SECTION 02513 ASPHALT CONCRETE PAVING PART 1 – GENERAL 1.1
DESCRIPTION OF WORK
A.
The extent of asphalt concrete paving work is shown on the approved design drawings and includes restoring to original conditions the work disturbed during the execution of contract work. The work includes provision, spreading and compacting of roadway and shoulders in compliance with these specifications.
B.
Related Work: 1.
Section 02232 Road Base
2.
Section 02577 Pavement Marking
1.2
QUALITY ASSURANCE
A.
Referenced Standards: 1.
2.
3.
American Association of State Highway and Transportation Officials (AASHTO). M20
Penetration Grade Asphalt Cement
M43
Crushed Stone and Crushed Slag for Bituminous Concrete Base Course
M81
Cut-back Asphalt (Rapid -Curing Type)
M140
Emulsified Asphalt
American Society for Testing and Materials (ASTM): D1559
Resistance to Plastic Flow of Bituminous Mixtures using Marshall Apparatus
D2041
Theoretical Maximum Specific Gravity of Bituminous Paving Mixtures
Saudi Arabian Standard - Ministry of Communications (MOC) Standard Specifications for Road and Bridge Construction.
P.O. Number : 7200018725
B.
Tests for Proposed Materials: 1.
2.
C.
Coarse and Fine Aggregates: (a)
Sieve Analysis: AASHTO T27. (ASTM C136)
(b)
Unit Weight and Voids in Aggregate: AASHTO T19 (ASTM C29)
(c)
Soundness Test: AASHTO T104 (ASTM C88)
(d)
Sand Equivalent Test: AASHTO T176 (ASTM D2419)
(e)
Abrasion of Coarse Aggregate: AASHTO T96 (ASTM C131)
(f)
Sampling of Aggregates: ASTM D75
Asphalt Cement: Asphalt Institute MS-4 (a)
Penetration: AASHTO T49 (ASTM D5)
(b)
Viscosity (Kinematic): AASHTO T201 (ASTM D2170)
c)
Flash Point: AASHTO T48 (ASTM D92)
(d)
Penetration after Thin-Film Oven Test: AASHTO T179 (ASTM D1754)
(e)
Ductility: AASHTO T51 (ASTM D113)
(f)
Solubility: ASHTO T44 (ASTM D8)
(g)
Specific Gravity: AASHTO T228 (ASTM D70)
(h)
Sampling of Bituminous Materials: ASTM D140
Design of Mixes: 1.
Design job mixes using the Marshall method as described in MOC Specifications.
2.
Test aggregate and asphalt cement for each material or grade, and report the following: (a)
Bulk Specific Gravity of Coarse Aggregate: AASHTO T85 (ASTM C117)
(b)
Bulk Specific Gravity of Fine Aggregate: AASHTO T84 (ASTM C128)
P.O. Number : 7200018725
3.
(c)
Apparent Specific Gravity of Mineral Filler: AASHTO T100, or AASHTO T133 (ASTM D854)
(d)
Specific Gravity of Semi-Solid Bituminous Minerals AASHTO T228 (ASTM D70)
(e)
Apparent Specific Gravity of Asphalt Cement: AASHTO T166.
Test uncompacted asphalt concrete job mix and report the following: (a)
4.
Maximum Specific Gravity: AASHTO T209 (ASTM D2041).
Test compacted asphalt concrete job mix and report the following: (a)
Bulk Density: AASHTO T166. (ASTM D1188)
(b)
Marshall Stability and Flow: ASTM D1559. This is to include test for loss of Marshall stability by submergence.
(c)
Thickness: ASTM D 3549.
5.
Perform four (4) sets of tests required under 3, 4 and 5 above for each asphalt concrete mixture, unless otherwise directed.
6.
Conduct a density and voids analysis for each series of asphalt concrete mixture test specimens. Report the quantity of absorbed asphalt cement in Kgs. of dry aggregate, percent air voids, and percent voids in mineral aggregate.
D.
All materials and methods shall conform to MOC Sections 3.05, 4.01, 4.04 and as specified herein.
1.3
SUBMITTALS
A.
Materials List: Submit copies of a listing identifying the types and sources of materials proposed for this work.
B.
Testing Laboratory Reports: Submit copies of laboratory test reports for tests performed in the process of mix design.
C.
Material Certificates: Provide copies of material certificates. Material certificates shall be signed by the material producer and the Contractor, certifying that each material item complies with, or exceeds, specified requirements.
P.O. Number : 7200018725
1.4
JOB CONDITIONS
A.
Weather Limitations:
B.
1.
Do not apply bituminous prime and track coats when the ambient temperature is below 10°C and when the base surface is wet or contains an excess of moisture which would prevent uniform distribution and the required penetration.
2.
Construct asphalt concrete courses only when atmospheric temperature is above 10°C and when the underlying base is dry.
Grade Control: Establish and maintain the required lines and grades, including crown and cross-slope, for each course during construction operations.
PART 2 – PRODUCTS 2.1
MATERIALS
A.
Granular Base Course: Reference Section 02232 "Roadway Base."
B.
Base Course Aggregate: Sound, angular material conforming to ASHTO 283, ASTM D692, ASTM D1073 or ASTM D1241, except gradation as specified below. 1.
C.
Combined aggregate within the following gradation limits: (sand equivalent 45 minimum; wear standard 25% maximum). Gradation and percent passing shall be specified in MOC 3.05 Class B.
Wearing Course Aggregate: Material conforming to AASHTO M79 and AASHTO M29, except gradation as specified below. 1.
Combined aggregate within the following gradation limits: (sand equivalent 45 minimum; wear standard 25% maximum). Gradation and percent passing shall be as specified in MOC 4.04 Class B.
D.
Mineral Filler: Limestone dust, portland cement, or other suitable inert material complying with the requirements of AASHTO M17, (ASTM D242) as applicable in MOC.
E.
Asphalt Cement: Comply with the requirements of AASHTO M20. 1.
F.
Penetration Grade: 60 - 70
Prime Coat: Cut-back asphalt type complying with the requirements of AASHTO M82 (ASTM D2027).
P.O. Number : 7200018725
1. G.
Grade: MC-1 or MC-70.
Tack Coat: Asphalt base complying with the requirements of AASHTO M81. 1. G
Grade: RC-2 or RC-250.
2.2
ASPHALT-AGGREGATE MIXTURES
A.
Provide job-mix formulas for each asphalt-aggregate mixture, complying with the asphalt concrete mix requirements, as herein specified.
B.
Tolerances: The following are the maximum permitted variations from the jobmix formula for each type of asphalt concrete mixture:
C.
1.
Aggregate Retained in No. 4 Sieve or Larger: Plus or minus 5 percentage points.
2.
Aggregate Passing No. 4 and retained on No. 200 Sieves: Plus or minus 5 percentage points.
3.
Aggregate passing No. 200 Sieve: Plus or minus 1.5 percentage points.
4.
Asphalt Cement Content: Plus or minus 0.3%.
5.
Temperature of Mixing: Plus or minus 10 degree C.
Performance Requirements: Base Course
Wearing Course
Marshall Stability, Kg.
500 min.
700 min.
Marshall Flow MM units
2.4 min. 5.0 max.
2.4 min 4.0 max.
Percent Air Voids
3.0 min. 7.0 max.
3.0 min 5.0 max.
60 - 75
70 - 80
Voids Filled with Asphalt Percent D.
Sampling and Testing During Paving Operations: 1.
Perform tests and inspections in accordance with ASTM D290 and as specified herein except all testing is to be performed by the approved Independent Testing Laboratory.
P.O. Number : 7200018725
2.
Sample at point of delivery and perform Marshall Analysis for each 500 tons produced but not less than once per days operation.
3.
Sample Hot Bins and perform grading analysis for each 500 tons produced but not less than once per day.
4.
Test shall be completed as soon as possible and test results are to be made available to the MARAFIQ within 24 hours of sampling.
PART 3 – EXECUTION 3.1
SURFACE PREPARATION
A.
Remove all loose material from the compacted subbase surface by power broom or proof rolling immediately before applying prime coats.
B.
Prime Coat: Uniformly apply the prime coat, distributed at the rate of 0.65 to 1.75 liters per sq m by calibrated distributor truck, over the compacted subgrade surface. Apply sufficient material to penetrate and seal, but not flood, the surface; use test strip to accurately determine spread rate. Allow to cure and dry as long as required to attain penetration and evaporation of the volatile, and in no case less than 48 hours. No traffic shall be allowed over prime coat.
C.
Tack Coat: Apply to contact surfaces of previously constructed bituminous concrete or portland cement concrete and similar surfaces. Distribute at the rate of 0.25 liters per sq m of surface. 1.
Apply tack coat by brush to contact surfaces of curbs, gutters, manholes, and other structures projecting into or abutting asphalt concrete pavement.
2.
Allow surfaces to dry until tack coat material is at proper condition of tackiness to receive the asphalt concrete mixture.
3.2
FRAME ADJUSTMENTS
A.
Set frames for manholes and other such units within areas to be paved, to final grade.
B.
Surround frames set to grade with a ring of compacted asphalt concrete base prior to paving. Place asphalt concrete mixture to 25 mm below top of frame, slope to grade, and compact with hand tamp.
3.3
PREPARATION OF THE MIX
A.
Aggregate Storage: Keep each component of the various sized combined
P.O. Number : 7200018725
aggregates in separate stockpiles. Maintain stockpiles so that aggregate sizes will not be intermixed or segregated. B.
Asphalt Cement Preparation: Heat the asphalt cement at the mixing plant to a viscosity which can readily be pumped and distributed throughout the asphalt concrete mixture. Add asphalt cement binder to aggregate at a temperature between 135°C and 163°C.
C.
Aggregate Preparation: Dry aggregates and deliver to the mixer at a temperature between 121°C and 163°C. Maintain the temperature between these limits according to the penetration grade and viscosity characteristics of the asphalt cement, ambient temperature, and workability of the mixture, while the asphalt cement is being added. 1.
D.
Mixing: Accurately weigh or measure dried aggregates and weigh or meter asphalt cement to comply with the job-mix formula requirements. Do not heat asphalt cement above 163°C at the time of introduction into the mixer. 1.
E.
Dry aggregates to reduce the moisture-content to prevent the asphalt concrete mixture from foaming, slumping, or segregating during hauling and placing operations.
Mix aggregate and asphalt cement to achieve 90 – 95% of coated particles for base mixture and 85 – 90% of coated particles for surface mixture.
Delivery: Transport asphalt concrete mixtures from the mixing plant to the project site in trucks having tight, clean compartments. If required, spray hauling compartment surfaces with a lime-water mixture or other approved lubricant. 1.
Provide covers over asphalt concrete mixture when delivering to protect the mixture from weather and to prevent loss of heat.
2.
During periods of cool weather or for long-distance deliveries, provide insulation around entire truck bed surfaces.
3.4
PLACING THE MIX
A.
General: Place the asphalt concrete mixture on the prepared surfaces, spread and strike-off using an acceptable bituminous paver. Spread mixture at minimum temperature of 139°C. Inaccessible and small areas may be placed by hand. Place each course in the required amounts so that when compacted, it will conform to the indicated grade, cross-section, and thickness.
P.O. Number : 7200018725
B.
Pavement Placing: Unless otherwise directed, begin placing along the centreline of areas to be paved on a crowned section, and at the high side of sections with a one-way slope, and in the directions of traffic flow. 1.
Place in strips not less than 3 meters wide, unless otherwise acceptable to MARAFIQ. After the first strip has been placed and rolled, place all succeeding strips and extend rolling to overlap previous strips.
2.
Complete all base course for a section before placing any surface course materials. Place mixture in as continuous an operation as possible.
C.
Hand Placing: Spread, tamp and finish the mixture using hand tools in areas where the use of machine spreading is not practical. Place mixture at a rate that will ensure proper handling and compacting before mixture becomes cooler than acceptable working temperature.
D.
Joints: Carefully make joints between old and new pavements, or between successive days' work, to ensure a continuous bond between adjoining work. Clean contact surfaces of sand, dirt, or other objectionable material and apply tack coat. Construct joints to have the same texture, density, and smoothness as other sections of the asphalt concrete course.
E.
Offset transverse joints in succeeding courses not less than 600 mm. Cut back the edge of the previously placed course to expose an even, vertical surface for the full course thickness.
F.
Offset longitudinal joints in succeeding courses not less than 150 mm. When the edges of longitudinal joints are irregular, honey-combed, or inadequately compacted, cut back all unsatisfactory sections to expose an even, vertical surface for the full course thickness.
3.5
COMPACTING THE MIX
A.
General: 1.
Begin rolling operations as soon as the mixture will bear the weight of the roller without excessive displacement. Do not suddenly change the line or direction of rolling.
2.
Compact the mixture with hot hand tampers or vibrating plate compactors in all areas inaccessible to rollers.
3.
Do not permit heavy equipment, including rollers, to stand on the finished surface before it has thoroughly cooled or set.
P.O. Number : 7200018725
B.
Procedure: Start rolling longitudinally at the extreme lower side of sections and proceed toward the center of the pavement. Roll to slightly different lengths on alternate runs of the rollers. Do not roll center of sections first under any circumstances.
C.
Breakdown Rolling: Accomplish the breakdown or initial rolling immediately following the rolling of transverse and longitudinal joints and the outside edge. Operate rollers as close as possible to paver without causing displacement.
D.
Check the crown, grade, and smoothness after the breakdown rolling. Repair displaced areas by loosening at once with lutes or rakes and filling, if required, with hot loose material before continuing rolling.
E.
Second Rolling: 1.
Follow the breakdown rolling as soon as possible, while the mixture is hot and in condition for proper compaction.
2.
Continue the second rolling for at least 3 complete coverages or until the mixture has been thoroughly compacted.
F.
Finish Rolling: Perform finish rolling while mixture is still warm enough for removal of roller marks. Continue rolling until all roller marks are eliminated and the course has attained the required density.
G.
Patching: 1.
Remove defective areas for the full depth of the course.
2.
Cut sides perpendicular and parallel to direction of traffic flow, and with edges vertical.
3.
Apply a tack coat before placing new asphalt concrete mixture.
4.
Compact by rolling to the required surface density and thickness.
H.
Protection: After final rolling, do not permit vehicular traffic on the asphalt concrete pavement until it has cooled and hardened.
3.6
MINIMUM QUALITY REQUIREMENTS
A.
General: In addition to other specified conditions, comply with the following minimum quality requirements: 1.
Provide final surfaces of uniform texture, conforming to the required grades and cross-sections.
P.O. Number : 7200018725
2.
B.
C.
D.
Take 100 mm diameter pavement specimens of each completed course, from locations as directed by the MARAFIQ. At least one specimen shall be taken for each 300 linear meters. Repair holes from test specimens as specified for patching defective work.
Density: When subjected to 50 blows of the standard Marshall hammer on each side of the specimen the minimum acceptable density of the in-place course material is as follows: 1.
Ninety-six (96%) percent of the average density recorded from 3 laboratory specimens.
2.
Correlate the location of the cut-out specimen to be the same area as the material from which the laboratory specimens were made. Verify from previous recorded data.
Thickness: In-place compacted thicknesses will not be acceptable if exceeding the following allowable variation from thicknesses shown on the drawings. 1.
Base Course: 10 mm, plus or minus.
2.
Wearing Course: 6 mm, plus or minus.
Surface Smoothness: Test and record the finished surface of each asphalt concrete course for smoothness, using a 3 meter straightedge applied parallel with and at right angles to centerline of paved area. Surfaces will not be acceptable if exceeding the following tolerances for smoothness: 1.
Base Course Surface: 12 mm
2.
Wearing Course Surface: 5 mm
3.7
PAVEMENT MARKING
A.
Paint markings in accordance with the drawings and as specified in Section 02577.
P.O. Number : 7200018725
