GB2314337A

GB2314337A - Material for bridge joints and/or for repairing the surfacing of roads and other load-bearing surfaces

Info

Publication number: GB2314337A
Application number: GB9613072A
Authority: GB
Inventors: James Mcintosh; Edward John Jenkins
Original assignee: M J HIGHWAY TECHNOLOGY Ltd; Roadtex Ltd
Current assignee: M J HIGHWAY TECHNOLOGY Ltd; Roadtex Ltd
Priority date: 1996-06-21
Filing date: 1996-06-21
Publication date: 1997-12-24
Also published as: GB9613072D0

Abstract

A material for repairing cracks or potholes in roads or other load-bearing surfaces or for forming a bridge joint comprises wood chips covered with a bitumen. In one embodiment a hot bitumen/wood chips mixture is applied to a surface to be repaired. In other embodiments the bitumen is applied to a surface or mould, to which a layer of reinforcing fibres may have been applied, chips are then applied and then further bitumen is applied. The sheet formed in the mould may then be used eg to repair a crack in a road.

Description

IMPROVED MATERIAL FOR BRIDGE JOINTS AND/OR FOR REPAIRING THE SURFACING OF ROADS AND OTHER LOAD-BEARING SURFACES This invention relates to an improved material which can be used for repairing cracks or potholes in roads, parking areas, aircraft parking and movement areas, and any other such load-bearing area. Usually, but not always, such a loadbearing area is formed of concrete.

It has in the past been proposed to repair damage to road surfaces or other load-bearing surfaces using a material comprising a bituminous binder with aggregate incorporated. Similarly it has been proposed to provide bridge joints of bituminous binder with reinforcing fibres and optionally including aggregate.

Accordingly, a first aspect of the present invention provides a material for bridge jointing or repair of roads and other load-bearing surfaces comprising :- a bituminous binder, and wood chips totally covered by said binder.

A further aspect of the invention provides a method of forming a bridge joint, comprising :- mixing wood chips in a heated, flowable bituminous binder, agitating the wood chips and binder until the surface of the wood chips is covered by the binder, and applying the mixture to the bridge joint area whereupon it cools in situ to provide the desired bridge joint.

Yet a further aspect of the present invention provides a method of repairing a crack or pothole in a road surface or any other load-bearing surface, comprising:mixing wood chips in a heated, flowable bituminous binder, agitating the warm mixture to ensure that the surface of the wood chips is covered by the bituminous binder, applying the mixture of wood chips and binder to a dry crack or pothole to be repaired, and lightly rolling the surface of the applied mixture.

If the load-bearing surface to be repaired is cracked the surface may first be cut to define a groove to receive the repair material.

The present invention surprisingly uses, as a jointing or repair material, wood chip in a bituminous binder and it has been found that such a material both resists the aggressive effects of weather and furthermore provides a degree of resilience to a repair or joint material which accommodates the repeated compres sion and relaxation due to traffic moving over the surface patch or joint, again without suffering damage in the short term.

The jointing or patching material of the present invention has a bituminous binder at least a part of which may be rubberised bitumen, and wood chip serving as coarse particulate material therein.

The wood chips used may be of any desired size commensurate with the function to be achieved from the material, but a size range of from 1 to 5 mm, preferably from 2 to 5 mm, more preferably approximately 3 mm, is considered advantageous. Larger sizes of wood chip may in some cases be desired.

If desired conventional stone aggregate may be incorporated in the coarse particulate material as well as the wood chips. Sand may also be included as finer particulate material. The bituminous binder may include chopped rubber, and may include polymeric additives to serve as elasticiser and/or stabilizer. Such a polymer additive based on Styrene Butadiene Styrene (SBS) or Styrene Isoprene Styrene (SIS) is available from Enichem Elastomers Ltd of London. Equally, the bituminous binder may include reinforcing fibres, for example glass fibres or polyamide fibres, or even metal fibres. Such fibres may comprise up to 5% of the total, but preferably from 0.5 to 1.5% of the total weight.

Where reinforcing glass fibres are used these may be chopped to a length of approximately 30 mm.

It is preferred that the material have the wood chips, with or without any other particulate material, added to the binder and agitated therein before application of the resulting mixture to the area to be filled and/or repaired.

It is also possible for the binder to be applied first to serve as a kind of primer after which the wood chips, with any optional further particulate material, are applied to the still wet binder and then lightly rolled in, and then a traffic bearing overlay, for example in the form of an additional surface dressing, may be applied.

Such a surface dressing may optionally comprise a conventional black top or MacAdam surface, for example having a thickness of up to 200 mm, but more preferably in the range of from 30 to 50 mm thickness. Such a surface dressing keeps the wood chips free from moisture which might cause degradation of the chips over a period of time.

With this separate application of the binder and the wood chips, the binder may if desired be of a more liquid, less viscous, consistency, for example in the form of a bitumen emulsion our a polymer-modified bitumen emulsion, which can then be sprayed over the surface before application of the wood chips. However, alternatively the bituminous binder may be poured rather than sprayed in which case such a low viscosity emulsion is not required.

In one example it is possible for rubberised bitumen binder material to comprise at least approximately 50% by weight of the material in accordance with the invention, the remainder of up to 70% by weight being made up of the particulate material comprising wood chips, with or without some conventional stone aggregate. More preferably the wood chip, with or without the optional stone aggregate, may comprise 30% of the total weight.

The material may if desired be preformed as a strip which can then be inserted in a groove accurately cut around an area to be repaired or cut around a bridge joint area to be sealed, and the material in accordance with the invention can then be integrated with the surface, e.g. concrete or asphalt, to be repaired or sealed, by any suitable means such as by applying heat to soften the binder, provided the heat is not such as to initiate combustion of the wood chips. For use as a bridge joint the size of the coarse particulate material may be larger, for example 14 to 20 mm is preferred.

Although the material in accordance with the present invention will normally be used for localised bridge jointing or repairing of load-bearing surfaces, it may equally be applied to a surface area as an overall layer or membrane, in which case the wood chips will be of smaller dimension that would be contemplated for a patching or repairing material. They may, for example, be from 1 to 3 mm in size.

This membrane layer application is particularly suitable for lightly loaded paths or driveways or other areas which are to be walked on or to carry light vehicles rather than to bear regularly the load of heavy vehicular traffic. The wood chips will impart a degree of compression to the finished material; the binder, optionally with its reinforcing fibres, will provide the necessary resistance to cracking.

If desired a polymeric primer composition based on polyamines, such as POLYRAM L 200 available from Ceca S.A. or WETFIX 300/N available from Akzo Nobel Inc. of Waco, Texas, or Kling Beta 2700 also available from Akzo Nobel Inc., may be incorporated in the bituminous binder so as to cause a better bond with the underlying area, e.g concrete or asphalt, to be patched or sealed.

The total particulate content may be from 30 to 70% of the material, by weight.

EXAMPLE 1 A pothole in road surfacing on private ground was patched by use of the material in accordance with the present invention.

Firstly a rubberised bitumen filler was heated to render it flowable. Then 30%, by weight, of wood chips having a cross-sectional dimension in the range 1 to 5 mm was added to the flowable binder and was agitated therein until the entire surface of the wood chips was covered with the bituminous binder.

The material of wood chip and binder was then poured into the dry pothole and lightly rolled in order to promote bonding of the binder to the surface of the road metal in the pothole.

After repeated passage of vehicles over the repair, no residual subsidence of the patch was noticeable, and the patch remained in position.

EXAMPLE 2 Warm polymer modified bitumen, including an adhesion-promoting primer of POLYRAM (R.T.M.) was poured on to the floor of a mould on to which a matrix of chopped glass fibres of approximately 30 mm length had been laid. Particulate material comprising wood chips in the size range 1 to 5 mm and aggregate of 1 to 5 mm in size was then spread on the surface of the warm bitumen binder. More bituminous binder was then applied over the particulate material.

The mixture was then lightly rolled to cause the fibres to be integrated into the bottom of the binder to improve the tensile strength of the composite material.

When the binder had cooled it was removed from the mould and lightly rolled up to allow it to be stored until it was needed for use. Before use, a patch of the material was cut to size to fit a groove cut in the surface to be required, and then the surface opposite to that bearing the particulate material was heated with a blow torch to soften the binder sufficiently for it to adhere to the floor of the groove at the repair site.

EXAMPLE 3 The process of Example 2 was repeated but with the wood chips stirred into the warm flowable binder before the binder was poured into the mould. The aggregate was then applied, but no further binder was added.

It is estimated that the life of such a repair could be as much as 5 years.

Since it would normally be expected that a road surface would be replaced within a 5 to 7 year interval the patch could be adequate until the next overall road repair.

The fibres may if desired instead be mixed in with the bituminous binder before pouring of the binder into the mould as described in Example 2 and Example 3.

The same technique applied in the above examples could be used for repairing pathways, driveways, parking areas1 garage floors, aircraft pavements and other similar surfaces.

Claims

1. A material for bridge jointing or repair of roads and other loadbearing surfaces comprising :- a bituminous binder, and wood chips totally covered by said binder.

2. A material according to claim 1 wherein said wood chips have a cross-sectional dimension in the range of from 1 to 5 mm.

3. A material according to either of the preceding claims, and including reinforcing fibres in the binder.

4. A material according to any one of the preceding claims, and further including a polymeric primer in the bituminous binder.

5. A material according to any one of the preceding claims, and further including stone aggregate and/or rubber chips.

6. A material according to any one of the preceding claims wherein the content of wood chips and any stone aggregate or rubber chips is from 30 to 60% by weight of the total material.

7. A material according to any one of the preceding claims in the form of a sheet of the bituminous binder having wood chips embedded therein.

8. A method of forming a bridge joint, comprising :- mixing wood chips in a heated, flowable bituminous binder, agitating the wood chips and binder until the surface of the wood chips is covered by the binder, and applying the mixture to the bridge joint area whereupon it cools in situ to provide the desired bridge joint.

9. A method according to claim 8, wherein the wood chips have a cross-sectional dimension of from 14 to 20 mm.

10. A method of repairing a crack or pothole in a road surface or any other load-bearing surface, comprising :- mixing wood chips in a heated, flowable bituminous binder, agitating the warm mixture to ensure that the surface of the wood chips is covered by the bituminous binder, applying the mixture of wood chips and binder to a dry crack or pothole to be repaired, and lightly rolling the surface of the applied mixture.

11. A method according to claim 10, wherein said wood chips have a cross-sectional dimension of from 2 to 5 mm.

12. A method according to either of claims 10 and 11, wherein the repair is to a crack in a concrete surface, and including the step of cutting a groove in the concrete surface around the crack to define a clear groove to receive the repair materials.

13. A method according to any one of claims 8 to 12 and including adding reinforcing fibres to the bituminous primer.

14. A method of repairing a crack or pothole in a road surface or other load-bearing surface, substantially as herein before described with reference to the Example.

14. A method according to any one of claims 8 to 13, and further including the step of adding stone aggregate to the bituminous primer.

15. A method according to claim 14, wherein said stone aggregate is added after application of the repair material to the crack or pothole to be repaired.

16. A method according to claim 15, wherein the addition of stone aggregate is followed by the or a rolling operation on the repaired surface.

17. A method of repairing a crack in a road surface or any other loadbearing surface, comprising:- taking a preformed sheet of repair material comprising a fibre reinforced bituminous binder enclosing wood chips so that the surface of the wood chips is totally covered by the binder; cutting a groove in the surface to be repaired, to a depth equivalent to the sheet of repair material; lightly heating the sheet of repair material to soften the binder, placing the sheet of repair material in said groove; and lightly rolling the repair material into the groove to promote adhesion of the sheet in the groove.

18. A method according to claim 17 and including the step of cutting the sheet of repair material to match the area of the groove.

19. A method of forming a sheet of repair material for repairing roads and other load-bearing surfaces, comprising placing a matrix of reinforcing fibres on the floor of a mould, pouring a heated flowable bituminous binder on to said matrix of reinforcing fibres, applying wood chips to the surface of said bituminous binder, applying further bituminous binder over the wood chips to cover the wood chip surface totally with the binder, and after cooling of the bituminous binder removing the composite material from the mould as a sheet.

20. A method of forming a sheet of repair material for roads and other load-bearing surfaces, comprising mixing wood chips in a heated bituminous binder to cause the binder to cover the wood chip surface totally, applying a matrix of reinforcing fibres on to the floor of a mould, pouring the mixture of wood chips and bituminous binder on to the matrix of reinforcing fibres, and after cooling of the binder removing the composite of fibres, binder and wood chips from the mould as a sheet.

21. A method according to claim 19 or 20, and including the step of lightly rolling the composite of fibres, binder and wood chips in the mould to integrate the fibres into the binder.

22. A method according to any one of claims 8 to 21 wherein there is also stone aggregate in the bituminous binder.

23. A material for repairing roads or other load-bearing surfaces, substantially as hereinbefore described with reference to any one of the accompanying Example.

24. A method of forming a bridge joint in accordance with claim 8, and substantially as herein before described.

25. A method of repairing a crack or pothole in a road surface or other load-bearing surface, substantially as hereinbefore described with reference to Example 1.

26. A method of forming a sheet of repair material, substantially as hereinbefore described with reference to Example 2.

27. A method of forming a sheet of repair material, substantially as herein before described with reference to Example 3.

Amendments to the claims have been filed as follows

1. A material for repair of roads and other load-bearing surfaces comprising :- a bituminous binder, and wood chips totally covered by said binder.

7. A method of repairing a crack or pothole in a road surface or any other load-bearing surface, comprising :- mixing wood chips in a heated, flowable bituminous binder; agitating the warm mixture to ensure that the surface of the wood chips is covered by the bituminous binder; and pouring the mixture of wood chips and binder into a dry crack or pothole to be repaired.

8. A method according to claim 7, wherein said wood chips have a cross-sectional dimension of from 2 to 5 mm.

9. A method according to either of claims 7 and 8, wherein the repair is to a crack in a concrete surface, and including the step of cutting a groove in the concrete surface around the crack to define a clear groove to receive the repair materials.

10. A method according to any one of claims 7 to 9 and including adding reinforcing fibres to the bituminous binder.

11. A method according to any one of claims 7 to 10, and further including the step of adding stone aggregate to the bituminous binder.

12. A method according to claim 11, wherein said stone aggregate is added after application of the repair material to the crack or pothole to be repaired.

13. A material for repairing roads or other load-bearing surfaces, substantially as hereinbefore described with reference to the accompanying Example.