GB2122126A

GB2122126A - Reinforced concrete

Info

Publication number: GB2122126A
Application number: GB08210881A
Authority: GB
Inventors: John David Clapson
Original assignee: Square Grip Ltd
Current assignee: Square Grip Ltd
Priority date: 1982-04-14
Filing date: 1982-04-14
Publication date: 1984-01-11

Abstract

The invention relates to an apparatus for supporting reinforcement in concrete during casting. It consists of a rod (2) which is mounted at its ends on frames (4) to support reinforcements (6). In order to restrict bending of the rod (2), the frames (4) are coupled to the rod (2) at points spaced along its length by for example, auxiliary struts (16). This arrangement enables reinforcement (6) to be supported at a high level in the body as it is cast, while providing unrestricted space below it for services (20). <IMAGE>

Description

SPECIFICATION Concrete reinforcement supports This invention relates to devices for supporting reinforcement for a reinforced concrete structure prior to the casting of concrete therearound.

Particularly it relates to the support of reinforcement from one side of the structure to be formed.

According to the present invention, a device for supporting reinforcement prior to casting concrete therearound comprises a rod supported at either end on a frame which is in turn supported on feet which in use rest on a base surface of the casting mould or shuttering. This arrangement enables reinforcement to be supported at a substantial distance from the base of the mould, and reduces the chances of staining in the cast structure either by the supported reinforcement, or by the frames.

The feet of each frame are normally enclosed in plastic or non-ferrous caps, further reducing the staining risk.

Flexure of devices according to the invention is often unavoidable because of the weight of reinforcement being supported and indeed, as few devices as possible will be used for reasons of economy and to preserve so far as possible the homogeneity of the concrete. To enable the use of devices according to the invention in which the frames are widely spaced, it is proposed herein to enhance the rigidity of the device by a structural design which restricts bending of the rod when the device is in use, but continues to ensure that the support forces are all transmitted to the base surface of the mould or shuttering through the end frames. This may be accomplished by simple struts extending diagonally from the frames to the rod, or by a triangulated structure or catenary system which provides direct support for the rod at one or more points along its length.Normally this would take the form of a simple framework suspended between the two end frames. It is appreciated of course though, that when a particularly long length of rod is needed, intermediate support therefor can only practically be provided by an additional frame. Under these circumstances, any auxiliary framework may be coupled to such an additional frame.

The invention will now be described by way of example and with reference to the accompanying schematic drawings wherein: Figure 1 shows a device according to the invention supporting reinforcement in part of a mould; Figure 2 is an end view of the device shown in Figure 1; Figure 3 is a moment diagram showing the bending effect of loads on a device without struts; and Figure 4 is a moment diagram showing the bending effect of loads on a device with struts.

The supporting device shown in Figures 1 and 2 comprises a rod 2 borne on a frame 4 at either end. Supported on the rod 2 is steel reinforcement 6. Figure 1 also shows reinforcement 8 supported close to the base 10 of the mould or shuttering on a rod 12 which is in turn supported on mounts 14.

These lower devices may also be in accordance with the invention, but a supporting structure for the rod 1 2 (such as is described below for the rod 2) cannot normally be incorporated and conventional propos or spacers are used.

The device shown in Figures 1 and 2 includes struts 1 6 which serve to rigidify the rod 2, and avoid the need for one or more additional frames.

Each strut 1 6 is in the form of a rod bent to a V-shape and slung over the rod 2 and frame 4 as shown. It is welded to the rod and frame at the points at which it rests thereon. The effect of these struts 16 is shown in Figures 3 and 4. Figure 3 shows how the bending moment in the rod 2 would vary along its length under uniform loading were there no auxiliary support for the rod; and Figure 4 shows how the maximum moment is reduced when the struts 1 6 are included. As can be seen, the maximum moment can be reduced by of the order of 50% so long as some horizontal restraint is applied at the base of the frames 4.

This is provided by the friction between the base 10 of the mould and the frames which may be enhanced by the use of feet 1 8 of rubber or other suitable, preferably non-ferrous material.

The device of the invention provides a simple yet effective solution to the problem of supporting reinforcement at a high level within a casting mould while minimizing the amount of nonconcrete material exposed in the eventual casting, and maximizing the space made available for enclosing services such as pipe and cablework 20.

As can be seen from Figure 1, the cover thickness 22 shown is only disrupted by the bases of frames 4 and mounts 14.

1. A device for supporting reinforcement prior to casting concrete therearound to form a cast concrete body, which device comprises a rod mounted at either end on a frame having feet for supporting such frame on a base surface, the rod being coupled to each frame at points spaced along its length to restrict bending of the rod.

2. A device according to Claim 1 wherein at least one strut extends between each frame and at least one point along the length of the rod to provide extended support therefor.

3. A device according to Claim 2 wherein each frame is secured directly to the rod, and wherein a strut extends diagonally from each frame and is secured to the rod at a point spaced along its length towards the other frame.

4. A device according to any preceding Claim wherein each frame has a triangular configuration.

5. A device according to Claim 3 and Claim 4 wherein said at least one strut is in the form of a V-shaped member secured at its distal ends to the respective frame, and at its crotch to the rod.

6. A device according to Claim 5 wherein both the frames and the V-shaped member extend over the rod.

7. A device according to Claim 1 including a

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Concrete reinforcement supports This invention relates to devices for supporting reinforcement for a reinforced concrete structure prior to the casting of concrete therearound. Particularly it relates to the support of reinforcement from one side of the structure to be formed. According to the present invention, a device for supporting reinforcement prior to casting concrete therearound comprises a rod supported at either end on a frame which is in turn supported on feet which in use rest on a base surface of the casting mould or shuttering. This arrangement enables reinforcement to be supported at a substantial distance from the base of the mould, and reduces the chances of staining in the cast structure either by the supported reinforcement, or by the frames. The feet of each frame are normally enclosed in plastic or non-ferrous caps, further reducing the staining risk. Flexure of devices according to the invention is often unavoidable because of the weight of reinforcement being supported and indeed, as few devices as possible will be used for reasons of economy and to preserve so far as possible the homogeneity of the concrete. To enable the use of devices according to the invention in which the frames are widely spaced, it is proposed herein to enhance the rigidity of the device by a structural design which restricts bending of the rod when the device is in use, but continues to ensure that the support forces are all transmitted to the base surface of the mould or shuttering through the end frames. This may be accomplished by simple struts extending diagonally from the frames to the rod, or by a triangulated structure or catenary system which provides direct support for the rod at one or more points along its length.Normally this would take the form of a simple framework suspended between the two end frames. It is appreciated of course though, that when a particularly long length of rod is needed, intermediate support therefor can only practically be provided by an additional frame. Under these circumstances, any auxiliary framework may be coupled to such an additional frame. The invention will now be described by way of example and with reference to the accompanying schematic drawings wherein: Figure 1 shows a device according to the invention supporting reinforcement in part of a mould; Figure 2 is an end view of the device shown in Figure 1; Figure 3 is a moment diagram showing the bending effect of loads on a device without struts; and Figure 4 is a moment diagram showing the bending effect of loads on a device with struts. The supporting device shown in Figures 1 and 2 comprises a rod 2 borne on a frame 4 at either end. Supported on the rod 2 is steel reinforcement 6. Figure 1 also shows reinforcement 8 supported close to the base 10 of the mould or shuttering on a rod 12 which is in turn supported on mounts 14. These lower devices may also be in accordance with the invention, but a supporting structure for the rod 1 2 (such as is described below for the rod 2) cannot normally be incorporated and conventional propos or spacers are used. The device shown in Figures 1 and 2 includes struts 1 6 which serve to rigidify the rod 2, and avoid the need for one or more additional frames. Each strut 1 6 is in the form of a rod bent to a V-shape and slung over the rod 2 and frame 4 as shown. It is welded to the rod and frame at the points at which it rests thereon. The effect of these struts 16 is shown in Figures 3 and 4. Figure 3 shows how the bending moment in the rod 2 would vary along its length under uniform loading were there no auxiliary support for the rod; and Figure 4 shows how the maximum moment is reduced when the struts 1 6 are included. As can be seen, the maximum moment can be reduced by of the order of 50% so long as some horizontal restraint is applied at the base of the frames 4. This is provided by the friction between the base 10 of the mould and the frames which may be enhanced by the use of feet 1 8 of rubber or other suitable, preferably non-ferrous material. The device of the invention provides a simple yet effective solution to the problem of supporting reinforcement at a high level within a casting mould while minimizing the amount of nonconcrete material exposed in the eventual casting, and maximizing the space made available for enclosing services such as pipe and cablework 20. As can be seen from Figure 1, the cover thickness 22 shown is only disrupted by the bases of frames 4 and mounts 14. CLAIMS

7. A device according to Claim 1 including a catenary system extending between the frames, which system is coupled to the rod to restrict bending thereof.

8. A device according to any preceding Claim including an additional frame coupled to the rod between the first-mentioned frames.

9. A device according to any preceding Claim wherein the feet of the frames are enclosed in caps.

10. A device for supporting reinforcement prior to casting concrete therearound to form a concrete body substantially as described herein with reference to the accompanying drawings.

11. A reinforced concrete body cast using a device according to any preceding Claim.