GB2065193A

GB2065193A - Reinforced concrete slab, particularly for floors

Info

Publication number: GB2065193A
Application number: GB8033119A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-10-22
Filing date: 1980-10-14
Publication date: 1981-06-24
Also published as: ATA685179A; GB2065193B; BE885811A; DE8027569U1; AT362917B

Abstract

A reinforced, prefabricated concrete slab, particularly a prefabricated concrete floor unit, wherein the reinforcement is in the form of tubular members 3 of sheet steel embedded in and extending through the concrete slab, the reinforcement being profiled and/or provided with holes or recesses in order to provide a secure bond between the reinforcement and the concrete. In this way a void shuttering is incorporated into the slab as a reinforcement. <IMAGE>

Description

SPECIFICATION Reinforced concrete slab for floors or the like This invention relates to a slab, particularly to concrete slabs usable for floors or the like, comprising a steel reinforcement and replacement bodies of the sheet steel.

Such slabs, particularly pre-fabricated concrete floor units which are used as load-bearing structural elements, are, as already mentioned, provided with a steel reinforcement to guarantee sufficient strength. They are further provided with hollow spaces or replacement bodies in order to reduce the weight of the slabs and the amount of concrete required.

Prior art steel reinforcements employ rods, mats or prestressed rods.

It is the advantage of prestressed reinforcements that the strength of the slabs is increased, whereas the amount of steel required for such reinforcement is reduced. However, prestressed reinforcements have the adverse effect, that buckles are formed on the structural elements, which may be to different degrees on the individual slabs. Current manufacturing means or methods are not able to eliminate such differences.

According to another prior art a slab-shaped structural is provided with a reinforcement of sheet metal a part of the sheet metal reinforcement is bent to a replacement body arranged in the concrete. The major part of the reinforcement rests, however, against the outer face of the concrete slab.

The bond between the concrete and the sheet metal reinforcement is not provided in the region of the hollow bodies but in the region of the web between the hollow and the outer slab. The hollow body does, therefore, not or only to a very smail extent contribute to reinforcement.

It is, therefore, the object of the present invention to provide a slab of the afore-described kind characterized by optimum reinforcement and to eliminate the adverse effect of buckle formation on the slabs, In accordance with the present invention, this is achieved by providing that the replacement bodies are formed by hollow bodies fully surrounded by concrete and having a jacket of sheet steel, said hollow bodies serving as void shuttering, said jackets of said hollow bodies being profiled and/or provided with holes or recesses, thus providing a bonding effect between said jackets and the concrete.

The fact that the replacement bodies in accordance with the present invention fully or at least substantially form the reinforcement of the slabs compensates for increased costs due to the increased amount of steel required in the slabs.

Due to the fact that the reinforcement formed by profiles of the hollow bodies is an ordinary reinforcement no buckles are formed on the slab surface as in the case of prior art prestressed reinforcements of round steels.

In order to reduce the amount of steel required and to substantially maintain the degree of reinforcement at the same time, a preferred embodiment of the present invention provides that at least part of the jackets of the hollow bodies is made of an expanded metal.

A further preferred embodiment provides that the profiles forming the hollow bodies are cylindrical or of rectangular or square crosssection.

In the following two embodiments of the invention will be described in greater detail by means of the figures of the drawing without being limited thereto.

Figure 1 shows a schematic view of a slab in accordance with the present invention.

Figure 2 shows a perspective view of a second embodiment of a slab in accordance with the present invention, Figures 3 and 3a, each, show perspective views of a hollow body in accordance with the present invention, Figure 4 shows a perspective view of a further embodiment of a hollow body in accordance with the present invention, and Figure 5 shows a schematic cross-sectional view of a hollow body formed by two shells.

The slab in accordance with the present invention substantially comprises a concrete body 1 manufactured in a conventional manner of sand, cement, water and further aggregates, e.g. foamed plastic beads in a conventional shell mould.

In accordance with the present invention, profiles forming the hollow bodies 2 and having jackets 3 of sheet steel are arranged in the slabs.

The hollow bodies 2 extend over the total breadth or length of the slab 1.

The hollow bodies 2 may have different crosssections. Circular and rectangular cross-sections have proved most advantageous.

In order to improve the bond between the hollow bodies 2 and the surrounding concrete, said hollow bodies 2 are, for example, provided with profiles 4 (Fig. 3) or with recesses 5 (Fig. 4).

Said recesses 5 cause a loss of sheet steel cross-sections, which could be used for static purposes, said loss being compensated for by the high amount of sheet steel in the slab 1.

The hollow bodies 2 can at least partially be made of expanded metal. Fig. 5 shows an embodiment in which the hollow body 2 is formed by two shells, 2', 2". The upper shell 2' is made of expanded metal. The lower shell 2" serves, above all, for reinforcement purposes, and both shells together form the hollow space in the slab 1.

1. A reinforced, prefabricated concrete slab wherein the reinforcement comprises a plurality of tubular members of sheet steel embedded in and extending through the concrete slab, said members being externally profiled and/or provided with apertures or recesses to provide enhanced bonding of the reinforcement to the concrete.

2. A slab according to claim 1, wherein the tubular members are at least partially constructed

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Reinforced concrete slab for floors or the like This invention relates to a slab, particularly to concrete slabs usable for floors or the like, comprising a steel reinforcement and replacement bodies of the sheet steel. Such slabs, particularly pre-fabricated concrete floor units which are used as load-bearing structural elements, are, as already mentioned, provided with a steel reinforcement to guarantee sufficient strength. They are further provided with hollow spaces or replacement bodies in order to reduce the weight of the slabs and the amount of concrete required. Prior art steel reinforcements employ rods, mats or prestressed rods. It is the advantage of prestressed reinforcements that the strength of the slabs is increased, whereas the amount of steel required for such reinforcement is reduced. However, prestressed reinforcements have the adverse effect, that buckles are formed on the structural elements, which may be to different degrees on the individual slabs. Current manufacturing means or methods are not able to eliminate such differences. According to another prior art a slab-shaped structural is provided with a reinforcement of sheet metal a part of the sheet metal reinforcement is bent to a replacement body arranged in the concrete. The major part of the reinforcement rests, however, against the outer face of the concrete slab. The bond between the concrete and the sheet metal reinforcement is not provided in the region of the hollow bodies but in the region of the web between the hollow and the outer slab. The hollow body does, therefore, not or only to a very smail extent contribute to reinforcement. It is, therefore, the object of the present invention to provide a slab of the afore-described kind characterized by optimum reinforcement and to eliminate the adverse effect of buckle formation on the slabs, In accordance with the present invention, this is achieved by providing that the replacement bodies are formed by hollow bodies fully surrounded by concrete and having a jacket of sheet steel, said hollow bodies serving as void shuttering, said jackets of said hollow bodies being profiled and/or provided with holes or recesses, thus providing a bonding effect between said jackets and the concrete. The fact that the replacement bodies in accordance with the present invention fully or at least substantially form the reinforcement of the slabs compensates for increased costs due to the increased amount of steel required in the slabs. Due to the fact that the reinforcement formed by profiles of the hollow bodies is an ordinary reinforcement no buckles are formed on the slab surface as in the case of prior art prestressed reinforcements of round steels. In order to reduce the amount of steel required and to substantially maintain the degree of reinforcement at the same time, a preferred embodiment of the present invention provides that at least part of the jackets of the hollow bodies is made of an expanded metal. A further preferred embodiment provides that the profiles forming the hollow bodies are cylindrical or of rectangular or square crosssection. In the following two embodiments of the invention will be described in greater detail by means of the figures of the drawing without being limited thereto. Figure 1 shows a schematic view of a slab in accordance with the present invention. Figure 2 shows a perspective view of a second embodiment of a slab in accordance with the present invention, Figures 3 and 3a, each, show perspective views of a hollow body in accordance with the present invention, Figure 4 shows a perspective view of a further embodiment of a hollow body in accordance with the present invention, and Figure 5 shows a schematic cross-sectional view of a hollow body formed by two shells. The slab in accordance with the present invention substantially comprises a concrete body 1 manufactured in a conventional manner of sand, cement, water and further aggregates, e.g. foamed plastic beads in a conventional shell mould. In accordance with the present invention, profiles forming the hollow bodies 2 and having jackets 3 of sheet steel are arranged in the slabs. The hollow bodies 2 extend over the total breadth or length of the slab 1. The hollow bodies 2 may have different crosssections. Circular and rectangular cross-sections have proved most advantageous. In order to improve the bond between the hollow bodies 2 and the surrounding concrete, said hollow bodies 2 are, for example, provided with profiles 4 (Fig. 3) or with recesses 5 (Fig. 4). Said recesses 5 cause a loss of sheet steel cross-sections, which could be used for static purposes, said loss being compensated for by the high amount of sheet steel in the slab 1. The hollow bodies 2 can at least partially be made of expanded metal. Fig. 5 shows an embodiment in which the hollow body 2 is formed by two shells, 2', 2". The upper shell 2' is made of expanded metal. The lower shell 2" serves, above all, for reinforcement purposes, and both shells together form the hollow space in the slab 1. CLAIMS

2. A slab according to claim 1, wherein the tubular members are at least partially constructed of expanded metal.

3. A slab according to claim 1 or 2, wherein the tubular members are of circular or rectangular cross-section.

4. A slab according to any one of claims 1-3, wherein the tubular reinforcement members are embedded in the slab in parallel array.

5. A slab according to any one of claims 1-4, wherein the tubular reinforcement members comprise two longitudinally extending shells assembled to form a tube.

6. A slab according to claim 1, substantially as hereinbefore described with reference to the accompanying drawings.