surface shall be continuous at such locations. Such defects shall be not greater than 3 mm in depth or a quarter of the laminate depth whichever is the smaller. Such defects shall not appear extensively on single mouldings and shall not be repeated through a production run.

(f)

Inclusions There shall be no visible inclusions of extraneous matter other than permitted fillers and aggregates.

(g)

Delamination There shall be no visible delamination.

H1.4.13

Trial Erection A sufficient proportion of the fabricated sections of the structure must be trial assembled to demonstrate the correctness of fit of the various sections.

H1.5

RTR Liners for Pumping Stations and Manholes RTR (reinforced thermosetting resin) liners for Pumping Stations and Manholes shall be manufactured to the dimensions given on the drawings, within the following tolerances: (i)

A manufacturing tolerance of 10 mm on the nominal diameter will be allowed provided that a tight fit is achieved between the liner and the slab liner.

(ii)

Liners shall be supplied in lengths to suit requirements.

(iii)

Minimum thickness shall be 6.5 mm.

(iv)

The out of squareness shall not be greater than 10 mm.

(v)

The deviation from straightness of the bore of the liner shall not exceed 20 mm.

Although the liners are not designed to be structural, they shall have a sufficient stiffness to withstand: (i)


Buckling or distortion in transit, storage or handling.

Page H-7 of 31


(ii)

Specifications

A hydrostatic head of 8 metres without distortion damage, leakage or permeation when installed.

All liners shall be clearly and indelibly labelled on both inside and outside surfaces showing (i)

Name of manufacturer

(ii)

Date of manufacture

(iii)

Nominal internal diameter

(iv)

Minimum thickness

The manufacturer shall provide shop drawings of proposed roof and reducing slab liners prior to manufacture for approval. The manufacturer shall stipulate the maximum deflection of the slab liner that can be permitted without causing surface cracking to the gel coat and the Contractor shall take care not to exceed this limit. H1.6

RTR Sealing Plates to Access Covers RTR (reinforced thermosetting resin) sealing plates to access covers shall be designed to be gas-tight when bolted in the frames. They shall have a minimum thickness of 4.5 mm and shall be capable of withstanding a static load of 150 kg applied centrally over a 150 mm square surface area with a deflection measured at the centre not exceeding 25 mm.

H1.7

Valves and Penstocks - General Requirements Valves shall be classified according to their pressure rating (maximum working pressure at 20oC) expressed in bars. Unless otherwise specified, all valves and penstocks shall be anti-clockwise opening and operated by hand wheel; the maximum effort required, applied at the circumference of the hand wheel, to operate the valves against the maximum unbalanced head shall not exceed 250 N. Unless otherwise detailed or approved all hand wheels shall be made of cast iron and shall have the words “open” and “close” in English and in Arabic with arrows indicating the direction of rotation cast on. Where “Operation by Tee Key” is specified the valve or penstock shall be supplied with a suitable yoke with a squared cast iron cap of standard size keyed to the valve spindle. Tee keys shall be galvanised and shall be sufficiently strong to withstand all operational loads without deformation. Valves and penstocks of all types shall be capable of withstanding corrosion in the ambient conditions and any parts manufactured from a material which is not itself corrosionresistant must be protected. Paint systems shall be as specified in Section G (Corrosion Protection and Surface Coatings) or as specified elsewhere for individual valves or penstocks. For sewage applications, nylon or other thermoplastic materials susceptible to attack from hydrogen sulphide shall not be used without the Engineer's approval. Works tests on valves greater than 300 mm nominal diameter will normally be witnessed. Works tests on other items will not normally be witnessed except where so specified or required by the Engineer. Before delivery to site all working surfaces shall be thoroughly cleaned, and, if metal, protected with grease. The initial charges of oil, grease and similar materials necessary


Page H-8 of 31


Specifications

for the correct setting to work and operation of valves and penstocks shall be provided by the Contractor. Packing must be sufficient to ensure the complete protection of fittings during transit and storage. H1.8

Gate Valves for Water Supply Gate valves shall be generally to BS 5150 or BS 5163 and unless higher pressure ratings are specified elsewhere, gate valves shall have a pressure rating of 10 bars. Flanges shall have a pressure rating of 16 bars and shall be drilled accordingly. Unless detailed otherwise, valve bodies shall be of cast iron, gates shall be of wedge pattern, and gate and body mating faces shall be of gunmetal. Stems shall be of stainless steel, aluminium bronze or high tensile brass and shall be non-rising unless otherwise detailed. Stem nuts shall be of aluminium bronze, high tensile brass, or gunmetal. Where resilient seal valves are detailed, the Specification shall be as above for metal faced valves except that the gate shall be of cast iron covered with a suitable resilient facing material. Valves greater than 300 mm in diameter which are to be actuator operated or fixed in a horizontal position shall be fitted with machined gunmetal shoes on the wedge working in machined gunmetal channels in the body. Valves greater than 300 mm in diameter shall be fitted with drain plugs. Indicators, hand wheels, caps for key operation, extension spindles, capstan headstocks, locking devices and other detailed requirements shall be provided as specified or shown on the drawings. All valves shall be ‘open end’ tested by an approved method and shall be watertight at the appropriate test pressure.

H1.9

Gate Valves for Sewage and Related Fluids Gate valves shall be generally to BS 5150 or BS 5163 and unless higher pressure ratings are specified elsewhere, gate valves shall have a pressure rating of 10 bars. Flanges shall have a pressure rating of 16 bars and shall be drilled accordingly. Valve bodies shall be of cast iron, gates shall be of wedge pattern, and gate and body mating faces shall be of gunmetal or aluminium bronze. Stems shall be of stainless steel, aluminium bronze, high tensile brass or gunmetal and shall be non-rising unless otherwise detailed. Stem nuts shall be of aluminium bronze, high tensile brass, or gunmetal. Valves shall not be fitted with resilient seals without the Engineer's written approval. Valves greater than 300 mm in diameter which are to be actuator operated or fixed in a horizontal position shall be fitted with machined gunmetal shoes on the wedge working in machined gunmetal channels in the body. Indicators, hand wheels, caps for key operation, extension spindles, capstan headstocks, locking devices and other detailed requirements shall be provided as specified or shown on the drawings. Valves greater than 300 mm in diameter shall be fitted with drain plugs. All valves shall be “open end” tested by an approved method and shall be watertight at the appropriate test pressure.


Page H-9 of 31


H1.10

Specifications

Non Return Valves Non-return valves shall be to BS 5153 and shall be of the single door swing check type. They shall have a pressure rating of 10 bars. Flanges shall be to BS 4504 with a pressure rating of 16 bars and shall be drilled accordingly. Valves shall be copper alloy faced and resilient seated. All valves shall be clearway, and lugs provided on screwed seats etc. for assembly shall be removed. Valves shall, unless otherwise specified, be capable of passing solids not exceeding 90 millimetres. Valves shall be provided with a removable cover on top of the body casing, to enable the hinge and door to be inspected or removed. The door opening shall be restricted to a maximum of 70 degrees at the hinge, measured from a plane passing through the hinge at right angles to the axis of flow. Valves shall be provided with extended spindles to the doors fitted with lever arms suitable for balance weights. When specified, limit switches shall be provided, operated by external cams rigidly attached to the door spindles. The limit switch shall operate when the valve door has moved through approximately 10 degrees. The switch shall provide one normally open and one normally closed electrically separated contacts of the make before break type.

H1.11

Valves for Gas Pipelines Valves for gas pipelines shall be to the appropriate approved Standard. Unless otherwise specified or detailed, valves shall be suitable for 100oC operating temperature and shall have a pressure rating of not less than twice the specified maximum operating pressure of the pipeline (subject to a minimum rating of 4 bars). When subjected to an approved hydrostatic test at the required pressure rating the valves shall not leak.

H1.12

Cast Iron Butterfly (Disc) Valves Butterfly (disc) valves shall be generally to BS EN 593. Bodies shall be of cast grey or ductile iron, discs shall be of cast grey or ductile iron, stainless steel or gunmetal, and shafts and internal fastenings shall be of stainless steel. For valves greater than 300 mm in diameter, bearings shall be of the sealed, selflubricating type and disc seals shall be renewable. Unless detailed otherwise: (i)

Disc seals shall be of the resilient type.

(ii) body.

Valves greater than 600 mm in diameter shall have support feet cast onto the

(iii)

Valves shall be provided with hand wheel and worm reduction gearing in a fully enclosed cast iron gearbox.

(iv)

Valves shall be “Tight Shut Off” (TSO) : when tested as required by BS EN 593 there shall be no visible leakage at the appropriate test pressure.

(v)

Valves shall have a pressure rating of 10 bars. Flanges shall have a pressure rating of 16 bars and shall be drilled accordingly.


Page H-10 of 31


H1.13

Specifications

Cast Iron Penstocks Penstock gates, frames, brackets and pillars shall be of close grained cast iron. Mating surfaces of gates and frames shall be of non-ferrous metal (excluding aluminium) accurately machined to ensure a watertight fit in the closed position. Adjustable wedges with non-ferrous faces shall be fitted to all penstocks having a waterway area exceeding 0.3 m2. Unless otherwise detailed, operation shall be by means of rising phosphor bronze or stainless steel screwed spindles working in gun metal nuts for clockwise closing. Extension spindles, where required, may be of galvanised mild steel unless otherwise detailed and shall be connected to the screwed spindle with a suitable muff coupling. Universal joints shall be provided at cranks. Rising spindles to be installed in the open air shall be protected with a suitable corrosionresistant and weatherproof metal or plastic cover.

H1.14

Plastic Composite Penstocks Penstock frames, brackets and pillars shall be manufactured from stainless steel, protected mild steel or protected cast iron as appropriate. Penstock gates shall be faced in an approved plastic material capable of withstanding corrosion from the anticipated conditions. They shall be reinforced and designed to withstand deflections capable of damaging bonds or seals between the component elements of the gate when subjected to the maximum head specified. Mating surfaces of gates and frames shall be of an approved plastic material and shall be accurately machined or moulded to ensure a water-tight fit when in the closed position. Adjustable wedges of corrosion resistant material shall be fitted to all penstocks which have a waterway area exceeding 0.3 m2. Unless otherwise detailed, operation shall be by means of rising phosphor bronze or stainless steel spindles working in gunmetal nuts for clockwise closing. Extension spindles, where required, shall be of stainless steel unless otherwise detailed and shall be connected to the screwed spindle with a suitable muff coupling. Universal joints shall be provided at cranks. Rising spindles to be installed in the open air shall be protected with a suitable corrosionresistant and weatherproof plastic cover.

H1.15

Cast Iron Flap Valves Flaps and frames shall be of close grained cast iron. Mating surfaces of flaps and frames shall be of non-ferrous metal (excluding aluminium) machined to ensure a watertight fit in the closed position. Hinge pins shall be of phosphor bronze or stainless steel; all flaps shall be double hung and seated off the vertical. Hinge pins and mating surfaces shall be greased during assembly and shall be smeared with grease before packing and again after installation.


Page H-11 of 31


H1.16

Specifications

Plastic Flap Valves Plastic flap valves shall be manufactured from an approved plastic mated with stainless steel or coated mild steel frames where appropriate. The flap shall be weighted to assist closing and shall be suitably braced and reinforced. Hinge pins and fasteners shall be of stainless steel and all flaps shall be double hung (or equivalent) and seated off the vertical. Mating surfaces shall be accurately moulded or machined to ensure a water-tight fit in the closed position.

H1.17

Air Relief Valves Except where detailed otherwise, air relief valves shall be the double orifice type, integrating small and large orifice operation into a single unit assembly with a single pipeline connection. All valves shall be designed to prevent pneumatic closure and to ensure closure when all air has been released. All valves shall be supplied with an isolating valve or valves including bevel gearing where necessary, and, where required, a short length of double flanged pipe to increase the height of the valve above the pipeline. Valves for sewage and effluent systems shall be designed to prevent blockage by solids and shall incorporate a large volume auxiliary float chamber to isolate the air valve seat and orifice from the fluid. Float elevators and guide rods of such valves shall be of stainless steel. Valves for potable water pipelines shall be insect and vermin proof at the outlet vents leading to the atmosphere. Unless other pressures are specified elsewhere, air relief valves shall have a minimum pressure rating of 10 bars. Flanges shall have a pressure rating of 16 bars and shall be drilled accordingly.

H1.18

Underground Fire Hydrants Underground fire hydrants and their surface boxes shall conform to an approved Standard and, if installed for fire-fighting purposes, to the requirements of the appropriate local authority responsible for fire fighting. Gate valves shall be as specified elsewhere. Screw down hydrants shall have stainless steel, high tensile brass or aluminium bronze spindles and gunmetal, high tensile brass, aluminium bronze or die-cast brass spindle nuts and body seatings. Screw-down valve seats shall be of the resilient type. Valve bodies and duckfoot bends shall be of cast grey or ductile iron. Stem caps shall be of cast iron and suitable for tee key operation. Screwed outlets shall be of gunmetal, die-cast brass or high-tensile brass and shall be supplied with a plastic cap connected with a galvanised chain or other approved flexible device.


Page H-12 of 31


Specifications

Hydrants shall have a pressure rating of 16 bar unless otherwise detailed and shall show no visible leakage when pressure tested in accordance with the approved Standard. H1.19

Marking of Valves, Penstocks, and Hydrants Valves, penstocks, hydrants and similar items shall be marked as follows: (i)

(ii)

H1.20

Embossed or stamped on the main body or frame casting: (a)

the name or distinctive mark of the manufacturer;

(b)

the Standard to which the item has been manufactured;

(c)

the pressure class where appropriate;

(d)

the nominal size;

(e)

for uni-directional valves, an arrow indicating the direction of flow.

Labelled or painted conspicuously on the main body of the item and on the outside of packing cases: (a)

the weight of the item in tonnes or kilograms;

(b)

the item reference number given in the contract documents or drawings;

(c)

the name of the Employer and the project or contract name or number.

Hydraulic or Pneumatic Actuators for Valves and Penstocks Unless otherwise specified, all hydraulic or pneumatic valve and penstock actuators shall consist of a double acting piston and cylinder suitable for operation with oil or compressed air as specified and shall be suitable for remote automatic/manual control. For valve operation, the cylinders shall be directly mounted on the valve bonnet with a suitable distance piece. For penstock operation, the cylinders shall be mounted on the operating platform with extension spindles where necessary. Graduated indicator plates showing the degree of opening shall be fitted to the cylinders. Actuators shall be fitted with limit switches where specified. Actuators shall be supplied complete with all necessary ancillary equipment including small bore pipe work, manually operated multi-valves, stop cocks, pressure gauges and hydraulic or pneumatic units.

H1.21

Electric Actuators for Valves and Penstocks Electric motor operated actuators for valves and penstocks shall have totally enclosed drive units and reduction gearing and hand operating gear the use of which automatically disengages the electric motor. Limit switches and torque limiting devices shall be provided to prevent over-running. Each drive unit shall, unless otherwise specified, be complete with starter, anticondensation heater, local operating buttons, local and remote selector switch and circuits for remote indication of gate open or closed all housed within a weatherproof enclosure with a weatherproof terminal box with provision for cable glands for the incoming electricity supply, remote indicating lights and control signals.


Page H-13 of 31


Specifications

Where remote control is specified 24V dc interposing relays shall be provided. H1.22

Access Covers and Frames and Surface Boxes (i)

Unless otherwise specified or approved by the Engineer, access covers and frames shall be of cast iron to BS 497 Part 1 and shall be to the dimensions shown on the Drawings. Covers and frames having minimum clear openings outside the ranges of BS 497 Part 1 shall nevertheless comply with the provisions of that Standard where applicable. Covers and frames shall be heavy duty (BS 497 Grade A) or medium duty (BS 497) Grade B, class 1) as detailed. If not so detailed, covers and frames in major roads shall be heavy duty and elsewhere shall be medium duty. Covers shall have keyways closed on the underside with no projections above cover level and positioned such that each cover balances and can be lifted in a horizontal plane. Double triangular covers shall have two keyways on each half cover. Frames shall incorporate recesses for prising bars. All surfaces of covers and frames shall be protected in accordance with system 1 of Schedule No. G3 except for access covers having machine faced seatings where such faces shall not be protected. Any transit damage to the approved coating system shall be made good prior to installation

H1.23

(ii)

Covers with a stipulated minimum clear opening of 600 x 600mm or less shall, unless detailed as non-rocking, be seated in a sealing groove and shall be sand and gas tight. Non-rocking covers shall be as specified in paragraph (iii) below.

(iii)

Covers with a stipulated minimum clear opening of 675 x 675mm shall be heavy duty, non-ventilating and shall, with their frames, incorporate non-rock triangular point suspension (machine faced seatings are not acceptable). Seating points shall bear sloping faces to minimise the risk of sand and grit lodging on them. Frames shall incorporate a lip formed accurately near the bottom of the frame to accept an RTR sand and gas tight sealing plate as specified in Clause H1.6 which shall be supplied with the cover and frame.

(iv)

Multiple covers and frames for pumping stations and large chambers shall be heavy duty, non-rocking and shall be sand and gas tight. Where multiple triangular covers are detailed they shall incorporate non-rock triangular point suspension and not machined seatings. Ductile iron covers and frames may be used for pumping stations.

(v)

Surface boxes shall also be of cast grey unless otherwise specified or approved by the Engineer

(vi)

Surfaces boxes and covers to manholes and chambers shall have cast on letters in English and Arabic as specified or instructed by Engineer to indicate the function of the fitting or structure. Covers and Frames shall be clearly marked with the country of manufacture and the name of the manufacturer.

Access Gratings and Frames Access gratings and frames shall be used on stormwater drain chambers where indicated on the Drawings or as instructed by the Engineer.


Page H-14 of 31


Specifications

Stormwater chamber access gratings and frames shall be minimum 550 dia. clear opening, lift-out non-rocking, cast grey or ductile iron in accordance with BS EN 124, Grade A, class 1. All gratings and frames shall be fitted with GRP sealing plates to prevent the ingress of sand during the dry season and shall be protected in accordance with system 1 of Schedule No. G3. H1.24

Ladders Ladders shall be RTR, aluminium alloy or mild steel and comply with BS 5395. Material of ladders shall be selected in line with area of application considering local environment conditions and should be approved from the Engineer. Unless a higher grade of protection is detailed, all mild steel ladders ladder components shall be zinc dipped after fabrication and painted. Stringers shall be 65mm by 12mm strip and spaced 375mm apart. The rungs shall be 25mm reduced to 20mm dia. at the ends and riveted over. They shall be spaced at 225mm centres. Ladders shall be provided with welded-on fixing brackets or the ends of the stringers shall be turned over to form fixings as shown on the Drawings. Where extended stringers are required they shall not be less than 1100mm high. Safety hoops shall be provided where indicated to the dimensions shown for circular pattern as Figure 3 of BS 5395. Aluminium ladders shall be fabricated from Grade 6082 aluminium complying with BS 1474. After fabrication they shall be anodised in accordance with BS EN 12373 Grade AA 25 unless specified otherwise. Aluminium alloy ladders shall have 25 mm diameter solid rungs passing through and fillet welded at 225 mm centres to 75 mm by 38 mm channel stringers spaced 380 mm apart. Aluminium angle cleats shall be welded to the top and bottom of each stringer and drilled for a 20 mm diameter fixing bolt. All aluminium surfaces in contact with concrete shall be protected by a suitable insulating spacer. RTR ladders shall be dimensionally similar to mild steel ladders for rung widths and spacings. The treads of rungs shall have a non-slip finish. Fixing bolts, washers and nuts for all ladders shall be of stainless steel. For steel and aluminium ladders suitable non-conducting spacers shall be used to separate the metal surfaces of the ladder from the structure to which it is attached.

H1.25

Staircases Fabricated staircases shall be mild steel, aluminium alloy or RTR as detailed and comply with BS 5395. Material of fabricated staircase shall be selected in line with area of application considering local environment conditions and should be approved from the Engineer. Unless a higher grade of protection is detailed, all mild steel staircase components, shall be zinc dipped after fabrication and painted. Aluminium alloy staircases shall be structural marine quality aluminium grade 6082 to BS 1474. After fabrication they shall be anodised in accordance with BS EN 12373 Grade AA 25 unless specified otherwise. When staircases are constructed from a combination of materials (e.g. mild steel structural members and aluminium treads and guard rails), suitable non-conducting spacers shall be used at all connections.


Page H-15 of 31


H1.26

Specifications

Open Mesh and Chequer Plate Flooring Open mesh and chequer plate flooring shall be of aluminium alloy or RTR (reinforced thermosetting resin) as detailed. The flooring shall be designed in accordance with BS5395: Part 2 and BS 4592: Part 1 generally for general duty (regular 2-way pedestrian traffic). Deflection shall not exceed 1/200 x span for metal flooring or 1/100 x span for RTR flooring. Flooring shall be supplied in easily handled panels and each panel shall not normally exceed 25kg. Where removal of panels will not be required for any operation and maintenance requirements, or permanent lifting equipment is available, this may be increased to 40kg subject to the Engineer’s approval. All flooring shall generally be supported on curbing cast into the top of the supporting walls. The curbing shall be sized to suit the flooring so that the upper surface of the flooring is flush with the top edge of the curbing. Flooring shall be clipped or bolted down and adjacent panels clipped, or stitch bolted, together. The flooring shall be fixed so as to produce a finished appearance that is straight, level and true to dimensions. All flooring shall have a non slip surface.

H1.27

Hand railing

H1.27.1

General Hand railing shall be of aluminium alloy or RTR (reinforced thermosetting resin). Material of hand railing shall be selected in line with area of application considering local environment conditions and should be approved from the Engineer. Hand railing shall be designed in accordance with BS6180 and BS 5395. Stanchions shall be designed to withstand a horizontal load generally in accordance with “general duty” (regular 2-way pedestrian traffic) but “heavy duty” may be required in critical areas. The recommendations of Appendix B of BS6180 shall be followed if there is a possibility of vehicular impact. Toe plates shall be provided to all handrail other than on the sloping section of stairs or where there is an existing concrete upstand. Toe plates shall be a minimum of 100mm high above floor level and any gap between the toe plate and the floor level shall be less than 15mm. The plates shall be fixed at each stanchion and factory assembled corner pieces used. Hand railing shall generally be provided1100mm high with a knee rail at 550mm. Further details are shown on the Drawings. Hand railing shall be fixed so as to produce a finished appearance that is straight, level and true to the required dimensions. The Contractor shall submit full dimensioned illustrations of the details of the handrails, including joints and samples, for the Engineer’s approval prior to manufacture. The Engineer may require tests on handrail assemblies to confirm suitability.

H1.27.2

Aluminium Alloy Hand railing Unless otherwise specified or ordered, aluminium Hard railing shall be fabricated from extruded aluminium tube to BS EN 515, 573 and 755 Grade 6082 (structural marine quality) or equivalent and shall be anodised to BS EN 12373 Grade AA 25.


Page H-16 of 31


Specifications

Stanchions shall be formed from nominal 57mm O.D. x min. 6,35mm thick wall tube for the lower section and 57mm O.D. x min. 3.25mm thick wall tube for the upper section. Stanchions shall have torpedo sections at the top and centre to connect the handrail with approved clamping device. Stanchions shall be fixed to concrete using grade 316 stainless steel resin anchor bolts, washers and nuts. Nylon washers shall isolate the bolts from the stanchion. Where possible stanchions shall be side palm mounted. Handrail joints shall be of the concentric internal expanding type and concealed, wherever possible, within the stanchion. Where handrail joints have to be made outside the stanchion, the exposed connection shall accurately fit together to form a hairline joint. All bolts, washers and nuts for fixing hand rails and standards to structures shall be of stainless steel with suitable non-conducting spacers to separate the metal surfaces from the structure. H1.27.3

RTR Hand railing RTR guard railing shall be to the general dimensions shown on the Drawings. Handrails and standards shall be of tubular or box section as required and the Contractor shall submit details and samples of the rails, standards and fixings he proposes to use together with the manufacturer’s specification literature for the Engineer’s approval. This must state the maximum spacing of stanchions recommended to accommodate a horizontal loading of 740N/m without undue deflection.

H1.28

Safety Chains, Safety Ropes and Fittings Safety chains to hand railing shall be supplied by the hand railing manufacturer to the dimensions shown on the approved drawings. The safety chain shall be 316L stainless steel. Except where otherwise detailed on the approved drawings, safety chains or ropes shall be fitted in manholes across the entries to all sewers exceeding 700 mm diameter and shall be manufactured of polypropylene or other material capable of withstanding continuous exposure to severe corrosive conditions occurring in sewers carrying septic sewage and groundwater. Fittings shall be of 316L stainless steel. All safety chains shall be capable of withstanding an impact loading equivalent to 1950 Nm/sec.

H1.29

Nuts, Bolts, Screws, Washers and Grommets Nuts, bolts, screws, washers generally shall be stainless unless otherwise specified. Grommets shall be synthetic rubber to BS 1767 or similar approved type. Stainless steel items shall be made from steel classification 316S16 as defined in Section H1 of this Specification. Nuts, bolts and screws shall have coarse metric threads. Bolting for pipes and fittings shall comply with the approved standard. Spheroidal graphite iron bolts for use with ductile iron pipes and fittings shall have a tensile strength of 500 N/mm2. Bolt lengths shall be sufficient to ensure that nuts are full-threaded when tightened in their final position. At least two washers shall be provided with each nut and bolt set.


Page H-17 of 31


H1.30

Specifications

Fixing Bolts and Building-in Material Fixing bolts, nuts and washers shall be of stainless steel Grade 316S16 as defined in Section H1 of this specification. The bolts may be rag bolts, expansion bolts, or resin bonded bolts. The Engineer may require tests to confirm suitability. When the bolts, nuts and washers are used for fixing aluminium items they shall be insulated from the aluminium by a non-metallic sleeve and under washer. The building-in material for use with rag bolts shall be a proprietary epoxy non-shrink grout or a proprietary non-shrink mortar or caulking compound.

H1.31

Step Irons Step irons for chambers shall be either zinc dipped (but not painted) malleable iron complying with the relevant requirements of BS 1247 or of stainless steel as detailed. Unless otherwise detailed stainless steel step irons shall be fabricated from 25mm solid bar twice bent to form a ‘U’ shaped rung with 375mm tread width and two legs 350mm long the ends of the bars being ragged for building 175mm into the concrete wall. The tread of the rung and at least the first 125mm of the adjoining legs shall be stamped or ribbed to provide a non-slip surface.

H1.32

Hand Blocks Hand blocks shall be provided with lifting and operating chains of the dimensions detailed and shall be of the specified capacities which shall unless otherwise approved be clearly inscribed on the block. Each block shall be works tested to 150% of the working load and a confirmatory manufacturer's test certificate shall be provided.

H1.33

Weirs All type of weirs (sharp crested rectangular, V-notch etc) shall be of stainless steel plate of minimum 6mm thickness.

H1.34

Glass Reinforced, Hot Pressed, Sheet Moulding Compound Potable Water Tank SCOPE This specification shall apply to the tanks assembled by the Hot pressed Sheet Moulding Compound (SMC) panels, manufactured from fibre-glass reinforced polyester compound, filler, unsaturated polyester resin, pressurised and moulded by hydraulic process where used for Potable water storage, Treated Effluent water storage and Irrigation water storage. Applicable Standards: - BS 7491 BSEN 13280 ASTM 3841 General The Product manufacturer shall submit the relevant product catalogues/descriptive literature stating manufacturing process, material, mill certificates of accessories, and instructions on construction or erection manual, handling, periodic inspection and maintenance. The tank capacity shall be as shown in the approved drawing. The product manufacturer’s Shop drawing shall indicate the capacity as given above, and the tank type, design load


Page H-18 of 31


Specifications

parameters, dimensions, materials, fabrication details, clearance, field jointing, tolerances, support details, integration of piping components, anchorage, partition etc. The panel specification sectional design according to tank size and application flexibility shall be submitted for the approval of the Engineer. These panels shall be non- toxic, hygienic for water storage and ultra violet protection against algae growth. The panel thickness to be designed based on (FEM) Finite Element Method study with a safety factor 6times the actual hydrostatic water pressure according to BS 7491 and the relevant design calculation shall be submitted for engineer’s review. Tank material shall be virgin reinforced fiber-glass mat ‘E’ type comply with BS 3691/3496/3396/3749 standards, the mixed filler and unsaturated polyester resin comply with BS 3532 Type-B & BS 5480. The tank shall be suitable for 100% humidity and > 50°C Water temperature, corrosion proof, UV stabilized, non-toxic, non-staining, smooth inner surface & algae resistant. The colour of tank panels & components shall be light Grey, pigmented as such to reduce the heat absorption. The process shall be hot press using SMC material. Different process like RTM/cold press shall not be acceptable. The SMC Panel structure shall be double skin with foam material heat insulation type (25 mm Polyurethane, density 40 kgs/m3 with thermoplastic vacuum moulded cover for top, side panels, and bottom). The tank should be opaque to help reduce evaporation of disinfectant and inhibit algae growth. Maximum measured light transmission value inside a closure cover tank shall not exceed 0.05%. Tank exterior frames, pipe fittings, fasteners, supports, etc. shall be protected against weather conditions. Interior strengthening reinforcing steel shall be with stainless steel pipe section min dia 32 mm grade 444 (carbon content < 0.025). Tank shall be erected above ground with General arrangements shown in the approved drawing and a clear access of not less than 1m all around. Flexible connectors shall be used to avoid stress & vibration transfer to the water tanks. Manufacturer’s instructions and guidelines concerning storage of tank parts and accessories general site conditions of tank location, erection method, usage and operation of the water tanks shall be strictly observed. The water level indicator shall be as recommended by tank manufacturer. Manufacturer’s representative certified and experienced bodies shall fix the tank. The manufacturer must be a member of, or affiliated with quality control or certification authority, relevant to GRP tanks & fittings proposed for incorporation in the works. ISO 9001 certification is required for the tank manufacturer. Construction The tank body shall be configured to quadrilateral panel assembling type and secure assemblage space and maintenance space around the tank. The Wall Panel configuration


Page H-19 of 31


Specifications

shall be as follows: 1 x 1.5m and 1 x 2 m panels shall be used at the top part, while 1x1 m panels shall be used at the lower part of the wall. Example: 2.5m High tank: 1 x 1 (bottom) + 1 x 1.5 (top) 4.0m High tank: 1 x 1 (bottom), 2 nos + 1 x 2 (top) External and internal reinforcing parts section shall be capable to withstand the expected load such as water pressure, wind load, live load, etc.…. Tank roof panel top supporting metal reinforcements shall be installed outside to avoid the chlorine gas corrosion. Internal / external Reinforcing parts: Internal Reinforcement shall be used at the lower part of the tank (MATERIAL SUS 444, NO WELDING, SECTION PIPE DIA 32 MM MIN), while the upper part (Large panels 1.5 M, 2 M) must be externally reinforced with top external stays, vertical external frame and bottom external bracket due to the following reason: “Chlorine from disinfectant generates rust on upper part of internal reinforcement material (SS) which are not under water, say 1.5 m section below the ceiling”. Tank accessories, structural reinforcing / frames, fasteners, & components shall be as given below. GRP HOT PRESSED SECTIONAL (PANEL) WATER TANKS Sr. No. 1. 2. 3.

PHYSICAL CHARACTERISTICS SPECIFIC GRAVITY TENSILE STRENGTH (Longitudinal transversal) FLEXURAL STRENGTH

4.

IMPACT STRENGTH

5. 6. 7. 8. 9. 10. 11. 12. 13.

WATER ABSORPTION GLASS CONTENT LIGHT TRANSMISSION COEFFICIENT OF THERMAL EXPANSION THERMAL CONDUCTIVITY BARCOL HARDNESS CAVITY TOXICITY MICRO- BIOLOGICAL GROWTH

14. 15.

ULTRA –VIOLET RESISTANCE OPACITY

STANDARD

VALUES

ASTM D 792 ASTM D 638;BS 2782; ASTM D 2841 ASTM D 790; BS 2782; ASTM D 3841; BS 5734 ASTM D 256;BS 2782; BS5734 ASTM D 570; BS 7491 ASTM D 2584; BS 2782

1.8 (1000 Kg/cm2 ± 15%)

ASTM D 696

(1900 Kg/ cm2 ± 15%) (59 kgf.cm/cm2) Not greater than 0.10% More than 30% < 0.05% 1.7 x 105 /°C

BS 6920 BS 6920

0.15 kcal/m/hr/°C >40 Less than 1% Nil Nil

BS 2782 / BSEN 578

Stabilised / resistant ≤ 0.02

ASTM D 2583; BS 2782

Contents of the panel tank COMPONENTS Tank Panel Material Nuts, Bolts, Washers Sealant / Gasket External Reinforcement Internal Reinforcement External Ladder Internal Ladder Vol 3, Section3 – Civil Specifications

STANDARD ITEMS Hot pressed SMC- grey colour SMC Suitable for storing drinking water S/S grade 316L in contact with liquid water PVC foam Structural steel hot dipped galvanised S/S grade 444 angle stays, tie angles or tie rods Stainless steel 316 grade L Stainless steel grade 444 Page H-20 of 31


Specifications

COMPONENTS Roof Support Level Indicator (optional) Steel Skid

STANDARD ITEMS 75mm diameter Pipes S.S grade 444 Mechanical float switch/clear tube/or painting Hot dip galvanised & epoxy coated structural steel channels Smooth internal and external finish S/S 316L rods diameter 12 mm Water temperature up to 50°C

Finishing Tie Rods Resistance

Properties of Insulation (Polyurethane) Density Thermal Conductivity Closed cells Operation Temperature Insulation Thickness Light transmission

38 to 40 Kg/m3 0.018 to 0.020 kcal/m/hr/C° 90 to 95 % + 80° C 25 mm 0.00%

Panel Tank Accessories Accessories / Fasteners External Base frame, Wall panel joints, (Frames, Flanges bars, and Roof stays) External Ladder Roof access Manholes, Min. 900 mm dia, clear opening. Equipped with locking device. Bolts, nuts, washers Fittings Ventilation hole, Internal Corner frames, stays, Tie rods etc. Roof support (pipe 75mm Ø) Ladder Bolts, nuts, washers

Material

Corrosion Protection

Structural Steel channel sections

Hot dip galvanised and epoxy & Polyurethane coated.

Stainless steel grade 316L GRP , SMC

-

SS 316L Copper alloy / PVC ABS Material with PE Screen

Specified Coating & Insulation UV protection

Stainless Steel G:444

-

Stainless steel G:444 Stainless steel G:444 Stainless steel G:444

-

Hinge : Stainless steel grade 316L

Quality Control The manufacturer / Supplier shall take necessary measures to satisfy the client that water tank supplied for use within its domain meets the requirements detailed. This shall be repeatedly done every five years or as and when called by the owner during guarantee period. Tanks shall be erected, tested and commissioned for use by the manufacturer/ Local Agent under the supervision of engineer’s representatives. The manufacturer / local agent shall carry out periodic inspection of tank algae growth and remedial measures. Whenever composition or manufacturing process of particular component part is changed or modified, the affected component part shall have to be tested in the presence of Engineer.


Page H-21 of 31


Specifications

All testing and inspection costs shall be borne by the contractor. The GRP hot pressed water tank shall comply the requirements of British Standard BS 7491 / ASTM D3841. The tank operating atmospheric pressure shall be tested under ‘tank full’ condition for water tightness and structural soundness. Water tank shall be subject to a standing leak test for 24 hours, during which time all joints shall be carefully examined. Noticed defects shall be rectified immediately and the test to be repeated. In house QA/QC records: (mill certificate for SS 444 accessories and SMC) shall be provided along with tank supply to the site. Upon the completion of the erection, tank shall be cleaned and disinfected by the contractor, as per the manufacturers guideline. Inlet, Outlet & Over Flow Pipes UPVC material (socket / flange type). Overflow pipe shall be placed in same level of inlet pipe. Outlet pipes shall be kept level at least 10cm above the tank bottom. Drain Pipe Drainpipe shall be fixed at bottom most level of the tank. Approval of Local / International Health Authorities The tank manufactured shall be certified by International Authority to meet the requirements of BS 6920 for products approved for potable water usage. The following certificates to be provided for engineer’s review and approval.  

WRAS (UK) approval up to 50°C FDA (USA) approval for SMC material

Potable water tank must comply with BS 7491 requirements. The following test reports by Independent Authority is to be provided by the manufacturer for Engineers review, during submittal stage:         

Permanent compressive strain test. Sunlight transmission test Physical properties test (tensile, Bending, Elastic modulus, Barcol hardness, Water absorption) Leakage test Deflection test Metal toxicity test of Stainless steel in contact with water. Test of Sealing gasket in accordance with Japanese Food Sanitation Law Opacity Test to BS EN578 : 1994 Testing of GRP for use in contact with water intended for human consumption.

A guarantee of fitness for storing, effluent water shall be obtained from concerned local government agencies (Municipality & Town planning / Environment & Health Section), and a copy provided to the Engineer. Certificate should cover accessories and component parts of the Water tank in question. Guarantee Certificates


Page H-22 of 31


Specifications

Manufacturer, importer or supplier of the water tank shall provide a certificate of guarantee, against manufacturing and erection defects covering a period of minimum ten (10) years from the date of erection. During the guarantee period, tank component parts and accessories found deteriorated, defective shall be replaced by the manufacturer at his cost. H1.35

GRP Baffles Material 1. Fibreglass reinforced polyester resin composite laminate shall exhibit the following minimum properties: Property

Test Method

Minimum Requirement

Impact Notched , Izod Heat Distortion Water Absorption after 24 hours Tensile Strength Thermal Expansion Flexural Strength Flexural Modulus Barcol Hardness

ASTM D 256 ASTM D 384 ASTM D 570

13.5 Nm 79°C Max 0.20%

ASTM ASTM ASTM ASTM ASTM

62 MPa 10.5 x 10-6 mm/mm/°F 110 Mpa 6 Gpa 40

D D D D D

638 696 790 790 2583

2. “ECR” glass fibre and vinyl ester Epoxy resin shall be used in full laminate. 3. Perform hardness tests on the resin-rich surfaces of the test samples. 4. Prepare test coupons in accordance with appropriate ASTM test method. 5. The manufacturer shall maintain a continuous quality control program and upon request shall furnish certified test results of the physical properties. 6. Laminate shall be 75 mm thick and shall contain a gel-coat on each surface a minimum of 20 mils thick. Components 1. The Baffle System component shall be as shown in the Drawing. Each segment shall be moulded using gel-coated exterior surfaces, vinyl resin and fibreglass reinforcement (ECR “C” glass). H1.35

Glass Reinforced Plastic Tanks for Chemical Storage Scope of Work Furnish all labour, materials, equipment, and incidentals required to install, field test, complete and make ready for service vertical, flat bottom, seamless, fibreglass tanks for chemical storage and make-up, as shown on the Drawings and as specified herein. Related Work A. Field painting external as specified in protective coating schedule Or pigmented coating recommended by the manufacturer.


Page H-23 of 31


Specifications

B. Chemical feed pumps are as shown in the drawing. C. Instrumentation is as shown in the drawing. D. Piping, valves and appurtenances and pipe hangers and supports are shown in the drawings. E. Process mixers are as shown in the drawing. F. The chemical compatibility of the liner internal proposed shall be based on the process fluid storing inside. G. The size and capacity of the tank shall be as shown in the drawing. H. The geometry and supports of the tank shall be as shown in the drawing. Submittals A. Submit to the Engineer the shop drawings showing details of construction and erection as follows: 1. The type and category of tanks shall be related to the three categories given in Table 2 of BS4994: 1987 to suit the various chemicals storing inside. 2. The chemicals storing inside the tanks are Ferric chloride, caustic & Polymer. 3. Dimensions of tank, fittings and attachments. 4. Wall thickness (shell, head and base). 5. Location of fittings, attachments and joints. 6. Width and thickness of joint overlays. 7. Resin used and complete description of chemical resistance for all materials that will come in contact with material stored. 8. Weight of tanks and fittings. 9. Statement that fabrication is in accordance with these Specifications. 10. Complete structural calculations for each tank, including all accessories and tank supported appurtenances to be furnished by others. 11. Description of fabrication method. 12. Laminate samples. 13. Description of hold-downs. 14. Description of nozzles showing details of construction and attachment to tank. 15. Instructions for handling, storage and installation of tanks. 16. Installation list of tanks with similar applications. B. Samples Representative laminate samples of both the filament wound cylindrical shell and the heads shall be furnished. These samples shall be from plant production and shall be representative of actual construction, workmanship, appearance and surface hardness of tanks to be furnished. The Engineer may reject any tank which does not meet the standard of the representative samples. C. In the event that it is impossible to conform with certain details of the specifications due to different manufacturing techniques, describe completely all non-conforming aspects. D. Drawings shall be approved by the Engineer prior to start of fabrication. Approval of Drawings by the Engineer shall not release the Contractor of responsibility of compliance with specifications. All proposed changes in specifications shall be stated in writing. No fabrication may start prior to approval of proposed changes by the Engineer. E. Submit shop inspection and test records as specified herein. Reference Standards A. American Society for Testing and Materials (ASTM). 1. ASTM D3299- Standard Specifications for Filament-Wound Glass-Fibre Vol 3, Section3 – Civil Specifications

Page H-24 of 31


Specifications

Reinforced Thermo set Resin Chemical-Resistant Tanks. 2. BS 4994:1987 Design and construction of vessels and tanks in reinforced plastics. 3. BS 476-7. 4. ASTM C 581 5. ASTM C 582 6. ASTM D 4097 B. Occupational Safety and Health Administration (OSHA). Quality Assurance A. Tanks shall be constructed by a single manufacturer that has at least 10 years prior experience in construction of fibreglass tanks for similar applications. B. Should equipment which differs from these Specifications or as shown on the Drawings be offered and determined equal to that specified and shown, such equipment shall be acceptable only on the basis that any revisions to the design and/or construction of the structure, piping, appurtenant equipment, etc., required to accommodate such a substitution shall be made at no additional cost to the client and be as approved by the Engineer. System Description A. The tanks shall be constructed of fibreglass reinforced polyester with chemical resistant backing layer internal and shall be vertical, cylindrical, flat bottom, furnished with all accessories as specified herein. B. Tank accessories and fittings shall be of the sizes and arrangement as detailed on the Drawings. Delivery, Storage and Handling A. The Contractor shall require the manufacturer to assume responsibility for packaging to prevent damage to the tanks during normal transit and handling. B. Flange faces shall be protected from damage. All openings are to be securely covered to prevent entrance of dirt, water and debris. C. Tanks shall be mounted on skids or protective framework so constructed as to provide for easy handling for fork truck or similar device and be provided with lifting lugs, cleats, etc. to permit handling by crane, nozzles manholes, or other fittings shall not be used for lifting. D. Tanks shipped horizontally shall be supported by cradles supporting 120 degrees of the tank circumference. E. Instructions shall be provided for unloading and installation of the tanks. Products

General A. The use of manufacturer's name and model or catalogue number is for the purpose of establishing the standard of quality and general configuration desired. B. Like items of materials, equipment shall be the end products of one manufacturer in order to provide standardization for appearance, operation, maintenance, spare parts and manufacturer's service. C. Hold-down devices shall be provided by the manufacturer

Materials A. Resins used for the tanks shall be a commercial-grade corrosion-resistant thermo set, fully tested and acceptable for the service conditions. Resins shall not contain fillers, pigments,


Page H-25 of 31


Specifications

dyes, or colourants. A chemotropic agent that does not interfere with either visual inspection of laminate quality or with corrosion resistance of laminate, may be used. B. Clear ultraviolet absorbers shall be used in final resin coats.

GRP Tanks The GRP tanks shall be manufactured strictly in accordance with the specified standards. The GRP tanks shall be constructed using the filament winding process and shall be capable of storing the chemicals specified above at service temperatures in excess of 82°C. The manufacturer shall be responsible for the design and structural integrity of the tanks. All glass reinforcement used shall be 'ECR' type only. The type of chemical barrier to be used shall be agreed between the manufacturer and the Engineer prior to manufacture the tank where a thermo set lining is used it shall be as specified in CL 7 & 8 of BS 4994: 1987. All parts shall be designed and proportioned as to have lateral strength and stiffness, to especially adapted for the work to be done. Ample room and facilities shall be provided for access. Tanks shall be non-insulated suitable for vertical installation in an enclosed thermally controlled or outdoor environment as specified. Tanks shall be designed so that no external bracing, ribs, hoops, or support wires are required. Top of tank must be capable of supporting weight of maintenance personnel. There shall be no vertical joints (in axial direction) in the cylindrical shell. The entire thickness of the cylindrical shell (inner surface, interior layer and exterior layer) shall be built up prior to removal of the shell from the mandrel. The longitudinal strength of the cylindrical shell shall be at least 25 percent of the hoop strength. Regardless of the theoretical design requirements, the minimum total laminate thickness of the filament wound tank shall NOT BE LESS THAN 10mm with stiffeners external. The tank wall thickness shall be designed by the manufacturer in accordance with BS 4994/ ASTM D 3299 and relevant calculations shall be provided for engineer’s review. Where a tank is intended to contain flammable fluids the external surface layers shall be modified so as to have a surface spread of flame characteristic which at least complies with class 1 requirements of BS 476-7. The knuckle radius of the top and bottom heads shall be a minimum of 40-mm. Heads may be fabricated integrally with the shell or may be fabricated separately. Heads fabricated separately shall be moulded with an integral skirt. The minimum skirt length shall be l00-mm. The entire head including knuckle radius and skirt shall be fabricated in one piece. Tanks shall be completely fabricated in the shop. No field assembly is permitted. All surfaces exposed to chemicals shall be resin rich with "c" glass and the thickness of this inner most layer shall be a minimum of 0.5mm. A backing layer of 2mm thick normally containing a minimum of 1.2 kg/m2 "CSM" between 25% - 33% glass content by mass with epoxy based vinyl ester resin.


Page H-26 of 31


Specifications

The heat distortion temperature of the fully cured resin system used for the GRP laminate shall not be less than 20 degree C higher than the design temperature of the tank when determined as described in BS 2782 method 121A. The exterior layer of laminate shall consists two layers of "C" glass resin rich outer liner and the minimum thickness shall be 1 mm. The structural layers shall be with ECR glass and ISO resin and no sand filler Shall be used. The laminate shall consist of Hoop glass, CSM, glass cloth & woven roving as necessary. External ribs shall be used to meet the stiffness requirements not less than 10,000 N/ m2. No paints or pigmented, coloured or dyed resins shall be used on the outside surface of the tank. The tanks shall be made with machine made shaft liner. Tanks specified herein to require interior baffles shall be sized and oriented within the tank as recommended by the mixer manufacturer. Tank baffles shall be of GRP attached to the tank walls by Gusseted Brackets, at the locations recommended by the mixer manufacturer. Accessories (1) The fibreglass tanks shall be equipped with the accessories as shown on the drawings. (2) Each tank shall have an identification label laminated to the exterior surface which shall indicate manufacturers name, address, model number, and date of manufacture, capacity, design temperature and the pressure rating. Installation The contractor shall install the tanks in accordance with the drawings and the manufacturer's instructions. Compliance The manufacturer shall provide a compliance statement for the products supplied in accordance with relevant standards given in CL 7.4.1.4. Test Requirements Degree of cure of the laminate by Barcol hardness in accordance with ASTM D 2584. Chemical resistance of the resin in accordance with ASTM C581 Wall thickness in accordance with ASTM D 3567. The glass content of the inner liner and the interior layer combined in accordance with STM D 2584. The surface spread of flame characteristic in accordance with BS 476-7. All test result should comply with the relevant standard requirements. Field Testing After installation the tank shall be field tested by filling with water. The tank & fittings shall hold water without loss, evidence of weeping or capillary action for a period of 24 hrs prior to acceptance. Guarantee The finished product shall be guaranteed for a minimum of 50 years design life.


Page H-27 of 31


Specifications

Inspection Should any defects become evident during inspection, testing or within the guarantee period the contractor shall repair or replace the tank or fitting as approved by the Engineer. Additional Labelling Each tank shall be labelled with the name of relevant liquid content proposed, operating and safety instructions and other warning if necessary.


Page H-28 of 31


Specifications

H2

INSTALLATION

H2.1

Installation of Access Covers and Surface Boxes Access cover and surface box frames shall be bedded on cement mortar which shall be haunched over the base and sides. Where blockwork or brickwork is shown on the Drawings this shall be adjusted to allow for the frames to be set to the required levels and inclinations. Concrete haunching to frames shall only be carried out with the cover in position. Sealing grooves, mating surfaces and all exposed gaps between covers and frames shall be filled or coated with a vegetable based, high melting point grease after all construction activity has ceased. Keyways shall be packed with cotton waste or similar approved material to prevent the ingress of sand and stones. Where sets of lifting keys are required they shall be delivered to the Engineer at or prior to take over or occupation by the Employer of the relevant sections of the work.

H2.2

Fixing Metalwork and Machinery Where expansion and resin bonded fixing bolts are to be used the fixing bolt holes shall be as specified by the bolt manufacturers. The holes for other fixing bolts may be dimensioned on the drawings and prepared by boxing or drilling. If they are not so dimensioned they shall be formed by methods which shall be agreed in advance with the Engineer. Where a group of holes has to be formed for a number of bolts for fixing one item, the formers shall be securely fixed together before the concrete is poured around them. The boxes shall be suitably protected to avoid extraneous matter falling into them. Methods to be adopted for building bolts into prepared holes shall be agreed in a Method Statement. The methods shall take account of the materials being used and the equipment or machinery that is to be fixed. The timing and sequence of the building-in shall be determined by the Contractor if he, or a nominated Sub-Contractor, provides the item to be fixed. Where the item to be fixed is provided under a separate contract the building-in shall be carried out only when instructed by the Engineer. Unless otherwise specified, all items to be fixed shall initially be set on adequate packers and the bolts shall then be located in their correct positions. The building-in shall then be carried out in the manner specified by the bolt manufacturer (for expansion bolts) or by the supplier of the building-in material. The bolts shall not be brought into use until they are effectively anchored and any building-in material has achieved adequate strength. The bolts and nuts shall be tightened only by the party responsible for erection of the item. This party may be the Contractor, a sub-contractor (nominated or otherwise) or another Contractor. When agreed with the Engineer the voids below or behind the item shall be filled with a dry mix 1:3 cement/sand mortar or an approved proprietary material. This shall be done so as to form a solid and effective bedding the extent of which will either be detailed in the documents or agreed with the Engineer. Any shrinkage in the bedding shall be dealt with by packing, caulking, grouting and/or tightening the fixings, as appropriate.


Page H-29 of 31


H2.3

Specifications

Installation of RTR Manhole and Pumping Station Liners The construction methods employed shall be so as to ensure that a completely water and gastight seal is made preventing any exposure of the concrete to the corrosive liquids and gases present. In particular: (i)

The rebates formed in the concrete base slab and benching in which the liner is positioned shall be tightly packed with a suitable sealant in accordance with the recommendations of the liner manufacturer and to the approval of the Engineer.

(ii)

Any holes required in the liner for pipe work shall be carefully cut to the required diameter, the cut edge sealed as specified, and any space between the liner and the pipe sealed with an approved mastic sealant or as otherwise detailed on the drawings.

(iii)

The liner and slab liner shall be bonded together with RTR to provide a totally watertight joint.

RTR liners shall be handled in the same manner as RTR pipes. In addition, extra care shall be taken to avoid damage to the liners which are not designed to carry loads. The manufacturer shall visit the Site to demonstrate to the Contractor in the presence of the Engineer the methods of handling, lifting and assembly, including formation of the joints between the chamber liner, shaft liner and slab liner. It is emphasised that these liners are not designed to withstand the pressure exerted by the concrete during construction. H2.4

Cutting and Sealing of RTR (Reinforced Thermosetting Resin) Exposed ends of RTR which is cut, for any reason, shall be sealed with an approved resin before incorporating the cut RTR in the work. No cut RTR shall be used until the resin has cured. The resin shall comply with the requirements of Clause H1.4 and shall be pigmented so that the areas where it has been applied are easily identifiable. The resin shall be delivered to site in sealed containers bearing the name of the manufacturer and properly labelled as to its contents and shelf life.

H2.5

Installation of Lifting Equipment Runway beams and rails for travelling cranes shall be set within the dimensional tolerances permitted by the crane manufacturer. Before lifting equipment is used it shall be tested and certified by the relevant testing authority to lift and maintain a minimum test load of 125% of the safe working load. During this overload test each movement in turn shall be manoeuvred and the equipment shall sustain the load under full control. The tests shall be carried out in the presence of the Engineer or his duly appointed Inspecting Engineer.


Page H-30 of 31


H2.6

Specifications

Fixing of Weir Plates Weir plates shall generally be fixed in accordance with the details shown on the approved Drawings. Walls to which weir plates are to be fixed shall be finished smooth and to a uniform profile. The joint between the wall and the weir plate shall be free of leaks when tested as specified for a water-retaining structure.


Page H-31 of 31


Specifications

TABLE OF CONTENTS Page No. SECTION J – ROADWORKS AND LANDSCAPING J1

J2

1

ROADWORKS

1

J1.1

Design of Roads

1

J1.2

Earthworks for Roads

1

J1.3

Finish and Protection of Sub grade

1

J1.4

Material and Construction of Sub-base

1

J1.5

Tolerances

1

J1.6

Asphaltic Pavements

2

J1.7

Weather Limitations

2

J1.8

Precast Concrete Kerbs and Edgings

2

J1.9

Precast Concrete Paving Slabs

2

J1.10

Laying of Precast Concrete Kerbs and Edgings

2

J1.11

Laying of Precast Concrete Paving Slabs

2

J1.12

Testing

2

J1.13

Interlocking Block Paving

3

J1.14

Laying of Interlocking Block Paving

3

LANDSCAPING

4

J2.1

Submissions

4

J2.2

Materials and Workmanship

4

J2.3

Existing Trees

4

J2.4

Replacement of Existing Trees

4

J2.5

General Filling

4

J2.6

Time for Planting

4

J2.7

Irrigation

4

J2.8

Maintenance

5

J2.9

Replacement

5

J2.10

Vines and Climbers

5

J2.11

Shrubs

5

J2.12

Trees

5

J2.13

Agricultural Soil – Top Soil

6

J2.14

Top Soil Additives:

6

J2.15

Irrigation Water

7

J2.16

Drainage Pipes

7

J2.17

Surface Preparation

7

J2.18

Preparation of Soil and Plant Pits

7

J2.19

Planting and Seeding

7

J2.20

Staking and Anchoring Trees

8

J2.21

Maintenance

8

J2.22

Defects Liability

9


Page i of i


Specifications

SECTION J – ROADWORKS AND LANDSCAPING J1

ROADWORKS

J1.1

Design of Roads The Contractor shall prepare the detail design of roads, hard standings, and associated drainage, to the approval of the Engineer, on the basis of the arrangement shown on the Drawings to provide vehicular access to all major items of plant and equipment. Carriageway widths and turning circles shall be as specified in the particular specification, on the Drawings or as appropriate to the maximum size of transport envisaged for operation of the works. Pavement design for roads and hard standings shall generally be in accordance with The Ministry of Housing requirements and the typical details shown on the Drawings. The design shall be based on a design life of 60 years and traffic weight and volumes envisaged for operation of the works. The Contractor shall make his own assessment of the traffic and the sub grade CBR at the site and accordingly design the thickness of the road base and surfacing. Carriageway construction and surfacing to hard standings shall be resistant to diesel and other chemical spillage.

J1.2

Earthworks for Roads The earthworks for roads shall generally be in accordance with Section C of the Specification supplemented by Clauses 612, 613 and 614 of the current version of the Roads Directorate General Specification for Roadworks.

J1.3

Finish and Protection of Sub grade The finished surface of the sub grade shall be approved by the Engineer before any subbase material is placed. The sub grade, once it has been finally compacted, shaped and approved, shall be protected and kept well drained. Plant and materials shall not be stored or stockpiled on the formation. Contractor's traffic shall not be permitted to pass over the completed sub grade unless otherwise approved by the Engineer. The Contractor shall, at his own expense, repair any soft spots or damage caused to the sub grade.

J1.4

Material and Construction of Sub-base The granular material used in the sub-base shall comply with the requirements specified in Section C for Class 2 and Class 3 fill. All material shall be placed, spread evenly and compacted, spreading shall be undertaken concurrently with placing. The material shall be spread in one or more layers so that after compaction the total thickness is as required. Compaction of the sub-base shall be to 98% of the maximum dry density in accordance with BS 1377 and shall be completed as soon as possible after the material has been spread. Where compacting plant is of insufficient capacity, the sub-base shall be laid in two or more layers.

J1.5

Tolerances Alignment, level and surface regularity tolerances shall be as specified in Section 700 of the current version of the Roads Directorate General Specification for Roadworks.


Page J-1 of 9


J1.6

Specifications

Asphaltic Pavements Asphaltic surfacing shall be accordance with Section 900 of the current version of the Roads Directorate General Specification for Roadworks, mix references GW20, W20, B28 and L10. Only asphalt companies currently approved by the Ministry of Housing for the supply of the relevant material shall be used.

J1.7

Weather Limitations Bituminous courses shall be constructed only when the base is dry and when the weather is not rainy.

J1.8

Precast Concrete Kerbs and Edgings Precast concrete kerbs and edgings shall comply with Clause 1001 of the current version of the Roads Directorate General Specification for Roadworks.

J1.9

Precast Concrete Paving Slabs Pre-cast concrete paving slabs shall comply with Clause 1002 of the current version of the Roads Directorate General Specification for Roadworks. Slab dimensions may be varied from those specified to suit the required pathway widths.

J1.10

Laying of Precast Concrete Kerbs and Edgings Precast concrete kerbs edgings shall be laid true to line and level. Any unit of kerb or edging deviating more than 3mm in 3m shall be made good by lifting and relaying. Where practicable kerbs shall be laid before paving. Kerbs shall be bedded on a layer of 3:1 sand-cement mortar with grade C45/20 bedding and backing shaped to the required cross-section as indicated on the Drawings. All concrete shall be protected with a coating of road oil. For radii of 1.0, 3.0 and 5.0 specially cast circular kerbs shall be used. For radii 5.0 to 12.0, half length kerbs shall be used. Kerbs shall be jointed with cement mortar.

J1.11

Laying of Precast Concrete Paving Slabs The formation for paving slabs shall be prepared as specified for roads, except that proofrolling will not be required. Paving slabs shall be laid to the required cross-falls using a minimum of five pats of mortar not less than 150mm diameter to each slab. On circular work, where the radius is 12m or less, all slabs shall be cut on both edges to the required line. Joints shall be uniform in width not exceeding 12mm and grouted with mortar.

J1.12

Testing The Contractor shall carry out tests at such intervals as the Engineer may direct to demonstrate that the materials for the granular sub-base and road-base comply with the Specification and that the specified density for the sub-grade, sub-base and road base are being achieved.


Page J-2 of 9


Specifications

The Contractor shall inspect and test each area of layer for compliance with surface level accuracy. J1.13

Interlocking Block Paving Blocks shall be precast concrete, 60mm thick to BS 6717 having an interlocking pattern and colour to the approval of the Engineer.

J1.14

Laying of Interlocking Block Paving The formation for blockwork shall be prepared as specified for roads, except that proofrolling will not be required. Blockwork shall bedded on a minimum of 50mm of sand. All edges of the paving shall be retained by precast concrete edgings to secure the perimeter stones and sand levelling course. Laying shall be in accordance with the following: 1.

Pavers shall be clean and free of foreign materials before installing.

2.

Installation should start from corner or straight edge and proceed forward over the undisturbed sand levelling course.

3.

Paving work shall be plumb, level and true to line and grade; shall be installed to properly coincide and align with adjacent work and elevations.

4.

Paving stones should be installed hand tight and level on the undisturbed sand levelling bed.

5.

Concrete or masonry sand should be spread over the installed paving stones so that it may be vibrated into the joints.

6.

A roller or plate vibrator shall be used to compact the stones and to vibrate the sand into the stone joints

7.

Excess sand should be swept into the joints or disposed of from surface area

8.

The completed paving stone installation should be washed down and cleaned to provide a clean finished workmanlike installation.


Page J-3 of 9


J2

LANDSCAPING

J2.1

Submissions

Specifications

Prior to commencement of any landscaping work, the Contractor shall submit to the Engineer for approval his detailed proposals for the landscaping scheme including the proposed species of grass, trees and shrubs. Hard landscaping of interlocking concrete block pavement shall be provided between surrounding asphalted roads to access various process units J2.2

Materials and Workmanship All landscaping materials and work shall be in accordance with Section 20 of the current edition of the Ministry of Housing Standard Specification for Building works.

J2.3

Existing Trees Existing trees shall be retained as far as possible. Any existing trees obstructing the new works shall be carefully removed and either stored (or replanted) for use in the new landscaping scheme. Existing trees not affected by the new works shall be protected from damage and disturbance resulting from the Contractor’s operations.

J2.4

Replacement of Existing Trees Should any existing tree not affected by the new works be damaged or killed as a result of the Contractor’s operations then it shall be replaced by the Contractor by an equivalent mature tree of the same variety.

J2.5

General Filling General filling shall be carried using selected excavated material as specified in Section C. Fill shall be neatly trimmed to form a level surface and stable sloping embankments as indicated on the drawings to suit the finished structures and roads.

J2.6

Time for Planting In programming the planting work the Contractor shall take due regard of the accepted seasons for planting as specified in the Section 20 of the Ministry of Housing Standard Specification for Building Works. Should the time for completion be such that landscaping works would be carried out at a time when planting is inadvisable then the Contractor may apply to the Engineer for permission to postpone the planting until a more suitable time of year. Should this delay mean that the planting has to be carried out after the date of completion of the Works then the Contractor shall give satisfactory undertakings to carry out the outstanding landscaping during the Notification of Defects Period.

J2.7

Irrigation An automatic irrigation system, utilising final treated effluent, shall be provided for the irrigation of the landscaping throughout the whole of the plant


Page J-4 of 9


J2.8

Specifications

Maintenance All new plants and grasses shall be maintained for not less than 12 months after planting. This shall take the form of irrigation, re-staking, pruning, weeding, tilling, etc. to ensure sufficient growth is achieved by all plants until Completion of the Works.

J2.9

Replacement Any trees, shrubs or areas of grass which fail to show satisfactory growth or wither and die shall be replaced by the Contractor. The responsibility for the irrigation and maintenance of these replacement plants shall remain with the Contractor until such time as they exhibit satisfactory growth.

J2.10

Vines and Climbers The type of vines and climbers shall as follows or similar approved: Blooming:

Bougainvillea Spectabilis

Green:

Ipomea purpurea Jasminum Officinale.

Plants shall be healthy and vigorous, well branched and densely foliated when in leaf. J2.11

Shrubs The type of shrubs shall as follows or similar approved::

J2.12

Evergreen: :

Dodonea Viscosa Jasminum humile

Blooming:

Hibiscus Rosa Sinensis Lantana Camara Nerium Oleander Bouganvillae Spectabilis

Trees Trees may selected from the following or alternatives proposed to suit the concept of the landscaping scheme and the local conditions: evergreen ornamental trees: Encalyptus spec Acacia Cyanophylla Casuarina equisetifolia Casuarina glauca Ficus mitida Tamarix Apphylla Deciduous ornamental trees: Vacaranda Sp Melia azedaract Morus alba Palm Trees:


Page J-5 of 9


Specifications

Phoenix dcatylifera Oreadoxa regia Cbamaerops humilis Washingtonia filifera The trees not grown in Container shall be planted immediately after delivery to the site. The stem and 50% of the leaves should be protected against drying out with jute bandage. Palm trees with a heights over 3m must have a root ball, with a diameter of 1m. J2.13

Agricultural Soil – Top Soil Soil shall be obtained from sources approved by the Ministry of Agriculture and shall have the following characteristics. Clay max. 60% Sand min. 40% pH value max. 8.3. The Contractor shall provide Soil analysis, showing the pH value, electrical conductivity, Ca CO 3 , texture as well as the contents of nitrogen, phosphorus, potassium and magnesium. The maximum levels of acceptance are: Phosphorus Magnesium Potassium

P205 Mg K20

10 mg/100 g soil 10 mg/100 g soil 4 mg/100 g soil

If the value of electrical conductivity is higher than 2000 micro mhos/cm, leaching of the soil in a well drained area will be necessary with a suggested water quantity of 300 ltr/m with a soil depths of 30 cm. In order to get the top soil conditioned for cultivation, the soil shall be mixed with soil improvers according to sand and soil analysis. Soil improvers: Organic fertilizer 5% Peat moss Shredded bark Organic resin foam Inorganic fertilizer

10% 10% 5% 200 gr/m3

A sample of agricultural soil shall be submitted for approval and all material delivered to the site must conform to the approved sample. J2.14

Top Soil Additives: a.

Inorganic Fertilizer The inorganic fertilizer shall be in compound form containing N (Nitrogen), P 2 0 5 (phosphorus) and K 2 0 (Potassium) in an adequate mix to suit the purpose. They shall be delivered in original unopened containers and bear the manufacture’s analysis.

b.

Organic Fertilizer. Organic fertilizer shall be cow manure, sheep manure, poultry manure, compost or sludge. They must be thoroughly pulverized, sterilized, and decomposed.


Page J-6 of 9


c.

Specifications

Peat moss: Peat moss shall be of a quality acceptable for use as a soil amendment and shall have a pH range from 3.7 to 5. It shall be unfertilised and consists only of sphagnum.

d.

Organic Resin Foam Organic resin foam shall be urea-formaldehyde foam formulated for horticultural use, resistant to breakdown in the prevailing climate conditions, with an estimated life of more than 10 years and shall be flaked up to 30mm in size with minimum moisture absorption of 50% of volume.

J2.15

Irrigation Water Water for irrigating plants and leaching operations should be sweet water or tertiary treated final effluent. Water analysis showing the pH value, the hardness and the electrical conductivity shall be provided by the Contractor for any water used for interim irrigation.

J2.16

Drainage Pipes Drainage pipes for plant pits and beds shall be plastic polyvinyl chloride pipes 100mm in diameter or approved alternative.

J2.17

Surface Preparation Areas which are to be landscaped shall be prepared as follows:

J2.18

a.

The area shall be cultivated to the full depth of agricultural soil which shall have a minimum thickness of 450mm. Where mechanical cultivators cannot be used, the work shall be carried out to the same depth by hand.

b.

All stones over 50mm diameter shall be removed from site to an approved tip.

c.

All rubbish, large stones and weed roots shall be collected and removed from site to an approved tip.

d.

The area shall be graded to remove all irregularities and to produce evenly running falls. This operation shall not reduce the approved depth of agricultural soil. Finished levels shall be 25mm lower than all surrounding finished levels unless otherwise specified.

e.

The Engineer shall be notified when these operations are taking place and his approval obtained before any planting.

Preparation of Soil and Plant Pits Soil shall be conditioned as per clause J2.13 and the recommendations of soil analysis report. Fertiliser shall not be applied more than 24 hours prior to tilling operations. Tillage depth shall be 300mm and water shall be added before, during and after all mixing operations to soil. Stockpiled, windblown sand shall be cleaned of all stones, sticks, plants and other foreign materials before being spread.

J2.19

Planting and Seeding a.

Vines, Climbers, Shrubs and Trees.


Page J-7 of 9


Specifications

Planting season shall be between November and March. Plant pits shall be excavated with sides as nearly vertical as possible. The following sizes shall be maintained: Vines and Climbers:

500mm square x 700mm deep.

Shrubs:

Shrubs pits shall be 300mm greater in diameter than the spread of roots. Depth should allow a minimum 100mm topsoil mix under the root balls. If the shrub is less than 80cm high, the size of the pit should be 500 square x 500mm deep.

Trees:

Tree pit shall be 600mm greater in diameter than the spread of the roots of tree and sufficiently deep to allow for a 150mm layer of planting soil under the root. If the tree is not higher than 2m, the size of the pit shall be 1000 square x 1000mm deep.

Before planting container grown plants. Some of the roots shall be cut and removed. In freeing the roots at the periphery of the soil some of the soil shall be broken away to provide better contact between the root ball and fill soil. The hole shall be backfilled with top soil, taking care in not leaving any air pockets. Then a shallow basin shall be built around the tree pit so that water soaks down into the root ball b.

Palm Trees Planting season for Palm trees shall be between September and March. The size of pits for palm trees shall be as follows: Palm tree up to 4m:

2500 x 1500 x 1500mm deep

Palm tree over 4m:

2000 square x 2000mm deep

Before starting planting all injured, dry and damaged root shall be cut off. The leaves of palm trees shall be cut back by a quantity of 30% in one level to reduce water requirements. After setting the palm tree the pit shall be filled with top soil. J2.20

Staking and Anchoring Trees Staking shall be done at the same time as planting. For vines only one stake shall be used. For trees, two stakes are necessary. The trunk shall be tied to the stake in one level. Trees with a height of more than 3m, or with a trunk circumference of more than 1.8m, shall be anchored using 3 stakes and guy wires.

J2.21

Maintenance a.

The Contractor shall be responsible for the maintenance of planted areas for the duration of the Contract and during the defects liability period.

b.

All stakes and ties must be regularly checked and repaired or replaced as necessary.

c.

Watering during the defect liability period must be undertaken daily and the application must be sufficient to soak the soil to below root depth.

d.

The Contractor shall provide the Employer a Landscape Maintenance Manual before the issue of the final Inspection Certificate.


Page J-8 of 9


J2.22

Specifications

Defects Liability Inspection will be carried out at the end of the Defects Liability Period. Any plants and trees found to be dead shall be replaced by the Contractor at his own expense.


Page J-9 of 9


Specifications

TABLE OF CONTENTS Page No.

SECTION L – BUILDING WORKS

1

L1 L1.0 L1.1 L1.2 L1.3 L1.4 L1.5 L1.6 L1.7 L1.8 L1.9 L1.10 L1.11 L1.12 L1.13 L1.14 L1.15 L1.16 L1.17 L1.18 L1.19 L1.20 L1.21 L1.22 L1.23 L1.23.1. L1.23.2. L1.23.3. L1.23.4 L1.24 L1.25 L1.26

BUILDING WORK MATERIALS General Damp-Proof Courses Damp-Proof Membranes Metal Lathing Mastic for Pointing Softwood Timber for Carpentry and Joinery Hardwood Timber for Joinery Flush Doors Internal Timber Door Frames Door Seals Ironmongery Glass Glazing Compounds Windows and Doors Roller Shutter Doors External Doors and Frames External Windows Emergency Doors Roof Lights Signs Wall Tiles Concrete Blockwork Wall ties Movement Joints Joint Fillers Bond-breakers and backing strips Primers Joint Sealants Cement Mortar Mortar Plasticizers Chemical Resistant Mortar.

L2 L2.1 L2.2 L2.3 L2.4

BUILDING WORKMANSHIP General Roofing General Rainwater Outlets Galvanized Steel Sheet


Page i of ii

1 1 1 1 1 1 1 1 2 2 2 2 2 2 3 4 5 5 6 6 6 6 6 7 7 7 7 8 8 8 8 9 13 13 13 13 13


Specifications

L2.5 L2.6 L2.7 L2.8 L2.9 L2.10 L2.11 L2.12 L2.13 L2.14 L2.15 L2.16 L2.17 L2.18 L2.19 L2.20 L2.21 L2.22 L2.23 L2.24

Movement Joint Sealing Damp-Proof Courses Openings Frames Cavity Walls Tolerances Scaffolding Filled Blocks Surface Finish Joint Reinforcement Anchors Granolithic Flooring Protection of Flooring Wall-Tiling Cement Plastering Wall Painting Rendering with Plain Finish Metal Lathing, Expanded Metal and Wire Mesh Plumbing Systems Sanitary Systems

13 13 14 14 14 14 15 15 15 15 15 16 16 16 16 16 16 17 17 17

L3 L3.1 L3.2 L3.3 L3.4 L3.5 L3.6 L3.7

STRUCTURAL STEELWORK General Bolts and Nuts Welding Consumables Erection Welding Fabrication Tolerances Dissimilar Metals

18 18 19 19 19 20 21 21

L4 L4.1 L4.2 L4.3 L4.4 L4.5 L4.6 L4.7 L4.8

STEELWORK COATING SYSTEMS General Coating System 1 Coating System 3 Coating System 4 Coating System 5 Coating System 6 Coating System 7 Coating System 8

23 23 24 24 25 26 26 26 27

L5 L5.1 L5.2 L5.3

METALWORK Cleanliness Pricing Aluminium Windows and Doors

29 29 29 29


Page ii of iii


L5.4 L5.5 L5.6 L5.7


Specifications

Fly Screens Louvers Sealing Joints Cat Ladders

32 32 32 32

Page iii of iii


Specifications

SECTION L – BUILDING WORKS L1

BUILDING WORK MATERIALS

L1.0

General All building materials shall comply with Bahrani Building Regulations and where discrepancy exists between quoted the quoted standards and specifications hereafter and the regulations then the latter shall prevail. Building works shall generally comply with the Ministry of Housing Standard Specification for Building Works.

L1.1

Damp-Proof Courses Flexible damp-proof course materials for walls and lintels shall meet with the following requirements:

L1.2

Type 1:

Bituminous damp-proof course materials with asbestos base and complying with BS. 6398.

Type 2:

Black polythene damp-proof course materials complying with BS. 6515.

Type 3:

Pitch polymer damp-proof course materials having a minimum thickness of 1.27mm and a minimum weight of 1.45 Kg/m2

Damp-Proof Membranes The damp proof membrane on concrete floors shall be a cold applied bitumen solution manufacture applied in two coats to give an impervious finish.

L1.3

Metal Lathing Metal lathing shall be galvanised steel lathing having a weight of 1.60 kg/sqm. Where necessary mesh to take render coats shall be 13 mm No.22 galvanised wire mesh.

L1.4

Mastic for Pointing Mastic for pointing shall be approved Butyl joint sealing compound of approved colour applied by gun in full accordance with the manufacturer's instructions.

L1.5

Softwood Timber for Carpentry and Joinery Softwood timber for non-structural members shall be of the class suitable for the purpose for which it is intended. The moisture content shall be less than 20% at the time of fixing or such lesser moisture content as is necessary to ensure adequate performance for the purpose and position of the members.

L1.6

Hardwood Timber for Joinery Hardwood timber for joinery shall be of the Class suitable for the purpose for which it is to be used. Hardwood shall be F.A.S. (first and second) or equal quality of the species described. Samples of each type of hardwood shall be submitted to the Engineer for approval before any joiners work is commenced. Hardwood for joinery work generally shall be teak.


Page L-1 of 33


L1.7

Specifications

Flush Doors Internal and external flush doors shall comply with BS 459 Part 2. Fire check flush doors and frames shall comply with BS 459 Part 3.

L1.8

Internal Timber Door Frames Internal timber door frames shall be in hardwood of a species approved by the Engineer. 13 mm thick plywood grounds shall be fixed in structural openings to the full thickness of the wall with open channel exposed type galvanised mild steel. plaster stop beads set oversailing the grounds at reveals and heads. The grounds shall be fixed to walls with holdfasts. Wooden door frames to single and double leaf single action doors shall be in two pieces each overall opening 75 mm x 38 mm screwed to the S W grounds and pelleted. Doors frames to double action swing doors shall be on grounds as for other doors but frames shall be in one piece overall opening 130 x 38 mm face grooved with neoprene seals.

L1.9

Door Seals Door seals to the outer stiles, the frame and the meeting stiles of double action swing doors shall be of the neoprene brushing type set in with aluminium screws the seals to brush onto PVC inserts in an aluminium alloy channel section similarly fixed. Threshold seals in neoprene to the bottom of doors shall be set in upstand type aluminium holding channel. All door seals shall be to the approval of the Engineer.

L1.10

Ironmongery Generally hinges to all timber and aluminium doors shall be stainless steel washered butt hinges and be fixed with stainless steel screws. Unless specified elsewhere, external doors shall be fitted with 5 level mortice locks incorporating separate dead bolts. Internal doors shall be fitted with single bolt dead locks. All exposed parts and striking plates shall be stainless steel. Two keys shall be provided for each lock. All doors shall have aluminium level furniture with internal latch springs. The handle plate shall be fixed with stainless steel screws and shall incorporate the keyhole. External doors shall be fitted with overhead door closers to prevent slamming.

L1.11

Glass Obscure panels to window frames shall be formed in 4 mm thick toughened opaque float glass in approved colours. Internal screens, doors, inspection panels and aluminium framed glass doors shall be in 4 mm thick Georgian wired plate glass, or approved equivalent.

L1.12

Glazing Compounds


Page L-2 of 33


Specifications

The putty and mastic for glazing is to be a type approved by the window manufacturer. Glazing in timber doors and screen shall have both glass and beads bedded and back puttied and the putty trimmed off flush. Glass edges in aluminium window frames are to be filled with acrylic sealant. Glazing is to be carried out using mastic glazing tape externally and PVC vision strip internally. L1.13

Windows and Doors Windows and doors shall be of good quality and robust and shall be to the approval of the Engineer. General details are given on the Drawings Weather-stripping shall: 1.

be made from materials known to be compatible with aluminium

2.

not shrink or warp nor adhere to sliding surfaces or closing surfaces

3.

not promote corrosion when in contact with the aluminium alloy used, and

4.

be resistant to deterioration by weathering.

Joints in frames shall be made neatly and accurately either by welding or by mechanical means (e.g. cleating and screwing) and may have flush stepped or lapped surfaces. Welded joints shall be cleaned off smooth on the surfaces which are exposed when the window or door is in the closed position or where they come into contact with glazing. Flush joints formed by mechanical means shall be in line to within the limits permissible. Hinges and pivots shall be either of suitable corrosion resistant materials or if not compatible with the frame material shall be separated from the frame by materials that are compatible with it. Hardware including its fittings shall be of suitable corrosion resistant materials. Materials or finishes, which are not compatible with the frame materials, shall not be used unless they are satisfactorily separated from the frame by materials that are compatible with it. Screws (self tapping and wood) nuts bolts washers and other fastenings shall be of stainless steel or aluminium. Stainless steel fastenings shall be grade 316S. Provision shall be made for suitable fixing devices. Where such devices are built in and not exposed directly to the weather they may be made from steel which has been hotdip galvanised or zinc sprayed or zinc plated and passivated. Glazing beads gaskets glass adapters and glazing compounds shall be of materials compatible with the frame material and finished thereon. Windows and doors shall be such that glazing or re-glazing on site is possible without the need to remove the outer frame from the structure of the building. They shall comply with the British Standards Institution "Severe Exposure" Quality Assurance standard. All opening windows shall be fitted with suitable insect screens. The Contractor shall submit details of manufacture including sections of frame members and no orders shall be placed until such details have been approved by the Engineer.


Page L-3 of 33


L1.14

Specifications

Roller Shutter Doors

L1.14.1 Scope This section comprises the minimum requirements for the design and erection of roller shutter doors. L1.14.2 Technical Data Requirements The Contractor shall submit to the Engineer for approval: Manufacturer’s published specifications. Shop detail and erection drawings Detailed painting and coating specifications and procedures. L1.14.3 Design Requirements All components of the doors shall be designed to withstand and remain operable under a steady wind load due to the maximum wind speed of 45m/s. Windlocks shall be provided to prevent slats disengaging from guides. L1.14.4 Delivery and Storage Doors and materials shall be delivered to the jobsite in packages or bundles which are clearly marked, to identify fully the contents. Pre-finished materials shall be enclosed and interleaved as required to prevent damage or defacement caused by handling or weather. Door shall be stored off the ground, under cover, and accessible at all times for piece by piece inspection. L1.14..5 Materials of Construction Door Curtain: The door curtain shall be constructed of interlocking, roll formed steel slat of flat configuration. Size and gauge shall be as required to provide the curtain with adequate stiffness. Slats shall be hot-dip galvanized and painted. Two galvanized steel angles of equal weight shall be securely fastened back to back to the bottom of curtain for reinforcement. Accessories: Doors shall be equipped with the following accessories: •

Loop-type rubber or neoprene astragal attached to bottom bar.

•

Rubber or neoprene hood baffle.

•

Weather seal at jambs.

Miscellaneous: Mechanisms, box, motor covers and manual control gear shall be coated during manufacture..


Page L-4 of 33


Specifications

Lintels and structural steelwork shall be coated during manufacture.. L1.14.6 Finishing After installation all exposed elements of the roller shutter doors shall be painted.

L1.14.7 Operation Doors shall be motorized and operated by an electric motor of sufficient power to raise the door with a velocity of not less than 250 mm per second. Doors shall have a standard 3 push button control station mounted on the inside wall together with a weatherproof, key operated control station mounted on the exterior side. Doors shall have a manual emergency stand-by system, consisting of a hand chain, sprocket and reduction gear arranged to raise the door with a pull of approximately 150 N. L1.15

External Doors and Frames External doors and frames shall be of good quality, and robust. External doors shall be so designed that they swing to the closed position unless deliberately held open. The doors and frames shall be fitted with efficient draught excluders. Glazing to external doors shall be in polished plate toughened glass complying with BS 952 Table 5. Samples of toughened glass shall be submitted to the Engineer for his approval. All external glass shall be in tinted brown to the approval of the Engineer.

L1.16

External Windows External windows and frames shall be of good quality, and robust. All hardware shall be supplied and fixed by the manufacturer and shall match the finish of the surfaces of the units and shall be replaceable without removing the outer frame from the structure. Fasteners shall be designed so that they cannot be released from the outside by the insertion of a thin blade or other simple tool. Windows shall meet the performance requirements of “severe (a) exposure", that is a maximum three second gust speed of 45 m/s. All surfaces in contact with blockwork, concrete render or other alkaline materials shall be coated with two coats of black bitumen solution or similar approved protective coating. All unit surfaces which will be visible when the window is fixed in position shall be protected after manufacture by low tack tape or other suitable means capable of being removed after installation of the window to leave clean undamaged anodised surfaces. All windows shall equal or exceed the following performance requirements: There shall be no water leakage when tested at 330 mm water gauge and air filtration shall be less than 12 mlh/m when tested at 40 mm water gauge.


Page L-5 of 33


L1.17

Specifications

Emergency Doors Emergency doors where shown on the drawings or instructed by the Engineer shall be fitted with approved panic bolts Part 1 to the inside of the doors and the doors shall be designed to open outwards.

L1.18

Roof Lights Roof lights shall be of clear plastic conforming to BS 8213, Part 1 (Cleaning and safety) and BS CP 153, Part 2 (Durability and maintenance). Roof lights shall be permanently fixed, and shall not be readily interfered with by unauthorised persons. The mounting shall be to upstand kerbs cast into the roof slab.

L1.19

Signs Room designation sign, name plates and fire exit direction signs shall be made from engraved plastic laminate, screw fixed in required positions. All signs shall be in both Arabic and English lettering to the approval of the Engineer.

L1.20

Wall Tiles The tiles shall be 150 x 150mm and of the best quality ceramic tiles available. The quality and colour shall be approved by the Engineer.

L1.21

Concrete Blockwork Precast concrete blocks used in manholes, chambers, and structures shall be made using sulphate resisting cement Type V. Precast concrete blocks generally shall comply with BS 6073 Part 1 Blocks in external walls shall be min. 190 mm thick. Those in internal partition walls shall be min. 100 mm thick. Block dimensions shall be as follows with the indicated tolwerances: Length:

390mm (+3mm, -5mm)

Height:

190m (+3mm, -5mm)

Width:

90mm, 140mm, 190mm or 290mm.(+3mm, -2mm av. +4mm, -4mm at any individual point)

Precast concrete blocks shall be solid, hollow or cellular complying with BS 6073. Blocks shall have a minimum compressive strength of not less than 7.0 N/mm2 unless otherwise noted on the drawings. Where concrete blocks are cast on Site by the Contractor they shall be made in approved concrete block making machines. All casting shall be carried out with the block making machines under cover. The concrete shall be put into the machine moulds in thin layers and properly tamped. On removal from the machine the blocks shall be carefully cured. After placement on racks under sheds the blocks shall be kept wet for three days. Curing shall be continued for a further five days the blocks being kept on racks in the open under mat covers and kept wet. Further curing shall take place by leaving the blocks under mat covers for a further seven days without wetting. If the Contractor wishes to use steam-cured concrete blocks he shall request the approval of the Engineer to the methods of curing proposed.


Page L-6 of 33


Specifications

Blocks shall be carefully packed in transport and unloaded and stacked on delivery by hand or other approved means so as to avoid damage to surfaces. Blockwork shall be constructed using cement sand mortar and joints shall not be less than 6 mm thick nor more than 10 mm thick at their narrowest part. Where appropriate, the courses shall be laid level or parallel to the axis of the Work and with parallel neat and regular joints. Vertical joints shall be kept true and in perpendicular alignment as appropriate. Immediately before being laid, the blocks shall be thoroughly soaked in clean water and before continuing partly completed work the exposed bed joint shall be likewise soaked. The courses shall be built up uniformly and no portion of the wall during laying shall rise more than one metre above any other portion of the wall. No bats or broken blocks shall be allowed except where necessary for closures. The joints shall generally be not more than 6 mm in the beds and 10 mm at the ends or such other dimensions as may be agreed by the Engineer. All joints shall be completely filled flush with mortar. All blockwork shall be protected during erection from the effects of heat, sun and rain by suitable covering. Curing finished work shall be as specified for concrete. L1.22

Wall ties Wall ties shall be stainless steel. Unless otherwise specified or approved by the Engineer they shall be of the vertical-twist strip type. Special anchor ties for connecting brickwork blockwork or masonry to dovetail slots case in concrete shall be of similar specification and approved by the Engineer.

L1.23

Movement Joints

L1.23.1. Joint Fillers Joint fillers shall be compressible, non-staining, resistant to damage handling and shall not be extruded from joints when movement occurs. Joint fillers shall have the characteristics detailed in table 5 of BS 6093 and shall be of the following types. Type 1

Wood fibre/Bitumen

Type 2

Cork/Resin

Type 3

Bitumen/Cork

Type 4

Cellular plastic and rubber

The type and dimensions of joint fillers shall be 20mm thick Type 2 unless otherwise specified. L1.23.2. Bond-breakers and backing strips Bond-breakers shall be thin one-sided self adhesive tape or closed cell foam backing strip as specified on the drawings.


Page L-7 of 33


Specifications

L1.23.3. Primers Primers shall be fully in accordance with the requirements and recommendations of the sealant manufacturer. L1.23.4 Joint Sealants Joint sealants shall comply with the following:

L1.24

i)

One part polysulphide sealants shall comply with BS5215.

ii)

One part polyurethane based sealants shall be gun applied.

iii)

Silicone sealants shall comply with type A (low modulus) requirements of BS5889.

iv)

Two part polysulphide based sealants shall comply with the relevant requirements of BS4254. Pouring grade shall be applied to horizontal upward facing joints and gun grade to joints or any other aspect or inclination. Other two-part polymer-based sealants of gun or trowel grade shall comply with the physical and test requirements of BS4254.

v)

Two part polyurethane based sealants shall be non sag type and gun applied.

vi)

Sealants shall in all cases be carefully selected as appropriate for their climatic and environmental exposure. The Contractor shall supply to the ENGINEER copies of written recommendation(s) and guarantee(s) from the manufacturer as to suitability of the product(s) for each individual structure and for the methods of installation. All sealants shall be approved by the ENGINEER prior to their incorporation with the works.

vii)

Primers for use with joint sealants shall be compatible with, and obtained from the same manufacturer as, the adjacent sealant. Primers shall have no harmful effects on the brickwork, blockwork or finishes.

viii)

For general usage, two part polysulphide based sealants shall be used unless otherwise specified or approved by the Engineer

Cement Mortar Cement mortar shall consist of cement and sand gauged by volume in wrought wooden boxes in the proportion of 1 part of Sulphate Resisting Portland Cement to 3 parts of sand. Mortar shall be mixed until the colour and consistency are uniform and shall be mixed only as and when required.

L1.25

Mortar Plasticizers Mortar Plasticizers shall not contain chlorides. Mortar Plasticizers shall be used only with the approval of the Engineer. Plasticizers shall be used strictly in accordance with the recommendation of the manufacturer.


Page L-8 of 33


L1.26

Specifications

Chemical Resistant Mortar.

L1.26.1 General Chemical resistant mortar shall be used in corrosive environment for internal pointing of blockwork in underground structures and for internal rendering of concrete surfaces including concrete blockwork where specified or where the installation of plastic lining is impractical. The purpose of the mortar is to resist bio-degradation in septic sewage environments which include sulphuric acid up to 10 % concentration (w/w) and up to 35°C. Chemical resistant mortar shall be of a type and make approved by the Engineer. This section covers the requirements for chemical-resistant resin mortars for bedding, jointing or pointing bricks, concrete blocks or tiles, to be used as a corrosion-resistant lining in sewers, manholes, chambers and related structures. The mortar may have to be applied and cured in damp or wet conditions. Mortar required for pointing may have to be applied by gun, through a small diameter nozzle reaching to the bottom of the pointing groove. Internal concrete surfaces not protected with plastic lining shall be protected with chemical resistant mortar at least 10 millimetres deep. The concrete surface shall be prepared to provide a key for the mortar strictly in accordance with the mortar manufacturer’s instruction. The connection between the plastic linings shall be detailed and constructed in accordance with instructions and recommendation of both material manufacturers. L1.26.2 Information to be submitted by the Contractor Certificates Where the Contractor wishes to submit results of tests previously carried out on materials those results shall be submitted with certificates from the independent testing laboratories used. Sampling The Contractor shall arrange to have samples of chemical-resistant resin mortar tested by a laboratory approved by the Engineer and suitability for the purpose of compliance with this Specification shall be established to the satisfaction of the Engineer before any such product is used in the Works. Further samples shall be taken during the period of application at the rate of one sample for every 1000 kg of mortar delivered for use and tested by any or all of the procedures necessary to establish compliance with this Specification, as required by the Engineer. If any sample fails to comply, application shall cease until suitability and compliance with the Specification has been re-established to the satisfaction of the Engineer. Manufacturer’s Literature. Any samples of chemical-resistant resin mortars submitted by the Contractor for the approval of the Engineer, shall be accompanied by a complete set of the literature issued by the manufacturer describing their product. In addition to the manufacturer’s standard data sheets, details of other installations where the mortar has been used, and any references as to its suitability should be included. L1.26.3 Material and Properties Description


Page L-9 of 33


Specifications

The mortar shall be an intimate mixture of liquid resinous material and a setting agent and may contain appropriately selected filler materials. When mixed these components shall form a mortar, with a workability suitable for the proposed method of application, that subsequently hardens. Composition The liquid resin shall be any solvent-free resinous material capable of forming a chemical resistant mortar when mixed with a suitable catalyst and if required, a filler material. The filler material if used, shall be compatible with the liquid resin, of the chemical resistance required and of a size that will permit the preparation of a minimum joint thickness of 3.0 mm. The mixed mortar shall not adversely affect or be affected by other construction materials with which it will properly come into contact, including fixtures and fittings. Colour The colours of individual components sufficiently different from each other components will be apparent by visual chemical-resistant resin mortar shall be tiles to be pointed.

of the chemical-resistant resin mortar shall be so that complete, homogenous mixing of the inspection. The colour of the completely mixed appreciably different from that of the bricks and

Packaging The components of the chemical-resistant resin mortar shall be pre-measured and packaged by the manufacturer in units sized to suit the method of application. All packages shall be clearly marked as to size, contents, mixing instructions, safety precautions, storage requirements and date of expiration of the contents. Shelf Life The unmixed components of the chemical-resistant resin mortar shall have a minimum shelf life after delivery to the site of 12 months when stored at a temperature between 5oC and 45oC. Pot Life Where it is proposed to apply the mortar by trowel the working time after initial mixing of the resin, filler material and hardener shall be a minimum of 60 minutes at a temperature of 20oC and 30 minutes at 45oC. The pot life of the mortar shall be considered exceeded when the mortar can no longer be applied to a prepared surface without curling behind the trowel according to ASTM C308. If it is proposed, subject to the approval of the Engineer, to apply the mortar by some other method (e.g. by gun) the working time after mixing shall be of a length suitable for the proposed method of application. Mortar applied at any time during the pot life shall have the specified properties when cured. Bond Strength The chemical-resistant resin mortar shall form a bond with the brick, tile or concrete, or with a cured surface of itself, with a minimum strength subject to substrate cohesive capacity, of 3 N/mm2. This bond strength shall be achieved regardless of whether the mortar is applied to a dry, a damp or wet surface without priming or other form of surface preparation. The bond strength shall be tested and measured in other form of surface preparation. The bond strength shall be tested and measured in accordance with ASTM C 321 using samples of the actual construction materials.


Page L-10 of 33


Specifications

Compressive Strength The chemical-resistant resin mortar shall have a minimum compressive strength of 15 N/mm2 Tensile Strength The chemical-resistant resin mortar shall have a minimum tensile strength of 5 N/mm2 Modulus of Elasticity The chemical-resistant resin mortar shall have a maximum elastic modulus of 9 kN/mm2 Chemical Resistance The cured chemical-resistant resin mortar shall be capable of resisting attack by any constituents that may normally or occasionally be present or which may form within the system by a combination of physical, chemical and biological reactions. In particular, the mortar shall be capable of resisting attack from extended exposure to sulphuric acid in concentrations up to 15%, oils, greases and petrol.. The tests shall be conducted using petrol at 20oC. The maximum changes in weight, compressive strength and bond strength shall be measured after 7, 28, 56 and 84 days. The results of the tests, for petrol and each acid concentration and temperature shall be plotted on a graph, against time elapsed and submitted for approval by the Engineer. While discolouration and loss of gloss on the surface of these tested specimens is acceptable, there shall be no surface cracks, etching, pitting or softening of the exposed surface. If the test solution becomes discoloured during the test, the test shall be continued with fresh solution and there shall be no further discolouration. Shrinkage The chemical-resistant resin mortar shall have a shrinkage not exceeding 0.5% when tested after curing for 84 days at a temperature of 70oC Absorption The cured chemical-resistant resin mortar shall have an absorption not exceeding 3.0% Curing The chemical-resistant resin mortar shall achieve its service strength in a period not exceeding 7 days at temperatures ranging from 10°C to 45°C in dry, damp or wet conditions. The properties of the cured mortar shall not be impaired by curing in dry, damp or wet conditions at any temperature ranging from 5°C to 45°C. L1.26.4 Testing The standards for testing the material described above shall not be less than as follows: For Resistance to Chemicals:

Tested in accordance with ASTM C 267.

For Working and Setting Time:

Tested in accordance with ASTM C308.

For Bond Strength:

Tested in accordance with ASTM C321

For Absorption:

Tested in accordance with ASTM C 413.


Page L-11 of 33


Specifications

For Shrinkage:


For Tensile Strength:


For Modulus of Elasticity:


For Thermal Compatibility:


Testing shall be carried out to the Engineer’s approval before any product is used in the Works. Testing shall be carried out subsequently at the rate of one set of tests per 1000 kg of mortar delivered to Site. L1.26.5 Storage and Application The manufacturer’s recommendations for storage of the components of chemical-resistant resin mortar shall be followed. In all cases, storage shall be in a dry, cool place with containers tightly sealed and away from open flame. Components that have exceeded their shelf life or have become wet shall not be used. The manufacturer’s recommendations for the safe use of the chemical-resistant resin mortar shall be followed. Workers shall wear gloves when handling the product. In the mixing and working areas there shall be no open flame and adequate ventilation shall be provided. The components of the chemical-resistant resin mortar are to be supplied in pre-measured quantities. Under no circumstances shall these quantities be divided to mix smaller batches. Mixing of the chemical-resistant resin mortar shall be in strict accordance with the manufacturer’s recommendations. The temperatures of the component shall be such that the temperature of the mixed mortar is between 150C and 400C. Mixing shall be thorough and complete such that the mortar is a homogeneous colour and free from lumps and air bubbles. In no case shall mixed mortar that has become unworkable be re-tempered with resin liquid or by any other means. Once mortar has become unworkable, it shall be discarded. The manufacturer’s recommendations for surface preparation and for application and spreading of the mortar shall be followed. The joints shall be completely raked out to a depth of 25 mm. The surfaces to which the mortar is applied shall be free from dirt, debris, grease, oil and other materials that would prevent the formation of a sound bond. Where surfaces are damp or wet such special measures as are recommended by the manufacturer for these conditions shall be adopted. The joints shall be carefully inspected by the Contractor prior to mortar application.. A smooth, even surface shall be achieved, flush with the surface of the blocks or tiles. The manufacturer’s recommendations for curing the chemical-resistant resin mortar shall be followed. The temperature during the curing period shall be kept within the range of 50C to 400C. Special consideration shall be given to curing in damp or wet conditions.


Page L-12 of 33


L2

BUILDING WORKMANSHIP

L2.1

General

Specifications

All workmanship shall comply with Bahraini building regulations and where discrepancy exists between quoted the quoted standards and specifications hereafter and the regulations then the latter shall prevail. L2.2

Roofing General Reinforced concrete roof slabs shall be covered by an approved concrete insulating screed with a minimum thickness of 50 mm and a three layer built-up bituminous roof sheeting. When required, joints shall be formed in the insulating screed. A vapour barrier and ventilation to the bituminous roof sheeting shall also be provided. If applicable, the hatch in the roof shall be provided with an insulating sandwich panel in a thickness of 50 mm consisting of coated polyurethane foam or similar approved. The Contractor shall submit samples and references to the Engineer for his approval of the materials he intends to use before ordering these materials.

L2.3

Rainwater Outlets Rainwater roof outlets shall be fitted with circular gratings and sized for the down-pipes. A sample of the type of rainwater outlet to be used shall be submitted to the Engineer for approval.

L2.4

Galvanized Steel Sheet Galvanized steel sheet for covering roof movement joints shall be 20 gauge (1.00 mm thick).

L2.5

Movement Joint Sealing Joints shall be clean and dry at the time of priming and sealing. All movements joints shall be provided with a bond breaker. Primer shall be applied in accordance with the manufacturers recommendations and the joint sealed as soon as the primer is tack dry. Adjacent surfaces shall be marked as necessary and visible joints shall be visually acceptable. All workmanship shall be in accordance with the manufacturers instructions and recommendations including backing, priming, application and curing. All jointing work shall be executed prior to painting of adjacent surface. Unless otherwise specified, movement joints in blockwork shall be provided at maximum 6 metre centres and shall be 20mm wide and 12mm deep.

L2.6

Damp-Proof Courses a. Damp-proof courses shall be laid on an even mortar bed, free from any projections that may puncture the material. b. Damp-proof courses shall be lapped at least 150mm at joints and angles and be bedded on and covered with a bed of mortar. At locations where a downward movement of water is to be prevented, Type 2 materials shall be welted and Type’s 1 and 3 lapped and sealed in accordance with the manufacturer’s recommendations.


Page L-13 of 33


c.

Specifications

Damp-proof courses shall be continued vertically for 150mm where the wall abuts a concrete column or wall.

d. Damp-proof membrane under the ground slab shall be sealed to the damp proof course in every adjoining wall. e. Damp-proof courses near ground level shall be provided at 150mm above finished ground level or as detailed on the drawings. L2.7

Openings Reveal blocks shall be used by the side of openings and at the exposed wall junctions to give a straight plane surface. Use of mortar for making the ends of blocks plane shall not be permitted. Openings, holes, sinkings, mortises, sleeves and any other inserts for other trades shall be correctly located and formed as the work proceeds. No chasing of the work shall be permitted unless approved by the Engineer. Approval for chasing will be given only when the contractor uses tools which cleanly cut masonry and the machiners ability to cut an acceptable chase shall be demonstrated. Before any chasing is carried out, the walls shall be allowed to set thoroughly. No horizontal or diagonal chases shall be permitted and joint reinforcement shall not be cut. Chases shall be repaired by using mortar or other materials as approved by the Engineer.

L2.8

Frames All wooden window and door frames shall have ties and lugs built in where required and on completion the frames shall be pointed on exposed sides with gun grade mastic tested to B.S 3712 or other sealant approved by the Engineer. Where the frames are built in they shall be bedded in the same mortar as that used for the walling.

L2.9

Cavity Walls Cavity walls shall consist of a cavity separating an outer and inner skin, each of which may be either brickwork, blockwork or stone. The two skins shall be tied together with ties which are properly bedded in the mortar beds and joints and are at staggered centres, 900mm horizontally and 400mm vertically. Ties shall be carefully laid such that they do not fall towards the inner part of the wall. All cavity walls shall be closed at jambs and openings. A damp-proof course shall be built into the closure to form a moisture barrier. The cavity shall be kept free from mortar, rubbish and other deleterious matter which may facilitate the passage of moisture to the inner skin. Cavity tray damp-proof courses shall be provided where lintels, sills or any other solid object bridges the cavity. The cavity tray shall be installed such that a slope is provided towards the outer skin and weep holes shall be provided at 800 mm centres to allow any water accumulating in the cavity to escape from the building. Plastic or cotton insect screen cloth shall be provided on the cavity side of the weep holes.

L2.10

Tolerances Permissible deviations in level from the specified dimensions, shall be not more than 3mm/m height in level for the brickwork or 5mm/m height for blockwork. Permissible deviation in plumb shall be not more than 2mm/m height and not more than 5mm per storey.


Page L-14 of 33


L2.11

Specifications

Scaffolding Scaffolding shall be totally independent of all masonry work. No supports shall be allowed to pass through the walling unless otherwise agreed by Engineer.

L2.12

Filled Blocks All hollow blocks at the following locations shall be filled with concrete having a compressive strength at 28 days of not less than 40 N/mm2 i)

At sides of openings

ii) At intersections and junctions between concrete columns and or concrete walls where wall ties are used. iii) Under sills. iv) In blocks supporting in-situ concrete. v) In the bottom course of a block wall L2.13

Surface Finish All masonry which is to receive plaster, stucco or similar finish shall have a sufficient wrought keyed surface. The joints and beds shall be raked out to a depth not exceeding 5mm by using a raking key with shoulders to prevent deeper raking. The raking shall be carried out as the work proceeds. When not treated with paint, all fair faced Calcium Silicate brickwork and blockwork shall be treated with an approved water repellent conforming to B.S. 6477, Grade 4, immediately after each section of work is completed. All exposed masonry shall present a consistent visual appearance comparable to an approved sample panel.

L2.14

Joint Reinforcement Joint reinforcement, where required shall be fully embedded in the mortar. The reinforcement shall be laid with minimum lap of 150mm at overlap locations and junctions and shall have a minimum 25mm cover when bedded in the wall.

L2.15

Anchors Where masonry walls abut concrete walls or columns, anchors shall be provided at a vertical spacing of six courses for brickwork and three courses for blockwork. Anchors shall consist of anchor slots cast into the concrete member and dovetailed anchors unless otherwise indicated on the drawings or approved by the Engineer. When approved by the Engineer anchors or ties may be cast into the concrete and bent down after the removal of formwork. All anchors shall be securely bedded into the mortar bed of the walling and not into the bricks or blocks. At the junctions with concrete wall and concrete and steel columns fixing shall be provided across movement joints that will ensure lateral stability but allow movement of the wall in the longitudinal direction.


Page L-15 of 33


L2.16

Specifications

Granolithic Flooring Granolithic flooring shall have a minimum thickness of 75 mm

L2.17

Protection of Flooring All finished surfaces shall be properly protected until completion of the Contract. Terrazzo tile and in-situ flooring shall be protected with a layer of clean sawdust. PVC tile floors and carpets shall be protected with polythene sheeting.

L2.18

Wall-Tiling Walls or part of walls which have to be tiled shall be floated off with mortar consisting of Portland Cement, shell lime or similar approved and sand in the volume ratio 1/2 : 1 : 4 before tiling. The tiles shall be fixed evenly with an approved adhesive. The joints shall be narrow and of uniform width and shall be filled with approved white proprietary tile grout. Filling with grout shall be according to the manufacturer's instructions. Where necessary, tiles shall be cut and properly fitted.

L2.19

Cement Plastering Internal walls and ceilings shall be plastered with 1 : 4 Portland Cement-sand mortar. Total thickness of plaster on internal walls shall be 20 mm. Before plastering is carried out, the joints shall be raked out to a depth of at least 5 mm. The surface of the wall shall be cleaned of all foreign matter before application.

L2.20

Wall Painting The surface of the cement plastered walls and ceilings shall be primed and painted with a washable and weatherproof wall paint. The paint to be used shall be the best quality plastic emulsion paint available. The colour will be selected by the Engineer. If necessary, walls and ceilings shall be cleaned beforehand to the satisfaction of the Engineer. All paint shall be applied according to the manufacturer’s recommendations.

L2.21

Rendering with Plain Finish Plain finished rendering shall be carried out with 1: 5 cement-sand in two or three coats. Three coat work shall be carried out on metal lathing and on other backgrounds which the Engineer determines by inspection to be too uneven to permit two coat work. Rendering applied to external walls shall contain a waterproofing agent to the approval of the Engineer. Where rendering is to be applied to surfaces of concrete or blockwork such surfaces shall be treated by means approved by the Engineer to provide a mechanical key for the rendering. Surfaces shall be cleaned of all residual mould oil dust loose particles and other deleterious material before rendering work is begun. Particular care shall be taken to cure newly applied rendering as specified herein for concrete.


Page L-16 of 33


Specifications

The coat shall have a wood float finish to true planes and regular curves and to an even surface. Arises shall be rounded and in true alignment and a hollow fillet shall be run at internal angles. L2.22

Metal Lathing, Expanded Metal and Wire Mesh Metal lathing and all such forms of reinforcement and backings to plaster shall be in galvanized steel. Samples of lathing etc., shall be submitted to and be approved by the Engineer before the use in the work.

L2.23

Plumbing Systems Hot and cold water plumbing systems shall generally conform to BS 6700 and BS 8000Part 15, or to local standards and regulations. General details are shown on the Drawings.

L2.24

Sanitary Systems Sanitary systems shall generally conform to BS 5572 and BS 8000- Part 13, or to local standards and regulations. General details are shown on the Drawings.


Page L-17 of 33


L3

STRUCTURAL STEELWORK

L3.1

General

Specifications

Hot rolled and hollow structural steel sections shall be mild steel complying with the requirements of BS 4360 Grade 43A and 43C subject to the additional requirements of BS 449. Where the use of proprietary designs of prefabricated building frames is proposed, the standards to which they are manufactured shall be no less rigorous than those stated above. Structural steel work shall be provided and fixed complete with all plates, cleats, bolts, etc. cut to lengths and sizes and drilled as shown on the drawings. Steel tubes shall be seamless tubes in accordance with BS 1387 or with BS 1775. Unless otherwise required by the Contract all forms of steel used shall be of standard section and shall be of the exact dimensions. Should the Contractor be unable to obtain steel to the required dimensions he shall submit alternative propose to the Engineer for his approval. Two copies of all detailed working drawings, calculations, etc. prepared by or on behalf of the Contractor shall be submitted to the Engineer for his approval. Any approval by the Engineer shall in no way relieve the Contractor of his responsibilities for the work under the Contract. The workmanship shall be of the best quality and all persons employed in the factory or site shall be competent and skilled in their respective trades. The design and detailing of connections and workmanship shall be in accordance with the drawings and BS 449 to transmit the loads specified by the Engineer. The work shall be erected, fitted and temporarily bolted together for the approval of the Engineer before any riveting or welding is carried out. During erection and prior to the construction of any necessary stiffening members, temporary bracing will be provided as necessary to ensure the stability of the framing against wind or accidental force. Shop and site joints will be formed by galvanized high strength friction bolts to suit the plant, equipment and erection procedure of the steel work Contractor, due regard being paid to efficiency, appearance and ease of maintenance. Site connections generally will be made with black bolts, with a minimum of two bolts to any connection, except where fitted bolts, high strength friction grip bolts, or site welding, are specifically referred to in the Specification or on the drawings. High strength friction grip bolts shall be tightened by a part-torque part-turn method. After bedding down of the joints, each nut and the protruding threads of bolt shall be permanently marked to record their relative positions. The nuts shall then be tightened to the approval of the Engineer by the part-turn of the nut method. High strength friction grip bolts will generally be preferred to fitted bolts. The surfaces of members joined by friction grip bolts shall be free from oil and paint, etc. Portal frame site connection at apex and knee where they employ HSFG Bolts in tension, such bolts shall be torqued up to their proof load. Plates and sections shall be true to form. Stiffeners, plates and the like shall be ground to fit the profile of the member. Sections to be cut to 'exact' lengths shall be accurately cold sawn or machined. Preparation of edges by flame-cutting shall, wherever practicable, be


Page L-18 of 33


Specifications

done by machine. Cold sawn, machine-cut and flame-cut edges shall be cleaned free of burrs and slag and left as smooth and regular as those produced by edge planing. All holes shall be drilled. Not less than 28 days before the fabrication or steel work is to begin the Contractor shall submit detailed shop drawings to the Engineer. Fabrication shall not commence until the Contractor has received the Engineer's approval of his..... Such approval does not in any way relieve the Contractor of his responsibilities to produce an adequate and safe scheme. Chequer plates may be clipped to supporting members unless stated otherwise in the Contract drawings. The surface pattern of adjacent plates shall be matched to lay in the same direction. Purlins shall, where possible, be fabricated to span continuous over two bays. To achieve this purlin joints should be staggered, with suitable continuity joints for single bay length members. PS 'Z' type purlins shall be connected with PS jointing sleeves. Holding down bolts will be supplied as required for building into the supporting concrete members. L3.2

Bolts and Nuts Steel bolts and nuts for structural steelwork shall be high strength friction grip bolts conforming to BS 4395 or black bolts conforming to BS 4190. Washers shall conform to BS 4320 with a tolerance of 1.5mm on the diameter of the hole. When bolting to diminishing sections tapered washers shall be used. High strength friction grip bolts shall be used in conjunction with approved proprietary load indicating washers.

L3.3

Welding Consumables All welding consumables (electrodes, wire, filler rods, flux, shielding gas and the like) shall comply with the requirements of BS 5135. Weld electrodes for metal arc welding shall conform to BS 639 and with the requirements of the appropriate weld procedure.

L3.4

Erection All erection work is to be carried out in a safe manner. Sequence - The Contractor will supply the Engineer with a schedule showing the order of erection based against a time scale. The Contractor shall supply temporary bracing to the building until blockwork is completely grouted. The bracing shall remain on the structure until 10 days after the last column and bond-beam has been completed. Immediately upon arrival on site of the materials, the Contractor shall check through all items and report to the Engineer any shortages (including nuts, bolts, washers, etc. or damage to any member. Damaged members shall be set aside and immediately repaired to a state where they comply with the fabrication specification unless in the Engineer's opinion, they are damaged beyond repair and have to be replace.


Page L-19 of 33


Specifications

All members shall be carefully handled to avoid local buckling, damage to paint, gouging and other undesirable defects. Only competent people shall handle the materials. On no account shall members be tipped or dropped off trucks or mishandled with forklifts. The steel work will be stacked in areas provided clear of traffic and stacked on dunnage. The Contractor shall supply and install adequate screens and covers for the protection of operators and work when welding is being done out of doors during inclement weather. This protection shall ensure that no water or other deleterious matter finds its way into the joint during the welding operation and that the work is adequately protected from cold draughts of air. If, in the opinion of the Engineer, the weather is entirely unsuitable, the Contractor shall, when so instructed, cease all outdoor welding operations. The Contractor shall supply and install scaffolding which, in the opinion of the Engineer, is adequate and sufficiently comfortable to permit the operators to produce welding of the required standard. This in on way relieves the Contractor of his statutory obligations regarding scaffolding. In the event of misfits the Contractor will immediately notify the Engineer who will prescribe what corrective measures are to be taken. Under no circumstances will the Contractor take it upon himself to remedy the situation by a cutting and welding operation. Unless shown to the contrary on the drawings, or unless prior approval to the contrary is given by the Engineer, it is the Contractor's responsibility to ensure that all members after erection and after application of all dead loads are level, plumb and straight. The Contractor shall not erect steel work using HSFG bolts where the facing surfaces contain anything between them other than clean steel or inorganic zinc silicate paint. All bolts, nuts and washers shown on the drawings as HSFG shall comply with BS 3139 Part 1 and the assembly to follow will comply with BS3294 Part 1 Code for High Strength bolting. All bolts shall have coronet load indicating washers fitted and nuts tightened in accordance with the code and the manufacturer's specification. Al bolts and nuts to be cadmium plated or equal. These shall be tightened in sequence (where used) and tensioned with a torque wrench. Al threads on the nut will be fully engaged. The Contractor will responsible for touching up all damaged paint work, whether occurring in transit or during handling and erection. Touch-up paint must be compatible with the original galvanizing system. L3.5

Welding All welding carried out during fabrication or erection shall be in accordance with the requirements of BS 5135 and as shown on the approved detail drawings. Details of the proposed weld procedures shall be submitted to the Engineer for approval at the same time as the detail drawings. All connections shall be welded in such a manner as to make the finished connections neat and smooth in appearance and suitable for painting. All slag shall be removed and all sharp projections shall be round smooth. Before welding is commenced either in the fabrication shop or on Site, weld procedure tests shall be carried where directed by the Engineer.


Page L-20 of 33


Specifications

All welders employed either in the fabrication shop or on Site shall pass qualification tests relevant to the weld procedures in use. Welders shall have satisfactory evidence of having been engaged in welding for at least 9 months in the preceding 12 month period. If the work of any welders employed on the Contract is unsatisfactory, the Contractor shall carry out such further welder qualification tests as are necessary to demonstrate that the welders are proficient. Welds shall be subjected to non-destructive testing by processes which may include but shall not necessarily be limited to radiographic, ultrasonic, magnetic particle, or dye penetrant methods, depending on the type of weld and its position in the structure. The standards of acceptance shall be at least equivalent to BS 5500: Table 5.7, If any work shows defects or fails to comply with the requirements of the detailed drawings or Specification for any reason it shall be repaired or rejected, even though it may have been carried out by qualified welders using approved procedures. L3.6

Fabrication Tolerances The general tolerance on all dimensions shall be + 2 mm. Holes shall be aligned such that fasteners can be freely inserted through the members at right angles to the contact face. Where holes in members cannot be aligned without damaging or distorting the structure or (unless the Engineer shall permit) reaming the holes, the member or members shall be rejected. A structural member shall not deviate from straightness (or from the specified shape) by more than: 1 /1,000 of the lengths between lateral restraints in the case of compression members and beams, or 1 / 500 of the overall lengths (maximum 25 m) in the case of other members. A structural member shall not deviate from its intended length by more than: ± 1 mm in the case of compression members faced at both ends for bearing, or + 0 to – 4 mm in the case of other members. Lengths of components shall be such that cumulative variations do not prejudice the accurate alignment of the completed structure. Where two steel surfaces are required to be in contact to effect a bearing or frictional contact, the surfaces shall be prepared so that at least 90 % of the area is touching before any clamping force is applied.

L3.7

Dissimilar Metals Where dissimilar metals are used in close proximity to structural steel members or their connections, contact between such metals and the steel shall be avoided unless the Contractor can demonstrate to the satisfaction of the Engineer that contact between the dissimilar metals will not lead to galvanic corrosion. Contact between aluminium or aluminium alloy and galvanized mild steel will be permitted. For fixing aluminium to steel structures, bolts, nuts, washers and screws shall be galvanized.


Page L-21 of 33


Specifications

Where galvanized parts might otherwise become sacrificial anodes to the main structure, or where the electrolytic potential difference exceeds 250 mV, the parts shall be separated by an insulating medium of adequate strength.


Page L-22 of 33


Specifications

L4

STEELWORK COATING SYSTEMS

L4.1

General The coating systems for steelwork shall be as listed below depending on the application and as detailed in the following sections. The Contractor shall submit his painting programme together with the manufacturer's documentation for the Engineers approval. The paint manufacturers instructions shall be followed closely, particularly regarding coat thicknesses, drying time, pre-treatment, etc. The base coat shall be applied in the shop within four hours of sandblasting. The surfaces which shall not be affected by the welding operations shall be painted with an intermediary coat. For painting on site, the following shall apply. Welding zones and zones which have been damaged shall be carefully cleaned and made smooth as described above. After cleaning and smoothening, a base coat and an intermediary coat shall be applied. All surfaces shall receive two coats of finishing paint. The total thickness of paint shall be not less than 280 micron.

System No

Application

1

Ferrous surfaces, including items of structural steelwork subject to atmospheric exposure and operating at up to 100 °C.

2

Not used.

3

Ferrous surfaces in contact with soil or water not specified to be zinc metal sprayed , galvanized, or mortar coated.

4

Ferrous surfaces within 100 mm of a site weld line, all ferrous surfaces encased in concrete, and for temporary protection to ferrous surfaces.

5

Ferrous surfaces subject to atmospheric exposure, not insulated, and subject to operating temperatures between 100 °C and 500 °C

6

Proprietary coating systems.

7

Internal surface of ferrous storage tanks, pipe ends receiving flange adaptors and flexible couplings and inside surfaces of socket joints.

8

Galvanising

Coating thickness for liquid coatings are referred to throughout as minimum dry film thickness (m.d.f.t.).


Page L-23 of 33


L4.2

Specifications

Coating System 1 Ferrous surfaces, including items of structural steelwork subject atmospheric exposure and operating at up to 100 °C

L4.3

1

Prior to blast cleaning, surface irregularities and surface contaminants shall be removed.

2

Blast clean surfaces to visual standard of Sa 2½ in accordance with SIS 05 5900

3

Surface amplitude of between 50 and 75 microns shall be obtained.

4

Method of coating application, drying/curing conditions and overcoating sequence shall be in accordance with coating manufacturer’s recommendations.

5

Ensure surface to be coated is free from dust, grit or foreign matter immediately prior to coating application.

6

Immediately prior to coating application ensure surfaces still have Sa 2 l/2 surface quality.

7

Coating thickness.

Primer

Undercoat

Intermediate

Finish Coat

Zinc-rich 2-pack epoxy

High-build 2pack epoxy

High-build 2pack epoxy

Polyurethane acrylic .

50 microns m.d.f.t.

100 microns m.d.f.t.


40 microns m.d.f.t

Total Dry Film Thickness


Coating System 3 Ferrous surfaces, except inside surfaces of water storage tanks, in contact with soil or water, not specified to be zinc metal sprayed, galvanized, or mortar coated. 1


2

Blast clean surfaces to visual standard of Sa 2½ in accordance with SIS 05 5900.

3


4

Method of coating application, dry/curing conditions and overcoating sequence shall be in accordance with coating manufacturer’s recommendation.

5

Ensure surface to be coasted is free from dust, grit or foreign matter immediately prior to coating application.


Page L-24 of 33


Specifications

6

Immediately prior to coating application ensure surfaces still have Sa 2½ surface quality.

7

Coating thickness.

8

Additional inspection requirements.

Finish Coat


Pure solvent-free polyurethane

.

1.5 mm m.d.f.t.

1.5 mm m.d.f.t

The coating shall be compatible with the application of cathodic protection and cathodic disbondment test data shall be submitted by Contractor for Engineer’s approval. The use of a primer to improve cathodic disbondment characteristics may be acceptable subject to Engineer’s approval. L4.4

Coating System 4 Ferrous surfaces within 100 mm of a site weld line, temporary protection for surfaces and all ferrous surfaces encased in concrete. 1


2

Blast clean surfaces to visual standard of Sa 2½ in accordance with SIS 05 5900.

3


4

Method of coating application, dry/curing conditions and overcoating sequence shall be in accordance with coating manufacturer’s recommendation.

5


6

Immediately prior to coating application, ensure surfaces still have Sa 2 ½ surface quality.

7

Coating thickness.

Coating


2 – pack epoxy zinc phosphate primer

25 to 50 microns m.d.f.t.


Page L-25 of 33


L4.5

Specifications

Coating System 5 Ferrous surfaces subject to atmospheric exposure, not insulated and subject to operating temperatures between 100 °C, and 500 °C. 1


2

Blast clean surfaces to visual standards of Sa 3 in accordance with SIS 05 5900.

3


4

Method of coating application by gas flame or electric arc process using aluminium wire.

5


6

Immediately prior to coating application, ensure surfaces still have Sa 3 surface quality.

7

Coating thickness.

8

Apply sealing coat.

Coating

Sealer Coat

Aluminium metal spray 150 to 250 microns thick

L4.6

Aluminium silicone, minimum thickness to achieve complete sealing and coverage

Coating System 6 Items of equipment which due to their use and/or complexity are not suitable for coating with any of the coating systems defined elsewhere in this Specification may, on the Engineer’s approval, be coated with Contractor’s standard heavy duty coating system(s). In such circumstances, the Contractor shall submit full details of the proposed coating system(s) for review and approval by the Engineer prior to ordering. The Contractor’s submittal to the Engineer shall include but not necessarily be limited to the following:

L4.7

a)

Proven suitability of the coating system for an aggressive salt laden environment.

b)

Contractor’s procedures and specification for substrate surface preparation, coating application and quality control.

c)

Coating manufacturer’s data sheets and recommendation for surface preparation and coating application.

d)

The m.d.f.t.’s for each coating application and for the total coating system.

Coating System 7


Page L-26 of 33


Specifications

Internal surfaces of ferrous storage tanks. 1


2

Blast clean surfaces to visual of Sa 2 ½ in accordance with SIS 05 5900 – 1967.

3


4

Method of coating application, drying/curing conditions and overcoating sequence shall be in accordance with coating manufacturer’s recommendations.

5

Ensure surface to be coated is free from dust , grit or foreign matter immediately prior to coating application.

6

Immediately prior to coating application ensure surface still has Sa 2 ½ surface quality.

7

Coating thickness.

8

Additional inspection requirements.

Primer

Undercoat and Intermediate Coats

Finish Coat

2-pack epoxy zinc phosphate

High-build 2-pack epoxy

High-build e-pack epoxy

25 microns m.d.f.t.

100 microns each m.d.t.f.




The Contractor shall submit to the Engineer test certificates from the proposed coating manufacturer to demonstrate compatibility of the coating system with the substances to be stored in the tank. Additionally, coating to be used in water storage tanks shall be compatible with the application of cathodic protection and cathodic disbondment test data shall be submitted by Contractor for Engineer’s approval. L4.8

Coating System 8 Surfaces required to be hot dip galvanized are ladder, racks, cable trays, stair-treads, gratings, grilles, hand railing, bolts, nuts, washers and other miscellaneous carbon steel or low alloy steel items unless otherwise specified. Other surfaces requiring galvanizing shall be as shown on drawings and in the Specifications. Galvanising shall be carried out only after completion of all welding, drilling, grinding and other fabrication activities associated with the items to be galvanized. Steels to be galvanized shall not be susceptible to embrittlement by the galvanising process.


Page L-27 of 33


Specifications

Galvanising shall be in accordance with BS 729 or equivalent. The minimum zinc coating weight shall not be less than 610 gm/m² of surface area or, for threaded fasteners only, 305 gm/m² of surface area. The galvanized surfaces shall possess a uniform bright metallic sheen free from defects. In special cases, and at the Engineer’s sole discretion, threaded fasteners may be zinc electro-plated and passivated. Steels possessing a minimum specified ultimate tensile strength of 100 kg/mm² or greater shall be heat treated prior to passivation. Where galvanised ferrous metals are specified to be painted, the following shall be applied: Preparations:

Degrease Abrade or pre-treatment etching primer

Primer:

1 coat of zinc chromate primer, 25–50 microns m.d.f.t.

Finishing:

2 coats alkyd gloss finish, 50 microns m.d.f.t.


Page L-28 of 33


L5

METALWORK

L5.1

Cleanliness

Specifications

The Contractor is advise to take particular care of the anodised aluminium surfaces by using masking tape or other methods of protection and is warned that the Engineer may require the removal and replacement of aluminium work which has been damaged due to lack of adequate protection. All materials shall be free from scale, rust damage or defects. All welding, bracing or hot forging shall be carried out by approved processes. All metal work shall be approved by the Engineer before starting painting works. All steel items which are not galvanized or zinc-coated are to be primed with a coat of approved rust proofing primer applied to all surfaces at the workshop or on site immediately after delivery and before erection and to be touched up where necessary after erection. L5.2

Pricing The cost of supplying and fixing metal work generally are to include for horizontal, raking or vertical work, cutting members to length, for all shop and site welding, grinding, drilling, countersinking, bolting, riveting, assembling, adjusting and fixing complete. Rates for items manufactured in the shop shall include for preparing and submitting shop drawings for the Supervising Officer's approval before manufacturing commences.

L5.3

Aluminium Windows and Doors Extruded aluminium sections should be in alloy AIMgsi.5 with temper F22 (DIN Specifications) or equivalent. All visible surfaces of the sections shall have a powder coated finish. Samples of colour shall be submitted for the Engineer’s approval before work commences. The sections shall be powder coated to a minimum thickness of 80 microns. The supplier must submit necessary evidence to the satisfaction of the Engineer that the thickness of coating is not less than 15 microns. In case of doubt the Engineer reserves the right to send sample pieces to independent testing laboratories, at the cost of the supplier. If the testing laboratory report states that the thickness or quality of the anodisation is deficient, the Employer may ask the supplier to treat the order as cancelled and the supplier in such a case shall immediately indemnify the Employer of any/all losses incurred by the supplier. 

Contractor shall provide 10 years warranty.

Aluminium doors and windows are to be obtained from an approved supplier and shall include all necessary ironmongery. The doors and windows shall be constructed of extruded powder coated aluminium sections with joints accurately machined to ensure perfect fit and mechanically jointed. All items shall be strengthened, tapped and modified as necessary to receive ironmongery. Windows shall be fixed light or opening as shown on the drawings. Opening lights shall be Vol 3, Section3 – Civil Specifications

Page L-29 of 33


Specifications

hung or sliding as shown on the drawings complete with approved fly-screens. Where opening lights are hung, solid aluminium hinges with stainless steel pins and washers shall be used. Ironmongery shall be provided, and samples shall be submitted to the Supervising Offices for approval. Where glazing beads are used, they shall be of matching aluminium. Glass shall be as specified in Glazing Section of the Preambles. All frames should be made to fit the actual openings with a 5mm clearance all round. Discrepancies in overall width or height exceeding 5mm will not be allowed and the frames will be rejected in such cases. Any small discrepancies shall have the gaps suitably backed and then filled with gun-applied mastic sealant. At all opening windows and doors and where there are louvered screen and doors, a fly screen shall be provided to the approval of the Engineer, constructed following the principles and specifications as described elsewhere in this Specification. Insect screens shall be in aluminium mesh, or stainless steel 18 x 16 meshes per inch. The gap between the insect screen and the shutter shall be covered with an adaptor PVC section. For reference to window types see general arrangement drawings, elevations and quantities. Tolerances are to be approved by the Engineer before manufacture. All ironmongery which is to have the same finish as the frames it is on shall be approved by the Engineer. The Contractor shall provide shop drawings for aluminium windows and doors which shall be submitted to the Engineer for approval. A sample of typical window is to be submitted at actual size using the specified glass and frame colour, clearly labelled complete with Ironmongery. Approval by the Engineer of the shop drawings shall not relieve the Contractor of his responsibilities under the Contract. All assembly screws shall be in 18-8 stainless steel. Glazing sections shall be in special heat-resisting PVC and of channel type. glazing sections on each side of the glass will not be permitted.

Separate

Sliding Windows and Doors Weather-stripping - high density acrylic or wool weather pile shall be used. There should be double brushes at every contact between shutter and frame sections for complete insulations. These should be present consistently throughout the unit between the inside and the outside and no portions without it are permitted. The rollers for sliding shutters for both windows as well as doors shall be of adjustable type. The adjusting screws must be accessible in the assembled state of the shutters and a vertical adjustment of 7mm should be possible.


Page L-30 of 33


Specifications

All sections for sliding windows and doors should be of tabular shape and the sections dimensions of the sections should be not less than 60 x 40mm.

cross

The outer frame must be suitable for accommodating sliding fly screens as required. The handle-latch set should have all visible surfaces of anodised aluminium or similar nonrusting materials to approval. The handle must have a proper grip. A small projecting flange or a recess in the shutter sections cannot be accepted to serve as handles. The latching mechanism should not be surface mounted but should be concealed within the sections. Sash rails of vertical sliding windows are to be of tabular box sections with corner joints of outer frames and sashes interlocked, and the balance mechanism is to be an approved proprietary product. Side Hung Windows, Doors and Ventilators All windows and doors should be weather-stripped with heat resistant PVC sections. The weather fighting action should be achieved by a positive compressive action against the PVC section and should not depend on an external contact with the PVC section. At every contact between two weather-stripping sections should be provided for complete weather protection. The bottom sections for hinged doors must be capable of being adjusted vertically if necessary. The gap between the bottom section and the floor should be covered with a pair of special flay-type PVC sections. The shutter sections for both windows as well as doors shall be of tabular type and shall be of overall size as shown on drawings and door sections shall be of overall size as shown on drawings too (including flanges). The shutters of the windows and doors should be assembled with concealed corners of high rigidity. Hinges should be concealed within the sections. Hinges shall be anodised aluminium with stainless steel pins and nylon washers. Handles shall be in anodised aluminium and mounted with self-lubricating nylon washers. A mortice cylinder rim automatic deadlock of high quality with double pin tumbler is to be used. Windows shall have anodised aluminium handles and a latching mechanism securing the shutter to the frame both at the top and bottom. The glazing vinyl shall be in heat resisting PVC and of channel type. Individual glazing sections on both sides of the glass will not be permitted. Fittings were required: (a) Single action door closer concealed in the head bar of the outer frame and mounted on an adjacent pivot at the threshold and deadlock fitted.


Page L-31 of 33


Specifications

(b) The left hand leaf of double doors with flush bolts at head and sill with deadlock fitted to the right hand leaf. (c) Escape doors to have panic bolt assembly with vertical elements concealed in the stile and door closer as in (a). L5.4

Fly Screens Fly screens shall be fitted to all opening leaves of windows consisting of a separate metal sub frame filled in with fly wire as previously described. The fly screens shall be adequately secured with suitable slips, set screws or turn buckles and shall be removable for maintenance purposes. Fly screens doors shall consist of similar sections to the metal casement doors and shall be fitted with removable panels of fly wire, in manner similar to that described for window fly screens.

L5.5

Louvers For details of louvered windows refer to window details. aluminium. Fly screens will be fitted externally to all louvers.

L5.6

Louvers will generally be

Sealing Joints The Contractor shall ensure that joints are dry and remove all loose material, dust and grease. Joints shall be prepared in accordance with sealant manufacturer's recommendations using recommended solvents and primers where necessary. Adjoining surfaces which would be impossible to clean if smeared with sealant shall be masked. Backing strips shall be inserted in all joints to be pointed with sealant. When using backing strips, the Contractor shall not leave gaps and shall not reduce depth of joint for sealant to less than the minimum recommended by the manufacturer. Cavities shall be filled and jointed with sealant in accordance with the manufacturer's recommendations. Sealant shall be tooled to form a smooth flat bead. Excess sealant shall be removed from adjoining surfaces using cleaning materials recommended by the sealant manufacturer, and shall be left clean.

L5.7

Cat Ladders Cat ladders where noted on the drawings shall be aluminium and unless otherwise detailed shall be constructed as follows. Stringers shall be 50mm x 6mm (2" x ½") flat attached to the structure with 75mm x 75mm x 6mm (3" x 3" x ½") plates bolted to the structure so than the clearance of the stairs from the structure is not less than 300mm (12").


Page L-32 of 33


Specifications

Treads shall be formed of 19mm (¼") tube riveted to the stringers. Safety loops shall be fitted to cat ladders more than 2m (6'6") long and thereafter at 1m (3'3") intervals. The width across the loop shall be 685mm (2'3") and the distance from the centre line of the stringers to the inside of the back of the loops measured at right angles to the stringers shall be 762mm (2'6"). The loop material shall be minimum 50mm x 12mm (2" x ½").


Page L-33 of 33


Specifications


SECTION M – GRP FABRICATED COVERS FOR ODOUR CONTROL SYSTEM

1

M1

GENERAL DESCRIPTION

1

M2

REFERENCE DOCUMENTS AND STANDARD SPECIFICATIONS

1

M3

GENERAL

1

M4

GRP FLAT COVERS

2

M5

ACCESS HATCHES

3

M6

SEALING AND ASSEMBLY

3

M7

FIXING AND HARDWARE

3

M8

LIGHT

4

M9

FRESH AIR INLETS

4

M10 FOUL AIR OUTLETS

4

M11 FINE SCREEN CHANNEL

4

M12 AERATED GRIT CHANNELS

4

M13 FLOW SPLITTER CHAMBER

4

M14 ANAEROBIC AND ANOXIC TANKS

4

M15 SUBMITTALS

5

M15.1

Product Data

5

M15.2

Shop Drawings

5

M15.3

Samples

5

M15.4

Quality Assurance

6

M15.5

Warranty

6

M16 PRODUCTS

6

M16.1

6

General

M17 GRP DOME AND FLAT SHEET COVERS

10

M18 GRP COVERS DESCRIPTIVE REQUIREMENT

11

M19 GRP DOME AND FLAT SHEET AESTHETIC COVERS

12

M20 TECHNICAL SCHEDULE

12

M20.1

Technical Schedule – Covers

12

M20.2

Technical Details

12


Page i of iii


Specifications

M21 GRP LAMINATION

13

M22 FEATURES

13

M22.1

Assembly

14

M22.2

Non-Return Valves

14

M22.3

Pressure Rating

14

M22.4

Structural Loading for Covers

14

M22.5

Cover Structural Supports

14

M22.6

Temperature ratings

15

M22.7

Wind Loadings

15

M22.8

Gaskets and Sealants

15

M22.9

Fixing, handles and associated fittings

15

M22.10

Access, Inspection Covers and Hatches

15

M22.11

Chemical Resistance

15

M22.12

Personnel Protection

15

M22.13

Name – plates

16

M22.14

Fastenings and Miscellaneous

16

M22.15

Painting

16

M23 QUALITY CONTROL AND PERFORMANCE TESTS

16

M23.1

Quality Control tests and records (To be witnessed by the Engineer) 16

M23.2

Examination after testing

17

M23.3 Information and requirements to be agreed and to be documented prior to Design and manufacture the covers. 18 M23.4 Requirements to be agreed and documented prior to design and manufacturer the covers. M23.5

19

Minimum categories & Type of Covers for Design basis consideration 20

M23.6 Design documentation and shop drawing requirements from the manufacturers

21

M23.7

Smoke Testing

21

M23.8

Works Testing

21

M23.9

Inspection and Performance Testing

21

M23.9.1

Site Testing

21

M23.9.2

Installation of GRP Dome & Flat Covers

22

M24 PACKING AND DELIVERY

22

M24.1

Labels and Markings

22

M24.2

Packing

22

M25 DOCUMENTATION SUBMITTAL

23

M25.1

Detailed Design

23

M25.1.1

Conceptual (Preliminary) Drawings and Data

23

M25.1.2

Approved For Construction Drawings and Data

23

M26 AS CONSTRUCTED DRAWINGS

24

M27 OPERATION AND MAINTENANCE MANUAL

24

M28 TESTING AND COMMISSIONING

24


Page ii of iii


Specifications

M29 TRAINING

25

M30 MANUFACTURER’S PRE-QUALIFICATION

25


Page iii of iii


Specifications

SECTION M – GRP FABRICATED COVERS FOR ODOUR CONTROL SYSTEM M1

GENERAL DESCRIPTION The work included in this section comprises design, fabrication, supply, delivery, installation, testing and commissioning GRP covers, for the odour control system; furnishing all labour, equipment, appliances and materials and performing all operations for: 1. GRP flat covers with chequer plate wearing surface. 2. GRP non-slip flat covers. 3. GRP smooth curved dome shaped covers. The scope of works shall include for:  Covers  Access hatches on covers  Inspection hatches on covers  Fresh air inlets on covers  Foul air outlets from covers  Penstock/slidegate covers  Flanged duct connections to covers  Allowances on covers for instruments, cut around existing equipment etc.  Supply of Pressure Relief Valves if required  Nuts, bolts and all fittings relevant to covers  Gaskets and sealant to ensure covers and interfaces can be made air tight  Site consumables  General Arrangement Drawings of Covers  Shop drawings of covers  Installation Manuals  O & M manuals  Engineering support (i.e. assistance during installation, commissioning  Delivering to site  Independent Design review  Structural design of covers  Balancing of air flows Fresh air inlet and foul air outlet arrangement (number and location) on covers shall be designed to provide 100% air circulation below the covers reducing risk of gas entrapped at corners which could cause corrosion problem.

M2

REFERENCE DOCUMENTS AND STANDARD SPECIFICATIONS - EUROCOMP Code – Design of Composite Structures - BS 4994: 1987 Design and Construction of vessels and tanks in reinforced plastics. - DIN 18820 Part 1 - 4 - Engineer’s tender drawings for tank opening dimensions and interfacing tank structures available for supporting the covers.

M3

GENERAL GRP Covers for the sewage odour control system must have the following key attributes: 1. Shall be highly resistant to the corrosive atmosphere over a service period of at least 25 years. 2. Shall be able to free span over a range of 6 –14metres, without incorporating any metal components in the covering system, except for fasteners. 3. Shall have good seal between cover panels and to the concrete tanks 4. Shall be readily accessible / removable for maintenance of the tank and its contents 5. Shall be light weight in order to minimise the loading on the concrete walls and for handling by service personnel in key access areas.


Page M-1 of 25


Specifications

6. Shall have a design basis that is well proven over time to ensure minimal damage in the course of day to day access, traffic and prevailing environmental conditions (sun, wind) 7. Shall be readily and economically transportable from factory to site. Each unit part shall not be greater than 30m2 with a mass of under 350 kg. In the design stage of a cover system, close and early co-operation between the cover supplier and the engineer is essential. M4

GRP FLAT COVERS (a) Pedestrian Trafficable Type 







    

The manufacturer’s design shall include, in all cases, a chequer plate pattern top surface or sanded surface in coloured UV resistant Gelcoated resin matrix and a structural core as required for the load rating and the span of panel. Panels shall be monolithic GRP construction which provides both the necessary corrosion barrier and structural contribution to the overall panel duty application. Corrosion barrier should be in the form of a ‘C’ Glass surface veil as last layer on the face exposed to tank atmosphere. External surface exposed to open air should be Gelcoated UV resistant smooth surface. Loads for pedestrian/maintenance traffic are commonly 2.5 kPa live load. Loads up to 7.0 kPa for wheeled appliances, or superimposed loads such as mechanical items, shall be accommodated with appropriate designs where required. Panel sizes shall be designed to be self supporting with only Gelocated GRP composite construction without any use of metals as metals are prone for corrosion in Sewage environments. All handles, lifting lugs, hinges, bolts, hard ware etc shall be in 316 stainless steel. Joints between panels shall generally overlap to ensure a good seal. Seals shall be compressible neoprene or equal as EPDM. Long span trafficable covers shall incorporate GRP beams, stiffeners which eliminate the need for separate supports attached to the concrete walls/floors. Each plant is custom engineered and detail drawn prior to manufacture, ensuring rapid on-site installation with minimal problems.

(b) Non - Pedestrian or Non – Trafficable Lightweight covers for non- pedestrian or non- trafficable areas may be flat or profiled to suit. (c) Curved (Profiled) Covers For areas generally not requiring regular Pedestrian trafficable access, curved covers shall generally be used. Various profiles shall be used, depending upon the span. Maximum self-supporting span shall be 20 meters. The Construction shall generally be a combination of the shape contribution and thin GRP Gelcoated laminate to provide the desired result. The external surface shall be coloured (as approved by the Engineer) with a UV resistant gelcoat, the internal surfaces featuring the corrosion barrier for long spans. Formed components of single shell FRP produced in tools (mould) that are specially manufactured for this surface or ribs may be incorporated. The structures should have proven their suitability and must be confirmed by a static calculations.


Page M-2 of 25


Specifications

In all designs, the aim is to minimise areas under covers where algae growth can occur or foreign material become impinged. All external surfaces of the covers should be so designed to eliminate ponding of water over the cover. All covers must be designed to be self draining for any water due to rain or otherwise on or surfaces and drainage outlets should be left into the tanks with water sealed U traps made of PVC or other non metallic materials. All fittings and fixings shall be 316 stainless steel.

M5

ACCESS HATCHES All covers require some form of access hatch for day to day plant operational purposes, and larger hatches for major tank and contents maintenance. Man access shall be provided by a panel section up to 1200mm x 1200 mm, which is hinged and features a quick release locking device. Low weight limit of 15-20 kg maximum set to enable a person to open. All hatches shall be integrated with regard to the shape into the cover elements and shall be fitted with particular seals. For less frequent access, cover panels shall be removable, singly or in sets of 3 or 4 (up to 8m width). The Hatch cover interface with hatch opening on main panel should be designed to provide a push fit & gas tight seal with compressible Neoprene gasket mechanically locked in to the periferry of the cover lid. The access cover latch also should be so designed that the neoprene remains in compressed state when the latch is closed.

M6

SEALING AND ASSEMBLY For covers to work effectively and the odour extraction facility to be able to perform its function, covers must be fully sealed. Seal material shall be neoprene or similar approved which is moulded shape. Compressible extruded neoprene Gaskets with minimum 40% compression having the specified properties shall also be used. The minimum neoprene section width should be 20mm. The use of air curing Semi-liquid sealing materials is not acceptable, except in very small areas where a moulded seal is not practical. All cover elements should overlap at the joints, preferably all elements should be executed alternatively lying on top and bottom so that every second element can be removed towards the top independently from the adjacent element. The cover elements shall be screwed together but it shall be detachable from outside. Laminated steel plates with incised thread shall be used for such connection. The use of automotive set serves shall not be permitted. The element on top shall have a hole thread insert of the element at the bottom shall be designed for M10 Screws.

M7

FIXING AND HARDWARE All fixings shall be set into concrete with epoxy and be located outside the seal. Minimum bolt size shall be M12 diameter unless otherwise indicated. Hinges, latches, handles, bolts etc shall be 316 stainless steel.


Page M-3 of 25


M8

Specifications

LIGHT No light shall penetrate the covers. The use of vision panels in covers is therefore not required

M9

FRESH AIR INLETS To obtain foul air dilution and a flow beneath the covers, fresh air inlets shall be incorporated into the covers. These may be upstanding non return type or flush fitted plate type, their locations shall be a matter for resolution with the process engineers.

M10

FOUL AIR OUTLETS Foul air outlets comprising a flanged riser bonded into the cover shall be sized and positioned. They should be included in the cover supply to ensure proper installation and ongoing warranty of the cover unit. The number of such outlets and positions shall be advised by the Engineer.

M11

FINE SCREEN CHANNEL These areas are traditionally high pedestrian loading, especially around the screens. Covers shall be non-slip plate, load bearing, in panels to about 100 kg for areas not subject to regular access, 25-40 kg for areas requiring access via manual opening/hinged hatches. Flat covers spanning upto 3meters which incorporate GRP beams shall be used in lieu of separate support beams bolted to the concrete. The minimisation of fixed beams/supports attached to the concrete walls is required so as to maximise clear entry space once covers are lifted. Chequer plate finish, pedestrian trafficable covers, loading shall be 5KN/m2.

M12

AERATED GRIT CHANNELS The aerated grit channels shall be more economically covered with curved covers. Access to the baffles, air pipe etc to be included. Inlet and distribution channels shall be pedestrian trafficable covers. Foul air draw off points shall be included to suit duct design. Covers shall be fitted with pressure relief valves. The design of Pressure Relief Valve will be as approved by the Engineer.

M13

FLOW SPLITTER CHAMBER This area shall utilise pedestrian trafficable flat covers as necessary. The receiving chamber may use a curved profile with one or two flat crossover panels. Access to the flow splitter weir shall be provided through the GRP covers (adjustment, clean out). Self-lifting, hinged cover panels shall be provided to enable scum removal.

M14

ANAEROBIC AND ANOXIC TANKS


Page M-4 of 25


Specifications

The anaerobic and anoxic tanks of the bio-reactors shall be more economically covered with curved covers. Common feed channel shall be of pedestrian trafficable flat covers. Access to the baffles, air pipe etc to be included. Inlet and distribution channels shall be pedestrian trafficable covers. Foul air draw off points shall be included to suit duct design. Covers shall be fitted with pressure relief valves. The design of Pressure Relief Valve will be as approved by the Engineer. M15

SUBMITTALS

M15.1

Product Data 1. Manufacture’s catalog data showing: a. b.

c.

d. e.

M15.2

Dimensions, spacings and construction details. Design calculation and tables showing limits for span length and deflection under various uniform and concentrated loads, Laminate design and thickness & choice of construction etc. Compliance with the EUROCOMP Code for limiting states for stresses and deflections shall be demonstrated for each load case. Materials of construction. Selected resin & Glass specification shall be submitted clearly showing the maximum temperature resistance to the sewage environment. The heat distortion temperature of the fully cured resin system used for the reinforced laminate shall be not less than 20°C higher than the design temperature of the covers. The Glass mat used shall be ‘ECR’ type as specified in CL 7.1.6. Manufacturers prequalification for successfully completed the covering of sewage treatment tanks for odour control with minimum 20,000 m2 covered area in a single plant. 100 days acid immersion test conducted in accordance with ASTM C581 @ 50°C in 10% concentrated sulphuric acid on GRP Cover sample coupons and submit the test data to prove the chemical resistance.

Shop Drawings 1. Shop drawings of all GRP products shall be submitted to the Engineer for approval in accordance with the requirements. 2. Drawings to Indicate detail fabrication and erection of each GRP fabrication. a.

3. M15.3

Include plans, elevations, sections and details of GRP fabrications and their connections. b. Show anchorage and accessory items. c. Clear sections showing all interfaces with supporting tank structures shall be included. Copy of Euro comp code is to be provided for the Engineer’s reference.

Samples 1. Samples of each type of GRP product proposed shall be submitted for approval. This shall be in the form of 300 x 300 mm specimen cut from a cover section to identify: a.


Surface texture and finish for externally visible areas. Page M-5 of 25


b. c. d. e. f. M15.4

Specifications

Laminate build up layers with thickness of each layer including gel coat. S.S accessories Neoprene gasket with coverlid sample. Samples of glass mats, and non-catalysed resin and the gel coat material Various colour samples of covers to choose the desired colour on site.

Quality Assurance A. Material covered by these specifications shall be furnished by a reputable and qualified manufacturer of proven ability who has regularly engaged in the manufacture and installations of GRP systems for atleast 10 years. B. Manufacturer’s Prequalifications 1. 2.

Firms shall be experienced in successfully producing GRP fabrications similar to that indicated for this project, with sufficient production capacity to produce required units without causing delay in the work. Firms shall have successfully completed covering of sewage treatment tanks or odour control with minimum 20,000 m2 covered areas of tank in any single plant.

C. Substitution of any component or modification of system shall be made only when approved by the Engineer and at no additional cost to the Employer. D. In addition to the requirements of these specifications, Contractor shall comply with manufacturer’s instructions and recommendations for such work. M15.5

Warranty A. Manufacturer and the Contractor shall jointly guarantee the completed GRP products installation to be free of defects in workmanship and or materials for a minimum period of Twenty Five (25) years from the date of Taking Over of the Works. B. Warranties and guarantees by the suppliers of various components in lieu of single source responsibility by the GRP products manufacturer will not be accepted. 1. 2.

The manufacturer shall be solely responsible for the warranty. In the event of a failure in the installation or a component is proven defective in service during the warranty period, the Contractor and manufacturer shall repair or provide a replacement without any additional cost to the Employer.

Contractor shall furnish Employer with the manufacturer’s guarantee and warranty certificate for all materials and components duly registered by the manufacturer. M16

PRODUCTS

M16.1

General A.

GRP fabrications shall be designed, fabricated and installed to withstand the specified structural loads without exceeding the allowable design working stress of the materials involved, including anchors and connections. 1. 2.


Loads shall be applied to produce the maximum stress and deflection less than allowable as per EUROCOMP code in each respective component of each GRP fabrication. Details of the secondary support system where required by the manufacturer shall be furnished to the Engineer for approval.

Page M-6 of 25


3.

Specifications

All calculations on selection of structural sizes shall be furnished to the Engineer for approval.

B. Materials used in the manufacture of the GRP products shall be new stock of the best quality and free from all defects and imperfections that might affect the performance of the finished product. C. All materials shall be of the kind and quality specified and where the quality is not specified, it shall be the best of the respective kinds and suitable for the purpose intended. All Glass mats used shall be ECR type powder bound and the resin used shall be epoxy based vinylester throughout the laminate wall. D. All GRP covers, shall be manufactured using a handlay up contact compression moulded, Light Resin Transfer Moulded or pultrusion process utilising an Epoxy based vinyl ester resin with flame retardant and ultra-violet (UV) inhibitor additives. All external surface shall be Gelcoat pigmented with vinylester resin. It shall be a composite laminate consisting of a corrosion resistant liner, barrier layer, a structural layer and an exterior Gelcoated resin rich layer. 1.

Two layers of “C” glass chemical resistant ‘ECR’ type surface veil shall be applied at the inner most layers covering the interior surface and minimum 700 gm/m2 Gelocat pigmented outermost layer covering the exterior surface. 2. GRP shapes shall achieve a flame spread class 1 in accordance with BS 476 Part 7. 3. The Barcol hardness of the inner & outer surface shall not be less than 35 when tested with a Barcol Impresser. E. All GRP items shall be corrosion resistant to raw sewage, sodium hydroxide, and sodium hypochloride as well as a 5% concentration of either Sulphur dioxide or Hydrogen sulphide, ammonia, methane and carbondioxide gases emitting from sewage. F. After fabrication, all cut ends, holes and abrasion of compression moulded and pultruded GRP shapes shall be sealed with a compatible resin coating to prevent intrution of moisture or other elements. G. GRP products exposed to weather shall contain an ultraviolet inhibitor and shall additionally receive one mil thick U.V. coating to shield from ultra-violet light. No item of fabrication shall be exposed to the external humid environmental without Gelcoate surface to avoid water ingress into the laminate. If Pultruded sections are used, these shall be fully encapsulated on compression moulded or contact moulded GRP laminates with proper Gelocated surface exposed to atmosphere. H. All exposed surfaces shall be smooth and true to form wherever applicable. I.

Colour shall be as instructed by the Engineer.

J.

Contact Moulded Flat and Curved Monolithic Panels: 1. Minimum Glass content in structural layer shall be 55% with multiaxial Glass, woven glass, CSM glass. For Resin rich corrosion barrier layer with C-Glass surface veil, the resin content shall be minimum 90%. 2. Resin used for lamination shall be vinylester based Bisphenol ‘A’ Epoxy and fire retardency to class 1 as per BS 476 Part 1. 3. Mechanical Properties Property

Test Method

Flexural Strength Tensile Strength

ASTM D790 ASTM 368


Page M-7 of 25

Minimum Requirement 300MPa 200 Mpa


Tensile Modulus Compressive Strength Flexural Modulus Izod Impact Strength

Specifications

ASTM ASTM ASTM ASTM

638 D695 D790 D256

14 GPa 150 MPa 13 GPa 12 J/cm

K. Compression Moulded Profiles: 1. 2. 3. 4.

L.

Minimum glass content shall be 55%. Compression moulded with continuous woven strand of “ECR” type reinforcing fiberglass together with vinylester formed at a minimum pressure or 2 bars to minimize porosity. Cure temperature shall be in excess of 93°C to assure proper adhesion of resin to glass fiber. Mechanical Properties:

Property

Test Method

Minimum Requirement

Flexural Strength Compressive Strength Flexural Modulus Izod Impact Strength

ASTM ASTM ASTM ASTM

245 MPa at 65°C 213 MPa at 22°C 18 GPa at 65°C 40 Nm at 22°C

D790 D695 D790 D256

Pultruded Profiles 1. 2. 3.

Minimum glass content shall be 70% continuous. “ECR” glass fiber reinforcements in continuous woven strands. Mechanical Properties.

Property

Test Method

Tensile Strength: Longitudinal direction Transverse direction

ASTM D638

Compressive Strength: Longitudinal direction Transverse direction

ASTM D695

Flexural Strength: Longitudinal direction Transverse direction

ASTM D790

Shear Strength: Longitudinal direction Transverse direction

ASTM D2344

Tensile Modulus: Longitudinal direction Transverse direction

ASTM D638

Compressive Modulus: Longitudinal direction Transverse direction

ASTM D695

Flexural Modulus: Longitudinal direction Transverse direction

ASTM D790


Page M-8 of 25

Minimum Requirement 200 MPa 48 MPa 200 MPa 100 Mpa 200 MPa 69 MPa 30 MPa 30 MPa 17 GPa 6 GPa 17 GPa 7 GPa 11 GPa 6 GPa


Specifications

Property

Test Method

Shear Modulus: Longitudinal direction Transverse direction

ASTM D2344

Density Water absorption (24 hr immersion) Barcol hardness Coefficient of thermal expansion Thermal conductivity

ASTM D792 ASTM D570 ASTM D2583 ASTM D696 ASTM C177

Minimum Requirement

3 GPa 3 GPa 1.66 – 1.94 g/cm3 Max 0.60% 45 8 x 10-6 mm/mm/°C 0.5 W/mK

M. Laminating Procedures The laminating procedures requiring approval shall include the following. a. General. Laminates of a basically similar construction to that proposed for the cover wall barrel and the domed web ends of the cover to be fabricated shall be tested in accordance with the specified standards. b. Flange web construction. Samples of the manufacturer’s standards forms of such details shall be laminated and their construction demonstrated as satisfactory by visual inspection of the finished sample, followed by inspection of cross sections taken through the flange/ web on two planes at right angles to each other. For each type of construction, there shall be at least one test piece each to represent details up to 50 mm nominal bore and of greater than 50 mm nominal bore. c. Cover shell. Samples of the manufacturer’s standard forms shall be laminated and their construction demonstrated as satisfactory by visual inspection of the finished sample, followed by inspection of cross sections taken through the shell on two planes at right angles to each other. For each type of construction, there shall be at least one test piece each to represent details up to 50mm nominal bore and of greater than 50mm nominal bore. d. Special forms of construction. Any special form of construction shall be demonstrated as giving satisfactory results by visual inspection of the finished sample and by examination of sections cut through the critical areas of the construction. e. Butt jointing. These shall be demonstrated as satisfactory by visual inspection of a finished mock up and of three sections cut through the sample on planes normal to that of the joints. N. Production samples for mechanical tests on laminates General Samples from waste areas such as cut-outs for branch openings shall be made available for inspection and appropriate testing, provided that they are typical of the laminate represented. Note: In the majority of cases such samples will not be flat and therefore there may be difficulty in carrying out all the mechanical tests which could normally be done on a flat sample. The properties of laminates are determined to a considerable extent by the type of glass reinforcement, the type of resin and the glass resin ratio and what is required from production samples is a clear indication that the properties of the laminate produced match the properties used in design. This information may be obtained by measuring the thickness of the laminate, burning off the resin to obtain the glass content, and examining the glass which remains to determine the type of glass and the number of layers. If the


Page M-9 of 25


Specifications

lap shear strength of the laminate is also determined, there shall be enough information to provide an adequate guide to the mechanical properties of the laminate. As an alternative to using cut-outs for test samples, specimen laminated shall be prepared by the operators working on the production laminate. These specimens shall be laid up at the same time with the same materials and in the same manner as the item they represent and cured under the same conditions as the main laminate. Testing The following tests shall be carried out on all samples to verify laminate construction and determine typical properties as given in Table 7-26. a) b) c) d) e) f) g) h)

visual examination of a prepared cross section of the cut-out or prepared samples; thickness of the laminate lap shear strength of laminate as specified in relevant standard. glass content (BS 2782: Method 1002); number of layers of glass and the type; acetone test (see B.18) of BS 4994 Barcol hardness of the inner and outer surfaces (see B.14); of BS 4994; the minimum requirement shall be at least 90% of the hardness value published by the resin manufacturer for the particular system. Glass Transition temperature in accordance with ASTM with D3418:99

When vinylester resins are used for the fabrication of covers and if following the Barcol test there is any doubt about the state of cure of the laminate, a residual styrene test shall be carried out. The residual styrene content of the laminate shall not exceed 2% by mass of the resin content of the sample or a glass transition temperature test, shall be carried out on a cut out cover production sample and the ‘Tg’ value observed shall not be lower than 80°C. relevant graph showing the ‘Tg’ value achieved shall be provided for engineer’s verification. The following tests shall be carried out when it is required to verify the mechanical properties of the laminate: 1) 2) 3) M17

ultimate tensile unit strength (see B.6); of Bs 4994 unit modulus (see B.7); BS 4994 ultimate compressive unit strength (see B.8); BS 4994

GRP DOME AND FLAT SHEET COVERS  



GRP dome or flat covers shall be provided for all the relevant tanks as shown on the Drawings. All covers shall be self-supporting from their periphery, and shall be pre-shaped segments or flat having various surface finish specified with gasket over lapping and screwed. Design Requirements 1. The design life shall be 25 years. The design and installation for all GRP covers shall incorporate provisions for thermal expansion and contraction over a range of ambient conditions specified. 2. Design safety factor of 4 and limiting states as per EUROCOMP Code for stress and deflection limits shall be applied to all load combinations. 3. Complete structural design calculation and shop drawings shall be submitted for Engineer’s approval.


Page M-10 of 25


M18

Specifications

GRP COVERS DESCRIPTIVE REQUIREMENT

Type ‘A’ Cover

Self

supporting

Type ‘B’ Self supporting Cover

Type ‘C’ Self Supporting Cover Trafficable

 

Live Load = 2.5 kN/m2 Features = Curved

 

Live Load = 2.5 kN/m2 Features = Non-Slip Flat Covers

 



Wind Load = 160 kM/h



Wind Load = 160 km/h





Internal Vacuum load: (- 0.5 kN/m2)



Internal Vacuum load: (-0.5 kN/m2)



Internal Pressure : 0.5 kN/m2





Panel Size : As designed by the manufacturer to suit the structure.





Live Load = 5.0 kN/m2 Features = Flat Covers pedestrian trafficable with chequer plate pattern & Load bearing anticipated Super imposed Load from mechanical Items = 7 kN/m2 Wind Load = 160 kM/h



Internal Vacuum load: (-0.5 kN/m2)







Panel size: As designed by the manufacturer to suit the structure.



Panel size : As designed by the manufacturer to suit the structure.

Joints between Panels: Neoprene or EPDM + S.S Screws



Joints between Panels Neoprene or EPDM + S.S Screws



Joint Between Panel Neoprene or EPDM + S.S Screws

GRP Beams : If Required, integrally moulded with Panels Surfaces finish external: Coloured with U.V Resistant GEL Coat



GRP Beams : If required, integrally moulded with Panels





Surfaces finish external: Coloured with U.V Resistant GEL Coat



GRP Beams = If required integrally moulded with Panels Surfaces finish external: Coloured with U.V Resistant GEL Coat



Support System = Structure production from moulds



Support System = Structure production from moulds



GRP Beams = If Required

All Fitting and Fixing : SS 316L Grade



All Fitting & Fixing : SS 316L Grade





All Fitting & Fixing : SS 316L Grade



Access hatches – required section as shown in the drawings









Gas tight Sealing – required with Neoprene + Sealant



Gas tight Sealing – required with Neoprene + Sealant





 Fixing & Hardware (a) To be set into concrete with an Epoxy outside the seal (b) Hinges, latches, handles, bolts etc Vol 3, Section3 – Civil Specifications

 Fixing & Hardware (a) To be set into concrete with an Epoxy outside the seal (b) Hinges, latches, handles, bolts etc Page M-11 of 25

Gas tight Sealing – required with Neoprene + Sealant  Fixing & Hardware (a) To be set into concrete with an Epoxy outside the seal (b) Hinges, latches, handles, bolts etc


Type ‘A’ Cover

Self

supporting

Specifications

Type ‘B’ Self supporting Cover

shall be SS .316 grade 

   

Light – No Light should penetrate through the covers Fresh air Inlet – Required Foul air Outlet – Required

Type ‘C’ Self Supporting Cover Trafficable

shall be SS .316 grade 

shall be SS .316 grade

Light – No Light should pass through the covers



Fresh air Inlet – Required Foul air Outlet – Required

 

Light – No Light should pass through the covers

Fresh air Inlet – Required Foul air Outlet – Required Lifting handles – As a safety feature, all lifting handles, and fixing both shall be recessed as per standard design. Rain Water Outlet – Appropriate rain water runoff is also to be considered, with water sealed U trap drain to the inside of the tanks. Note: Selection of Type A, B and C covers shall be based on specific area operation and maintenance requirement in addition to the covers design limitations and requires prior approval from Engineer.

M19

 

GRP DOME AND FLAT SHEET AESTHETIC COVERS      

GRP dome or flat aesthetic covers shall be provided for all the process tanks other than the tanks with odour control covers. GRP dome or flat aesthetic covers shall be similar to the odour control covers however the purpose of these covers is to enhance the plant’s aesthetic appearence. Structural design of aesthetic covers shall be similar to the odour covers. Gas tight sealing is not required for aesthetic covers. Adequate air inlet and outlets shall be provided to maintain the atmospheric pressure condition inside the covers. All covers shall be self-supporting from their periphery, and shall be pre-shaped segments or flat having various surface finish specified with gasket over lapping and screwed.

M20

TECHNICAL SCHEDULE

M20.1

Technical Schedule – Covers Individual Schedules to be completed for each set of covers offered.

M20.2

Technical Details The Contractor shall complete this Schedule giving manufacturer’s name and other details as required. All items supplied and/or installed must comply with the requirements of the specification.

Item

Offered

1. Covers 1.1 Place of Manufacture 1.2 Manufacturer 1.3 Type


Page M-12 of 25


1.4 1.5 1.6

No. Off Design Loading Size – Type A,B,C

Type Type Type Type Type Type

1.7

Weight per cover

1.8 1.9 1.10 1.11

Maximum span Maximum deflection (mm) Deflection /Span ratio Surface finish and UV resistance Fixing details Colour

1.12 1.13 1.14 1.15 M21

Specifications

A B C A B C

– – – – – –

GRP LAMINATION 1.

Laminate Sequence a. b. c. d. e. f.

Interior surface shall be resin rich corrosion barrier consisting of 0.50 mm thick with two layers of ‘C’ glass veil at 10% glass content and 90% resin. Surfacing veil shall be supported by 2.0 mm thickness barrier layer of woven roving or chopped strand “ECR” glass and vinyl ester resin. (ECR glass 2040% & resin 60-80%) Structure shall consist of alternating layers of ECR type multiaxial Glass or woven roving and chopped strand glass saturated with approved fire retardant Bisphenol A Vinylester resin to complete the required thickness. Total laminate thickness shall in no case be less than the design allowable safety factor of 4 or as per limiting states specified by EUROCOMP code for design of Composite Structures. Exterior surface shall be an exterior grade vinylester gel coat with ultra violet protection, fire resistant and pigmented cosmetic coating. No filler shall be permitted in the cover wall structure. 1. 2. 3.

g. M22

A paraffinated wax additive shall be used in conjunction with gel coat to eliminate the air inhibition (minimum 450 microns thick) Colour to be yellow or white unless otherwise approved by the Engineer. Coloured samples to be proposed for approval.

Cut edges or drilled holes must be deburred and resin or gel coat sealed.

FEATURES 1.

GRP Covers shall incorporate the following: a. b. c.


Fiberglass compression ring with cover. . Integral fiberglass tension ring. Internally moulded GRP ribs, beams and stiffeners. Any core used should be non metallic and fully encapsulated inside GRP laminate.

Page M-13 of 25


d. e. f. g. h. M22.1

Lifting lugs suitable for handling, installing and removing each segment are to be embedded at balance points in each segment. Drip lip shall be integrally moulded near the periphery of each panel segment to prevent condensate from seeping onto tank wall exterior. Alternatively provide separate FRP wall cover filled with an inner and other trickling edge. Gasketing for all joints and back flange of dome roof segments shall be neoprene. All assembly fastners and anchors shall be Grade 316L stainless steel.

Assembly 1. 2. 3. 4.

M22.2

Specifications

Fiberglass cutouts from dome segments shall be identified and shipped with cover. Cut outs shall be used by the Engineer to determine proper thickness, glass content and laminate sequence. Assembly of dome segments shall be such as to allow all bolting to be performed from exterior of dome roof. The assembled segments shall be bolted through the radial joints at a maximum of 1.5m centres during erection to render the cover a unified dome structure.

Non-Return Valves Non-Return valves will be constructed from SS316 stem with fiberglass gate and SS handle and locking mechanism. Non-Return valves shall be located where they can easily be operated from a walkway/ground level. Where it is unavailable dampers may be located in overhead duct runs provided a means of operation from ground level is developed by the contractor. Use of chains to address this requirement shall not be acceptable.

M22.3

Pressure Rating The covers shall be rated for a minimum pressure of –0.5kPa (g). Structural design shall also consider loading scenarios where potential negative pressures due to blockage of the air inflow points occurs.

M22.4

Structural Loading for Covers Covers shall be designed with safety of all personnel during manufacture, transportation installation, commissioning, operation and decommissioning in mind. The Subcontractor shall demonstrate during detailed design that each aspect has been considered. The contractor shall outline in their proposal how this shall be agreed.

M22.5

Cover Structural Supports The contractor shall design and supply all necessary supports for the covers if necessary. Any support under the cover shall be either SS316 or Fiberglass. The ultimate support for the covers shall be the tank walls. Contractor shall supply reaction force details with magnitude and directions for all reactions imposed by covers onto supporting tank structure. Cover shall be fabricated only after approval of these reactions report by the Engineer.


Page M-14 of 25


M22.6

Specifications

Temperature ratings

  M22.7

The ambient temperature at site may vary between 10 - 50 Degrees Celsius in the shade. Surface temperatures are likely to exceed this and should be accounted for in the design. The covers shall be exposed to direct sunlight. Incident solar radiation loadings shall be determined by the contractor in accordance with geographical location. Wind Loadings

The maximum wind velocity shall be considered based on Bahrain meteorological data. M22.8

Gaskets and Sealants All gaskets, regardless of where they are used, should conform to the following: Resistant to UV If self-adhesive strip is applied, this should maintain its adhesive properties for the design life (25 years)  Neoprene (or equivalent) Gaskets should be easily compressible, air tight and return to their original shape when load is removed.  Gaskets/sealant should be able to be removed and replaced it they become damaged.  Instructions for application of gaskets should be provided in the installation and maintenance manual;  Design life of gaskets should match that of the covers (25 years) or a replacement schedule and spares should be provided. Any non-conformances with the above requirements shall be listed in detail in Technical Schedule of cover.  

M22.9

Fixing, handles and associated fittings   

M22.10

Fixings should be suitable for under cover use (i.e. be able to withstand corrosion) and the use of dissimilar metals which may lead to galvanic corrosion should be avoided. Design life of all fixings should match that of the covers and ducts (25 years) Expansion, joints, cap plates, sliding joints etc. should be constructed of materials which do not deteriorate over time. Access, Inspection Covers and Hatches The contractor shall also be required to supply and install access hatches in the location as required.

M22.11

   M22.12

Chemical Resistance The Contractor shall design for peak gaseous H2S of 200ppm and shall advise the chemical resistance of the covers to condensate of low pH = 1. The cover production samples shall be subjected to 100 days acid immersion test as specified in Table 7-6 and comply the requirements specified. The Barcol hardness at cover internal surface after the acid test shall not be less than 35. Personnel Protection


Page M-15 of 25


Specifications

Equipment shall be guarded in accordance with the requirements of the Dubai Health and Safety Regulations and Guidelines. Guards shall be strong enough to withstand personnel and other loads during maintenance and inspection activities. Appropriate workplace health and safety warning signs complying with relevant Standards shall be fastened to all equipment. M22.13

Name – plates

A nameplate manufactured from grade 316 stainless steel shall be affixed to the cover by means of grade 316 stainless steel screws, stamped or engraved with the following information: Manufacturer’s name: Model/type description: Asset number: Serial number: Total weight: M22.14

Fastenings and Miscellaneous

All nuts, bolts, washers and other fastening systems used for covers and ducts shall be in grade 316 stainless steel. Any electrometric materials shall be in Nitrile rubber or EPDM, and consistent with the operating conditions, long-term exposure to direct sunlight and the required equipment design life. The holding down bolts shall be in stainless steel grade 316. M22.15

Painting

Painting of components shall be in accordance with relevant systems of Standard Specification. Manufacturer’s standard painting systems shall be considered suitable where they are equal to or better than the provisions of the Standard Specifications. Brief details of the painting system offered shall be entered into the Technical Schedules with its long performance test data. M23

QUALITY CONTROL AND PERFORMANCE TESTS

M23.1

Quality Control tests and records (To be witnessed by the Engineer)

Material records Record of resin type and quantity Record of glass type and quantity Record of personnel on the fabrication Record of layers and type of glass Vol 3, Section3 – Civil Specifications

Page M-16 of 25

Type ‘A’ Cover X X X X

Type ‘B’ Cover X X X X

Type ‘C’ Cover X X X X


Specifications

Record of cure system Record of post cure (when used) Quality Control Tests  Spark test on GRP Covers Prior to apply Gelcoat  Adequate documented information on the mechanical properties of the particular resin/glass laminate to be provided. If this is not available production test samples to be tested as required.  A production test coupon to be laminated with the cover obtained from cut-outs. The coupons to be tested, as follows.  Ultimate tensile unit strength (BS 2782 : method 1003)  Unit modulus (BS 2782 : method 1003)  Lap shear strength Bs 994 : 1987 B.9 Visual examination of cut-outs Ash test on cut – outs (L.O.I) Thickness measurementa Acetone test (polyester resin) BS4994 : 1987 (B.18)  Barcol hardness measurement BS 4994 : B14  Residual styrene (polyester resin) BS 4994 : B17 Acid immersion test in 10% concentrated sulphate acid @ 50°C in accordance with ASTM C581. Quality Control Records  Hardness test (Barcol)  Thickness measurement  Nameplate details  Documentation requirements Pressure /vac/hydrostatic head  Ultimate tensile unit strength  Unit modulus  Lap shear strength  Ash test on cut-out Independent inspection a To verify minimum design thickness. Particular attention is to be paid to points of discontinuity, at end attachments. Note: all Q.C tests are to be conducted prior to pigmented coating external    

M23.2

Type ‘A’ Cover X X

Type ‘B’ Cover X X

Type ‘C’ Cover X X

X

X

X

X

X

X

X X X X X

X X X

X X X

X X

X X

X X

X

X

X

X

X

X

X X X

X X X

X X X

X X X X X X

X X X X X X

X X X X X X

X

Examination after testing On completion of load and vacuum tests the cover shall be inspected internally and externally. Any indication of cracking, resin crazing or excessive strain shall be cause for failing the test. The cover linings shall again be spark tested after completion of testing; any evidence of cracks or weld defects of any necessary repairs the tests shall be repeated.


Page M-17 of 25


M23.3

Specifications

Information and requirements to be agreed and to be documented prior to Design and manufacture the covers. a)

Process conditions. 1) 2) 3) 4) 5)

b)

Site Conditions 1) 2) 3) 4) 5)

c)

Materials to be handled (names, concentrations and relative densities) including likely impurities or contaminates. Design pressure (or vacuum) including test requirements and design temperature. Operating pressure (or vacuum) and temperature. Mode of operation Any abrasion or erosion problems which may be encountered.

Nature of ambient atmosphere including any extremes of temperature. Superimposed loads, e.g. wind, snow and associated pipework Loads imposed by personnel during erection and operation Expected loading, e.g. traffic if any Seismic loading

Special Conditions 1)

d) e) f) g) h)

Formation of acidic droplets on interior surface of covers during condensation of H2s gas (acid rain) 2) Vibration due to adjacent plant 3) Agitation details within the covered tank 4) Danger of mechanical impact an damage 5) Loads imposed during transport 6) Finish, e.g. if fire-resisting Details of any special or additional tests or inspection required and where these are to be carried out Exemption to apply a pigmented coating to the covers before final inspection Facilities for testing Name of Inspecting Authority, if applicable Requirements for packaging, despatch and installation Nomenclature, symbols and units

Term Ultimate tensile unit strength (UTUS)

Definition The strength of a reinforcement type, expressed as force per unit width, per unit mass or reinforcement

Derivation Obtained from the fracture load of a laminate of known construction, in a tensile test

Load-limited allowable loading

The load permitted to be applied to a reinforcement type per unit width mass of reinforcement, not taking strain into account.

Determined by dividing the ultimate tensile unit strength by the design factor, k

uL

N/mm per kg/m2 glass

The load permitted to be applied to a reinforcement

Determined by multiplying the unit

uS


unit

Strain –limited allowable unit


Page M-18 of 25

Symbol u

Unit N/mm per kg/m2 glass


Term loading

Design loading design loading)

unit (layer unit

Unit modulus

Overall modulus

unit

Specifications

Definition type per unit width, per unit mass of reinforcement, taking only strain into account The load permitted to be applied to a reinforcement type per unit width per unit mass of reinforcement, for the cover under consideration. The ratio of the load per unit width to the corresponding direct strain, in a loaded tensile test specimen per unit mass of a single glass reinforcement type The calculated ratio of the load per unit width to the corresponding direct strain in full laminate of single or multiple glass reinforcement type.

Design Strength (laminate design unit loading)

The load carrying capacity of a laminate, expressed as force per unit width.

Unit load

The force per unit width carried by a laminate resulting from pressure or other loads applied to the cover.

M23.4

Derivation modulus, X, by the allowable strain for the particular laminate layer Whichever is the smaller or u S or u L at the design strain, Є d

Symbol

Unit

uZ


Obtained from the measured load and strain in a tensile test

X


Obtained from a summation of the products of unit modulus and mass of each glass reinforcement type in a laminate Obtained by summing the load carrying capacities of all the layers in the laminate (u, m, n, terms). The subscripts indicate a main (U LAM ) or an overlay (U OVL ) laminate. Obtained from the appropriate design calculations for the portion calculations for the portion of cover under consideration.

X LAM (may be identified by further subscript)

N/mm

U LAM U OVL

N/mm width

Q

N/mm width

Requirements to be agreed and documented prior to design and manufacturer the covers. The following items shall be agreed between the Inspecting Authority, where appropriate and the manufacturer shall be fully documented. Both the definitive requirements specified throughout the standard and the documented items shall be satisfied before a claim of compliance with this standard can made and verified. (a) (b) (c)

Resin system to be used shall be agreed between the engineer and the manufacturer Use of reinforcing materials other than those complying with BS 3396,BS 3691 or 3749, as appropriate. Mechanical properties of material as specified in the attached table


Page M-19 of 25


(d) (e)

Specifications

Type of chemical barrier to be used internal & UV protection coating external Design details 1) 2) 3)

(f) (g) (h) (i) (j) (k) (l) M23.5

Essential dimensions, including tolerances preferably on a drawing. Design calculations with references. Nominal thickness, including tolerances of corrosion-resistant lining gelcoat which does not contribute to strength 4) Form(s) of reinforcement including type, number and arrangement of individual layers. 5) Form(s) of local stiffening, where used. 6) Bolting and flange materials and details if required. 7) Gasket materials and details 8) Details of external. 9) Requirements for access and inspection openings Where the design incorporates reinforcement with directional properties, the orientation of the fibers Supports Any modification to the approved design Where site fabrication is employed, the special procedures to be adopted. Repair of laminate defects and method of repair Arrangements for access to manufacturer’s premises The provision of special test laminates and the extent of mechanical testing to be carried out either on cut-outs or prepared laminates.

Minimum categories & Type of Covers for Design basis consideration Type ‘A’ Cover

Contentsa Toxic gas from sewage Highly corrosive Corrosive Flammable Chemical compatibility of GRP with process

Type ‘B’ Cover

Type ‘C’ Cover

X X X X

X X X X

X X X X

X X X

X X X

X X X

T ≥ 60° C

X

X

X

Design pressure and/or vacuum as specified

X

X

X

Cover units shape & sizes

X

X

X

X X

X X

X X

X

X

X

Known long-term compatibility based on service experience Compatibility based on related performance data Only specimen data (dip coupons)available Design temperature, T

Geometry and supports Flat bottom support Any other, e.g. legs, skirts, saddles, rings and frames Other criteria If item is critical to safety


Page M-20 of 25


a

Specifications

Description of contents classification

Toxic

The contents could present a significant risk to health of persons exposed

Highly corrosive The contents could severely burn, blind, disfigure or maim an individual. Corrosive

The contents could cause damage to the skin or eye.

Flammable

The contents have a flash point equal to or less than 55°C.

a

M23.6

Heat distortion temperature of resin Design documentation and shop drawing requirements from the manufacturers Type ‘A’ Cover

Design Calculations a) b)

Type ‘B’ Cover

Type ‘C’ Cover

Independent approval required Calculations to cover 1) Hydrostatic loadings 2) Applied pressure 3) Applied vacuum 4) Wind loads 5) Lifting arrangements 6) Supporting 7) Seismic loading (if applicable)

Drawing requirements Covers general arrangement Full fabrication drawings showing method of manufacturer Installation procedure. M23.7

Smoke Testing Once installed all covers and ducts shall be smoke tested to check for leaks and to ensure airtight seal has been accomplished. Any leaks shall be repaired or sealed and the smoke test carried out again to prove.

M23.8

Works Testing Load testing of covers shall be carried out for at least one type of each cover produced.

M23.9

Inspection and Performance Testing

M23.9.1 Site Testing Pre-commissioning shall include Site Performance Proving Tests to demonstrate the performance and mechanical integrity of the covers.


Page M-21 of 25


Specifications

Pre-commissioning shall not commence until all documentation (including Operation and Maintenance Manuals) required to be supplied under the Contract have been approved by the Contractor. The Contractor shall provide all test instruments and tools necessary to carry out such tests. M23.9.2 Installation of GRP Dome & Flat Covers A. B.

Shall be in accordance with the manufacturer’s installation procedure. The cover system shall be so designed as to achieve minimum site activity. All covers shall be factory produced. Site assembly should be limited to inter panel joints and fixing to supporting tank structure. Only fittings shall be assembled at site. No cover fabrication at site shall be allowed without prior approval of the Engineer in exceptional situation.

M24

PACKING AND DELIVERY

M24.1

Labels and Markings All items shall be individually labeled prior to packing. Labels shall include the following information:



Contract Number



Item / Part Number

Marking  Applicable standard  Manufacture’s name  Design Load  Medium test pressure & working temperature  Year in which cover was completed  Resin & glass reference  The certifying work of the inspecting authority

Where items are manufactured for specific mating component parts, they shall all bear individual identification numbers and reference to the mating part identification numbers. M24.2

Packing All items shall be individually packaged for long term storage in a tropical environment, withstand the loads imposed during transportation. Goods shall be packed in wooden crates with weatherproofing inside to prevent damage or discolouration by exposure to the elements and potentially a lengthy storage period. Goods received in damaged packaging or crating may be returned to the contractor for re-manufacture and/or re-inspection and testing at the contractors cost. Crates shall be clearly marked in black stencilled lettering with the following information: Consignee’s name and delivery address as given in the subcontract. Consignor’s name and contact point. Contract number.


Page M-22 of 25


M25

Specifications

DOCUMENTATION SUBMITTAL The following information shall be supplied. 

Preliminary individual dimensioned general arrangement drawings of all equipment, and covers to be supplied under this sub-contract. These shall show all cover dimensions etc.



A priced Recommended Spares list.



Completed Technical Schedules



A detailed list of any deviations or omissions. Items not specified in this list shall be deemed included and comply with this specification.

M25.1

Detailed Design Drawings and data shall be submitted in stages for review as follows:

M25.1.1 Conceptual (Preliminary) Drawings and Data 



General arrangement and set-out drawings for the complete facilities showing overall dimensions, weights, hold down bolt layouts. Sufficient detail shall be shown regarding location of hatches, duct supports etc. to allow detailed design of other interfaces (e.g. duct support plinths) to be undertaken. Report on reactions imposed by covers onto the supporting tank structures for consideration by the engineers in design of tank structures.

M25.1.2 Approved For Construction Drawings and Data



Detailed covers layout drawings, equipment schedules, calculations, testing & commissioning schedules, full load rating Equipment drawings shall show key dimensions, plans and elevations, parts lists, materials of construction. Structural calculations report (with proper composites laminate design with micro & macro mechanical analysis) with material test certificates ( from National Physical Laboratory UK or equivalent Internationally reputed laboratory) supporting the material mechanical properties used in calculations.



All drawings shall be submitted in Auto CAD 2000.



Certified drawings of all proprietary items of mechanical equipment.



Draft maintenance procedures.



The Engineer’s review is only for acceptance of general conceptual design and for suitability in terms of dimensional constraints, e.g. overall arrangement, location of access, etc. it shall not in any way diminish the responsibility of the Contractor to comply with any of the specified requirements included for the equipment performance. The Engineer may elect to transmit electronic copies of accepted or commented drawings back to the Contractor or advise by correspondence in lieu of returning hardcopy drawings. Following receipt of accepted drawings, the Contractor shall resubmit each drawing to the Engineer, endorsed “For Construction”.


Page M-23 of 25


M26

Specifications

AS CONSTRUCTED DRAWINGS



During all stages of the work, the subcontractor shall maintain as constructed records on site. Records shall be available for inspection by the Engineer at any time.



Further to the requirements of the General Conditions of Contract regarding the Certificate of Practical Completion, the contractor shall be required to provide “As Constructed Drawings”.



As constructed information shall be amended on AutoCAD (R 2000) drawing files of the contract drawings. As-constructed amendments shall be identified by clouding on the drawings. Drafting standards shall be equal to the standard of the base drawings.



As constructed drawings shall be marked “As Constructed”, signed and certified by the Contractor as being a true representation of the works as constructed.

M27

OPERATION AND MAINTENANCE MANUAL The contractor will be required to provide operation and maintenance manuals for the equipment provided in accordance with the Specification. Copies of the Operation and Maintenance Manuals conforming to this Specification shall be provided by the contractor. The draft copies shall be submitted in accordance with the Schedule. The airflow balancing section of the O& M manual format shall be agreed with the Engineer prior to production. As a minimum the airflow balancing O&M shall set out: 

A general description of the procedure and equipment



The purpose of each component of the equipment



Hydraulic (or other measure) of the capacity of component of the process / equipment.



Mechanical, Electrical and control components of the equipment



Operational philosophy and control of the ductwork system



Troubleshooting guides



Maintenance requirements

M28

TESTING AND COMMISSIONING Testing and commissioning shall include, but not be restricted to: 

Design acceptance operation to demonstrate that all equipment and systems e.g. can be successfully and reliably operated under working conditions.



Satisfactory operation will be defined as meeting the following performance requirements:



Submission of final Operation and Maintenance manuals.


Page M-24 of 25


Specifications



Submission of any outstanding Work as Executed (WAE) records for all work under the contract, including re-submission of any WAE drawings that may require amendment as a result of changes during the commissioning process.



Conditions operation of the whole of the works for seven (7) consecutive days without any faults. During this period, if any failure occurs, the 7 day test shall recommence for a further 7 days, after the fault has been rectified.

In the event that the equipment fails to meet the guaranteed performance the Contractor shall carry out whatever remedial and ameliorative measures are necessary to achieve the guaranteed performance at his own cost. The certificate of practical completion will not be issued and final payment will be withheld until such time that all performance related criteria have been met or exceeded. The contractor shall produce all necessary documentation records as verification that installation testing and commissioning has been successfully completed. An up to date copy of developing test records shall be present on site at all times during construction and commissioning for information and review. Should the plant fail any test, the manufacturer Contractor shall take any actions deemed necessary to correct the failure and repeat the test. M29

TRAINING The Contractor shall provide a minimum of four (4) hours of competency based training and briefing for Client’s operations and plant maintenance staff. This shall be repeated in two separate sessions to fit in with work arrangements. The training shall be performed by experienced mechanical, personnel who are familiar with the installation. Training shall consist of, but not necessarily be limited to, the following. (a) Briefing on the equipment; / installation. (b) Servicing and maintenance requirements for the equipment; (c) Demonstration of any special servicing or maintenance procedures;

M30

MANUFACTURER’S PRE-QUALIFICATION The manufacturer shall have minimum 10years experience in manufacturing similar covers for STP and must submit the following documentations for the Engineer’s review. a) b) c) d)

List of references for the last 10 years. Certificate of completion from 5 clients. Test reports carriedout by independent authority on preview projects done for the last 10 years. The design calculation adopted for the similar covers installed during the last 10 years.


Page M-25 of 25


Specifications


SECTION N – PILE FOUNDATION

1

N1

GENERAL DESCRIPTION

1

N2

MATERIALS

1

N3

PILING METHOD

1

N4

CONCRETE FOR PILES

1

N5

REINFORCEMENT FOR PILES

1

N6

BORING FOR PILES

1

N7

PLACING CONCRETE

2

N8

EXTRACTION OF CASING

2


Page i of i


Specifications

SECTION N – PILE FOUNDATION N1

GENERAL DESCRIPTION Pile foundations if required shall be based on the detailed soil investigation carried out by Contractor. Contractor can refer the Ministry of Housing’s ground investigation survey results as a reference to understand the requirement. Pile depth shall be designed considering the existing underground aquifer at site. All pile foundation shall be bored cast-in-place concrete, all shall be constructed as per structural foundation requirement as per approved drawings and in compliance with BS 8004 requirements.

N2

MATERIALS  



N3

PILING METHOD  



N4



Concrete for piles shall be class 60 (as per Table D7 of Section D- Concrete Works, Volume 2, Section 3- Civil Specifications) and shall be in accordance with BS 8110 requirements. The concrete shall have sufficient workability to enable it to be placed and compacted by the methods used in forming the Piles.

REINFORCEMENT FOR PILES  

N6

The Contractor shall supply for approval all relevant details of the method of piling and the plant he proposes to use. The Contractor shall inform the Engineer each day of the intended program of piling for the following day and shall give adequate notice of his intention to work outside normal hours and public holidays. The Contractor shall submit to the Engineer his proposed sequence and timing for boring piles, having regard to the avoidance of damage to adjacent piles.

CONCRETE FOR PILES 

N5

The materials for the manufacture of the reinforced concrete shall be and in accordance to with BS 8110. The temporary casing shall be cylindrical and shall be of sufficient strength to maintain shape and location during boring and placement of concrete. The casings shall be sufficiently watertight to exclude ground water during placing of concrete. In case drilling mud is required, bentonite clay shall be used for the purpose.

The reinforcement for the piles to be high tensile deformed steel bars and shall conform to the requirement of BS 4449. Reinforcement in the form of a cage shall be assembled with additional support such as spreader forks and lacing, necessary to form a cage which can be lifted and placed without permanent distortion.

BORING FOR PILES

 

Prior to boring the Contractor shall the casing position for each pile during and immediately after placing the casing, and agree it with the Engineer. Casing shall be free from significant distortion. They shall be uniform cross-section throughout each continuous length. During concreting they shall be free from internal


Page N-1 of 2




N7

projections and encrusted concrete which might adversely affect the proper formation or piles. Where boring takes place through unstable water bearing strata, the process of excavation and the depth of casing employed shall be such that soil from outside the area of the pile is not drawn into the pile section and cavities are not created outside the casing as it is advanced.

PLACING CONCRETE   



N8

Specifications

The method of placing and workability of the concrete shall be such that a continuous monolithic concrete shaft of the full cross- section is formed. The concrete shall be placed without such interruption as would allow the previously placed batch to have hardened. The method of placing shall be approves. The contractor shall take all precautions n the design of the mix and placing of concrete to avoid arching of the concrete in casing. No soil liquid or other foreign matter which would adversely affect the performance of the piles shall be permitted to contaminate the concrete. Internal vibrators shall not be used to compact concrete.

EXTRACTION OF CASING 





Casing shall be extracted while the concrete within them remains sufficiently workable to ensure that the concrete is not lifted. During extraction the motion of the casing shall be maintained in an axial direction relative to the pile. When the casing is being extracted, a sufficient quantity of concrete shall be maintained within it to ensure that pressure from external, drilling fluid or soil is exceeded and that the pile is neither reduced in section nor contaminated. The concrete level within a casing shall be topped up where necessary during the course of casing extraction in such a way that the case of the casing is always below the concrete surface under the casting of the piles has been completed.


Page N-2 of 2


Specifications

SECTION S - SCHEDULE OF APPROVED STANDARDS & GUIDANCE PUBLICATIONS General Introduction Except where otherwise specified, all materials and workmanship shall conform to the requirements of the latest editions of the relevant Bahrain, European, and International Standards and Codes of Practice and any other Standards which are referred to in the Specification. The Standards and Codes shall be current at forty two days prior to the first date set for the delivery of Tenders. If necessary equivalent National Standards may be substituted for the Standards referred to in the Specification provided the Contractor shall have justified such substitution to the Engineer and only after written approval has been received from the Engineer. Matters not Covered by Standards Any materials and workmanship not fully specified herein, or covered by the Standards, Codes or Manuals, shall be of such type and quality so as to produce a first class work. In such circumstance, the Engineer shall determine whether all or any of the materials offered or delivered to the Site are suitable for use in the Works and the Engineer’s decision in this respect shall be final and conclusive. (1)

It is a basic requirement of the Contract that all materials and articles are manufactured/tested/supplied in accordance with recognised, approved, national or international Standards.

(2)

The Standards quoted in this schedule will be approved against the relevant Clause and/or item and give a guide as to quality requirements. This schedule does not prejudice the use of alternative, equivalent or superior Standards proposed by the Contractor in accordance with Section B of the Specification.

(3)

Reference to any Standard implies reference of all associated or related Standards referred to within that Standard.

(4)

The schedule includes reference to publications for guidance on current practice on some topics.

(5)

The editions of approved Standards used shall be those current 42 days prior to the date for the return of tenders.

(6)

The Contractor may be required to supply any of the Standards or publications listed in this schedule for the use of the Engineer (with English language translations where appropriate).

(7)

The following Standards Authorities and research bodies may be relevant to the Project and abbreviations for standards have been used in this schedule or elsewhere in the Specification: ACI American Concrete Institute P.O.Box 4754 Redford Station Detroit Michigan 48219 ANSI American National Standards Institute 11 West 42nd Street New York New York 10036 API American Petroleum Institute Division of Production


Page S-1 of 15


Specifications

300 Corrigan Tower Building Dallas Texas 75201 ASTM American Society for Testing and Materials 1916 Race Street Philadelphia Pennsylvania 19103 AWWA American Water Works Association 6666 West Quincey Avenue Denver Colorado 80235 BCPA BEC 82 New London

British Concrete Pumping Association Building Employer's Confederation Cavendish Street WIM 8AD

BRE Building Research Establishment Garston Watford WD2 7JR British Steel British Steel Plc Commercial Steels Marketing Services Dept. P.O. Box 1 Frodingham House Scunthorpe DN16 1 BP BS and BSI BSI Customer Services British Standards Institution 389 Chiswick High Road London W4 4AL Fax : +44 208 996 7001 C and CA formerly : Cement and Concrete Association now part of British Cement Association Wexham Springs Slough SL3 6PL CEN Comité Européen de Normalisation Rue de Stassart 36 B - 1050 Brussels The Chlorine Institute, Inc. 2001 L Street, N.W., Suite 506 Washington, D.C. 20036 Telephone: +1 202 775-2790 Fax: +1 202 223-7225 CIRIA Construction Industry Research and Information Association 6 Storey's Gate Westminster London SW1P 3AU Fax : +44 207 222 1708 Vol 3, Section3 – Civil Specifications

Page S-2 of 15


Specifications

CS The Concrete Society Devon House 12 - 15 Dartmouth Street London SW1H 9BL CP

Code of Practice, BSI

DoE, BRE Department of the Environment Building Research Establishment Transport and Road Research Laboratory London DIN Deutsches Institut fur Normung e.v. Beuth Verlag GmbH Burggrafenstrasse 4-10 1000 Berlin 30 EN Euronorm Boulevard de l' Empereur 5 1000 Brussels Belgium Euro Chlor Avenue E Van Nieuwenhuyse 4, box 2 B-1160 Brussels, Belgium Tel + 32 2 676 7211 Fax + 32 2 676 7241 HMSO Her Majesty's Stationery Office HMSO Publications Centre P.O. Box 276 London SW8 5DT MOWA Ministry of Works and Agriculture Government of Bahrain HSE Health and Safety Executive St. Hugh's House Stanley Precinct Bootle Merseyside L20 3QY ICE Institution of Civil Engineers Great George Street London SW1P 3AA IEE Institution of Electrical Engineers Savoy Place London WC2 ISO

International Standards Organisation

NACE National Association of Corrosion Engineers P.O. Box 218340 Houston, TX 77218 United States of America Vol 3, Section3 – Civil Specifications

Page S-3 of 15


Specifications

NJHSCWS National Joint Health and Safety Committee for the Water Service 1 Queen Anne's Gate London SW1H 9BT SIS Swedish Standards Institute Box 3295 S-10366 Stockholm 3 Sweden SSPC Steel Structures Painting Council United States of America WRc Water Research Centre (Engineering) Frankland Road Blagrove P.O. Box 85 Swindon Wiltshire SN5 8YR


Page S-4 of 15


Specifications

SECTION B – GENERAL OBLIGATIONS Safety, Health and Welfare

BS BS BS BS BS BS BS

3143 4465 5531 5973 6164 6187 7121

Safety Manual: BEF, BAS (2) “Code of Practice for Service Installation” – MOWA Guide : 'Construction Safety Manual' - BEC Safety Harnesses

BS BS BS BS

EN EN EN EN

354 355 358 361 to BS EN 365 inclusive

Safety in Sewers and at Sewage Works Guides: `Safety in Sewers and at Sewage Works' - ICE `Safe Working in Sewers and at Sewage Works'

NJHSCWS BS EN 60079-14 BS 6959 BS EN 132 to BS EN 139 inclusive BS EN 145 (BS 7170)

Abatement of Noise

Guide : 'Legislation and Practice on Noise Control on Construction Sites with particular relevance to Piling' - British Steel

Fire Safety Code of Practice

Ministry of Interior , Civil Defence and Fire Service Directorate

SECTION C - EARTHWORKS Use of Explosives

BS 5607

Support to Excavations

BS 6031 BS 6164 BS EN 1537

Guide : 'Trenching Practice'

Report 97, CIRIA

Site Investigation

BS 5930 including

Steel Sheet Piles

Guides : 'Piling Handbook' + others referred to therein - British Steel

Steel for Wailings, Capping and Tie Rods


Guide : 'The Standard Penetration Test (SPT): Methods’

BS BS BS BS BS BS

EN 10137-1 7668 EN 10029 EN 10113 EN 10155 EN 10210

Page S-5 of 15


Specifications

Control of Water

Guide : `Control of Groundwater for Temporary Works' - Report 113, CIRIA

Ventilation

BS 5720

Methods of Testing Soils and Relative Density Tests:

BS 1377

Rammer and Drop Method Sand-Cone Method Rubber Balloon Method Nuclear Methods Drive-Cylinder Method Sleeve Method

ASTM D 698 ASTM D1556 ASTM D2167 ASTM D2922 ASTM D2937 ASTM D4564

SECTION D - CONCRETE Water for Concreting

BS 3148

Cement: OPC (high C 3 A) SRC (medium C 3 A) SRC (low C 3 A)

ASTM 150 Type I or BS 12 ASTM 150 Type II or BS 12 ASTM 150 Type V or BS 4027

Guide : 'Sulphate and Acid Resistance, of Concrete in the Ground’ - BRE Digest 363, 1991 Methods of Testing Cement Heat of Hydration Test Acid Soluble Alkali Test

BS EN 196 BS EN 196-7 ASTM C186 BS EN 196-2

Aggregates

ASTM C33 or BS 882

Sampling of Aggregates

BS EN 1097-3

Aggregate Tests: Drying Shrinkage

BS 812, UK BRE Digest No. 35

Materials Finer than 75 Micron (Decantation Method)

BS 812

Clay Lumps and Friable Particles ASTM C142 Water Absorption

BS 812

Acid Soluble Sulphate

As BS 1377 but with acid solution

Acid Soluble Chloride

As BS 812 but with acid solution


Page S-6 of 15


Five Cycles of Soundness Aggregate Impact Value

Specifications

ASTM C88 BS 812

Aggregate (Fine) Grading

BS 882

Method of Test for Aggregate Organic Content

ASTM C40

Aggregates for Granolithic Concrete

BS 882

Reinforcement: Mild Steel and Deformed High Yield Cold Worked High Yield

BS 4449 BS 4449

Fabric Reinforcement

BS 4482 and BS 4483

Tying Wire

BS 1052

Epoxy Coated Steel Reinforcement

BS ISO 14654 ASTM A775/A775M

Admixtures BS EN 480-1 or ASTM C494 and Air Entrainment Agents BS 5075 or ASTM C260 Guides : Àir Entrained Concrete' CS Technical Report No. 18 `Guide to Chemical Admixtures for Concrete' - C & CA Curing Compounds

ASTM C171 and C309

Premixed Concrete

BS 5328

Design Constraints on Concrete Grades and Types

BS 114

Concrete Mix Design

Guide : `Design of Normal Concrete Mixes' UK, DoE, BRE : HMSO

Structural Use of Concrete Concrete Quality Control

BS 8110 BS 8007 BS 1881 ISO 1920

Guide : 'Testing Concrete in Structures : A guide to equipment for testing concrete in structures'. Tech. Note 143, CIRIA Determination of Air Content

BS 1881 Part 106

Thermometer

BS 1704

Formwork


Guides :

BS 5975 - Code of Practice for Falsework

Page S-7 of 15


Specifications

'Concrete Pressure on Formwork' - Report 108, CIRIA Bending Reinforcement

BS 8666

Batching, Transporting and Placing of Concrete

BS 1305 BS 5328

Guides :

'The Manual and Advisory Safety Code of Practice for Concrete Pumping' - BCPA 'Concreting Deep Lifts and Large Volume Pours' - Report 135, CIRIA 'Mass Concrete' - CS Digest No. 2 ‘Guide to concrete Construction in the Middle east’ – CIRIA

Water Bars

BS 903 BS 2571 BS 2782

Expansion Joint Filler

ASTM D1752

Joint Sealing

BS BS BS BS

Dowel Bars

2499 4254 5212 6213

BS 6744

Precast Concrete

BS 5911 BS 5642 BS 7263

Precast Concrete Manhole Segments

BS 5911 Part 200

SECTION E - PIPELINES AND PIPEWORK Concrete Pipes

BS 5911

Asbestos Cement Pressure Pipes and Joints

BS EN 512 ASTM C296 DIN 19800/1 ISO 160

Asbestos Cement Pipes for Sewerage and Drainage

BS EN 588 ASTM C428 ISO 881

Clay ware Pipes

BS EN 295 ASTM C700

Extra Chemically Resistant Clay ware Pipes

BS EN 295

uPVC Pressure Pipes

BS EN 1452 ASTM D2241 DIN 8061/2 ISO 2505


BS 8010

Page S-8 of 15


Specifications

ISO 3114 ISO 3472 - 3 uPVC Pressure Fittings

BS 4346 ISO 2035 ISO 2043 - 5 ISO 2048

uPVC Gravity Pipes and Fittings BS 4660 (up to 160 mm) BS EN 1401 (200 mm to 630 mm) ASTM D2729 DIN 19534 Reinforced Thermosetting Plastic

BS 5480, Pipes (RTR) ASTM D3262 ASTM D3517 ASTM D3754 AWWA C950

Pipe Joints Strain Corrosion Test

ASTM D4161 ASTM D3681

Resin Elongation Test

BS 4994 Method C5

Ductile Iron Pipes, Fittings and Joints

BS EN 598 BS EN 545 ISO 2531 DIN 28600

Grey Iron Pipes, Fittings and Joints

BS 4622 ISO R13

Flanges for CI and DI Pipework

BS EN 1515

Flange Gaskets

BS 2494 (Materials), BS EN 1514 (Dimensions)

Cast Iron Drain Pipes and Fittings

BS 437

Cast Iron Rainwater Pipes

BS 460

Cast Iron Soil, Waste and Ventilation Pipes

BS 416

Steel Pipes

BS 534 , BS 3601

Concrete Porous Pipes for Under Drainage

BS 5911 Part 114

Clay ware Field Drain Pipes

BS 1196

Perforated Clay Pipes and Fittings

BS EN 295

Plastic Pipes for Use as Light Duty Sub-Soil Drains

BS 4962


Page S-9 of 15


Ogee Jointed Concrete Pipes

Specifications

BS 5911 Part 10

Elastomeric Joint Sealing Rings BS 2494 , ISO 4633 Rubber Hardness (IRHD)

BS 2782-365A ISO 48 ISO 1400 ISO 1818

Shear Test Procedure for

BS 5911 Part 100 (Concrete)

Flexible Joints

BS EN 295/BS 65 (Clay) ASTM D3262/D3517/4161 (RPM) ASTM D3212 (uPVC)

Thrust and Anchor Blocks in

Guide to the Design of Thrust Blocks for Buried Pressure Pipelines - Report 128, CIRIA

Trenchless technology Pipe Jacking

Guide : 'Inspection to Trenchless Technology' - ISTT, UK Guide : 'Best Practice for Pipe Jacking' - Pipe Jacking Association,UK

Pipes for Micro tunnelling

BS EN 295-7ASTM C1208 BS 5911 Part 120 (draft EN 1916)

Guide : 'Simplified Tables of External Loads on Buried Pipelines' - HMSO Packing Rings

BS EN 120BS EN 312

SECTION F - BRICKWORK AND BLOCKWORK Bricks General

BS EN 772

Special Bricks (Shapes/Dimensions)

BS 4729

Calcium Silicate Bricks

BS 187

Concrete Blocks

BS EN 772

Sand for Mortar

BS 1199 and 1200

Methods of Testing Sands

BS EN 1097

Lime for Mortar

BS 890 BS 6463

Mortar Plasticizers

BS 4887

Pigments for Cement Products

BS 1014

SECTION G - CORROSION PROTECTION AND SURFACE COATINGS Corrosive Environments


BS 8102, BS CP102

Page S-10 of 15


Specifications

Tests for Membranes: Puncture Resistance Tensile Strength

ASTM E154 BS 2782

Water Absorption

ASTM D570

Bituminous Emulsion

BS 434 Part 1

Waterproof Building paper

BS 1521

Protective Coatings

BS 5493

Degreasing

BS 5493, BS 7773

Blast Cleaning

Zinc Metallisation :

BS 5493, BS 7079 ISO 8501-1 DIN 55928 SSPC-SPS (surface preparation specifications)

Hop Dip Galvanising

BS 729 ISO 1459

Zinc Spray

BS EN 22063

Extenders for Paints

BS 1795 ISO 3262

Glossary of Paint Terms Methods of Test for Paint

BS EN 97 BS 3900

Determination of Film Thickness BS 3900 Part C5 ISO 2808 Compatibility of a Product with the Surface to be Painted

BS 3900 Part C9 ISO 4627

Puff-off Test for Adhesion BS EN 24624 Surface Finish of Blast-Cleaned BS 7079 (Finish First quality) Steel for Painting ISO 8501-1 (Finish Sa 3) SSPC (Finish SP-5) Metallic Zinc-rich Priming Paint BS 4652 Liquid Organic Coatings and Finishes on Aluminium

BS 4842

CP for Protective Coating of Iron and Steel

BS EN ISO 12944 & BS EN ISO 14713

Powder Organic Coatings

BS 6496


Page S-11 of 15


Specifications

and Finishes on Aluminium Powder Organic Coatings and Finishes on Galvanised Steel

BS 6497

Specification of Materials paint & varnish standards)

ISO TC35

Holiday Detection

NACE Standard RP0188 NACE Standard RP0274 NACE Standard TM0384 ASTM G62

(ISO Catalogue list,

SECTION H – FITTINGS AND FABRICATED ITEMS Aluminium Alloy

BS 485 to 1301 inclusive (alloy N8) ISO 209 (Al-Mg 4.5 Mn) BS 8118

Wrought Steel General

BS EN 10084

Weldable Structural Steel

BS BS BS BS BS BS

Hot Rolled Sections

BS 4, BS EN 10210

Tubes

BS 6323

Hot Dip Galvanising for Mild Steel

BS EN ISO 1461

Stainless Steel

BS EN 10084

Steel Plates etc.

BS EN 10029 & BS EN 10048 Grades 316:S12 & S16 DIN equivalent grades Werkstoff Nos. 1.4404, 1.4435, 1.4401 & 1.4436 American Grades A151, 316 and 316L

EN 10137 7668 EN 10029 EN 10113 EN 10155 EN 10210

Reinforced Thermosetting Plastics: Manufacturing Standard

BS 4994

Resins

BS 3532 (Class B)

È' Type Glass Chopped Strand Mat Reinforcement

BS 3496 ISO R1888

È' Type Glass Woven Roving Fabrics

BS 3749


Page S-12 of 15


Tolerances

Specifications

BS 4549 Part 1

Quality Control: Cure - Barcol Hardness

BS 2782 Part 10 (Method 1001)

Glass Content


Flexural Strength


Ultimate Tensile Strength

BS 4994

Lap Shear Strength

BS 4994

Shear Strength of Bond

BS 4994

Peel Strength of Bond

BS 4994

Bolt Strength Test

BS 4549 Part 1 Appendix C

Electrical Properties

BS 2782 Part 2 (M. 221 & 232)

Valves - face to face and centre to face dimensions

BS EN 558 (BS 2080) , ISO 5752

Gate Valves for Water Supply Flanges

BS 5163 BS EN 1515

Flanged Gate Valves for Sewage

BS 5150 or BS 5163

Flanges

BS 4504

Access Covers and Frames, including ventilated

BS EN 124

Underground Hydrants

BS 750

Ladders

BS EN 131 (BS 2037) BS 4211 BS 5395 BS 1474 BS 1615 BS 729 ISO 1459

Road Gully Gratings

BS EN 124

Open Mesh and Chequer Plate Flooring

BS 5395, BS 4592 BS 6399 BS 1474 BS 1615 BS 729 ISO 1459


Page S-13 of 15


Specifications

Steel Guard railing

BS 1387 BS EN 10137 BS 7668 BS EN 10029 BS EN 10113 BS EN 10155 BS EN 10210 BS 5395 BS 6180 (Protective Barriers) BS 729 ISO 1459

Aluminium Guard railing

BS EN 515 & BS EN 573 BS 1472 BS 1474 BS 1615 BS 4211 BS 5395 BS 6180 (Protective Barriers) ISO 209

Steel Safety Chains

BS 3113

Polypropylene Rope

BS EN 696, BS 7648

ISO Metric Black Hexagonal Bolts, Screws and Nuts

BS 4190 ISO 885; ISO 888

Metal Washers for General Purposes

BS 4320, ISO R887

High Strength Friction Grip Bolts, Nuts and Washers

BS 4395 Parts 1 and 2 ISO 225

ISO Metric Black Cup and Countersunk Head Bolts and Screws with Nuts

BS 4933

Hot Dip Galvanising ISO 1459

BS EN ISO 1461

Electroplated Cadmium or Zinc Coatings

BS EN 12329 & BS EN 12330 ISO 2081 and 2082

ISO Metric Hexagonal Bolts Screws and Nuts

BS 3692

Bolting for Pipes and Fittings

ISO 2084

Spheroidal Graphite Iron Bolts ISO 1083

BS EN 1563

Rag Bolts

BS 1494


Page S-14 of 15


Specifications

Manhole Step Irons

BS 1247

Permissible Stresses and Design of Cranes

BS 2573

Hand Blocks

BS 3243

Chain Link Fencing and Posts

BS 1722 Part 1

Geotextile Fabric Filter Membrane

BS EN ISO 10319

Stainless Steel Clamping Systems

BS 1133 Section 15 BS 4853

Underground Services Warning Tapes

BS 2782 Parts 3 and 6 BS 5252

SECTION L - BUILDING WORKS Placing Damp-Proof Course


BS 8215

Page S-15 of 15

Specifications fro sewerage plant

Recommend Documents