GB2270270A

GB2270270A - Anti-slip surfaces

Info

Publication number: GB2270270A
Application number: GB9319284A
Authority: GB
Inventors: Eric Joseph Harvison
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-02-14
Filing date: 1993-09-17
Publication date: 1994-03-09
Anticipated expiration: 2011-02-14
Also published as: GB2270270B; GB9319284D0

Abstract

Anti-slip surfaces with retro-reflective characteristic, are obtained by applying to the surface a first coating of paint, distributing particles of mineral or other material on the coating before the coating has dried so that the particles sink partially into the first coating, then applying a second coating of paint over the particles and the first coating to lock the particles into the first coating with the particles projecting from the second coating, and distributing retro-reflective beads on the second coating before the second coating has dried to sink partially into the second coating such as to be bonded thereto and effectively overshadowed by the projecting particles. <IMAGE>

Description

Anti-Slip Surfaces This invention relates to anti-slip surfaces and especially to methods of providing traffic or other surfaces with anti-slip and retro-reflective characteristics.

According to one aspect of the present invention a method of providing a surface with anti-slip and retroreflective characteristic, comprises the steps of applying to the surface a first coating of paint, distributing particles of mineral or other material on the coating before the coating has dried so that the particles sink partially into the first coating, then applying a second coating of paint over the particles and the first coating to lock the particles into the first coating with the particles projecting from the second coating, and distributing retro-reflective beads on the second coating before the second coating has dried to sink partially into the second coating such as to be bonded thereto and effectively overshadowed by the projecting particles.

For optimum anti-slip characteristic it has been found advantageous for the particle size and the thicknesses of the two coatings of paint to be chosen in relation to one another, such that for the average-dimension of the particles, about one third of each particle projects from the second coating. The particles may be of aluminium oxide, silicon carbide (to give sharpness), zirconium (to give toughness), or plastics material (for example, for spark suppression), and may even be granules of rubber or cork (to give resilience and/or compliance). They may be applied by spray or a controlled gravity-feed system or by an electrostatic method.

The retro-reflective beads may be added by gravity feed or otherwise (for example by spray) either during application of the second coating of paint, or immediately afterwards before that paint has set. The beads as bonded to the surface by the second coating, are preferably of significantly smaller dimension than the particles used. They are preferably no more than twothirds the size, so that they will be readily overshadowed by the projecting particles.

Retro-reflective beads tend to present a slippery surface, especially when wet, but this does not have deleterious effect where they are effectively overshadowed, as with the method of the present invention, by the projecting particles. In this regard the beads may be interspersed between the particles to maximise the anti-slip characteristic and afford them good protection against dislodgement. However, they may be similarly, effectively overshadowed where they are included in strips or other narrow areas of the second coating which are surrounded closely by projecting particles but which are themselves free from those particles.

The paint used, which may be the same for both coatings and may contain fillers and/or pigments, may be an epoxyresin based paint.

The method of the present invention may be successfully applied economically and readily to paths, roadways, passageways, decks (for example on ships and oil platforms), helicopter landing pads and airfield runways and taxiways.

According to another aspect of the present invention there is provided an anti-slip and retro-reflective surface having a first coating of paint applied to that surface, particles of mineral or other material distributed in the first coating, and a second coating of paint over the particles and the first coating to lock the particles into the first coating, and wherein the particles project from the second coating, and retroreflective beads bonded partially into the second coating to project therefrom, are effectively overshadowed by the projecting particles.

Anti-slip and retro-reflective surfaces, and methods of providing them, in accordance with the present invention, will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a section illustrative of a combined anti-slip and retro-reflective surface laid in accordance with the present invention; Figure 2 shows a helicopter landing pad in accordance with the present invention; and Figure 3 shows part of an airfield taxiway with inset symbology, laid in accordance with the present invention.

Figure 1 shows a section through a two-coat anti-slip paint system that has been applied to a blacktop (for example, bituminous or tar macadam) or concrete surface of a path, roadway or airfield runway or taxiway, in accordance with the present invention. As an alternative, the traffic surface may be a metal or other deck for helicopter use on a ship or oil rig.

Referring to Figure 1, the swept and cleaned traffic surface 5 is given a first coat 6 of an epoxy-resin based paint to a thickness of 0.3 mm; in the case illustrated, the surface 5 has been previously primed with the paint to the extent necessary to enable the first coat 6 to be established without absorption into its sub-surface 7.

While the paint of the first coat 6 is still wet, mineral particles 8 having a 16-mesh grit size are applied evenly over the paint to sink into it-, at a rate of some 1 to 1.5 kg/m2.

A second coat 9 of the paint is applied to a thickness of 0.3 mm, over the first coat 6 to lock in the particles 8.

During application of this second coat 9, or immediately after, while the second coat 9 is still wet, glass beads 10 are distributed evenly over it to sink in partially, and to be firmly bonded into the coat 9 when it dries.

The beads 10, which are at least naminally spherical, have diameters generally within the range 0.18 to 0.40 mm, and are applied at a rate of some 400 to 500 g/m2.

They are interspersed between the significantly larger particles 8 to nestle down between them in'the second coat 9. The beads 10 are accordingly protected by the particles 8 and overshadowed shielded by them so as not te have any effect on the overall anti-slip characteristic of the surface.

By suitable masking, it is pdssible to confine the glass beads to certain areas only, of the anti-slip surface. A helicopter landing pad constructed in this way is shown in Figure 2.

Referring to Figure 2, the helicopter landing pad is a square area 11 marked with the conventional symbol consisting of an area 12 delineating the letter 'H', and an area 13 that delineates an enclosing circle. The whole of the square area 11 has the two-coat anti-slip surfacing system as provided by the mineral particles, but it is only the areas 12 and 13 that also include glass beads in the manner described with reference to Figure 1. The resultant retro-reflectivity of the areas 12 and 13 make them distinctive, but they are also distinguished from their surrounds within the area 11 by use of coloured paint for the second coat or for both the first and second coats.

In certain applications, strips or other narrow areas of the anti-slip surface may be masked so as to be left clear of the mineral particles, and then subsequently filled with beads to give that strip or other area retroreflectivity. This latter technique may be adopted especially where narrow lettering or other marking is to be inset into the anti-slip surfacing, and is to be very clearly visible at night. An example of application of this technique to the marking of an. airfield taxiway with an arrow and box symbol will now be described with reference to Figure 3. Figure 3 shows part of the taxiway with its anti-slip surfacing broken away to reveal the concrete base surface beneath.

Referring to Figure 3, the concrete base 14 of the taxiway is surfaced with a two-coat anti-slip system 15 that is inset with strips 16 and 17 of glass beads which delineate an arrow and an open-box symbol respectively.

The anti-slip system 15 is applied by a two-coat process comparable with that described above with reference to Figure 1, after the concrete base 14 has first been treated with a primer to improve adhesion of the system 15 with it. Immediately the first coat of the paint system has been applied to cover the base 14, the areas to be occupied by the strips 16 and 17 are masked off in order to keep them clear of the mineral particles distributed on the first coat in the process. Once the distribution of the mineral particles has been carried out, the masking is removed and the second coat of the system is then subsequently applied to cover the whole of the first coat, including the areas (for the strips 16 and 17) that are free of mineral particles.

Before the second coat is dry, masking is laid down around the mineral-free areas (strips 16 and 17) to leave them open, and the mineral-occupied regions around them covered over. Glass beads are now distributed throughout the revealed strips 16 and 17 to sink partially into the still-wet second coat and be held firmly there when the system has dried out. The masking confines the beads to the strips 16 and 17 so that on its removal in completion of the anti-slip surfacing operation, the arrow and openbox symbols delineated by the strips 16 and 17 are clearly recognisable through the distinctive retroreflectivity they exhibit.

The beads within the strips 16 and 17 are of significantly smaller dimension than the mineral particles used for the anti-slip surfacing so that the beads are protected (by being effectively overshadowed) to a certain degree by the mineral particles surrounding them in the surface. This protection is greater the narrower the strips 16 and 17, and provided the strips 16 and 17 are kept narrow, the anti-slip characteristic of the surface elsewhere can be maintained across the strips 16 and 17 without significant loss. In this respect, the strip-width is desirably significantly less than the smallest 'footprint' likely to occur on the surface.

The widths of the inset strips 16 and 17 of glass beads are significantly less than the widths of the narrowest tyres that are likely to be used on that surface. Thus, as a tyre of an aircraft passes across, or even along the strip, a significant proportion of the ground-contact area of that tyre (its 'footprint') overlaps the strip so as to remain in contact with the mineral-occupied surrounds of that strip and be afforded adequate antislip restraint.

The present application is a divisional application of Patent Application No 9103084.1 (2 242 144), which describes and claims a method of providing a traffic surface having anti-slip characteristic, comprising the steps of applying to the surface a first coating of paint, distributing particles of mineral or other material on the coating before the coating has dried so that the particles sink partially into the coating, and then applying a second coating of paint over the particles and the first coating to lock the particles into the first coating, the thicknesses of the first and second coatings being controlled in, relation to the average size of the particles to leave substantially one third of each particle projecting from the second coating. The parent application also claims an anti-slip traffic surface having a first coating of paint applied.

to that surface, particles of mineral or other material distributed in the first coating, and a second coating of paint over the particles and the first coating, and wherein the second coating locks the particles in the first coating with substantially one third of each particle projecting from the second coating.

Claims

Claims:

1. A method of providing a surface with anti-slip and retro-reflective characteristic, comprising the steps of applying to the surface a first coating of paint, distributing particles of mineral or other material on the coating before the coating has dried so that the particles sink partially into the first coating, then applying a second coating of paint over the particles and the first coating to lock the particles into the first coating with the particles projecting from the second coating, and distributing retro-reflective beads on the second coating before the second coating has dried to sink partially into the second coating such as to be bonded thereto and effectively overshadowed by the projecting particles.

2. A method according to Claim 1 wherein the paint used for at least one of the coatings has an alkyd or epoxyresin base.

3. A method according to any one of Claim 1 or Claim 2 wherein the same paint is used for the second coating as for the first.

4. A method according to any one of Claims 1 to 3 wherein both coatings of paint and/or the particles are applied by spray.

5. A method according to any one of Claims 1 to 4 wherein the thickness of the second coating is the same as, or is less than, that of the first.

6. A method according to any one of Claims 1 to 5 wherein the particles are of aluminium oxide, silicon oxide or zirconium.

7. A method according to any one of Claims 1 to 6 wherein the surface is primed before application of the first coating such as to ensure that the paint of the first coating is not absorbed into the surface.

8. A method according to any one of Claims 1 to 7 wherein the beads are added to a strip or narrow area of the second coating that is free from the particles.

9. A method according to any one of Claims 1 to 8 used for an airfield runway or taxiway, or for a helicopter landing pad, wherein markings of the runaway, taxiway or pad are delineated by the beads.

10. A method according to Claim 9 wherein the markings are also delineated by paint-colour differences within at least the second coating.

11. An anti-slip and retro-reflective surface having a first coating of paint applied to that surface, particles of mineral or other material distributed in the first coating, and a second coating of paint over the particles and the first coating to lock the particles into the first coating, and wherein the particles project from the second coating, and retro-reflective beads bonded partially into the second coating to project therefrom, are effectively overshadowed by the projecting particles.

12. An anti-slip surface according to Claim 11 wherein the beads occupy a strip or narrow area of the second coating that is free from the particles.

13. An anti-slip surface according to Claim 11 or Claim 12 for use as an airfield runway or taxiway, or as a helicopter landing pad, wherein markings of the runway, taxiway or pad are delineated by the beads.

14. An anti-slip surface according to Claim 13 wherein the markings are also delineated by paint-colour differences within at least the second coating.

15. A method of providing an anti-slip and symbol-marked traffic surface of a helicopter landing pad, substantially as hereinbefore described with reference to Figure 2 of the accompanying drawings.

16. A method of providing an anti-slip and symbol-marked traffic surface of an airfield taxiway, substantially as hereinbefore described with reference to Figure 3 of the accompanying drawings.

17. An anti-slip traffic surface provided by the method of any one of Claims 1 to 10 or Claim 15 or Claim 16.

18. A helicopter landing pad substantially as hereinbefore described with reference to Figure 2 of the accompanying drawings.