1. FLOOR SLAB AND ROOF SLAB SYSTEM
1.1 FLAT SLAB A flat slab is a two-way reinforced concrete slab th at usually does not have beams and girders, and the loads are transferred directly to the supporting con crete columns. Advantages of Flat Slab Flat Slabs are used by engineers in many building due to its advantages over other reinforced other reinforced concrete floor system in different cases. The most important advantages of flat slabs are given below: 1. Flexibility in room layout.
Partition walls can be placed anywhere. Offers a variety of room layout to the owner. False ceilings can be omitted.
2. Reinforcement placement is easier. As reinforcement detailing of of flat flat slab is simple, it is easier to place. 3. Ease of Framework installation. Big table framework can be used in flat slab. slab. 4. Building height can be reduced.
As no beam is used, floor height can be reduced and consequently the building height will be reduced. Approximately 10% of the vertical member could be saved Foundation load will also reduce.
5. Less construction time. Use of big table framework helps to reduce construction time. 6. Prefabricated welded mesh.
Standard sizes Less installation time Better quality control.
7. Auto sprinkler is easier.
Disadvantages of Flat Slab Flat slabs have some disadvantages also. The major disadvantages are given below. 1. Span length is medium. In flat plate system, it is not possible to have large span. 2. Not suitable for supporting brittle (masonry) partitions. 3. Use of drop panels may interfere with larger mechanical d ucting 4. Critical middle strip deflection In flat slabs, the middle strip deflection may be critical. 5. Higher slab thickness Compared to typical reinforced concrete two way slab system, the thickness of flat plate slabs are higher.
http://civiltoday.com/structural-engineering/31-advantages-disadvantages-flat plate-slab https://www.google.com.ph/search?q=FLAT+SLAB&source=lnms&tbm=isch&s a=X&ved=0ahUKEwjR1KjkoojWAhUEX5QKHcbpDf0Q_AUICigB&biw=1229 &bih=588#imgrc=S9rUeH_shtdnmM:
1.2 FLAT PLATE A flat plate is a one- or two-way system usually supported directly on columns or load bearing walls. It is one of the most common forms of construction of floors in buildings. The principal feature of the flat plate floor is a uniform or near-uniform thickness with a flat soffit which requires only simple formwork and is easy to construct. The floor allows great flexibility for locating horizontal services above a suspended ceiling or in a bulkhead. The economical span of a flat plate for low to medium loads is usually limited by the need to control long-term deflection and may need to be sensibly pre-cambered (not overdone) or prestressed. An economical span for a reinforced flat plate is of the order of 6 to 8 m and for prestressed f lat plates is in the range of 8 to 12 m. The span ‘L’ of a reinforced concrete flat plate is approximately D x 28 for simply supported, D x 30 for an end span of a continuous system, to D x 32 for internal continuous spans. Advantages of System:
1. Simple formwork and suitable for direct fix or sprayed ceiling 2. No beams — simplifying under-floor service 3. Minimum structural depth and reduced floor-to floor height. Disadvantages of System:
1. 2. 3. 4. 5. 6.
Medium spans Limited lateral load capacity as part of a moment frame May need shear heads or shear reinforcement at the columns or larger columns for shear Long-term deflection may be controlling factor May not be suitable for supporting brittle (masonry) partitions May not be suitable for heavy loads.
http://civildigital.com/basics-flat-plate-floor-system-advantages-disadvantages/
1.3 RIBBED FLOOR SLAB Ribbed floors consisting of equally spaced ribs are usually su pported directly by columns. They are either one-way spanning systems known as ribbed slab or a two-way ribbed system known as a waffle slab. This form of construction is not very common because of the formwork costs and the low fire rating. A 120-mm-thick slab with a minimum rib thickness of 125 mm for continuous ribs is required to achieve a 2-hour fire rating. A rib thickness of greater than 125 mm is usually required to accommodate tensile and shear reinforcement. Ribbed slabs are suitable for medium to heavy loads, can span reasonable distances, and are very stiff and particularly suitable where the soffit is exposed. For ribs at 1200-mm centres (to suit standard forms) the economical reinforced con crete floor span ‘L’ is approximately D x 15 for a single span and D x 22 for a multi-span, where D is the overall floor depth. The one-way ribs are typically designed as T-beams, often spannin g in the long direction. A solid drop panel is required at the columns and loadbearing walls for shear and moment resistance. Advantages:
Savings on weight and materials Long spans Attractive soffit appearance if exposed Economical when reusable formwork pans used Vertical penetrations between ribs are easy. Disadvantages:
Depth of slab between the ribs ma y control the fire rating Requires special or proprietary formwork Greater floor-to-floor height Large vertical penetrations are more difficult to handle.
https://civildigital.com/ribbedwaffle-slab-system-advantagesdisadvantages/
1.4 WAFFLE SLAB Waffle slabs tend to be deeper than the equivalent ribbed slab. Waffle slabs have a thin topping slab and narrow ribs spanning in both directions between column heads or band beams. The column heads or band beams are the same depth as the ribs. Waffle slabs achieve their strength by varying their height above ground. The higher the slab above ground – the deeper the beams. The deeper the beams – the more stiffness the system has. A Place for Waffle Slabs There is definitely a place for waffle slabs in the construction world. Waffle slabs work really well on sites that are almost flat, natural soils or controlled fill, that have good surface strength and where the natural ground surface falls away from the outsides of the building in all directions. They work well on non-reactive sites, slightly reactive clay sites and some moderately reactive clay sites. Waffle slabs are not recommended on highly reactive clay sites (Class H1 and H2) because the requirements for good drainage are almost impossible to achieve. Are Waffle Slabs a Great Idea?
Soft ground conditions. Extra bored piers or screw piers are required so that the system is supported on strong ground. Sloping sites. Waffle slabs are built on flat sites. On sloping blocks, the ground has to be made level first by digging some of it out or filling some of it in. Problems arise when some of the dirt dug out is used as uncontrolled fill on the low side of the b lock. All houses, even waffle slabs, need firm, even support to all parts o f the slab.
https://www.cornellengineers.com.au/beware-waffle-slabs/
1.5 LIFT SLAB Lift-Slab Construction is a precast method of construction of slab on the ground and then lifting it to the structure. A type of precasting used in building construction involves casting floor and roof slabs at or near ground level and lifting them to their final position, hence the name lift-slab construction. It offers many of the advantages of precasting and eliminates many of the storing, hand ling, and transporting disadvantages. It normally requires fewer joints than other types of precast building systems. Typically, columns are erected first, but not necessarily for the full height of the building. Near the base of the columns, floor slabs are cast in succession, one atop another, with a parting com-pound between them to prevent bond. The roof slab is cast last, on top. Usually, the construction is flat plate, and the slabs have uniform thickness; waffle slabs or other types also can be used. Openings are left around the columns, and a steel collar is slid down each column for embedment in every slab. The collar is used for lifting the slab, connecting it to the column, and reinforcing the slab against shear. To raise the slabs, jacks are set atop the columns and turn threaded rods that pass through the collars and do the lifting. As each slab reaches its final position, it is wedged in p lace and the collars are welded to the columns.
https://theconstructor.org/concrete/lift-slab construction/6824/
1.6 SPAN STRESS FLOOR SYSTEM 1. Unispan Floor Slab The Unispan flooring system consists of a series of 75mm thick precast, pressurised concrete slabs with reinforced concrete topping. This compo site construction allows clear spans of up to 8.0 metres. SIMPLE- Most contractors agree that Unispan is a simple form of construction. Slabs are typically 1200mm or 2400mm wide. FLEXIBLE- Unispan is easily adapted to any floor plan and individual slab widths can be custom made to suit individual requirements. Service holes can be allowed for in the slabs. MAINTENANCE- The Unispan flooring system is truly maintenance free. The slabs are cast on a steel mould and the soffit is flat. This means that Unispan may be left untreated, painted or decoratively sprayed to match colour schemes. Painted surfaces may require a thin plaster coat. SOUND TRANSMISSION- A major practical benefit of a concrete floor i s its ability to reduce noise transmission. Unispan concrete floors are quiet and do not creak with temperature and moisture changes. The table below shows sound the transmission ratings achieved by Unispan. CANTILEVERS- Balconies and decks can be created by cantilevering the slab up to 2000mm, while including a weather step at the building line. TRANSPORT- Unispan slabs must be handled and stacked at two points, by, or directly beside, the lifting eyes ERECTION- It is recommended that Unispan slabs be seated 75mm onto the supporting walls/beams and bedded on wet mortar or plastic bearing strips to ensure an even bearing at the correct level first. FIRE RESISTANCE RATING- Standard Unispan can provide up to a 1.5 hour FRR. MATERIALS- Unispan slab strength = 42 MPa at 28 days. Topping = 20 MPa at 28 days
https://www.scribd.com/document/159148542/ABT-5-Floor-Slab-System-Wall-PanelSystem-pdf
2. INTERSPAN FLOOR SLAB Interspan flooring system consists of 200mm wide precast pre-stressed concrete ribs spaced generally at 900mm centres with timber in fills placed between them. T he ribs have variable depth to suit the projects load/span requirements. This multi piece system is tied together with a 75mm in situ concrete topping and mesh reinforcing. This system has the benefit of being suitable for those tricky sites where access is a problem or poor foundation conditions dictate the use of a comparatively light weight floor. FLEXIBLE- Interspan is easily adapted to circular floor plans, where the use of other suspended flooring systems is difficult. Large floor openings of up to 700mm between ribs are easily accommodated. TIMBER INFILLS- Timber infill planks are merchant grade rough sawn timber. Timber in fills should be dampened prior to placing the concrete topping. Alternative timber types can be left with an exposed underside finish to create an architectural feature, e.g. polyurethaned macrocarpa or rimu SOUND TRANSMISSION- One of the major features of a concrete floor is the low sound transmission. The table below shows sound transmission ratings achieved by Interspan. TRANSPORT- Interspan Ribs must be handled and stacked at two points, at, or directly beside the lifting eyes. ERECTION- It is recommended that Interspan ribs be ideally seated 75mm onto the supporting walls/beams, and bedded on wet mortar, vinyl or plastic bearing strips to ensure an even bearing at the correct level. FIRE RESISTANCE RATING- Standard Interspan provides a 1 hour fire resistance rating. An increased fire rating can be achieved with specific design. ALTERNATIVE FLOORING SYSTEM- Hollowcore and Double Tee’s, are available for longer spans, and/or heavier loads. MATERIALS- Rib Strength= 42 MPa at 28 days Topping strength = 20 MPa minimum at 28 days.
https://www.scribd.com/document/159148542/ABT-5-Floor-Slab-System-WallPanel-System-pdf
3. HOLLOWCORE FLOORS Hollowcore is a 1200mm wide extruded, pre-stressed, voided slab unit with a reinforced concrete topping. Standard unit depths are 200, 300 and 400mm. Hollowcore is a 1200mm wide extruded, pre-stressed, voided slab un it with a reinforced concrete topping. Standard unit depths are 200, 300 and 400mm.Units are cut to a customised length and may have raking ends. Hollowcore is ideally suited for large floor spans with commercial loading. SOUND TRANSMISSION- One of the major features of a con crete floor is the low sound transmission. The table below shows sound transmission ratings achieved by Hollowcore floors. LIFTING AND HANDLING- Hollowcore floor slabs must be handled and suppo rted near their ends at all times. Fabric strops, purpose made clamps or lifting forks are recommended for installation. Chains or wire strops can be used but may cause some edge damage. Safety chains must always be used under units where clamps are used. ERECTION/END SEATING- A seating length of 75mm is recommended. Top surface of support should be packed using either damp mortar or a plastic bearing strip. Slabs must be positioned in contact with neighbouring units (unless otherwise noted). It is recommended to start placement working from the centre of the building out (where possible) as any construction tolerance can be spread over both sides of the slab area. PROPS- End props must be provided where they are required for stability of edge load ed beams. SHEAR CAPACITY- The shear capacity of extruded floor slabs is adequate for the uniformly distributed loads given in the load/span graphs. Concentrated loads near supports may result in high shear or strand bond stresses. Extruded slabs are not recommended for highway loadings, in truck docks or similar areas with high shear loads. FASTENING AND SUSPENSIONS- Light fastenings can be fixed in the area between strands by means of different anchors, bolts and sc rews. No fastenings must be attached within a 30mm radius of the pre-stressing strands. Heavier fastenings can b e attached either in the joint between slabs or through th e slab itself. The extra load due to suspension must be taken into account in the design calculations. A suspension point can be made at the joint between slabs by anchoringa steel rod into the joint concrete using a hook or welded steel piece on the end of the rod.
https://www.scribd.com/document/159148542/ABT-5-Floor-Slab-System-Wall-Panel-System
4. DOUBLE TEE FLOORS
Double Tee flooring units consist of two pre-stressed ribs and a co nnecting top slab. The ribs can vary in depth from 200 to 500mm.The connecting slab is2400mm wide x 50mm thick. DoubleTees are ideally suited for larger spanning floors with a wide variety of services suspended from the flooring system. Double Tees c an easily accommodate large floor voids/penetrations through the slab region. SOUND TRANSMISSION- A major practical benefit of a concrete floor i s its ability to reduce noise transmission. Double Tee concrete floors are quiet and do not creak with temperature and moisture changes. The table below shows sound transmission ratings achieved by Double Tees. FIRE RESISTANCE RATING- 2400 wide unit = 9 0 minutes BEARING CAPACITY- Where high shear loads are combined with support beams or walls of low material strength, a bearing capacity check according to NZS3101 should be made; e.g. masonry bearing walls. LIFTING- Lift Double Tees only at the lifting points provided. Chains or strops must be of correct length to carry equal load and must not be more than 300 off vertical. STORAGE- Double Tees if stored on site must be supported at their ends on firm ground. Bearers between layers in a stockpile must be vertically above each other and units of varying length should not be stacked upon each other. Ensure the bottom bearers are not pushed into the ground, resulting in the bottom unit being supported near mid span. SEATING- Flange supported Double Tees must be bedded on a sand cement mortar (the consistency of block laying mortar). This must be evenly spread just prior to the unit being placed. Double Tee legs should be placed on cement mortar or on plastic bearing pads. Double Tees are designed as pre-stressed sections as per NZS3101: Part 1:1995. For minimum seating requirements refer to NZS3101: Part1:1995, section .3.6.4.
https://www.scribd.com/document/159148542/ABT-5-Floor-Slab-System-Wall-Panel-System-pd
4.1 SLIP FORM METHOD Slipform construction is a method for building large towers or b ridges from concrete. The name refers to the moving form the concrete is poured into, which moves along the project as the previously poured concrete hardens behind it. The technique has also been applied to road construction. The technique was in use by the early 20th century for building silos and grain elevators. Vertical slipform relies on the quick-setting properties of concrete requiring a balance between early strength gain and workability. Concrete needs to be workable enough to be placed to the formwork and strong enough to develop early strength so that the form can slip upwards without any disturbance to the freshly placed concrete. A notable use of the method was the Skylon Tower in Niagara Falls, Ontario, which was completed in 1965. The technique was soon utilized to build the Inco Superstack in Sudbury, Ontario and the CN Tower in Toronto. It is the most common method for construction of tall buildings in Australia. From foundation to rooftop of even the very tallest projects, with the system’s hydraulic jacks, installing steel reinforcement and pouring concrete become much easier and faster, plus can be more efficiently controlled to assure the highest quality finished cement structure. SLIPFORM technology virtually eliminates unnecessary waste and hazard s, making this construction system even more efficient and economical. 1. SLIPFORM saves investment 2. SLIPFORM saves time 3. SLIPFORM saves labor 4. SLIPFORM is safety
https://theconstructor.org/construction/slipform-construction/185/
5. WALL PANEL SYSTEM
5.1 FLAT TYPE Flat type wall panel is a single piece of material, usually flat and cut into a rectangular shape, serves as the visible and exposed covering for a wall. FEATURES & BENEFITS 1. Energy efficiency is enhanced through the unique assembly design of the flat wall system, including thermal spacer blocks and fiberglass blanket insulation. 2. Special interlocking joint design allows panels to easily lock into for faster installation. 3. Can be combines with other Butle wall systems, or bricks, glass and other conventional materials. 4. 16” panel width, combined with the side “return leg”, enables application of almost any conventional finish on the interior of the wall system. 5. Factory-installed rigid insulation board for enhanced energy efficiency.
IDEAL USES Virtually any commercial or industrial building, from architectural applications to cold storage facilities.
https://www.scribd.com/document/275698609/Flat-Type-Wall-Panel-System
5.2 RIBBED TYPE Self-drilling, color-matched stainless steel capped Fasteners and a 36" p anel width give you rapid, economical installation. Comes in lengths up to 43', which can provide a continuous wall panel from foundation to leave. This eliminates the need for end lap s and as su re s yo u of wa ll in te grit y an d weather-tightness. These metal wall panels are available in 14 standard finish colors and a variety of cust om colo rs. 2 6 ga uge is st anda rd, but you also have the option of 22 or 24 gauge. BENEFITS 1. 2. 3. 4. 5. 6.
Variety of gauge thickness to meet most codes and specifications. Engineered for durability and aesthetic pleasing. Long panel lengths minimize end laps for optimum wall integrity. Superior paint finishes reduces maintenance costs. Eliminates the need for base trim and accelerates installation. Economical panel for most building applications.
APPLICATIONS Building Types
Retail Buildings Hangars Prison Facilities Equipment Maintenance Buildings Manufacturing Facilities Warehouses Distribution Centers
https://www.scribd.com/presentation/327040172/Wall-Panel-Systems
5.3 WINDOW TYPE WALL PANEL FEATURES AND BENEFITS 1. Provide the designer with an unlimited architectural vocabula ry of expression 2. Provide a significant design for any building type. 3. Offers quality and cost-effective construction. DESIGN OPTIONS 1. They may contain a single opening or a series of windows.
NARROW
SINGLE
WIDE
2. They are either one-storey in height and made as wide as possible, or cast narrower to span vertically for two or three floors.
SINGLE OR MULTIPLE USAGE
3. They can be recessed to optimize seasonal solar heat or to reduce glare. SHADING
WINDOW DETAILING 1. They can be in the same plane, without sills or projections. 2. They can be set in a deep coffer with margins projecting slightly. 3. They can be boxed out from general wall face.
FLEXIBILITY IN DESIGN 1. Promotes the use of master mold.
MASTER
LEFT HAND
HALF
RIGHT HAND
CORNER
2. Provides curved surfaces and works as corner u nits. 3. Offer flat or heavily sculpted profiles.
CURVED
ADVANTAGES 1. Cost and time efficient 2. Allows the fast fabrication of window frames and glass. 3. Has flexible design options. DISADVANTAGES 1. Heavy equipment for installation. 2. Changes are difficult because panels are made beforehand. 3. Heavily sculptured panels
https://www.scribd.com/presentation/327040172/Wall-Panel-Systems
5.4 TILT-UP WALL PANEL SYSTEM It is a technique of site casting concrete wall or elements, typically done on a horizontal surface and once cured, it is tilted vertically into place using a mobile crane. It is temporarily braced into its final standing position and is tied into the building’s roof and flooring system. HISTORY In 1907, Robert H. Aiken was designing and rebuilding retaining walls at the camp Logan riffle range in Illinois, thus tilt-up construction was born. However, du e to the expense of constructing tilting platforms, tilt-up did not catch on as a practical technique until 1946 when the modern mobile cranes were developed during World War 2. After the war, it became a popular technique. ADVANTAGES 1. 2. 3. 4. 5.
Fast, simple, and economical technique of construction. It eliminates the need for expensive transportation of materials. No expensive vertical formwork is required to finish the job. Low maintenance, it is not affected by moisture and weathering. Flexible, it can be easily removed and relocated if future expansion became necessary. 6. The fire safety rating of a concrete building will pro vide a fire endurance of two hours or more. DISADVANTAGES 1. Panels are engineered before work begins making changes difficult. 2. Complicated reinforcing patterns and layout of openings. 3. Lifting panels requires specialized equipment and third party en gineering to calculate the lifting loads.
https://www.scribd.com/presentation/327040172/Wall-Panel-Systems
