GB2252119A - Kerb overlay - Google Patents

Abstract

A kerb (4) at the side of a roadway is upgraded to extend its life by the application of an overlay of a conformable plastics material. The overlay comprises an inclined upstanding wall portion (22) and a transversely extending upper portion (24). The overlay is preformed or is formed in situ from molten plastics material. <IMAGE>

Description

UPGRADING KERBS The present invention relates to a method of upgrading a kerb at the side of a roadway, and to an overlay suitable for carrying this out.

Conventional roadways are provided with kerbs along either side, which define the edges of the road and help prevent the edges from breaking away. When a pavement for pedestrians runs alongside the road, the kerb provides a line of demarkation between the (usually) elevated pavement and the roadway itself along which cars and other vehicles are driven. Depending on the degree of usage, the expected life of a road or pavement having a tarmac finish is from 10 to 20 years. At the end of that time, the road and pavement may require resurfacing. Nowadays, kerbs are generally formed from precast concrete kerb stones laid end-to-end and bedded in concrete.Although the life expectancy of such kerbs is generally in excess of 20 years, it is common practice to replace apparently sound kerbs at the same time as resurfacing is carried out, to ensure that the kerbs do not break up before resurfacing is required again. The digging up and replacement of kerbs is a time consuming and costly exercise, particularly when such kerbs may be basically sound.

Patent specification GB 942255 discloses a kerb formed of a shell of synthetic plastics material, which is then back-filled with concrete or rubble to form the pavement. However, it is not suitable for upgrading a worn kerb since the shell includes a bottom flange which could not readily be filled beneath an existing kerbstone.

Patent specification GB 1196680 discloses a kerb formed of shaped sheet metal.

It is an object of the present invention to provide a method of upgrading kerbs without the need to replace the kerb, so as to provide an extra lease of life.

The present invention provides an overlay for upgrading a kerb, which comprises a longitudinally extending body having an inclined upstanding wall portion, and a transversely extending upper portion; the overlay being shaped for intimate contact with the kerb and being formed of a conformable plastics material.

The invention also provides a method of upgrading a kerb which comprises fixing the overlay over the exposed inclined side and upper surface of the kerb.

The overlay is generally of a thickness 10 to 30 mm.

This minimises any decrease in the width of the roadway due to overlays being applied to opposite kerbs, whilst at the same time providing the overlay with adequate strength and conformability. Moreover, since the height of the kerb is raised by the thickness of the overlay, this allows the pavement to be resurfaced by applying a further layer of surfacing material (for example tarmac) over the existing pavement.

The overlay is formed of a conformable plastics materials, such as a synthetic plastics or elastomeric material, or fibre glass. Preferably, the overlay is formed by continuously extruding a length of elastomeric material through a die. The overlay is usually applied in long lengths so as to minimise the number of joins (at which the overlay may become detached from the kerb).

Advantageously, the overlay is adhered to the kerb using a suitable resin (such as those currently used for adhering cats eyes to the road surface). Additional fixing holes may be provided at the end of lengths to allow the ends of the overlay to be bolted or screwed in place if necessary.

Preformed concrete kerbs currently used in the United Kingdom are provided in two major profiles. The first, which is predominantly used in built-up areas where a pavement is provided, is of substantially rectangular cross-section with the upper two thirds of one side inclined at an angle of approximately 70 to the horizontal. The second major kerb profile is similar to the first except that the inclined side is set at an angle of approximately 45 and this type of kerb is generally used to edge country roads without pavements. The overlay of the present invention can be produced in a variety of profiles to suit the particular kerb which is being upgraded.The overlay may even be applied to kerbs having substantially vertical sides provided that the angle between the sides and upper portions is appropriately strengthened to prevent breakage in use.

Since the overlay is formed of a plastics material, it may be produced in appropriate eye-catching or fluorescent colours and may even be pre-painted with appropriate parking restriction indications.

Although the invention primarily envisages the use of a preformed overlay, it is also possible to form the overlay in situ by applying the plastics material in a molten state to the kerb so as to form the wall portion and the upper portion. In particular a hot plastics material, such as a bitumen might be applied. The material might include colour agents or reflective glass powders. In order to provide structural integrity, the material may include reinforcing agents, such as fibres, particularly of glass or polymeric materials.

The molten material may be applied using technology currently available for the application of road surface lines and other markings.

In order to raise the pavement to the appropriate height, a make-up piece may be located on top of the existing kerb before the molten material is applied. The make-up piece may be preformed (e.g. from plastics material) or may be cast in situ (e.g. from concrete).

The present invention has the advantages that the kerb can be upgraded at a cost which is very much reduced compared to the cost of digging up and renewing a kerb.

Since the overlay may be applied quickly, there is minimal disruption of traffic along the roadway and no excavation is required. Moreover, since the overlay is formed of a plastics material, it is liable to minimise the risk of injury to pedestrians and lessen the chance of damage to car wheels and trims.

Embodiments of the present invention will now be described by way of example only with reference to the drawings wherein; Figure 1 is a cross-section through a roadway, kerb and pavement; and Figure 2 is a perspective view of a section of overlay for a 45 kerb.

Figure 1 shows an overlay 2 adhered to a concrete kerb 4 having a side inclined at approximately 70 which is provided at the edge of a roadway 6 and delineates a raised pavement 8.

The kerb 4 is formed of precast concrete kerb stones bedded in a concrete haunch 10. The pavement is formed from fill 12 topped with a layer of asphalt 14 level with the top of the kerb. In order to upgrade the kerb, the overlay 2 is applied in continuous lengths to the kerb and is adhered thereto by means of a layer 18 of epoxy resin.

The overlay comprises a lower vertical portion 20, an inclined sidewall portion 22 and a horizontal upper portion 24 arranged to match the profile of the kerb. The overlay may be taken around bends in the kerb by cutting wedges out of the upper portion 24. Alternatively, rounded or angled corner sections might be injection moulded from a similar plastics material. Further mechanical fixings (such as rivets, nails, screws etc.) may be provided if needed at the ends of lengths of overlay to help prevent them lifting from the kerb in use.

Once the overlay has been installed, the level of the roadway may be built up by the application of a further layer 26 of asphalt, which also helps anchor in place the lower portion 20 of the overlay. It may be desirable to provide this portion with ridges or a foot portion which help anchor the lower end of the overlay into the new layer of asphalt. The effective height of the kerb is raised by the thickness of the overlay (typically 12 to 25 mm) plus the thickness of the layer 18 of epoxy resin. This allows a further layer 16 of asphalt to be applied to bring the pavement level therewith. Once again, the upper edge 28 of the overlay may be provided with means, such as a ridge or flange which helps the upper edge of the overlay to be mechanically embedded into the new asphalt layer 16 and thus effectively retained in place.

Figure 2 shows a perspective view of an overlay for a kerb having a 45" inclined portion. A discrete length of the overlay is shown, though the overlay is normally provided in longer continuous lengths.

The use of the overlay allows a road and pavement to be resurfaced and a basically sound kerb to be upgraded in a expeditious manner with minimum cost and with minimal disruption to traffic and pedestrians.

Claims (7)

1. An overlay for upgrading a kerb, which comprises a longitudinally extending body having an inclined upstanding wall portion, and a transversely extending upper portion; the overlay being shaped for intimate contact with the kerb and being formed of a conformable plastics material.

2. An overlay according to claim 1 of a thickness 10 to 30 mm.

3. An overlay according to claim 1 or 2 in a substantially continuous length.

4. A method of upgrading a kerb which comprises applying an overlay over the exposed inclined side and upper surface of the kerb, the overlay having an inclined upstanding wall portion and a transversely extending upper portion and intimately contacting the kerb; the overlay being formed of a conformable plastics material.

5. A method according to claim 4 wherein the overlay is preformed, and is adhered to the kerb using a resin.

6. A method according to claim 4 wherein the overlay is formed in situ by application of plastics material in the molten state.

7. A method according to any of claims 4 to 6 wherein the overlay is of thickness 10 to 30 mm.