GB2306130A

GB2306130A - Manufacture of concrete pavers

Info

Publication number: GB2306130A
Application number: GB9520842A
Authority: GB
Inventors: Ka Lok Ho
Original assignee: K WAH CONSTRUCTION PRODUCTS LI
Current assignee: K WAH CONSTRUCTION PRODUCTS LI
Priority date: 1995-10-11
Filing date: 1995-10-11
Publication date: 1997-04-30
Also published as: GB9520842D0

Abstract

A method of making a concrete paver characterised in that it comprises the step of grinding at least one face of said concrete paver.

Description

Method of Making Concrete Pavers and Concrete Pavers Made by said Method This invention relates to a method for making concrete pavers and to concrete pavers made by said method.

Concrete pavers are inter alia used in the construction of pavements, shopping arcade floors and roads. They are currently made by mixing aggregate, cement and water. The resultant mixture is poured into a mould and allowed to set. The concrete pavers are then removed from the moulds and are ready for use.

A problem with prior art concrete pavers is that the top surface tends to wear quickly, particularly in areas of heavy traffic. This can quickly create unsightly "tracks" in large areas of concrete pavers which is not acceptable.

The present invention attempts to reduce this problem.

According to the present invention there is provided a method of making a concrete paver characterised in that it comprises the step of grinding at least one face of said concrete paver.

Preferably, the grinding is carried out no earlier than 72 hours after the formation of said concrete paver.

Advantageously, the grinding is performed with a diamond faced grinding machine.

Preferably, from 0.5mm to 2mm, and advantageously lmm is removed from the face of said concrete paver during said grinding.

Advantageously, the concrete pavers are "dry" moulded although they could also be "wet" moulded.

The present invention also provides concrete pavers when made by a method in accordance with the present invention.

In one embodiment, each concrete paver has a nominal size of 200mm in length, lOOmm in width and 59mm in height: the concrete paver nominally being 200mm in length, lOOmm in width and 60mm in height prior to grinding.

In another embodiment, each concrete paver has a nominal size of 200mm in length, 100mm in width and 79mm in height: the concrete paver nominally being 200mm in length, 100mm in width and 80mm in height prior to grinding.

For a better understanding of the present invention reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a top plan view of a concrete paver in accordance with the present invention, prior to grinding; Figure 2 is a cross-sectional view taken on line II-II of Figure 1; Figure 3 is a top plan view of a paver in accordance with the present invention; and Figure 4 is a cross-sectional view taken on line IV-IV of Figure 3.

Referring to Figures 1 and 2 of the drawings a "dry" mix of aggregate, cement and water is poured into moulds. The mixture is compacted in the moulds which are then removed. The mixture is then left to set and cure for 72 hours.

The aggregate comprises stones 1 and fine particles.

The stones 1 are reasonably evenly spread in the concrete paver 10 as shown in Figure 2, however, due to the shape and distribution of the stones 1, only a small percentage of the area of the top surface 2 of the concrete paver 10 comprises stones 1, as depicted in Figure 1.

Previously, the concrete pavers would be used at this stage. However, in the present invention, the top surface 2 of the concrete paver is ground using a diamond head grinding machine down to the level C-C marked on Figure 2. The resultant concrete paver 20 is shown in Figures 3 and 4 wherein a significantly larger percentage area of the top surface is made up of stones 1.

The concrete pavers 20 shown in Figures 3 and 4 are 200mm in length, l00mm in width and 59mm in height with a 45" bevel 3 of 7mm in length.

A laboratory report follows comparing test results of measured abrasion resistance of the ground top surface of a concrete paver made in accordance with the invention, with the unground bottom surface.

TEST REPORT conducted by STEVENSON CIVIL ENGINEERING LABORATORIES of Greenmount, Hong Kong Abrasion Resistance Tests The subject test is to determine the abrasion resistance on both sides of a sample of 20 concrete block pavers as supplied by way of a "tumbler test".

The test was conducted in accordance with Draft Standard AS/NZS DR 94039, Method 10: Method for determining abrasion resistance (tumbler test).

The samples used: Concrete block pavers with nominal dimensions, 200mm long, 100mm wide and 60mm thickness; one side of the pavers had been machine ground smooth to expose the aggregate, the opposite side of said paver was not ground. Measurements were taken from the ground top side of each sample and the opposite (bottom) face of each sample. The results are compared in the following table.

Origin of Sample: K. WAH Construction Products Limited, Hong Kong.

TEST RESULTS ABRASION RESISTANCE (Tumbler Test)

Type of Unit 60mm Rectangular 60mm Rectangular Concrete Pavers Concrete Pavers Texture of Medium/Coarse Smooth/Ground Wearing Surface Surface Date of Test 10 August 1994 15th August 1994 Specimen No. Abrasion Index (VA) Abrasion Index (VA) 1 2.2 1.6 2 1.3 0.8 3 2.2 1.5 4 L 2.0 1.7 5 1.9 1.6 6 1.2 1.0 7 1.7 1.2 8 1.8 1.3 9 2.0 1.6 10 2.0 1.2 11 1.6 1.3 12 2.2 1.7 13 2.3 1.7 14 1.9 1.4 15 2.1 1.9 16 1.5 1.1 Mean Abrasion 1.9 1.4 Index (Vaa) Standard 0.3 0.3 Deviation (s') Various modifications to the concrete paver described are envisaged, for example both the top and bottom of the concrete pavers may be provided with bevelled edges if desired.

Claims

1. A method of making a concrete paver characterised in that it comprises the step of grinding at least one face of said concrete paver.

2. A method according to Claim 1, wherein the grinding is carried out no earlier than 72 hours after the formation of said concrete paver.

3. A method according to Claims 1 or 2, wherein said grinding is performed with a diamond faced grinding machine.

4. A method according to Claims 1,2 or 3, wherein lmm is removed from said face during said grinding.

5. A method according to any preceding Claim, wherein said concrete pavers are made using dry moulding.

6. A concrete paver made by a method in accordance with any preceding Claim.

7. A concrete paver as claimed in Claim 6, having a nominal size of 200mm in length, 100mm in width and 59mm in height.

8. A concrete paver as claimed in Claim 6, having a nominal size of 200mm in length, 100mm in width and 79mm in height.

9. A concrete paver as claimed in any preceding claim having bevelled edges.

10. A concrete paver as claimed in Claim 9 which is rectangular and has bevelled edges on all eight edges.

11. A concrete paver substantially as hereinbefore described with references and as shown in Fig.3 and Fig.4 of the accompanying drawings.