Various Types of Precast Concrete Slabs

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Precast concrete options are cast in a factoryenvironment and include the followingprestressed concrete options: Hollow-core units Single-tee units Double-tee units Solid concrete units Beam and block floors

Precast reinforced concrete slabs include: Lattice girder slabs Biaxial voided slabs


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A hollow core slab , also known as a voided slab or hollowcore plank is a precast slab of prestressed concretetypically used in the construction of floors in multi-storyapartment buildings.

The precast concrete slab has tubular voids extending the

full length of the slab, typically with a diameter equal tothe 2/3-3/4 of the slab. This makes the slab much lighterthan a massive floor slabs of equal thickness or strength.

Reduced weight is important because of transportationcost and less cost of material (concrete). The slabs aretypically 120 cm wide with standard thicknesses between15 cm and 50 cm. The precast concrete I-beams betweenthe holes contain the steel wire rope that provide bendingresistance to bending momentum from loads.


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The single tee sections typically have a decksurface about 1.5 to 2 inches thick and aconcrete beam extending down from the decksurface along the longitudinal center of the

deck. The beam is usually about 8 inchesthick and about 24 inches tall.


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Double-Tee floor units are produced instandard widths of 2400mm and in depths ofbetween 250mm and 1000mm. The systemoffers greater structural capacity at longer

spans than hollowcore or wideslabs, but oftenrequires a deeper floor zone. The Double-Teesystem is the only system which offers asolution for spans over 16m.


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normally made of reinforced concrete butother materials are called plates . Thicknessof PLATE depends on span but 200 mm iscommon in residential houses or buildings.


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Solid Wideslab is sometimes referred to as "plateflooring" which is generally used in residentialdevelopments. Wideslab flooring contains aninternal mesh/strand which facilitates notchingand the forming of opes.

Wideslab is a solid precast slab, which is pre-stressed to provide excellent span/ ratio depth.The standard slab width is 2400mm and availablein depths of 80, 100, 125, 150 and 175 mmdepths (our standard sizes are 100 and 150mm).

Wideslab is often used with a structural screed,to aid stability of the structure and increase itsload capacity. Maximum spans are about 8.5m,depending on loads.


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Beam and Block is a flooring system composed ofpre-stressed concrete beams, with standardbuilding blocks laid between the beams. Laidtogether with purpose made split course andutilising our professional fixing teams, this helpsto generate a comprehensive flooring package.With the added design support we can help youachieve a value added flooring solution.

Insulated Infill blocks can be used to achieve

improved insulation values within the floor andsolid tray blocks can be used to achieve therobust detail for upper floors.


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Lattice girder slabs act as permanent formworkand as precast soffits for robust, high capacitycomposite floor slabs. They are cast with most, ifnot all, of the bottom reinforcement required; thetop reinforcement is fixed in situ. The units are

typically 50mm to 100mm thick and 1200mm or2400mm wide. They are generally propped during construction

and until the in situ concrete has gainedsufficient strength.

Typically spans of up to about 8m can beachieved (for an imposed loading of 5kN/mm2)with an overall depth of 300mm.


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The new BubbleDeck(r) system takes the concept of the filigreeflat floor slab and introduces a revolutionary method of virtuallyeliminating the concrete from the middle where it is notperforming any structural function, so dramatically reducingdead weight. The patented technique uses recycled plastichollow bubbles as void formers in the middle to eliminate 35%of the slabs self-weight, removing design constraints of high

dead loads and short spans.

Combining this technique with a flat slab construction spanningin two directions - the biaxial slab is connected directly to in-situ concrete columns without any beams enables up to 50%longer spans between columns.

The reduced environmental impact of the system is alsoimpressive with less concrete usage 1kg of recycled plasticreplaces 100kg of concrete and lower energy and carbonemissions.


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Solid panel - A panel of constant thickness; an allowance forsurface texture must be made in determining effective thickness. Hollow-core panel- A precast panel that has voids within the

thickness in one direction for the full length of the panel. Sandwich panel- A precast panel consisting of twolayers of concrete separated by a non-structural insulating core. Ribbed panel A precast panel consisting of a slab reinforced by

a system of ribs in one or two directions Mullion wall is a structural system in which the load of the floor

slab is taken by prefabricated panels around the perimeter


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Concrete Girder A concrete girder bridge is made of pre-

stressed concrete in an I-beam shape. Theconcrete is also reinforced with steel rods.

This combination is particularly effective inbridge construction.


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Various Types of Precast Concrete Slabs

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