WO2000004253A1

WO2000004253A1 - Method of laying a surface element, and element for use therewith

Info

Publication number: WO2000004253A1
Application number: PCT/GB1999/002322
Authority: WO
Inventors: James Mcintosh
Original assignee: M.J. Highway Technology Limited
Priority date: 1998-07-17
Filing date: 1999-07-19
Publication date: 2000-01-27
Also published as: GB9824872D0

Abstract

An array of decorative sheets (1, 2, 3, 4 and 5) is formed wiht a porous support fabric (4), preferably of woven glass fibre, in contact wiht the rear faces of the sheets. The assembly (1-6) can then be laid on a substrate surface by application, to the substrate, of uncured cold-curing resin optionally mixed with sand, and then placing the assembly of sheets on the uncured resin with the support fabric (6) in contact wiht the resin, and allowing the resin to cure. A method of manufacturing the sheets is also described.

Description

METHOD OF LAYING A SURFACE ELEMENT, AND ELEMENT FOR USE THEREWITH

The present invention relates to a method of laying surface elements, for example sheets textured to give the effect of blocks, bricks or cobbles on a ground surface.

In addition to laying bricks, cobbles, blocks or other similar elements to define a surface, it is known to provide sheets which are textured to resemble such surface elements as, for example, blocks, bricks or cobbles, but which are much thinner than the elements they resemble and are intended merely to provide a decorative effect resembling those elements, although the sheet itself is intended to be strong enough to withstand the pressure of people or traffic moving over it. For example, our GB-A-2, 312, 224 discloses a sheet of thermoplastic resin which can be heated to bond it to a surface such as a driveway so that stone chips or aggregate embedded within the sheets can be visible from above and will give the impression of a gravel driveway. Equally, our GB-A-2, 315, 786 discloses a sheet which is textured to have the appearance of blocks or bricks for laying on a ground surface, again using heat to bond the thin plastic sheet in place. It is an object to the present invention to provide a textured sheet which does not depend on the application of heat to bond it to a substrate. The substrate may, by way of example, be concrete or asphalt.

Accordingly a first aspect of the present invention provides a method of laying sheets on a substrate surface, comprising applying to the substrate surface uncured resin capable of curing at ambient temperature, placing on the uncured resin the assembly of a porous fabric having a plurality of the sheets mounted thereon in a desired array, and allowing the applied resin to cure while said sheets and support fabric are in contact therewith.

A second aspect of the invention provides an assembly of sheets for laying on a substrate comprising an array of sheets of cold-curing material in a desired array, each of said sheets having first and second opposite faces; and a porous support fabric integral with the second face of each of the sheets to hold the sheets in said array. A third aspect of the present invention provides a method of forming an assembly of sheets according to the second aspect, comprising moulding a plurality of sheets having opposite first side and second sides, said sheets being in a desired array; before the material of the sheets has cured placing over said second sides of the sheets a porous support fabric; and allowing the curing of the sheets to be completed with said support fabric in contact therewith, at ambient temperature.

A fourth aspect of the present invention provides a method of laying an assembly of sheets on a substrate surface, comprising applying to the substrate surface uncured resin capable of curing at ambient temperature, placing on the uncured resin a porous fabric to act as a stress-absorbing membrane interlayer, placing on the porous fabric a plurality of sheets arranged in a desired array, pressing the sheets into the uncured resin to cause the resin to permeate through the porous fabric into contact with the underside of the applied sheets, and allowing the resin layer to cure to bond the sheets and the porous fabric in place thereon.

In order that the present may be understood, the following description is given, merely by way of example, with reference to the accompanying drawing in which:

Figure 1 represents, in plan, a set of interlocking sheets held on a fabric support for laying in accordance with the method of the first aspect of the present invention; and

Figure 2 shows a side elevation of the array of Figure 1 when laid on a concrete substrate.

In Figure 1 there can be seen four sheets 1, 2, 3, 4 and 5 which are intended to form part of a repeating array which extends both vertically as viewed in the drawing and horizontally, although in this case only five sheets have been shown. The surfaces of the sheets visible in Figure 1 (uppermost in Figure 2) are coloured and textured in a desired manner to represent brick, stone or cobble.

The sheets 1 and 2 have adjacent edges lc and 2a close to one another with a gap therebetween to simulate mortar space which would exist if the sheets 1 and 2 were representative of bricks, and equally the sheets 1 and 2 each have (i) edges lb and 2b which are adjacent an edge 4d of the sheet 4, and (ii) edges Id and 2d which are adjacent the edges 3b of sheet 3 and 5b of sheet 5, but again leaving a gap of from 5 to 12 mm for simulating the mortar space. The five sheets 1, 2, 3, 4 and 5 are shown as mounted on a woven backing 6 to which they are affixed in such a way that they are held in the above-defined spacing. Although in this case the backing fabric 6 is woven, it could equally be a non-woven backing, although it is preferred that the fabric of the backing is sufficiently porous to enable a primer slurry (8 in Figure 2), to be referred to later, to exude through pores in the support fabric 6 for a purpose to be explained later during the description of the method of application of the sheets.

As shown in Figure 2, each edge of each sheet 1, 2, 3, 4, 5 is bevelled so as to define an upwardly divergent V-shaped gap between the sheets, to receive the excess resin "mortar" which is exuded through the fabric support 6 when the assembly of sheets is pressed down into the resin "mortar" during laying of the sheets. When the "mortar" has cured the V-shaped strip in this gap will be integral with the underlying mortar layer bonded to the substrate and will lock the adjacent sheets in place. The "mortar" preferably includes resin and sand but the sand may be excluded.

The sheets 1, 2, 3, 4 and 5 may be formed of any suitable material. The sheets may be formed of a mixture of acrylic copolymer and epoxy resin. Alternatively the sheets may be formed from a more conventional sand, cement and water mixture. The sheets could also be formed of a "mortar" mixture of sand and resin which may be an epoxy resin, but other cold-curing resins are possible. The above compositions are all capable of curing without the need for heating above ambient temperature. In practice the range of curing temperatures may be from -10°C to +20°C.

Optionally reinforcing fibres, e.g. chopped continuously extruded fibres of, say, about 10 mm in length, may be incorporated in the sheet material mix to enhance the tensile strength of the sheets and to improve their resistance to cracking when the underlying substrate cracks and movement occurs. The fibres may be of any suitable material, for example glass or polyester. Such fibrous reinforcement is particularly valuable when the sand/cement/water mixture is used for the sheets.

An example of an acrylic copolymer and resin composition which may be used for the sheet material mix includes an acrylic emulsion known as MAINCOTE(TM) which includes around 40-45% by weight of acrylic copolymer, 55-60% by weight of water plus small amounts of aqueous ammonia and individual residual monomers (both comprising 0.1% by weight or less). The resin component of the sheet material mix can be a liquid epoxy resin known as EUREPOX 756/67 W. The sheet material mix includes 6-7% and preferably 6.4% by weight of acrylic emulsion and 1.5-2%, preferably 1.6% by weight of epoxy resin, the rest being sand but with an optional minor amount of colouring pigment. Where the sheet material mix is formed using a traditional sand and cement mix, the mixture may include around three parts sand to one part cement by weight in addition to colour pigment (approximately 2% by weight) and optionally reinforcement fibre (up to about 2% by weight) in addition to water.

A third alternative for the composition of the sheet material mix comprises a mixture of sand and resin similar to the material used as the mortar, as described below. The material used for the sheets 1, 2, 3, 4 and 5 is preferably non-opaque, for example translucent or transparent and able to be coloured with a pigment to suit the desired profile of the upper face in Figure 2 (intended to be the upwardly facing surface when the sheets have been laid on a substrate such as 7 in Figure 2) . The surface may be profiled to resemble stone such as york stone, sandstone or granite set. Equally the profiling may resemble brick work, for example antique brick (old English brick) or modern brick. Where antique brick is being simulated the edges of the sheets will not be exactly straight so a ragged gap between adjacent sheets will occur. Equally for simulating London Cobble some of the sheets may be non-square, again giving rise to a non-rectangular gap between such sheets and others which may be truly square.

The dimensions of each brick-like sheet may, for example, be 4" square or a 6" x 4" rectangle.

If desired, the fabric support 6 may be parted, for example by cutting or tearing, so as to separate one or more of the sheets 1, 2, 3, 4 or 5 from the rest of the array, in order to allow individual sheets to be laid separately from the rest or to allow a normally regular (for example square) array to be broken up to give it an irregular periphery to allow laying in awkward areas. Thus, after such a parting operation, it is possible for only some of the sheets of the original array to be laid and for one or more of the others to be either laid or discarded, depending on the shape of the area to be covered. Glass fibre and polyester are preferred materials for the textile support sheet 6, so as to impart adequate strength to the array of sheets 1, 2, 3, 4 and 5... etc. to resist reflective cracking appearing in the individual sheets 1 to 5 etc as a result of a crack (such as 9 in Figure 2) in the underlying substrate 7, e.g. of concrete. In this respect a woven fabric support 6 acts as a stress absorbing membrane interlayer (SAMI) in the finished assembly of sheets on a substrate. This results from providing the individual sheets on a fabric support which is strong in tension but which may be flexible in shear so as to allow a degree of lateral movement of the sheets relative to one another so that the sheets themselves may remain intact in the event of cracking of the substrate, for example in the case of expansion and contraction of a concrete substrate, in that in the event of any relative movement of the substrate to either side of the crack 9 during thermally induced deformation (expansion or contraction) the sheets 2 and 4 are able to shift slightly with respect of one another in order to absorb the resulting stresses and to reduce the risk of cracking through the new surface (5, 2, 4, 8 in Figure 2) .

Furthermore, with a strong support fabric and a secure bond of the brick or stone or cobble-like sheets to the support sheet 6 it is possible for the array to be laid on non-flat surfaces, for example a dished paving surface, such that the array of sheets 1-5 adapts to the concavities or convexities of the substrate surface.

It may be desirable to colour the resin-sand pre-mix to provide the desired mortar effect to match the colouring and profiling of the sheets. In other words, where the sheets are coloured to give the appearance of brick the sand-resin pre-mix may be chosen to resemble mortar in brickwork. Examples of cold-curing resins which may be used with the present invention include a liquid epoxy resin known as EUREPOX 783 and a hardener EUREDOR 14, both available from Witco Corporation (UK) Ltd of Droitwich, Worcestershire. Such resins are able to complete curing at ambient temperatures. Although curing may be complete after 5 to 6 hours at temperatures in the range of 10°C to 20°C, curing at lower ambient temperatures may take place up to 24 hours. For low ambient temperatures a curing accelerator may be added, or a fast-curing resin may be chosen.

Whichever resin is used will preferably be non- opaque so as to be coloured by use of suitable fillers and/or other additives. When other than epoxy resins are used, a curing accelerator composition may be added just prior to the casting step.

In order to give an example of the method of the present invention, there now follows a description of one example of the laying of the assembly of sheets illustrated in the drawing. Although the substrate may be a vertical surface such as a wall, it is envisaged that the invention will find greatest application in the use for decorating patios or other paving areas.

EXAMPLE 1 The textile support is a woven polyester fabric having pores of the order of mm square and supporting the various sheets, in this case square sheets 100 mm x 100 mm (4" x 4") between 8 and 10 mm thick, such as 1, 2, 3 and 4 in interlocking arrangement in that the sheets occur in side-by-side rows with the gaps between two adjacent sheets of one row non-coincident with the corresponding gaps of the adjacent rows to either side of it (as illustrated in the drawing) . The gaps between adjacent sheets in any one row and the gaps between adjacent rows are standardised at approximately 10 mm.

In order to provide a fully integrated structure of the fabric support 6 with the sheets 1, 2, 3, 4, 5... etc., during moulding, the individual sheets 1, 2, 3, 4, 5... etc. being moulded of using a mixture of sand and a cold-curing resin are formed face down in the mould and then the fabric support sheet of woven glass fibre is applied to the rear face of the sheets 1, 2, 3, 4, 5... etc. before the resin of those sheets has cured. Thus when the sheets cure they are fully integrated with the fabric support sheet 6. In this example the resin

"mortar" comprises a pasty mixture of sand, EUREPOX 783 resin and EUREDOR 14 hardener, with colouring to resemble antique brick.

First of all the substrate surface (in this case a concrete patio surface) on which the sheets are to be laid is skimmed with a layer of a primer slurry comprising a mixture of sand and uncured resin, and that skimmed layer is rendered even. This allows any unevenness in the substrate (concrete) surface to be taken up by the resin-sand pre-mix which is in the form of a slurry. The slurry comprises another, more runny, mixture of sand, EUREPOX 783 and EUREDOR 14.

Then the various sheets 1, 2, 3, 4, 5... etc. on their woven fabric support sheet 6 are placed face-up on the surface of the "mortar" and pressed into position to the extent that some of the resin-sand "mortar" pre-mix exudes through the pores in the fabric support 6 to emerge in the gaps between successive sheets in a row and between adjacent rows, in the manner of mortar. The resin in the pre-mix is then allowed to cure to provide a stable coating comprising the sand and cured resin mix with the fabric sheet 6 thereon and the individual decorative sheets 1, 2, 3, 4, 5... etc. bonded to the fabric. EXAMPLE 2

A plurality of sheets, profiled and coloured to simulate London Cobble, is moulded as in Example 1, but without application of the fabric support 6.

The substrate surface is then coated with the same resin "mortar" as is used in Example 1 and, before curing of the mortar, a porous woven fabric SAMI of continuous filament polyethylene fibre is placed on the mortar.

Still before curing of the mortar, the sheets are then laid on the SAMI and pressed into place to cause the resin mortar to exude through the porous fabric and through the gaps between adjacent ones of the sheets so as to resemble pointing and so as to be capable, on curing, of bonding the sheets to the substrate.

Once the mortar has cured the thus applied layer of sheets is able to resist the reflective cracking phenomenon described above in that the stress-absorbing quality of the SAMI distributes any stress resulting from movement of the underlying substrate to the inter-sheet gaps in the array so that the individual sheets shift with respect to one another but do not undergo cracking in response to stress applied due to movement of the underlying substrate.

Claims

1. A method of laying sheets on a substrate surface (7), comprising applying adhesive to the substrate surface, placing the sheets on the adhesive, and allowing the applied adhesive to set while said sheets and support fabric are in contact therewith; characterised in that the sheets are first assembled on a porous fabric (6) having a plurality of the sheets (1, 2, 3, 4, 5) mounted thereon in a desired array; and in that the adhesive applied to the surface is an uncured resin (8) capable of curing at ambient temperature.

2. A method according to claim 1 wherein the array of sheets carried by the porous support fabric includes gaps between adjacent sheets, and including the step of pressing the assembly of sheets and support fabric against the uncured resin to cause some of the resin to exude through the gaps between the sheets .

3. A method according to claim 1 or claim 2, including the step of levelling the uncured resin before application of the assembly of sheets and support fabric thereto.

4. A method according to any one of the preceding claims, wherein said applied resin is mixed with sand.

5. A method according to any one of claims 1 to 5, comprising the step of parting the fabric support in order to separate at least one of said sheets from the rest of the array and then laying separately said removed sheet or sheets and/or the rest of the array.

6. A set of sheets for laying on a substrate, each of said sheets having first and second opposite faces; characterised in that the sheets comprise an array of sheets (1-5) of cold-curing material mounted in a desired array on a porous support fabric (6) integral with the second face of each of the sheets to hold the sheets in said array.

7. An assembly according to claim 6 wherein said support fabric is a woven fabric.

8. An assembly according to claim 6 or 7 wherein said support fabric is of glass fibre.

9. An assembly according to any one of claims 6 to 8, wherein said sheets are closely spaced apart from one another in said array.

10. An assembly according to any one of claims 6 to 9 wherein said second surfaces of the sheets have been rendered integral with said support fabric (6) by having the fabric brought into contact with the sheet before the material forming the sheets has cured.

11. A method of forming an assembly of sheets according to any one of claims 6 to 10, characterised by the steps of moulding a plurality of sheets (1-5) having opposite first and second sides, said sheets being in a desired array; before the material of the sheets has cured placing over said second sides of the sheets a porous support fabric (6) ; and allowing the curing of the sheets to be completed with said support fabric in contact therewith, at ambient temperature.

12. A method of laying an assembly of sheets on a substrate surface (7), comprising applying an adhesive to the substrate surface, and applying the sheets thereto, characterised in that the adhesive applied to the surface is an uncured resin capable of curing at ambient temperature, in that a porous fabric (b) is then placed on the uncured resin to act as a stress-absorbing membrane interlayer, and thereafter a plurality of said sheets (1-5) arranged in a desired array is placed on the porous fabric and pressed into the uncured resin to cause the resin to permeate through the porous fabric into contact with the underside of the applied sheets, and in that the resin layer is allowed to cure to bond the sheets and the porous fabric in place thereon.

13. A method according to claim 11 or 12, wherein said sheets have bevelled edges arranged such that the gap between adjacent sheets is divergent in a direction away from the substrate surface.

14. A method or assembly according to any one of claims 6 to 13, wherein the material used to form the sheets comprises a mixture of sand and resin.

15. A method or assembly according to any one of claims 6 to 13 wherein the uncured material used to form the shee s comprises a mixture of sand, cement and water.

16. A method or assembly according to any one of claims 6 to 13 wherein the uncured material used to form the sheets comprises a mixture of an acrylic emulsion, resin and sand.

17. A method or assembly according to any one of claims 6 to 16, wherein said mixture includes reinforcing fibres .

18. A method of laying sheets, substantially as described with reference to the accompanying example.

19. An assembly of sheets and a support fabric, substantially as described with reference to the accompanying examples.

20. A method of forming an assembly of sheets and a support fabric, substantially as herein before described with reference to the examples and as shown in the figures .