GB2081603A - Surface dressing - Google Patents

Abstract

A substrate such as a concrete decking or a car parking ground area to be surfaced is sprayed with a binder which is reinforced with chopped glass fibres, for example by being sprayed from a head having three nozzles, the central nozzle having the chopped glass fibres sprayed from it, and the outer two nozzles having a binder such as bitumen sprayed therefrom. A suitable aggregate, for example, of 10 millimetre chippings, is sprinkled on the thus coated substrate. Where the substrate is uneven, depressions may be filled with e.g. tarmacadam before spraying.

Description

SPECIFICATION Surface dressing The present invention relates to surface dressing of substrates, such as the ground, concrete decking surfaces, etc.

The surface dressing of various substrates has been carried out conventionally in a number of different ways including the laying of asphalt and other coverings. Such methods are most satisfactory, but can be rather time consuming and very expensive.

In recent years, car park areas have often been made available upon the demolition of a building, for a period of time until it is decided to rebuild on the same site. Naturally, the substrate of such car park areas is rough, and can be dangerous both to vehicles and people walking to and from the vehicles. Proposals have been made for providing a relatively inexpensive form of surface dressing in the form of fibreglass matting together with a binder, such as bitumen, pitch tar, or tar. Naturally, the substrates themselves are of a rather uneven nature, and it has been found that this method of surface dressing is not entirely satisfactory, because the fibreglass mats tend to bridge any depressions and sag thereinto, so that the resulting surface of the surface dressing is, to say the least, undulating.

It is now proposed, according to the present invention, to provide a method of surface dressing a substrate, comprising spraying onto the substrate to be surfaced, a binder which is reinforced with chopped glass fibres, and subsequently adding to the thus coated substrate a suitable aggregate.

Such a method can be carried out very swiftly indeed, and is therefore relatively inexpensive, and significantly less expensive than the hitherto known method of first of all spraying the surface, then laying onto it mats of fibreglass, and then spraying onto that a further layer of bitumen, and finally adding chippings.

Preferably deep depressions and potholes are prepared by filling them in with bituminous macadam or scalpings and the fibreglass is introduced aiready in chopped form and thus readily fills minor irregularities in the surface and in the filled potholes. The method can be carried out extremely rapidly and provides a durable and robust surface dressing, which is maintained as a coherent layer by the fibre glass which acts as a carpet or matting. This is far more permanent than can be achieved by known methods in which the loose chippings are simply stuck to the substrate by the binder. A surface prepared according to the invention prevents water from washing out "fines" in the substrate and prevents vehicle tyres from plucking out loose stones, which would cause the formation of potholes.

The method is advantageously carried out using a spraying head having three nozzles, preferably arranged with a central nozzle through which is sprayed the chopped glass fibre and two outer noz zles through which are sprayed a binder, such as bitumen. In one experiment carried out according to the present invention, a car park surface was pre pared by filling the potholes with scalpings, that is surfacing material removed from a road surface. The whole surface was then sprayed with a spray head having three such nozzles and immediately afterthe spraying was carried out, 10 millimetre chippings of aggrerate were sprinkled onto the sprayed area to produce a final surface dressing having a thickness of about 12 millimetres after rolling.

The provision of the glass fibres sprayed into the bitumen, together with the chippings, provided a strongly coherent finished surface dressing which is capable of withstanding the rigours of vehicles passing thereover, without there being any significant depressions in the top surface of the dressing, provided that the potholes and large depressions are refilled.

While the invention has been described as applied to a generally uneven substrate, it can equally be applied to a firmer substrate such as concrete decking.

1. A method of surface dressing a substrate, said method comprising spraying onto the substrate to be surfaced a binder which is reinforced with chopped glass fibres, and subsequently adding to the thus coated substrate a suitable aggregate.

2. A method according to claim 1, wherein deep depressions and/or pot holes are prepared by filling them in with bituminous macadam or scalpings.

3. A method according to claim 1 or 2, wherein the fibre glass is introduced already in a chopped form.

4. A method according to claim 3, wherein the fibre glass is introduced from a spraying head having three nozzles, the central nozzle having the chopped glass sprayed therefrom, and the two outer nozzles having the binder, such as bitumen, sprayed therefrom.

5. A method according to any preceding claim, wherein the aggregate is in the form of chippings.

6. A method according to claim 5, wherein the aggregate is in the form of 10 millimetre chippings sprinkled onto the substrate coated with a binder and chopped glass fibres.

7. A method of surface dressing a substrate according to claim 1, and substantially as hereinbefore described.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Surface dressing The present invention relates to surface dressing of substrates, such as the ground, concrete decking surfaces, etc. The surface dressing of various substrates has been carried out conventionally in a number of different ways including the laying of asphalt and other coverings. Such methods are most satisfactory, but can be rather time consuming and very expensive. In recent years, car park areas have often been made available upon the demolition of a building, for a period of time until it is decided to rebuild on the same site. Naturally, the substrate of such car park areas is rough, and can be dangerous both to vehicles and people walking to and from the vehicles. Proposals have been made for providing a relatively inexpensive form of surface dressing in the form of fibreglass matting together with a binder, such as bitumen, pitch tar, or tar. Naturally, the substrates themselves are of a rather uneven nature, and it has been found that this method of surface dressing is not entirely satisfactory, because the fibreglass mats tend to bridge any depressions and sag thereinto, so that the resulting surface of the surface dressing is, to say the least, undulating. It is now proposed, according to the present invention, to provide a method of surface dressing a substrate, comprising spraying onto the substrate to be surfaced, a binder which is reinforced with chopped glass fibres, and subsequently adding to the thus coated substrate a suitable aggregate. Such a method can be carried out very swiftly indeed, and is therefore relatively inexpensive, and significantly less expensive than the hitherto known method of first of all spraying the surface, then laying onto it mats of fibreglass, and then spraying onto that a further layer of bitumen, and finally adding chippings. Preferably deep depressions and potholes are prepared by filling them in with bituminous macadam or scalpings and the fibreglass is introduced aiready in chopped form and thus readily fills minor irregularities in the surface and in the filled potholes. The method can be carried out extremely rapidly and provides a durable and robust surface dressing, which is maintained as a coherent layer by the fibre glass which acts as a carpet or matting. This is far more permanent than can be achieved by known methods in which the loose chippings are simply stuck to the substrate by the binder. A surface prepared according to the invention prevents water from washing out "fines" in the substrate and prevents vehicle tyres from plucking out loose stones, which would cause the formation of potholes. The method is advantageously carried out using a spraying head having three nozzles, preferably arranged with a central nozzle through which is sprayed the chopped glass fibre and two outer noz zles through which are sprayed a binder, such as bitumen. In one experiment carried out according to the present invention, a car park surface was pre pared by filling the potholes with scalpings, that is surfacing material removed from a road surface. The whole surface was then sprayed with a spray head having three such nozzles and immediately afterthe spraying was carried out, 10 millimetre chippings of aggrerate were sprinkled onto the sprayed area to produce a final surface dressing having a thickness of about 12 millimetres after rolling. The provision of the glass fibres sprayed into the bitumen, together with the chippings, provided a strongly coherent finished surface dressing which is capable of withstanding the rigours of vehicles passing thereover, without there being any significant depressions in the top surface of the dressing, provided that the potholes and large depressions are refilled. While the invention has been described as applied to a generally uneven substrate, it can equally be applied to a firmer substrate such as concrete decking. CLAIMS

1. A method of surface dressing a substrate, said method comprising spraying onto the substrate to be surfaced a binder which is reinforced with chopped glass fibres, and subsequently adding to the thus coated substrate a suitable aggregate.

2. A method according to claim 1, wherein deep depressions and/or pot holes are prepared by filling them in with bituminous macadam or scalpings.

3. A method according to claim 1 or 2, wherein the fibre glass is introduced already in a chopped form.

4. A method according to claim 3, wherein the fibre glass is introduced from a spraying head having three nozzles, the central nozzle having the chopped glass sprayed therefrom, and the two outer nozzles having the binder, such as bitumen, sprayed therefrom.

5. A method according to any preceding claim, wherein the aggregate is in the form of chippings.

6. A method according to claim 5, wherein the aggregate is in the form of 10 millimetre chippings sprinkled onto the substrate coated with a binder and chopped glass fibres.

7. A method of surface dressing a substrate according to claim 1, and substantially as hereinbefore described.