CONSTRUCTIONAL MEMBER AND METHOD

Abstract: There is disclosed a constructional member comprising a bendable plate (10) of plastics material reinforced by an assembly (12) of steel wires on one face thereof, some of the wire in said assembly being spaced outwardly from the plate. The plate may have a textile fabric (11) bonded thereto to which the steel wire assembly (12) is adhered. The members may be used in the fashion of tiles to line a duct such as a sewer.

Description: CONSTRUCTIONAL MEMBER AND METHOD This invention concerns a constructional member and method primarily, though not exclusively, suitable for use in the lining or relining of a sewer. Means and methods for relining sewers are known from British Patent No. 2113739, which teaches the use of planks formed from mulitple layers of wire mesh. The planks are nailed to the internal walls of the sewer and redered with a cementitious material which is forced into and through the planks to fill the interstices thereof and the void between them and the sewer wall. In effect the sewer is lined with a shell of ferro-cement. This operation is very labour intensive. Furthermore, some sewers present special problems in that there is a high concentration of acid present which would attack the rendering and eventually penetrate to the reinforcing steel, thus destroying the lining. It is amongst the objects of the present invention to provide a means and method for simplifying the relining operation and also for dealing with such problem sewers. -2- According to the present invention there is provided a constructional member comprising a bendable plate of plastics material reinforced by an assembly of steel wires on one face thereof, some of the wire in said assembly being spaced outwardly from the plate. The plate may be of a thermoplastic polyolefin such as a high density polyethylene. The assembly of steel wires may be thermally bonded to the plate. A textile fabric may be bonded to the plate and the assembly of steel wires adhered to the fabric. The textile fabric may be stitch-bonded polyester. The fabric may be thermally bonded * co the plate. The assembly of steel wires may be secured to the fabric by any suitable bonding agent such as polyester, epoxy or phenolic resin adhesives. The adhesive may be applied over the whole face of the fabric or at discrete locations such as at spaced parallel strips. Wire from the assembly may be deformed from the face thereof for engagement with the adhesive to space the main body of the assembly away from the plate. The assembly may be comprised by planks formed from multiple layers of wire mesh. The layers may be of different kinds, some being of woven wire mesh ("chicken wire") others being comprised by two sets of spaced parallel wires at an angle to one another and welded together at their crossing points. The layers may be held together by folding or the wire mesh may be trapped between the two sets of parallel wires. The plastics plate takes the shape of the reinforcement assembly which may be bent to a desired form before or after being joined with the plate. The contructional members may be employed to form a lining within a tubular duct such as a sewer in a method in which the members are arranged with the wire reinforcement against the wall of the duct in the fashion of tiles with sealing means between their adjacent edges, some of the members being cut to size if necessary to close the lining such that it forms a self-supporting rigid structure and behind which a cementitious material is pumped to fill the void between the plates and the wall of the duct. The invention will be further apparent from the following description, with reference to the several Figures of the accompanying drawings, which show, by way of example only, one form of contructional member embodying same and its use in relining a sewer. Of the drawings:- ' Figure 1 shows a front elevation of the member; Figure 2 shows a side view of the member; Figure 3 shows a rear elevation of the member; Figure 4 shows a cross-section through the member on the line IV-IV of Figure 1; Figure 5 shows a cross-section through a sewer relind with the members of Figure 1; Figure 6 shows a section on the line VI-VI of Figure 5; and Figure 7 shows a cross-section on the line VII-VII of Figure 6 on an enlarged scale. Referring firstly to Figures 1-4, it will be seen that the constructional member comprises a bendable plate 10 of plastics material typically having a thickness of 3 mm, a length of 3 m and a width of 50 cm. The plate 10 is of a high density polyethylene and is backed by a sheet 11 of stitch-bonded polyester which has been thermally bonded thereto. An assembly 12 of steel wire reinforcement is bonded to the back of the plate 10 by spaced parallel strips 13 of an adhesive such as an epoxy resin adhesive. The assembly 12 comprises a plurality of layers of wire mesh arranged in superimposed relationship. Some of the layers consist of two sets of spaced parallel wires at an angle to one another and welded together at their crossing points. Other comprise woven wire mesh generally known as "chicken wire". The layers may be held together by folding as described in British Patent No. 2,113,739, or the woven wire layers may be trapped between two sets of crossing wires as described in British Patent No. 2,148,973. Wire in a outer layer of the assembly is deformed away from the main body of the assembly by a crimping operation to form ridges 14 which are embedded in the strips 13 whereby the main body of the assembly is spaced from the back of the plate 10. In use, for example, the members may be used, as shown in Figures 5 and 6, to line the interior wall W of a sewer. If structual reinforcement beyond that provided by the members is required as when reparing a delapidated brick-built sewer, reinforcing bar members may be fixed to the wall as an initial step. If the intent is merely to provide a chemically resistant lining to a modern concrete sewer, then members having a minimum of reinforcing steel might be used. In either event the members are laid in the fashion of tiles tc cover the surface of the wall W. An extruded sealing strip 30 (see Figure 7) is provided between the edges of adjacent plates, the strip 30 has a mushroom section protrusion 31 on its rear face. The members may be manufactured or subsequently shaped by bending the steel assembly to have a shape corresponding with that of the wall to be covered. If necessary the gap in the members lining the internal periphery of the wall W is closed by plates 10a cut to size so that the members form a rigiα self-supporting structure with their rearmost faces pressed against the wall W or any intermediate reinforcing bar which might have been installed. The void between the rear face of the plates 10 and wall surface is filled with a cementitious material C pumped through pre-formed or drilled apertures in the plates 10, which apertures are subsequently closed by plugs 40. In effect a layer of ferro-ce ent is formed behind the plates. The cementitious material surrounds the protrusions 31 thus keying the strips 30 to the structure. One advantage of lining a sewer in accordance with the invention is that the plates 10 act as shuttering for the cementitious filler, and no levelling by trowel of the finished surface is necessary. A further benefit arises from the self-supporting nature of the lining, avoiding the need to fix it, as by nailing, to the wall surface , an operation in itself further damaging to a decaying wall. Yet again, since the lining formed by the plates 10 is sealed, large lengths may be laid whilst flow through the sewer is uninterrupted, minimising, if not eliminating, the need for overpumping. It will be appreciated that it is not intended to limit the invention to the above example only, many variations, such as might readily occur to one skilled in the art, being possible, without departing from the scope thereof as defined by the appended claims. For example, the steel wire assembly may be heated and moved into engagement or whilst in engagement with a thermoplastic plate to become partially embedded therein and thus secured by thermal bonding.

Claims: C AIMS 1. A constructional memb r comprising a bendable plate of plastics material reinforced by an assembly of steel wires on one face thereof, some of the wire in said assembly being spaced outwardly from the plate. 2. A constructional member according to claim 1, wherein the plate is of thermoplastic polyolefin such as a high density polyethylene. 3. A constructional member according to claim 1, wherein the assembly of steel wires is thermally bonded to the plate. 4. A constructional member according to claim 1, wherein a textile fabric is bonded to the plate and wherein the assembly of steel wires is joined to the fabric. 5. A constructional member according to claim , wherein the textile fabric is stitch-bonded polyester. 6. A constructional member according to claim 4 , wherein the fabric is thermally bonded to the plate. 7. A constructional member according to claim 1, wherein the assembly of steel wires is secured to the fabric by an adhesive. 8. A constructional member according to claim 7, wherein the adhesive is applied over the whole face of the fabric. 9. A constructional member according to claim 7, wherein the adhesive is applied at discrete locations such as at spaced parallel strips. 10. A constructional member according to claim 7, wherein -the wire assembly is deformed from the face thereof for engagement with the adhesive to space the main body of the assembly away from the plate. 11. A constructional member according to claim 1, wherein, the assembly is comprised by planks formed from multiple layers of wire mesh. 12. A constructional member according to claim 11, wherein the layers are of different kinds, some being of woven wire mesh ("chicken wire") others being comprised by two sets of spaced parallel wires at an angle to one another and welded together at their crossing points. 13. A constructional member according to claim 12, wherein the layers are held together by folding. 14. A constructional member according to claim 12, wherein the wire mesh is trapped between ' the two sets of parallel wires. 15. A method of forming a lining within a tubular duct in which constructional members according to claim 1 are arranged with the wire reinforcement against the wall of the duct in the fashion of tiles with sealing means between their adjacent edges, some of the members being cut to size if necessary to close the lining such that it forms a self-supporting rigid structure and behind which a cementitious material is pumped to fill the void between the plates and the wall of the duct.

Inventors: RUSSELL DEREK VINCENT, RUSSELL, DEREK, VINCENT
Applicants: RUSWROE LIMITED
Application year: 1989
Main classification: E03F3
IPC codes: B29C70, C08J5, E03F3, E04F13, F16L55, F16L58