It is common practice in the construction industry to lay roads on a construction site prior to construction of buildings on the site. Roads of this type comprise base coat tarmac which is susceptible to spreading under the pressure of construction vehicles. In order to prevent this spreading, concrete kerbs are installed along road edges.

Installation of a concrete kerb comprises laying a base layer of semi-dry concrete, placing the kerb on top of the layer of concrete, then laying concrete at front and rear faces of the kerb to provide concrete stanchions. The concrete stanchions are patted into shape using a shovel. The kerb is fixedly secured to the base layer and stanchions by a bond formed between the kerb and the base layer and stanchions as the concrete dries.

Upon completion of the buildings on the construction site, top coat tarmac is laid on top of the base coat tarmac to complete the roads. Following completion of the buildings and the roads, the roads are usually adopted by a local council. The local council is then responsible for maintaining the roads.

A disadvantage of the current method of building roads is that kerbs are commonly damaged during construction work, for example by construction vehicles.

A local council will require the replacement of damaged kerbs prior to adoption of roads. The proportion of kerbs that are damaged and need to be replaced may be as high as 80%. Since the kerbs are fixedly secured to the base layer and the front and rear stanchions, it is very difficult to remove them. In order to remove a kerb, the front and rear stanchions must first be removed, typically by breaking them up. The kerb is then lifted from the base ; this may require considerable force.

It is known to lay temporary concrete kerbs of a uniform height and size at the beginning of a construction project. These temporary kerbs are retained until a construction project is near to completion, whereupon they are removed and replaced by conventional concrete kerbs. This method suffers from the disadvantage that removing the temporary kerbs is a difficult job which requires front and rear stanchions supporting the temporary kerbs to first be removed.

It is an object of the present invention to provide a kerb and a method of laying a kerb which overcomes the above disadvantages.

According to a first aspect of the invention there is provided a method of laying kerbs, the method comprising locating a first kerb in a base, wherein the first kerb is not fixedly secured in the base, the method further comprising subsequently removing the first kerb from the base and replacing the first kerb with a second kerb which is fixedly secured to the base.

Because the first kerb is not fixedly secured to the base, it may be easily removed and replaced by a conventional kerb (the second kerb). This allows a set of first kerbs to be quickly and easily replaced by a set of second kerbs when construction work adjacent to a road has been completed. The first set of kerbs may be reused.

Preferably, the base remains intact during removal of the first kerb and replacement with the second kerb. The phrase"not fixedly secured to the base"is not intended to mean that there is no bond between the first kerb and the base, but rather means that it is possible to remove the kerb from the base with the base remaining intact.

Preferably, the first kerb is removed from the base by lifting the first kerb vertically upwards using a lifting apparatus which engages with the first kerb.

Preferably, the first kerb is provided with a lubricant to reduce friction between the kerb and the base prior to location of the first kerb in the base.

Preferably, the first kerb is located in the base by placing the first kerb on a base layer, and then building front and rear stanchions against front and rear faces of the first kerb to form the base.

Preferably, the first kerb is provided with a sloping face, such that a stanchion of the base formed against the kerb will have a correspondingly sloping inner face.

This is advantageous because the slope introduces a gap between the first kerb and the stanchion when the first kerb is lifted by a small amount, thereby avoiding friction between the first kerb and the stanchion when the first kerb is removed from the base.

Preferably, the method further comprises, following removal of the first kerb and replacement with the second kerb, inserting grouting into a wedge-shaped gap formed between the sloping inner face of the stanchion of the base and the second kerb.

According to a second aspect of the invention there is provided a kerb for location in a base, the kerb being provided with an sloping face, such that a base formed against the kerb will have a correspondingly sloping inner face. As previously mentioned, the sloping face facilitates easy removal of the kerb from the base.

Preferably the angle of the sloping face is greater than 5 degrees from vertical from when the kerb is in an upright orientation.

Preferably, the sloping face is a rear face of the kerb.

Preferably, the sloping rear face extends from an uppermost surface of the kerb to a lowermost surface of the kerb.

Preferably, the sloping face is a front face of the kerb.

According to a third aspect of the invention there is provided a kerb for location in a base, the kerb being provided with handling means to facilitate removal of the kerb from the base.

Preferably, the handling means comprises one or more openings provided in the kerb into which a lifting means may be inserted.

Preferably, the one or more openings comprise one or more slots, each slot communicating with a chamber dimensioned such that an end of the lifting means may be passed into the slot and secured in the chamber, thereby allowing the kerb to the lifted using the handling means.

According to a fourth aspect of the invention there is provide a kerb provided with one or more channels which extend from an upper region of the kerb to a lower end of the kerb.

Preferably, the channels are defined by panels disposed at intervals along the kerb, the panels extending from an upper end of the kerb to a lower end of the kerb.

Preferably, the kerb is a cellular construction, the cells being the channels defined by the panels, the kerb being provided with front, rear and side walls.

Preferably, one or more portions of the kerb are substantially solid in order to accommodate the one or more openings.

The kerb according to any of the second, third or fourth aspects of the invention may be fabricated from elastomeric material.

Preferably, substantially vertical spaced apart grooves are provided in the kerb.

Preferably, the kerb is provided with a lubricant to reduce friction between the kerb and the base.

A specific embodiment of the invention will now be described, by way of example, only with reference to the accompanying figures, in which: Figure 1 is a frontal view of a kerb according to the invention; Figure 2 is a side view of the kerb shown in Figure 1 located in a base; Figure 3 is a side view of a conventional kerb located in the base shown in Figure 2; Figure 4 is a cross-sectional side view of the kerb shown in figures 1 and 2 ; Figure 5 is a top view of the kerb illustrated in Figure 4; Figure 6 is a front view of a kerb according to the invention; Figure 7 is a side of a the kerb shown in figure 6; Figure 8 is a front view of a kerb according to the invention; Figure 9 is a side view of the kerb shown in figure 8; Figure 10 is a perspective view of a cellular kerb according to the invention; Figure 11 is a front view and side view of a kerb according to the invention.

Referring to Figures 1 and 2 a first kerb 1 according to the invention comprises a base portion 2 and an upper portion 3. The upper portion 3 of the kerb has an inwardly sloping front face 4, and the lower portion 2 of the kerb has a vertical front face 5. An outwardly sloping rear face 6 extends from the top to the bottom of the kerb 1.

A pair of openings 7 are provided in the kerb 1. Each opening is configured to allow a T-shaped handle to be secured therein, and thereby allow the kerb to be lifted using the handles. The openings and handles are described further below.

In use, kerbs 1 are installed at a construction site during early stages of construction. The kerbs are located in a base which is laid along an edge of a base coat tarmac road surface 8. The base comprises a base layer 9, a front stanchion 10 and a rear stanchion 11. The base layer 9 is laid as semi-dry concrete with a flat upper surface. Kerbs 1 are positioned on the base layer 9. Concrete is laid at front 5 and rear 6 faces of the kerbs, and is patted using a shovel to form the front 10 and rear 11 stanchions. Thus, although Figure 2 shows a gap between the stanchions 10,11 and the kerb faces 5,6, this is for ease of illustration, and it will be understood that the stanchions 10, 11 are in contact with the kerb 1.

Inner faces of the stanchions 10,11 take the shape of the kerb. An inner face 12 of the front stanchion 10 is substantially vertical, and extends to just below the foot of the inwardly sloping front face 4 of the kerb. An outer face 13 of the front stanchion 10 slopes inwardly and is in contact with the road surface 8. An inner face 14 of the rear stanchion 11 slopes inwardly.

The kerb 1 remains in place until construction work at the construction site is close to completion, whereupon the kerb is removed and replaced with a conventional permanent kerb. The kerb 1 is removed by simply lifting it from the base. The sloping rear face 6 of the kerb 1, and correspondingly sloped inner face 14 of the rear stanchion 11, are such that lifting the kerb 1 by a very small amount will break any contact between the kerb 1 and the rear stanchion 11. A gap will form between the kerb 1 and the rear stanchion 11, allowing lateral movement of the kerb which will break any contact between the front face 5 of the kerb 1 and the inner face 12 of the front stanchion 10. The kerb 1 is thus easily lifted from the base.

It will be appreciated that the angle of slope of the rear face 6 of the kerb 1 need not be very large, merely sufficient that a gap is introduced between the kerb 1 and the stanchion 11 when the kerb is lifted by a small amount. Typically the angle of slope is between 7 degrees and 10 degrees from the vertical. It will be apreciated that any other suitable angle may be used. The slope of the rear face need not necessarily extend from the top to the bottom of the kerb 1, a portion of the rear face may for example be vertical. What is required is that the friction between the kerb 1 and the rear stanchion 14 is not so great that the kerb cannot be removed from the base without damaging the base.

It will be appreciated that the front face 5 of the kerb 1 may be sloped instead of or in addition to the rear face 6.

Referring to Figure 3, a top coat tarmac layer 15 is added to the base coat tarmac layer 8 when construction of buildings on a building site has been completed.

The kerb illustrated in Figures 1 and 2 has been lifted from the base and replaced with a conventional kerb 16. The conventional kerb 16 has a rear face 17 which is substantially vertical. An open wedge 18 is formed by the sloping front face 14 of the rear stanchion 11 and the rear face 17 of the conventional kerb 16. When the conventional kerb 16 has been located in the base, grouting (not shown) is poured into the open wedge 18, and agitated for example with a pole to remove bubbles. This grouting forms a wedge which presses the conventional kerb 16 against the front stanchion 10, thereby holding the conventional kerb 16 securely in place.

The kerb 1 shown in figures 1 and 2 may be fabricated from a suitable elastomeric material, for example rubber. Elastomeric material is preferred because it will not form a strong bond with concrete, thereby facilitating the easy lifting of the kerb 1 as described above. The elastomeric material also has the advantage that it is robust and is resistant to damage. Any other suitable material may be used.

A suitable lubricant, for example grease, may be applied to the kerb I before it is located in the base, to reduce friction between the kerb and the stanchions 10,11 when it is removed from the base.

Figure 4 shows a cross-section of the kerb 1, and figure 5 shows part of the kerb 1 from above. The opening 7 viewed from above is a slot which is dimensioned to receive a lowermost end of a T-shaped lifting apparatus 20. At a distance into the kerb 1 the opening 7 extends laterally outwards to form a chamber 21. The chamber 21 has the form of a pair of arcs each of which subtends approximately 90 degrees. In use, the lowermost end of the lifting apparatus 20 is inserted into the opening 7, and is then turned clockwise through 90 degrees. The lifting apparatus is thus securely located in the chamber 21 as shown in figure 4. Once the lifting apparatus 20 has been correctly located, and a corresponding lifting apparatus correctly located in an adjacent chamber of the kerb, handles 22 of the lifting apparatus are pulled upwards to remove the kerb 1 from the base (not shown).

In an alternative configuration, the kerb is provided with a pair of spaced apart slots which extend from the front face towards the rear face of the kerb. The slots are dimensioned and positioned so as to be suitable for receiving prongs of a forklift truck, or other suitable lifting apparatus. The slots are sufficiently high up the kerb that they are not obscured by the front stanchion.

It will be appreciated that the kerb may be provided with other suitable handling means to allow the kerb to be easily lifted from the base. For example, protrusions extending from the kerb could be gripped by construction workers to allow those workers to lift the kerb.

Figures 6 and 7 illustrate a kerb la according to the invention having a tapered upper portion 23. A kerb of this type is used when kerb height is to be lowered, for example for access to a driveway. The front and rear faces 4-6 of the kerb are sloped in the same way as the kerb illustrated in Figures 1 and 2. A base (not shown) includes a taper which corresponds to the taper of the upper portion 23 of the kerb.

The kerb is provided with a single opening 7 to facilitate removal of the kerb from a base.

Figures 8 and 9 illustrate a low kerb according to the invention. A kerb of this type is used at an access point, for example a driveway. The low kerb has a rear face 6 which slopes outwardly from a base of the kerb. The kerb is also provided with a narrow inwardly sloping front face 24. A base 25 used to hold the kerb is shown in Figure 9. The base has a rear stanchion 26 with an inner face 27 that slops inwardly from its foot. When a conventional low kerb is inserted into the base, an open wedge will be formed between the conventional low kerb and the inner face 27 of the rear stanchion 24, allowing the easy insertion of grouting.

The low kerb may not be sufficiently deep to be provided with an opening of the type shown in figures 4 and 5. Where this is the case, slots 28 are provided at ends of the low kerb, as shown in Figure 9. Tapered kerbs as illustrated in Figures 6 to 7 will usually be provided at either end of a low kerb. During removal of kerbs from a base, the tapered kerbs are removed to expose slots 28 in a low kerb. Lifting apparatus may then be used to lift the low kerbs using the exposed slots 28.

Figure 10 illustrates a kerb having a cellular form. The cellular form is advantageous because it reduces the amount of elastomeric material required to fabricate the kerb, thereby reducing the fabrication cost of the kerb. A further advantage of the cellular form is that it reduces significantly the weight of the kerb, making it easier to lift.

The kerb has the same exterior shape as the kerb illustrated in figures 1 to 3 (although any other suitable shape may be used). Side walls 31, the front face 32 and the rear face (not visible in figure 10) of the kerb are formed from a 20mm thickness of elastomeric material. A series of 20mm thick vertical panels 33 of elastomeric material are located at spaced apart points along the kerb. The panels 33 provide strength and structural rigidity to the kerb.

A lower end 34 and an upper end 35 of the kerb are not provided with a layer of elastomeric material, but are instead left open. This is advantageous because it provides an uninterrupted route for air to flow to the lower end 34 of the kerb, thereby preventing the formation of suction at the lower end 34 when the kerb is lifted from the ground.

Two spaced apart solid portions 36 are provided in the kerb. The solid portions are each provided with a slot 36 of the type shown in figures 4 and 5, which allow easy lifting of the kerb using a lifting apparatus.

Other forms of kerb which provide some of the advantages as the cellular kerb may be fabricated. For example, a kerb may comprise a substantially solid form within which a series of vertically disposed columns are provided. The columns have the dual purpose of allowing air flow to a lower end of the kerb, and reducing the volume of material required to construct the kerb. Other forms of kerb which provide these advantages may be used.

The cellular kerb may be fabricated by injection moulding or any other suitable technique. The elastomeric material is preferably rubber. The kerb may constructed from non-elastomeric material, although elastomeric material is preferred because it is relatively cheap and is not easily damaged.

A semi-cellular kerb 40 is shown in figure 11. The semi-cellular construction comprises a solid upper portion 41 and a lower portion 42 within which a series of chambers 43 are provided. Since the chambers 43 do not extend to the uppermost surface of the kerb 40, some suction will be generated at the base of the kerb upon raising the kerb 40 from a base. The suction generated is not prohibitive because the kerb 40 is much narrower than that shown in figure 10. The kerb 40 may be used as edging for a tarmac drive, the rear of a footpath, etc. Open chambers 44 are provided at either end of the kerb 40, and these allow easy lifting of the kerb 40, for example using a pickaxe.

Where a kerb according to the invention is fabricated from elastomeric material, it may be flexed to a required curvature to allow installation of the kerb at a corner of a road. In order to provide the kerb with a required degree of flexibility, vertical spaced apart grooves may be cut into a face of the kerb. The vertical grooves may be provided in a front face, a rear face, or both faces of the kerb to provide required flexibility for inwards and outwards flexing of the kerb.

As an alternative to cutting spaced apart grooves in one or both faces of a kerb, spaced apart markings may be provided to indicate where grooves should be cut in order to provide a required degree of flexibility.

Kerbs according to the invention are reusable, thereby providing significant costs savings.