Floor Systems and Roof Slab System

1. Floor Systems and Roof Slab System 

Flat Slab- are rectangular slab directly supported by columns without beam or girders. The slab is either uniform in thickness or provided with aquare symmetrical area directly above the column reinforced with bars running in two directions. The increased area directly above the column iscalled Drop Panel or simply Drop. Likewide, a flared head is employed in the construction of a flat slabe floor making a capital of the column.

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Flat Plate- when the column design Is not provided with capital, a straight flat underneath is provided in the slab throughout the system. The slat slab floor system is generally economical not only in terms of materials but also labor. It is the most suitable type of construction for industrial buildings having a wider live load and also for buildings where the use of capital is not objectionable.

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Ribbed Floor Slab-an economical type of flloor construction applicableonly to medium span with light or medium load. A ribbed floor slab conists of small adjacent T-Beam wherein the open spaces between the ribs are filled with clay tile, gypsum tiles or steel forms. Generally, the tiles measure 30x90cm with 10,15, 20, 25, 30 and 40cm placed at 40cm on center making the ribs 10cm wide.

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Waffle Slab- A waffle slab is a type of building material that has twodirectional 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.

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Lift Slab- a method of constructing concrete buildings by casting the floor or roof slab on top of the previous slab and then raising (jacking) the slab up with hydraulic jacks, so being cheaper and faster as not requiring boxing and supports for casting in situ.Johnstone Hall, a Clemson University dormitory in Clemson, South Carolina, was erected using this method in 1954. Several of the blocks have now been demolished, and campus legend says that that two other similar structures built elsewhere collapsed before completion. Lift slab construction was also involved in the L'Ambiance Plaza collapse in Bridgeport, Connecticut, in 1987, and resulted in a nationwide federal investigation into this construction technique in the United States, and Connecticut imposed a temporary moratorium on lift slab construction.

Span Sterss Floor System- 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. Most contractors agree that Unispan is a simple form of construction. Slabs are typically 1200mm or 2400mm wide. Unispan is easily adapted to any floor plan and individual slab widths can be custom made to suit individual requirements. Balconies and decks can be created by cantilevering the slab up to 2000mm, while including a weather step at the building line. Unispan slabs must be handled and stacked at two points, by, or directly beside, the lifting eyes. 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.

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Slip Form Method- 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, etc. It is a self-contained 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.

2. Wall Panel Systems  Flat-Type 

Ribbed Type

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Window Type and Wall Type

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Tilt-up Wall Panel System