ABT 5 Floor Slab System, Wall Panel System.pdf

EULOGIO “AMANG” RODRIGUEZ INSTITUTE OF SCIENCE AND TECHNOLOGY Nagtahan, Sampaloc, Manila

Research in  Alternative  Alternative Building Construction Construction System System (ABT 415)

Submitted by: Jaballas, Ragene S. Submitted to:  Arch. Rolan Rolan B. Alamillo Alamillo Submission Date: June 17, 2013

FLOOR SLAB SYSTEM

Floor Slab is a structural slab, usually concrete, used as a floor or floor or a subfloor.

Floor systems are the horizontal planes that must support both live loads  – people, furnishing, and movable equipment  – and dead loads  – the weight of  the floor construction itself. Floor systems must transfer their loads horizontally across space to either  beams or columns or to loadbearing walls. Rigid floor  planes can also be designed to serve as horizontal diaphragms that act as thin, wide beams in transferring lateral forces to shear walls.  A floor system may be composed of a series of  linear beams and joints overlaid with a plane of  sheathing or decking, or consist of a nearly homogeneous slab of reinforced concrete. The depth of a floor system is directly related to the size and proportion of the structural bays it must span and the strength of the materials used. The size and placement of any cantilevers and openings within the floor plane should also be considered in the layout of  the structural supports for the floor. The edge conditions of the floor structure and its connection to supporting foundation and wall systems affect both the structural integrity of the building and its physical appearance. Because it must safely supporting moving loads, a floor  system should be relatively stiff while maintaining its elasticity. Due to the detrimental effects that excessive deflection and vibration would have on finish flooring and ceiling materials, as well as concern for human comfort, deflection rather than bending becomes the critical controlling factor. The depth of the floor construction and the cavities within it should be considered if it is necessary to accommodate runs of mechanical or  electrical lines within the floor system. For floor systems between habitable spaces stacked one above another, additional factors to consider are the blockage of both airborne and the structure-borne sound and the fire-resistance rating of the assembly.

Except for the exterior decks, floor systems are not normally exposed to weather. Because they all must support traffic, however, durability, resistance to wear, and maintenance requirements are factors to consider in the selection of the floor finish and the system required to support it.

Concrete

Cast-in-place concrete floor slabs are classified according to their  span and cast form. Precast concrete planks maybe supported by beams or loadbearing walls. 



Cast-in-place Concrete Floor  Slab

Steel

  

Steel beams support steel decking or precast concrete planks. Beams may be supported by girders, columns, or loadbearing walls. Beam framing is typically an integral part of a steel skeleton frame system.

Composite beam is astructural member composed of two or more dissimilar materials joined together to act as a unit. An example in civil structures is the steel-concrete composite beam in which a steel wide-flange shape (I or  W shape) is attached to a concrete floor slab (see illustration). The many other kinds of composite beam include steel-wood, wood-concrete, and plastic-concrete or  advanced composite materials –concrete. Composite beams as defined here are different from beams made from fiber-reinforced polymeric materials. Steel-concrete Composite Beam Floor System

Wood

WAFFLE SLAB



A

reinforced

concrete slab with

equally

spaced ribs

parallel to the sides, having a waffle appearance from below. 

A

reinforced

concrete

floor

and

roof

construction

employing a square grid of deep ribs with coffers in the interstices.

WAFFLE SLAB  A waffle slab is a type of building material that has two-directional reinforcement on the outside of  the material, giving it the shape of the pockets on a waffle. This type of reinforcement is common on concrete, wood and metal construction. A waffle slab gives a substance significantly more structural stability without using a lot of additional material. This makes a waffle slab perfect for large flat areas like foundations or floors. The most common material for a waffle slab is concrete. These slabs are used as the foundation for  many different types of buildings and structures, but are most common in commercial or industrial buildings. Waffle foundations are resistant to cracking and sagging and can hold a much greater amount of weight than traditional concrete slabs. The top of a waffle slab is generally smooth, like a traditional building surface, but the underside has a shape reminiscent of a waffle. Straight lines run the entire width and length of the slab, generally raised several inches from the surface. These ridges form the namesake square pockets of the entire length and width of the slab. Other building materials have adopted the waffle design. It isn’t uncommon to find waffle ceilings in energy-efficient homes. These pockets both support the structure and help insulate the floor above by trapping hot air inside the pockets. This practice has spread to several other building materials such as sheet metal and fiberglass insulation. In both of these substances, the inherent reinforcement and insulating capabilities of the waffle shape are put to use, offsetting the parent material’s shortcomings. Resembling the food after which they are named, concrete waffle slabs are reinforced concrete floors and roofs that use a square grid of deep sides. This form of construction is used in airports, parking garages, commercial and industrial buildings, bridges, residences and other structures requiring extra stability.

Design There are three basic designs for concrete slabs that improve the strength-to-weight ratio. For each design, the top surface is flat while the underside is modulated with either a corrugated, ribbed or waffle design. Corrugated slabs are created when concrete is poured into a wavy metal form. This shape prevents the slab from sagging. Ribbed slabs add strength in one direction, while the concrete waffle slab design adds strength in perpendicular directions. Concrete slabs can be reinforced with rebar for additional strength.

Production Concrete waffle slabs can be purchased and shipped to the construction site as prefabricated or  precast sections, or they can be poured on-site. If prefabricated products are not in the budget, consider  purchasing casts for the concrete waffle slabs. According to Tradeline, waffle slab construction is defined as "a building system using concrete 'waffle slab' floors supported by columns. The waffle slab is a monolithic-poured concrete slab with a flat top surface and an under-surface made of a rectangular grid of  deep concrete beams running at right angles. The floor area between the grid beams is a thin flooring section. From the underside, the slab resembles a waffle. The floor is supported by columns spaced typically 30 feet on center."

Implementations Concrete waffle slabs are often used in clean rooms or in other areas that require isolation from lowfrequency vibrations, and areas that require low-floor deflection. PolySteel sells concrete waffle forms for walls. According to the company, insulating concrete forms earned a 4-hour fire rating and has a 27-year track record. The forms are available in 6", 8" and 10" sizes, plus 45 and 90 degree forms. Whether purchasing precast products or pouring the concrete on-site, concrete waffle slabs have many uses for commercial, industrial and residential projects.

WAFFLE SLAB Waffle Slab Forms Western produces custom prefabricated lightweight aluminum waffle slab forms to user  specifications. The aluminum waffle slab form is made with special provisions to facilitate stripping even when holes are drilled into the form. The quality of the finish is comparable to similar forms made of  fiberglass and other materials. Yet durability and cost-effectiveness are higher. Unlike fiberglass, UV light from the sun does not deteriorate the form surface. The consistent, durable forms are easy to arrange precisely. They nest closely for convenient stacking in the minimum space. The tapered shape, light weight, and special interior pulling lugs make stripping easy. All Western Forms fabricated waffle forms are continuously welded and internally braced to insure a long useful life.

Floor Joist Forming The five step process is pictured below. Floor joist slab forms are set in place. Once the forms are set the next step is to set the reinforcing steel. As soon as the steel is in position then it is time to pour  the concrete. When the concrete is cured the forms are removed to leave the concrete floor joists in place for the structure. Fast, quality construction to last a lifetime.

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 may control the fire rating Requires special or proprietary formwork Greater floor -to-floor height Large vertical penetrations are more difficult to handle.

LIFT SLAB It is the system of construction in which the floor slab and the flat roof are cast one over the other at ground level at round columns or in situ cast service, stairs and lift cores. Jacks operating from the columns or cores pull the roof and floor  slabs up into position. The consecutive slabs are separated through a medium like-wax dissolved in volatile spirit or polythene sheets or building paper. The slabs are cast monolithically and can be designed to span continuously between and across points of support and so employ least thickness of slab. Balconies and other extension columns are part of the slab.

Application Lift slab floating floor systems that incorporate spring isolator assemblies to decouple concrete slabs from non-isolated structural floors are used where vibration and impact are critical and of greater concern than airborne noise transmission. In instances when vibration and/or impact noise control are severe, the air space beneath the spring-isolated floor is vented. This enables the composite construction to yield the lowest natural frequency (fn) possible thereby enhancing performance against lower disturbing frequencies. If additional control of airborne noise is needed for a vented floating floor, the floor/ceiling composite will require partitions on the floating floor at the perimeter and/or an isolated ceiling. Representative examples of projects that can justify the use of spring lift slab isolators are bowling alleys, weight rooms, gymnasiums, aerobic activities, and dance studios. Spring isolators also are incorporated into lift slab floors supporting sensitive measuring equipment in order to mitigate vibrations that could compromise performance. While the bulk of isolated slabs can be supported using fiberglass or  neoprene pads, most often in formwork systems, spring-isolated lift slabs are needed for the most critical vibration and impact noise isolation requirements. Typically, the Model LSM system supports a four inch (4") thick standard weight (150 PCF) concrete slab using spring isolator mounts spaced up to 54" on center. First, Perimeter Isolation Board (Model PIB) is adhered to the perimeter of the floating floor area. Then, one (1) layer of 6-mil thick poly sheeting is rolled-out across the structural slab and up Model PIB, serving as a bond breaker between the nonisolated concrete structure and the concrete floor being floated. Next, isolator mounts are located and placed on top of the poly sheeting according to approved submittal drawings. Isolator mount spacing and capacity can vary depending on load requirements across the floating floor. Extra mounts may be required to carry additional loads imposed by, for example, walls and heavy equipment placed on the slab after it is lifted. Once the isolator housings are in place, steel concrete reinforcement bars are used to

interconnect the mounts. Additional reinforcement as dictated by conventional concrete slab design requirements may be required before concrete is poured level to the tops of the mounts. Up to 30 days may be required for the concrete to cure to strength. Once the concrete has cured properly, spring assemblies are inserted into the housings and the slab is lifted to the specified height. When the slab is lifted to specified height, the composite construction typically includes a 1" or 2" air cavity. Complete installation guidelines and isolator array plans and details are included in the project submittal package.

LIFT SLAB

LIFT SLAB

Stages in Construction The steel and concrete columns are the first fixed in position and the rigidly connected to the foundation and the ground floor slab is then cast. When it has matured it is sprayed with two or three coats of a separating medium consisting of wax dissolved in a volatile spirit. Polythene sheet or building paper may also be used as an alternative. The first floor slab is cast inside edge formwork on top of the ground floor slab and when it is turn coated or covered with the separating medium and next floor slab in cast on top of it. The casting of successive slab continues until all the floors and roof have been cast on one on the other on the ground. Lifting collars are cast into each slab around each column. The slab are lifted by jacks, operating on the top of each column, which lift a pair of steel rods attached to its lifting collar in the slab being raised.  A central control syncronises the process for the uniform lift from all directions.

The sequence of lifting slabs in depends upon: Weight of the slabs Height of the building Lifting capacity of jacks Cross sectional area of columns during initial lifting    

LIFT SLAB The bases of the columns are rigidly fixed to the foundations so that during lifting they act as vertical cantilevers. The load that the column can support at the beginning of the lift limits the length the length of the lower column height and no. of slabs that can be raised one at a time.  As the slabs are raised they serve as horizontal props to vertical cantilevers and so increasingly stiffening them.

Lifting Collars They are cast into each slab around each column providing a means to lift the slab and also providing shear reinforcement. They are fixed to columns by welding shear blocks to plates welded b/w column flanges and to the collar after the slab has been raised in position.

The connections to concrete columns are made by welding shear blocks to end of steel channels cast into the column and by welding the collar wedges. Concrete is cast around steel wedges for fire protection. The connections of extension columns are made by welding bolting or riveting splice plates to the flanges of columns at their junctions.

Advantages of the System Can be advantageous system in building with similar floor plans throughout the height of the building and where flush slab maybe desired.

LIFT SLAB Eliminates need for redundant formwork as only shuttering required on the edges-hence simplicity in casting. May also be employed to give waffle grid however compromising on the ease of casting.

Drop Slab His floor construction consists of a floor slab which is thickened b/w columns in the form of a shallow but wide beam  A drop slab is about the same dead weight and cost as a comparable slab and beam floor will have up to half the depth of floor construction from top of the slab to soffit of beams. For example on a twelve square column grid the overall depth on the slab and the beam floor would be about 1.2 where the depth of a drop slab floor would be about 600. Consequently this difference would cause a significant reduction on overall the height of construction of multi-story building with appreciable savings and cost.

Benefits Fabricated, non-cast isolator housings permit flexible product and system design that maximizes application opportunities for any slab thickness, air cavity, and/or load options. Spring isolator natural frequencies (fn) of 3.13 Hz for 1" rated deflection springs and 2.21 Hz for 2" rated deflection springs. Other rated deflection springs available. In-field acoustical testing yielded results of FIIC 72, FSTC 61 for a vented (non-vented floors can yield higher FSTC values) floating floor. Spring/neoprene cup combination improves performance against low-frequency noise. Proven effective for vibration isolation applications ranging from floors for sensitive lab measuring equipment (e.g., metrology and surgical labs) to sports floors over retail/commercial spaces. Factory installation and/or supervision available.

SPAN STRESS FLOOR SLAB

Stresscrete offers four  standard types of flooring units, Unispan, Interspan, Hollowcore

and

Double

Tee. Each has it's own unique characteristics and advantages, but which one is right for your project?

SPAN STRESS FLOOR SLAB 1.)Unispan Floor Slab The Unispan flooring system consists of a series of 75mm thick precast, prestressed concrete slabs with a reinforced concrete topping. This composite 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 is its abil ity 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.

SPAN STRESS FLOOR SLAB 2.)Interspan Floor Slab The Interspan flooring system consists of 200mm wide precast prestressed concrete ribs spaced generally at 900mm centres with timber infills placed between them. The 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 lightweight 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 infills 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 Systems 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

General Topping thickness =75mm Propping = from 1-4 props Rib centres = 900mm Fire rating 60 minutes

SPAN STRESS FLOOR SLAB 3.) Hallowcore 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. Units are cut to a c Hollowcore is a 1200mm wide extruded, prestressed, voided slab unit 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.ustomised 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 concrete 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 supported 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 loaded beams. Fire Resistance Rating  A standard fire resistance rating of Hollowcore units in the load span tables is 2 hours. Fire resistance ratings are unrestrained ratings and are based on minimum strand cover and equivalent concrete thickness requirements. 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.

Fastenings and Suspensions Light fastenings can be fixed in the area between strands by means of different anchors, bolts and screws. No fastenings must be attached within a 30mm radius of the pre-stressing strands. Heavier  fastenings can be attached either in the joint between slabs or through the 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 j oint between slabs by anchoring a steel rod into the joint concrete using a hook or welded steel piece on the end of the rod. Penetrations Small holes and recesses between strands at the position of the voids are usually made on the building site. Holes may be circular or  rectangular, and up to three are permitted in the same cross section (two for 300mm and 400mm units). Holes are considered to be in the same cross-section if they are less than 750mm apart in the longitudinal slab direction. When making holes, great care must be taken not to damage the slab. It is particularly important that the pre-stressing strands are not cut or exposed. Water in Cores Some construction practices and weather conditions can result in water being trapped in the cores. Holes may be drilled in the ends of all units to drain this water. Materials Strand - Stress relieved 7 wire strand to BS 5896 Topping strength = 20 MPa minimum at 28 days. Unit strength = 42 MPa at 28 days minimum. Hollowcore may be designed for other uses such as wall cladding, and retaining wall structures.

4.) Double Tee Floors Double Tee flooring units consist of two pre-stressed ribs and a connecting top slab. The ribs can vary in depth from 200 to 500mm.The connecting slab is 2400mm wide x 50mm thick. Double Tees are ideally suited for larger  spanning floors with a wide variety of  services suspended from the flooring system. Double Tees can easily accommodate large floor  voids/penetrations through the slab region. Sound Transmission  A major practical benefit of a concrete floor is 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.

Material Double Tee concrete strength = 42 MPa. Topping concrete strength = 20MPa. Topping thickness = 65 mm

SPAN STRESS FLOOR SLAB Fire Resistance Rating 2400 wide unit = 90 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: Part 1:1995, section .3.6.4. When choosing the right flooring unit for your project, you may need to consider the following: Ceiling Profile Unispan and Hollowcore have a flat unit profile, which may be left uncovered eliminating the need for a suspended ceiling to achieve a flat look. Interspan and Double Tees have a stepped profile and are easily fitted with a suspended ceiling to achieve a flat look. A stepped profile has the advantage of being able to run services parallel between the vertical ribs. Floor Loading And Design Services Each floor unit is individually designed to comply with the requirements of the New Zealand standards and Building Code. To ensure best practice, our staff maintains contacts with international professional groups and industry leaders. Overall Floor Depth The overall depth of the flooring system will vary depending on the concrete topping thickness (typically a minimum of 65 mm), flooring unit depth (dependant on span and load) and the ceiling cavity depth. For residential construction, Unispan is typically the shallowest flooring unit followed by Interspan. For commercial construction, Hollowcore is typically the shallowest flooring unit followed by Double Tee's. Floor Penetrations / Openings Interspan and Double Tee's can easily accommodate large floor penetrations. Most penetrations, both large and small can be allowed for in the flooring units with forward planning and specific design. It is more difficult to accommodate large penetrations in Unispan and Hollowcore because of the number  and location of the pre-stressing strands in the units. Our designers are able to offer you advice on how best to deal with each situation.

SPAN STRESS FLOOR SLAB Floor Finishes  All of the flooring units are typically designed to have a cast in situ concrete topping. The quality of  finish and treatment of the concrete topping surface should be specified and be compatible with any secondary finishes. Transportation Individual flooring units vary in weight and size and normally require trucking and craneage On Site Installation And Handling  All of our units require some form of on site mechanical handling. Crane capacity and site access should be considered when choosing a flooring unit. Interspan is the easiest and lightest unit to install, followed by Unispan, Hollowcore and Double Tee's. Durability Our standard flooring units can be designed for interior and exterior use. We should be made aware of the particular conditions at time of placing order. Fire Resistance Flooring units require different fire ratings depending on their utilisation and location within the structure. We should be made aware of any special fire rating requirements and our design team will incorporate these requirements into our design. Precamber   All of the flooring units are pre-stressed concrete elements. The pre-stressing force causes the unit to have an upward (positive) precamber. Once the topping concrete is placed, the precamber will normally reduce to a more level (neutral) position.

SLIP FORM FLOOR SLAB Slip form is similar in nature and application to  jump form, but the formwork is raised vertically in a continuous process. It is a method of  vertically extruding a reinforced concrete section and is suitable for  construction of core walls in high-rise structures  – lift shafts, stair shafts, towers, e tc. It is a selfcontained formwork system and can require little crane time during construction. This is a formwork system which can be used to form any regular shape or core. The formwork rises continuously, at a rate of about 300mm per hour, supporting itself on the core and not relying on support or access from other parts of the building or permanent works. Commonly, the formwork has three platforms. The upper platform acts as a storage and distribution area while the middle platform, which is the main working platform, is at the top of the poured concrete level. The lower  platform provides access for concrete finishing.

Benefits Careful planning of construction process can achieve high production rates

Slip form does not require the crane to move upwards, minimizing crane use. Since the formwork operates independently, formation of the core in advance of the rest of the structure takes it off the critical path  – enhancing main structure stability.  Availability of the different working platforms in the formwork system allows the exposed concrete at the bottom of the rising formwork to be finished, making it an integral p art of the construction process. Certain formwork systems permit construction of tapered cores and towers. Slip form systems require a small but highly skilled workforce on site.

Safety Working platforms, guard rails, ladders and wind shields a re normally built into the completed system. Less congested construction site due to minimal scaffolding and temporary works. Completed formwork assembly is robust. Strength of concrete in the wall below must be closely controlled to achieve stability during operation. Site operatives can quickly become familiar with health and safety aspects of their job High levels of planning and control mean that health and safety are normally addressed from the beginning of  the work.

Other considerations This formwork is more economical for buildings more than seven storeys high. Little flexibility for change once continuous concreting has begun therefore extensive planning and special detailing are needed. Setting rate of the concrete had to be constantly monitored to ensure that it is matched with the speed at which the forms are raised. The structure being slip formed should have significant dimensions in both major axes to ensure stability of the system. Standby plant and equipment should be available through cold jointing may occasionally be necessary.

WALL PANEL SYSTEM  A wall panel is single piece of material, usually flat and cut into a rectangular shape, that serves as the visible and exposed

covering for a wall. Wall panels are functional as well as decorative, providing insulation and soundproofing, combined with uniformity of appearance, along with some measure of durability or ease of  replaceability. While there is no set size limit for a piece of material fulfilling these functions, the maximum practical size for wall panels has been suggested to be 24 feet by 8 feet, to allow for transportation.

FLAT TYPE WALL SYSTEM

Flat Wall System is a factory-insulated flat wall system with concealed fasteners for a smooth, monolithic appearance.

Features & Benefits  Attractive broad-r ibbed design and embossed surface produces interesting shadows and consistent texture Special interlocking joint design allows panels to easily “lock” into place for faster installation ® Can be combined with other Butler  wall systems or brick, glass, and other conventional materials 16” panel width, combined with the side “return leg,” enables application of almost any conventional finish on the interior of the wall system Factory-installed rigid insulation board for enhanced energy efficiency  Available in several visually appealing colors

RIBBED TYPE WALL PANEL

For economy, Panel Rib beats wood, concrete, or masonry alternatives. Self-drilling, color-matched fasteners and a 36" panel width give you rapid, economical installation. Panel Rib comes in lengths up to 41', which can provide a continuous panel from foundation to leave. This eliminates the need for end-laps and assures you of wall integrity and weather-tightness. These panels are available in 13 standard KXL finish colors and a variety of custom colors. 26 gauges are standard, but you also have the option of 22 or  24 gauge.

Features  Available in 26, 24 or 22 gauge 36” wide panel with 1-1/4” high ribs 12” on center   Available up to 41’ in length Variety of color options with KXL finish and a 25 year paint warranty

Installed with self-drilling color- matched fasteners Optional crimped base feature

Benefits Variety of gauge thicknesses to meet most codes and specifications Engineered for durability and aesthetically 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

WINDOW TYPE WALL PANEL

TILT-UP WALL PANEL Tilt-up is a technique of site casting concrete walls or  element, normally on a horizontal surface and then tilting them vertically into place. Tilt-up, tilt-slab or

tilt-wall

is

a

type

of building and

a construction technique using concrete. Though it is a costeffective technique with a shorter completion time, poor  performance in earthquakes has mandated significant seismic retrofit requirements in older buildings. With the tilt-up method concrete elements (i.e. walls, columns, structural supports, etc.) are formed horizontally on a concrete slab; usually the building floor, but sometimes a temporary concrete casting surface near the building footprint. After the concrete has cured, the elements are "tilted" to vertical position with a crane and braced into position until the remaining building structural components (roofs, intermediate floors and walls) are secured. Tilt-up construction is a dominant method of construction throughout

North

America,

several

Caribbean

nations, Australia, and New Zealand. It is not significantly used in Europe or the northern two thirds of Asia. It is gaining popularity in southern Asia, the Middle East, parts of Africa, Central and South America. Concrete elements can also be formed at factories away from the building site. Tilt-up differs from prefabrication, or plant cast construction, in that all elements are constructed on the job site. This eliminates the size limitation imposed by transporting elements from a factory to the project site.