AU2012204144A1 - Improved paving material and method of manufacture - Google Patents

Abstract

A method of forming a paving material including forming a paving tile from a mix of materials, which includes silicon carbide and etching an upper surface of the paving material that is formed with a chemical reagent. 41.., pt ; '-4 @3 <7

Description

mcnnes patents AUSTRALIAN PATENTS ACT 1990 STANDARD PATENT SPECIFICATION TITLE: Improved paving material and method of manufacture APPLICANT: Pebblecrete In-situ Pty Limited 238 Woodpark Road Smithfield NSW 2164 INVENTORS: Frank Piperata (Australian Citizen) 6 Janpieter Road, BOX HILL Dominic G Piperata (Australian Citizen) 3a Yarrabin Road, KENTHURST Dominic F Piperata (Australian Citizen) 8 Dantic Place, CHERRYBROOK ADDRESS FOR SERVICE: HODGKINSON McINNES PATENTS Patent & Trade Mark Attorneys Level 21, 201 Elizabeth Street Sydney NSW 2000 HMcIP REFERENCE: P21465AU00 2 IMPROVED PAVING MATERIAL AND METHOD OF MANUFACTURE TECHNICAL FIELD The present invention relates to improvements to and in relation to the provision of paving stones and paving materials or surfaces. More particularly the present invention may be used to provide an upper surface of paving materials with additional grip or anti-slip characteristics. BACKGROUND TO THE INVENTION Ground covering materials used in outdoor areas need to perform effectively in the role in which they are used. Such ground covering materials may be employed, for example, to provide a pavement or sidewalk covering surface, to cover the upper surface of a mall or plaza, or may be used in domestic applications to cover outdoor areas such as patios. Some forms of outdoor ground coverings such as paving stones may also be used in indoor environments. For example the interior floor surfaces of shopping malls or other interior public areas may be covered with polished or decoratively finished paving stones. These types of ground covering materials need to be both hard wearing, resistant to damage and also easy to clean. Aesthetic appeal and an attractive finish is desirable, as is the provision of a non-slip or slip resistant upper surface which can provide traction to persons walking over the surface. The materials used in such applications also need to be cost efficient - although this characteristic is generally traded off against the aesthetics or attractiveness of the resulting finish provided.

3 Paving stones perform well in such applications but can be more expensive to use than less attractive materials such as asphalt or concrete. Paving stones are normally produced in large batches to a standard specification with the resulting appearance generally being dictated by the materials used. Paving stones are also normally provided with a flat and potentially slick upper surface via grinding or finishing processes. Another form of paving material with a relatively attractive finish is terrazzo. Terrazzo is formed by a single continuance expansive paving material which contains chips of attractive stones such as marble set together in a matrix material. The upper face or surface of the terrazzo is subjected to an abrasion or grinding process to expose these attractive chips of material and provide a smooth upper paving surface. Terrazzo is a similar style of paving material to paving stones, providing an attractive and aesthetically appealing final finish at a relatively higher cost rather than the more basic materials such as asphalt or concrete. Due to the process used to form terrazzo, the resulting upper face of this material also has a relatively slick and potentially slippery surface which pedestrians may struggle to find traction on when wet. One way of improving the grip or traction provided by paving materials is to apply an additional layer or coating of a roughening compound to the upper face or surface of the paving material. However, such additional upper surface layers can, over time, become susceptible to wear and tear and may be worn off the paving material over time. It would therefore be of advantage to have an improved form of paving material and/or improved method of forming such a paving material which could address any or all of the above issues. In particular, improvements which could provide improved grip or non-slip characteristics for a paving material would be of advantage.

4 SUMMARY OF THE INVENTION According to one aspect of the present invention there is provided a method of forming a paving material, characterised by the steps of forming a paving tile from a mix of materials which includes silicon carbide; and etching an upper surface of the paving material formed with a chemical reagent. According to a further aspect of the present invention there is provided a method of forming a paving material substantially as described above further characterised by the additional subsequent step of applying a sealing compound to an upper face of the etched paving material. Preferably the chemical reagent is an acid and in a most preferred embodiment, it is a mixture of 1 part hydrochloric acid (33%) to 7 parts water. According to a further aspect of the present invention there is provided a paving material formed from a mixture which includes silicon carbide, said paving material defining an upper face treated with a chemical reagent adapted to etch said upper face. According to yet a further aspect of the present invention there is provided a paving material substantially as described above wherein the etched upper face of the paving material is treated with a sealing compound. The present invention is adapted to provide both improved forms of paving materials over the prior art in addition to improvements in and relation to the manufacture and/or treatment of such paving materials. A paving material provided in accordance with the present invention incorporates an upper face which will normally be orientated upwards in use and is the surface that will be exposed to pedestrian traffic.

5 Reference in general throughout the specification will also be made to the invention being used to provide paving stones. Those skilled in the art should appreciate that such references to paving stones can encompass a wide range of different types of paving products. Such paving products in general are formed by stone like materials provided as cobble stones, paving stones or any other equivalent form of interlocking or co-operating stone based paving products. Those skilled in the art would however appreciate that the present invention may also be used in conjunction with other forms of paving materials other than just paving stones. For example, in one alternative embodiment the present invention may be employed in conjunction with terrazzo type paving materials, and reference throughout the specification in general to paving stones should in no way be seen as limiting. The present invention is adapted to provide a paving material and more particularly a paving stone formed from a mix of component compounds which include a measure or proportion of silicon carbide in the mixture used. Silicon carbide is a hard wearing material which can be bonded effectively to the other components of a paving material mixture using well known paving stone manufacturing processes. In a further preferred embodiment, the percentage composition of silicon carbide used to make up the resulting paving material may range from 3% to 5% of the mixture of material used. In such embodiments the mixture employed may be composed of or from the materials described below. Preferably, the paving material formed using the invention also undergoes a chemical etching process applied to the upper surface of the paving material. A chemical reagent is employed to etch this upper surface, preferably to remove component materials of the paving mixture other than silicon carbide from the upper surface of the paving material. This etching process can therefore present proud chunks or chips of silicon carbide in the 6 upper surface of the paving material which will provide for improved traction or anti-slip properties for pedestrians. In a further preferred embodiment the chemical reagent used to etch the upper surface of the paving material may be formed by an acid. Acid reagents are well known in the industry and can be used at various strengths or dilutions to control the degree of etching applied to the upper face of the paving material. For example, in one instance the reagent used may be 1 part Hydrochloric Acid Standard (33%) added to 7 parts water. In some embodiments the upper face of the paving material formed may also have applied a sealing compound after the etching of same. A sealing compound can be used to protect the upper face of the paving material from additional degradation or erosion after the required etching process has been completed. In a further preferred embodiment a penetrating sealing compound may be applied to the etched upper surface of the paving material. For example, in one embodiment a penetrating ceiling compounds such as Barricade sealer may be used in this role. The present invention may therefore provide improvements in and relating to paving materials in addition to improve methods of manufacturing same substantially as described above. Silicon carbide in the paving material mixture incorporates a hard wearing component which will at least be partially exposed by the etching process applied to the upper face or surface of paving material. As the silicon carbide forms part of the paving material itself, it will not gradually be worn away and degradation as would a surface only anti-slip layer applied to a paving material after the formation of such a paving material. Paving materials provided in accordance with the present invention therefore have improved anti-slip characteristics which are 7 resistant to wear and degradation over time due to the composition of materials used to form the resulting paving. In this specification, unless the context clearly indicates otherwise, the term "comprising" has the non-exclusive meaning of the word, in the sense of "including at least" rather than the exclusive meaning in the sense of "consisting only of". The same applies with corresponding grammatical changes to other forms of the word such as "comprise", "comprises" and so on. BRIEF DESCRIPTION OF THE DRAWING A preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawing in which: Figure 1 shows a block schematic flow chart of steps employed in the manufacture of a paving material in accordance with a preferred embodiment. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Figure 1 shows a block schematic flow chart of steps employed in the manufacture of a paving material in accordance with a preferred embodiment. Figure 1 illustrates an embodiment where paving stones are formed by a three step process. In the first step 1 of this process, a paving stone mixture incorporating silicon carbide as one of its components as used to initially form a basic paving stone.

8 At stage 2 of this process the upper face of the paving stone is subjected to an acid reagent wash. This acid reagent etches the upper face of the paving surface, exposing portions of the silicon carbide present within the paving stone mixture, leaving chips of silicon carbide to project out of the main upper face or body of the paving stone. At stage 3 of this process the acid etched paving stone is treated with a penetrating sealing compound to preserve the integrity of the upper surface of the paver when in use. It will be apparent that obvious variations or modifications may be made which are in accordance with the spirit of the invention and which are intended to be part of the invention, and any such obvious variations or modifications are therefore within the scope of the invention. Although the invention is described above with reference to specific embodiments, it will be appreciated by those skilled in the art that it is not limited to those embodiments, but may be embodied in many other forms.

Claims (13)

1. A method of forming a paving material characterized by the steps of: I. forming a paving tile from a mix of materials which includes silicon carbide; and II. etching an upper surface of the paving material formed with a chemical reagent.

2. A method of forming a paving material as claimed in claim 1 further characterised by the additional subsequent step of: III. applying a sealing compound to an upper face of the etched paving material.

3. A method of forming a paving material as claimed in claim 1 wherein the chemical reagent is an acid.

4. A method of forming a paving material as claimed in claim 3 wherein the chemical reagent is a mixture of 1 part hydrochloric acid ( 3 3%) to 7 parts water.

5. A method of forming a paving material as claimed in claim 1 wherein the percentage composition of silicon carbide is in the range of 3% to 5% by weight.

6. A paving material formed from a mixture which includes silicon carbide, said paving material defining an upper face treated with a chemical reagent adapted to etch said upper face. 10

7. A paving material as claimed in claim 6 wherein the chemical reagent is an acid.

8. A paving material as claimed in claim 7 wherein the chemical reagent is a mixture of 1 part hydrochloric acid (33%) to 7 parts water.

9. A paving material as claimed in claim 6 wherein the etched upper face of the paving material is treated with a sealing compound.

10. A paving material as claimed in claim 6 as formed or which provides a paving stone.

11. A paving material as claimed in claim 6 wherein the percentage composition of silicon carbide is in the range of 3% to 5% by weight.

12. A method of forming a paving material substantially as hereinbefore described with reference to the accompanying drawing.

13. A paving material substantially as hereinbefore described with reference to the accompanying drawing.