GB2068035A - Thermally and acoustically insulated hollow concrete walls - Google Patents

Abstract

Transversely and vertically extending first steel meshes 12, 13 are erected. Sheets of thermal/acoustic insulation 14 are supported on both sides of the meshes. Second meshes 16 are erected to extend longitudinally and vertically and are secured to the first meshes through the insulation layers. Concrete is sprayed over the second meshes 16, the sheets 14 serving as barriers. The result is a hollow wall having strength coupled with slight flexibility, is light in weight and has substantial thermal/acoustic insulation properties. <IMAGE>

Description

SPECIFICATION Construction of concrete walls This invention relates to the construction of walls for buildings.

The characteristics of solid reinforced concrete walls are weli known. For example they require shuttering in construction, are not expensive, are dense, strong, rigid, can bear heavy loading, and are poor insulators against the transmission of sound and heat energy. In certain circumstances this is by no means an ideal combination of characteristics for a wall. In particular the poor acoustic and thermal insulation offered by a solid concrete wall can lead either to a noisy building that is expensive to heat, or to the subsequent addition of various expensive acoustic and thermal linings to attempt to remedy the basic deficiency.

The considerable strength, weight and loadbearing capacity of a solid concrete wall is not always required, and the extreme rigidity can be a disadvantage in areas where soil movements or earth tremors are anticipated.

According to the present invention there is provided a method of constructing a wall comprising: erecting transversely and vertically extending first reinforcing members; supporting thermal and/or acoustic insulation material on said first members; erecting longitudinally and vertically extending second reinforcing members; securing said first and second members together; and spraying concrete against said second members to set thereon to form a wall.

The invention also provides a wall comprising transversely and vertically extending first reinforcing members, thermal and/or acoustic insulation material supported on said first members, longitudinally and vertically extending second reinforcing members secured to said first members, and sprayed concrete set on said second members to form a wall.

The insulation material may form two generally continuous vertical layers spaced apart transversely to define an air gap therebetween.

Said second members are preferably erected at both sides of said first members and the concrete then sprayed against both sets of second members to form a wall that is of concrete on both faces.

The second reinforcing members are preferably erected closely adjacent the supported insulation material whereby the insulation material acts as a barrier to sprayed concrete passing between elements of the second reinforcing members.

The first and second reinforcing members are preferably of steel mesh, e.g. of mild steel bars welded together in a square grid pattern as conventionally used in the construction of areas of reinforced concrete.

An embodiment of the invention will now be described, by way of example, with reference to the single Figure of the accompanying drawings.

The drawing shows a vertical section through a wall constructed according to the present invention. The wall is constructed as follows. A plurality of transversely and vertically extending first reinforcing members 10 are erected, spaced apart at for example 2 foot intervals along a footing or foundation 11. The first members 10 are conveniently formed from commercially available mild steel mesh, of about 4 inch square grid pattern. A sheet of such mesh is cut across halfway between two bars thereof to provide members 10 in the form of two upright bars 12 with a plurality of short cross bars 13 protruding about 2 inches beyond the uprights at each side.

Sheets 14 of thermal and/or acoustic insulation material are supported on both sides of the members 10 to form two generally continuous vertical layers with an air gap 1 5 therebetween.

The sheets, e.g. of polystyrene, can be simply pressed into position, the protruding ends of bars 13 serving as spikes that poke through the sheets.

The sheets should be less thick than the lengths of those protruding ends.

Secondary reinforcing members 16 are now erected adjacent the outer faces of the sheets 14, and are secured to the outer ends 1 7 of the bars 1 3 that have poked through the sheets. The ends 17 may be bent to form hooks or metal clips may be employed to secure the members 16 and 10 together. The second members 16 are also conveniently sheets of mild steel mesh in a 4 inch square grid pattern.

Finally concrete 18 is sprayed over both sets of members 16 by commercially available concrete spraying equipment, preferably of the pneumatically propelled type. The sheets 14 of insulation material serve as a barrier to sprayed concrete passing between elements of the steel grids 1 6. The concrete is suitably sprayed to a thickness of about 1 inch.

The result of the described method is a wall as illustrated, about 9 inches thick, comprising a 1 inch layer of reinforced concrete as each outer skin, 3 inches of polystyrene insulation in the form of two 16 inch thick layers and a 4 inch wide air cavity in the centre. It is found that such a wall has remarkable strength, and is moreover strong with a slight degree of flexibility, thereby giving it greater utility than a solid reinforced concrete wall in areas liable to soil movements or earth tremors.

This strength may arise from a certain resemblance the wall bears to an aircraft wing structure: the two outer skins are strong in compression and tension, being of reinforced concrete, and are connected together by metal mesh bracing allowing some slight relative movement between the two skins.

The described wall is also light in weight, inexpensive, simple to construct and is moreover provided with substantial thermal and acoustic insulation in the form of two layers of insulation material separated by the air gap.

Where a long wall is being constructed in an exposed situation, the wall would be formed in sections, in view of the potential for wind damage at the stages when sheets 14 are hung and before the sprayed concrete is set.

The first members 10 may be erected by mortaring their feet into drilled holes in the footing 11. Alternatively short upstanding lengths of reinforcement steel rod may be mortared or cast into the footing 11 at the required location and the members 10 secured thereto. The row of spaced members 10 are conveniently retained in their desired upright aligned positions by means of piano wires strung between two upright supports at the opposite ends of the wall line. For example a factory or warehouse wall may be set out for construction by this method by first erecting four steel columns, bolted to the footings, at the four corners of the building. The piano wires may then be strung between the columns to align the members 10 when first erected.

Claims (14)

1. A method of constructing a wall comprising: erecting transversely and vertically extending first reinforcing members; supporting thermal and/or acoustic insulation material on said first members; erecting longitudinally and vertically extending second reinforcing members; securing said first and second members together; and spraying concrete against said second members to set thereon to form a wall.

2. A method as claimed in claim 1 wherein said second members are erected at both sides of said first members and concrete is then sprayed against both sets of second members to form a wall that is of concrete on both faces.

3. A method as claimed in claim 1 or claim 2 wherein said second members are erected closely adjacent said supported insulation material, whereby the insulation material acts during said concrete spraying as a barrier to sprayed concrete passing between elements of the second reinforcing members.

4. A method as claimed in any one of claims 1 to 3 wherein said insulation material is supported to form two generally continuous vertical layers spaced apart transversely to define an air gap therebetween.

5. A method as claimed in any one of claims 1 to 4 wherein said first members include transversely extending spikes, and wherein said insulation material is supported on said first members by piercing said material with said spikes.

6. A wall comprising transversely and vertically extending first reinforcing members, thermal and/or acoustic insulation material supported on said first members, longitudinally and vertically extending second reinforcing members secured to said first members, and sprayed concrete set on said second members to form a wall.

7. A wall as claimed in claim 6 wherein said second members are provided at both sides of said first members, and sprayed concrete is set on both sets of second members to form a wall that is of concrete on both faces.

8. A wall as claimed in claim 6 or claim 7 wherein said second members are provided closely adjacent said supported insulation material to act as a barrier to sprayed concrete passing between elements of the second reinforcing members.

9. A wall as claimed in any one of claims 6 to 8 wherein said insulation material is supported to form two generally continuous vertical layers spaced apart transversely to define an air gap therebetween.

10. A wall as claimed in any one of claims 6 to 9 wherein said first members include transversely extending spikes, and wherein said insulation material is supported on said first members by being pierced with said spikes.

11. A wall as claimed in any one of claims 6 to 10 wherein said first and second reinforcing members are formed of steel mesh.

12. A method as claimed in claim 1 and substantially as described herein with reference to the accompanying drawing.

13. A wall when constructed by a method as claimed in any one of claims 1 to 5 and 12.

14. A wall substantially as described herein with reference to the accompanying drawing.