GB2180275A - Spacer device for reinforcement within concrete structures - Google Patents

Abstract

An integral moulded PVC spacer rests at its undulations upon parallel concrete reinforcing rods and carried clasped within ribbed portions of jaws on arms a further such rod which is thereby accurately placed and immobilised in relation to the underlying rods to improve the characteristics of the eventual concrete structure poured over and reinforced by the assembly. <IMAGE>

Description

SPECIFICATION Spacer device for reinforcement within concrete structures, and methods of use thereof This invention relates to reinforced concrete tech- nology and more especially to a device forfacilitating the accurate positioning of reinforcement bars in relation to each other and to the eventual structure.

The invention further relates to the assembly of bars so formed, and to a method offorming a reinforced concrete structure using such an assembly.

It is a well known technology to place an iron mesh or iron rods within a wet concrete structure so that when the concrete hardens an increased strength is observed compared to that of the unreinforced concrete. However, the accuracy of placement of such heavy reinforcement in the wet material is not high, and, provided that no reinforcement bars actually protrude at the surface, is often taken to be of secondary importance. Where some attempt is made to ensure a desired relative placement of such bars within the concrete it is conventional to use wire ties between successive bars so that at least the extentto which the tie opens is a measure of relative placement.

The results are however not accu rate.

The present invention sets out to overcome this problem.

In one aspectthe invention consists in a method of providing a reinforced concrete structure in which generally dimensionally stable spacers of polymeric material are mounted on specific metal reinforcing elements lying atan eventual lower level in the structure, and hold and immobilise at ortowards their upper parts, one or more reinforcing members at an eventual upper level, at a fixed and known relative spacing and configuration, thereby to define a reinforcing structure to be covered by subsequent poured ing of concrete.

Usually, the method comprises (i) pouring a layer of concrete, (ii) placing a first set of reinforcing members, typically rods, at a predetermined spacing on said layer (iii) either (a) arranging the said spacers on the rods andthereafterarranging an upper rod or rods for supporting by the spacers or (b) making a subassembly of at least one rod fixed to the upper parts of a plurality of spacers, and placing the sub-assembly for support at the spacer base upon the first set of rods.

Thereafter, if desired, step (iii) can be repeated, in eitherfashion. The whole ofthe concrete can be poured at the end ofthe assembly, or the concrete can be poured in stages during the assembly.

The hardened concrete structure resulting from such a method and containing such reinforcement assemblies is also an aspect ofthe invention.

Afurtheraspectoftheinventionisconstituted by polymeric spacers, especially when made of polyvinychloride, which are configured at lower edge regions so asto be capable of resting upon two or more parallel reinforcing rods, and which are configured at an upper portion so as to hold at least one further rod also parallel to the lower rods.

Preferably, in such a spacer,the upper portion has a resilient clip or clasp structure to prevent or hinder removal of a rod once immobilised. Accurate placement, down to an accuracy of 1 mm or less, is achievable by this method.

In the spacer, the lower portion may be designed for a single purpose, or may be multi-purpose, that isto say, be capable of fitting upon different spacings or arrangements of underlying rods.

The assembly and the method defined above lend themselves to further combinations with a further metal reinforcement unit, for location within the assembly and poured concrete, in those cases where the polymeric supports are not strong enough to resist bending of reinforcement bars.

The invention will be further described with refer encetotheaccompanying drawings, in which Figures 1 to 6 are perspective views or different embodiments of synthetic polymeric spacer members, and Figure 7 is a perspective view of a metal wire of bar supplementary reinforcement unit.

In Figure 1,the spacer generally indicated at 1 is an integral moulding of polyvinylchloride. At its bottom edge it is configured with undulations 2 that it may be readily supported upon spaced parallel reinforcement bars 3. The upper portion 4 of the spacer possesses angled opposing arms 5 carrying opposed jaws 6,which aresmooth and diverging in their upper parts 6a, and ribbed in their lower part 6b. Thus, a reinforcing bar (not shown) can be pushed down the between the faces Sa, push the arms 5 apart, and rest between and be gripped by the ribbed lower parts 6b of the jaws. Inthis configuration it takes up an accurate spaced relationship with, and parallel to, the rods 3.

This assembly can be done as a pre-assemblywith a numberof spacers 1 assembled on the same upper bathe assembly being thereafterstood upon the two level bars 3, or can alternatively be carried out in situ by placing a plurality of spacers and thereafter fitting the bar or bars acrossthis plurality of existing and located spacers.

Figure 2 shows an essentially similar spacer using the same reference numerals. It is different in proportions and it has a stiffer clipping or clasping action.

Figure 3 shows a further and similar spacer, in this case tailer, with a dependent extension 1 a and with differently configured undulations 2 to that shown in Figures 1 and 2. Also, the upper bar will not be held between ribbed portions shown as 6b in Figures 1 and 2, but wili be located within opening 7 by the lowermost edges of the jaws 6.

All of the foregoing embodiments are designed for single purpose use, that is to say, with underlying bars at a fixed and known spacing.

Figure 4 shows, however, a multi-purpose design.

This will fit over underlying rods (not shown) using various combinations of spaces 8 between the vanes 9. The ring-shape is interrupted at 1 Oto define resilient jaws 11 with shaped opposed faces 12 serving to direct an upper rod (not shown) into a central holding location 13 between flexible corrugated retaining membersi4 Figures 5 and 6 are generally analogous to Figures 1 to 3, but show three support rods 3 in each case, and an appreciably lighter support memberwith a central location forthe upper bar shaped rather as in Figure 3.

Figure 7 shows a further associated constructional unit made of metal to assist in support against bending of the reinforcing bars.

Claims (12)

1. Amethodofproviding a reinforced concrete structure in which generally dimensionally stable spacers of poiymeric material are mounted on specific metal reinforcing elements lying at an eventual lower level in the structure, and hold and immobilise, at or towards their upper parts, one or more reinforcing members at an eventual upper level, at a fixed and known relative spacing and configuration, thereby to define a reinforcing structureto be covered by subsequent pouring of concrete.

2. A method as claimed in claim 1 which comprises(i) pouring a layer of concrete, (ii) placing a first set of reinforcing members, typically rods, at a predetermined spacing on said layer (iii) either (a) arranging the said spacers on the rods and thereafter arranging an upper rod or rodsforsupporting by the spacers or (b)rnakinga sub-assembly of at least one rod fixed to the upper parts of a plurality of spacers, and placing the sub-assemblyforsupportatthe spacer base upon the fir set ofrods.

3. A method asclairned in claim 2 in which step (iii) is repeated at least once.

4. A method as claimed in claim 2 or 3 in which the whole ofthe concrete is poured atthe end ofthe assembly

5. A method as claimed in claim 2 or 3 in which the concrete is poured in stages du ring the assembly.

S.- The concrete structure containing reinforcing assemblies produced by the method as claimed in anyoneofclaims 1 to Sand subsequently allowed to harden.

7. A polymeric spacer config u red at lower edge regions so asto be capable of resting upon two or more parallelreinforcing rods and configured at an upper portion as to be capable of holding at least one further such. rod also parallel to the lower rods.

8. A polymeric spacer acclaimed in claim 7 when made of polyvinylchloride.-

9. A polymeric spacer as claimed in claim 7 or 8 in which the upper portion isnonfigured with a resilient clip or clasp stmcture to preventor hinder removal of a rod once irrimobilised therein.

10. A polymeric spaceras claimed in any of claims 7, 8 and 9 which the lower portion is designed for a single spacing between two rods.

11. A polymeric spacer.asclaimed in claims 7, 8 or 9 in which the lower portion is designed to be capable offitting upon different spacings of underlying rods.

12. A polymeric spaceras described herein with preference anyone of Figures 1 to 5 of the accompanying drawings.