FIELD

The present invention relates to a repair compound for carrying out repairs. More particularly, the present invention relates to a repair compound for carrying out repairs to roads, paving, concrete slab structures, etc. The present invention also relates to a method of using a repair compound to carry out repairs.

BACKGROUND

Road wear and damage is a serious and on-going issue. Roads become damaged with cracks and holes during normal use - for example by the repeated passing of heavy vehicles such as trucks or buses - and also during winter, where frosts and subsidence can cause or exacerbate damage. Repair works are disruptive to the normal flow of traffic, and they normally require closing at least one lane of a two-way flow (and then managing the traffic flowing in each direction), for a period of usually around 48 hours. This can often be more, depending on the extent of the damage. However, even minor repairs are extremely disruptive, and the area around a repair site will normally be closed to traffic for a period following the repair, in order to allow the repair material to fully cure or otherwise settle and harden.

In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art.

SUMMARY

It is an object of the present invention to provide a repair compound which goes some way to overcoming the abovementioned disadvantages or which at least provides the public or industry with a useful choice.

It is a further object of the present invention to provide a method of using a repair compound which goes some way to overcoming the abovementioned disadvantages or which at least provides the public or industry with a useful choice.

The term“comprising’’ as used in this specification and indicative independent claims means“consisting at least in part of. When interpreting each statement in this specification and indicative independent claims that includes the term“comprising”, features other than that or those prefaced by the term may also be present. Related terms such as“comprise” and“comprises” are to be interpreted in the same manner.

As used herein the term“and/or” means“and” or“or”, or both.

As used herein“(s)” following a noun means the plural and/or singular forms of the noun.

Accordingly, in a first aspect the present invention may broadly be said to consist in a repair compound, comprising: a plastic material comprising substantially 35-70% of the compound, by weight; a rock/mineral particulate material comprising substantially 20-40% of the compound, by weight; the plastic material and particulate material formed as a substantially homogonous mixture. This mixture in these proportions has been found to provide a hard-wearing, yet easy-to-use and apply, material, for repairs such as road repair, and similar repairs and construction, while using recycled materials to re-use material and keep costs low.

In an embodiment, the rock/mineral particulate material comprises one or more of: sand; glass aggregate; limestone chippings; granite chippings. These have all been found to be suitable for use in the mixture, and help to provide a hard-wearing yet easy-to-use material.

In an embodiment, the aggregate material has a size substantially the same size as crushed stone grade #8. This provides material of substantially the same size as that used in tarmacing road surfaces.

In an embodiment, the repair compound further comprises a UV stabiliser, Quencher or HALS comprising 0.1-1.5% of the compound, by weight. This helps to provide durability to the compound.

In an embodiment, the plastics material comprises one or more of plastic material #1 , #2, #4 #5, #6. These have been found to provide the desired mix of melt and wear qualities.

In an embodiment, the repair compound further comprises an oil material comprising substantially 0-30% of the compound, by weight.

In an embodiment, the oil material is a vegetable-based oil. This has been found to provide the correct qualities for use in the mixture, and can be used as a recycled material to keeps costs low and re-use material rather than discarding it.

In an embodiment, the repair compound further comprises Styrofoam/polystyrene comprising substantially up to 15% of the compound, by weight. In an embodiment, the compound is formed as solid extruded pellets. This allows the compound to be easily stored, transported and melted as required.

In an embodiment, the pellets have a size of substantially 10mm x 10mm. This provides an easy-to-form size that will also melt quickly and completely when heat is applied.

In an embodiment, the compound is stored in Polythene bags. These allow the compound to be added directly to a melting pot without unloading or decanting the compound from the bag.

In a second aspect, the present invention may broadly be said to consist in a method of using a repair compound, comprising the steps of:

(i) setting a melting container to a temperature of substantially between 165 and 240 degrees Celsius;

(ii) adding a repair compound as claimed in any one of the preceding statements to the thermoplastic melter;

(iii) allowing the repair compound to transition from a solid to a liquid;

(iv) pouring or otherwise decanting the liquid repair compound out of the melting container and into an area under repair as required, and allowing the repair compound to solidify. This method has been found to provide a rugged and durable repair that can be carried out quickly and easily.

In an embodiment, in step (i), the melting container comprises a thermoplastic melter. These provide a quick and easy method of melting and preparing the material.

In an embodiment, in the step of setting the temperature, the temperature is set substantially to 210 degrees Celsius. This has been found to be the most appropriate temperature for carrying out the melting process.

In an embodiment, the method of using a repair compound further comprises the additional step of adding aggregate over the filled repaired area as the repair compound solidifies and pressing the aggregate into the top surface of the repair compound. This helps to finalise repairs such as road repairs.

In an embodiment, the method of using a repair compound further comprises the further initial step of driving one or more anchor cleats into the surface of the repair area, so that the repair compound surrounds and binds to the anchor cleat or cleats once decanted into the repair area and allowed to solidify. This adds to the strength and durability of the repair

In a third aspect, the present invention may broadly be said to consist in method of forming a repair compound, comprising the steps of:

(i) setting a melting container to a temperature of substantially between 165 and 240 degrees Celsius;

(ii) adding a plastic material comprising substantially 35-70% of the compound, by weight, and; a rock/mineral particulate material comprising

substantially 20-40% of the compound, by weight;

(iii) allowing the plastic material to melt;

(iv) mixing the plastic material, oil material and glass aggregate to a homogenous consistency. This method has been found to produce a repair compound that is easy to form, easy to use, low-cost, and which uses recycled materials.

In an embodiment, in step (ii), the particulate material comprises one or more of: sand; glass aggregate; limestone chippings; granite chippings. These have been found to provide a suitable core material for the mixture, and are low-cost and easy to attain.

In an embodiment, the aggregate material has a size substantially the same size as crushed stone grade #8. This ensures that the material is substantially the same size as that used in tarmac road construction.

In an embodiment, the method of forming a repair compound comprises the further step of adding a UV stabiliser, Quencher or HALS comprising 0.1 -1.5% of the compound, by weight. This helps to ensure that the compound is robust and long- lasting.

In an embodiment, the UV stabiliser, Quencher or HALS is added after the plastic material and glass aggregate have been mixed to a smooth or homogenous consistency. This helps to ensure that the mix is consistent.

In an embodiment, the plastics material added in step (ii) comprises one or more of plastic material #1, #2, #4, #5, #6. These have been found to provide long-lasting and durable characteristics, while being suitable for melting and mixing.

In an embodiment in step (ii), an oil material comprising substantially 0-30% of the compound by weight is also added. In an embodiment, the oil material comprises a vegetable-based oil. This ensures that recycled material that is easy to attain and which is low-cost can be used.

In an embodiment, in step (ii), Styrofoam/polystyrene comprising substantially up to 15% of the compound by weight is also added.

In an embodiment, the method of forming a repair compound comprises the further step of allowing the compound to at least partly solidify and to extrude this as solid pellets. These allow the compound to be easily used, transported, and stored, as required.

In an embodiment, the method of forming a repair compound comprises the further step of storing the compound in Polythene bags. These allow the compound to be added to a melting pot or similar directly, while still in the bag, rather than unloading from the bag.

In an embodiment, in the step of mixing the plastic material, oil material and particulate to a homogenous consistency, the mixing is carried out using a paddle agitator. This allows quick and easy mixing.

With respect to the above description then, it is to be realised that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.

This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, felling within the scope of the invention.

BRIEF DESCRIPTION OF THE FIGURES Further aspects of the invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings which show an embodiment of the device by way of example, and in which:

Figure 1 shows a trailer mounted thermoplastic metier of the type that can be used with the repair material of the present invention.

Figure 2 shows an anchoring cleat that can be used with the repair material as part of the repair process, in order to assist with retaining the material within a repaired area.

DETAILED DESCRIPTION

Embodiments of the invention, and variations thereof, will now be described in detail.

The repair compound of the present invention comprises a mix of plastic materials and other ingredients, in certain proportions, and prepared in a certain manner. In an exemplary embodiment, the repair compound comprises the following materials, in the following proportions:

The main or primary ingredients are:

1. Plastic material #1, #2, #4, #5, and #6 in proportion 35-60% by weight. Plastic #1 is PET (Polyethylene Terephthalate). Plastic #2 is HDPE (High Density Polyethylene). Plastic #4 is LDPE (Low Density Polyethylene). Plastic #5 is Polypropylene/PP.

It has been found that plastics #3 PVC is unsuitable. However, all others can be used as required.

2. Rock/mineral particulate (aggregate or sand) in proportion 20-40% by weight. Although glass is preferred, non-glass aggregates can also be used, such as for example stone chippings such as clean limestone chippings or granite chippings. Any of these can be used as the sole particulate material, or in combination/as a mix, with others, it should be noted that 'particulate' as used in this specification covers a size range from sand grains upwards to pebble- size or larger. 'Chippings' as used in this specification means roughly or generally pebble-size, or smaller. That is, substantially or roughly the same size as crushed stone grade #8 (also known as 3/8”).

3. Cooking oil or similar in proportion 0-30% by weight can optionally be used. However, it is not an absolutely required ingredient, and the repair compound will work without this ingredient being present. Any vegetable-based oil can be used in place of recycled cooking oil, or recovered motor oil could also be used. A UV stabiliser, Quencher or HALS is also used if required. This comprises 0.1-1.5% of the mix by weight.

The mix can also contain up to 15% Styrofoam/polystyrene.

It is most preferred that recycled materials are used for the main ingredients listed above. However, one, two or three of these can be substituted for virgin material. Recycled material is however preferred as this gives the product an eco-friendly appeal. If made from recycled plastics, plastic bottles and caps can for example be used, with each 25kg of product containing around six hundred plastic bottles and lids, or a similar type of recycled product.

Using the ingredients above, the repair compound is prepared as follows:

• A thermoplastic melter is set, ideally at 210 degrees Celsius. This

temperature can be varied from as low as 165 degrees, up to 240 degrees Celsius, depending on the ambient temperature, the purity of the plastics used in the first listed ingredient above, and whether they contain any plasticisers. However, 210 degrees Celsius is the optimum temperature.

• The primary ingredients are added to the melting tank of the thermoplastic melter. These are then blended to a homogenous consistency by means of a paddle agitator within the melting tank of the thermoplastic melter. The ingredients can be added one at a time (i.e. all of any one particular ingredient added before any of the next ingredient is added), or a part at a time (e.g. add some of the plastic, then some oil, then glass, etc)

• Once the ingredients are well blended and uniform in consistency, the UV stabilisers, Quenchers or HALS can be added, if these are required.

At this point the material is ready for use, and can be used immediately if it has been prepared on or near a repair site, or the material can be formed into pellets or blocks and stored for use at a later date.

It should be noted that although a thermoplastic melter is used for the preferred embodiment, any suitable melting container can be used, for example, a steel pot hung over a gas burner or similar

If pellets are required, then the mix is extruded as pellets once homogenised, and bagged or stored after cooling and solidifying. It is preferred that plastic bags are used for reasons that are explained below. It is most preferred that 5kg Polythene bags are used. The pellets ideally have a size of substantially 10mm x 10mm, although sizes of between 4mm and 30mm are also suitable.

In use, maintenance/repair crews would have a thermoplastic melting pot on their vehicle (the same or similar to that used for line marking). An example of a trailer- mounted thermoplastic melter 1 is shown in figure 1. This is loaded with material from the 5kg bags as required in order to create sufficient material to carry out a particular repair. If a Polythene bag was used for storing the material, this can be added to the mix (e.g. the whole bag and contents can be placed in the melting pot without needing to open the bag) with the bag melting and dissolving into the mix while this is being prepared. Once the material has melted and stabilised at working temperature, the workers can either decant the mixture directly, for example by pouring this into a pothole or crack, or they can use a metal ladle or similar tool to decant the material and transport this the short distance required from the pot to the hole or crack, in order to fill this. The molten repair compound melts any road tar that it contacts in and around the repair site, and bonds with this to strengthen the repair. Once a hole or crack has been filled as required (e.g. to the brim and level with the surrounding surface) the workers can, if required, scatter coloured aggregate or sand over the fill and press this in, for example using a trowel. For roads or similar surfaces, the aggregate would ordinarily be black in colour but can be coloured for use when marking lines, at a zebra crossing, etc.

A repair compound formed with the material proportions outlined above, and mixed until it achieves homogeneity, has several advantages. For example, a mix prepared and used in the manner described above has the advantage that one worker can carry out a repair task in around 15 minutes, in contrast to the several hours and possible multiple visits over 24- or 48-hours that are required when using traditional road repair materials.

A repair compound formed according to the invention can be formed from relative amounts of ingredients that vary across a relatively broad range (as outlined above), and the fusion’ or 'homogenisation' temperature is also relatively wide (185-240 degrees Celsius, as outlined above).

However, it has surprisingly been found that a repair compound formed in this manner will be pourable when melted, yet hard wearing and durable when solid.

This is in contrast to melting plastic directly into holes or cracks, which produces a repair that is too firm and which can be removed easily (either deliberately or by accident) once cooled. This is a key and unexpected advantage of forming a compound according to the invention. A repair compound formed in this manner is 'eco-friendly' when recycled materials are used, and has the further advantage of reducing traffic delays and similar (which can indirectly add to pollution) due to the short turnaround time required for repairs.

The primary purpose for the compound described and claimed is for making repairs to potholes / fissures / splits in highways, roads and pavements, or similar. However, as well as road repair, a compound formed in this manner can be used in other fields such as construction, maintenance, landscaping, or any field in which there is a requirement for paving/tarmacing/concreting, etc, either for repair, or for direct first construction or building.

For larger potholes, or areas of high/heavy traffic, the repair compound can be 'anchored ¹ by means of an anchoring cleat the same or similar to that shown in figure 2. The anchoring cleat 2 in the preferred embodiment is of unitary metal

construction, and has an elongate body with barbs extending from the sides of the body along part or all of the length of the body. These act to anchor the cleat 2 into the ground when it is driven into the ground. The top of the anchoring cleat 2 is formed as a smooth, mushroom type head. When carrying out a repair, for example to a road pot hole, one or more of the barbed anchoring cleats 2 is/are first driven into and through the base course and/or binder course at the bottom of the hole and/or the sides of the hole, before any of the pouring or filling operations described above take place. Part of the length of the body and the head of the anchoring cleat 2 are left dear of the surface into which the anchor cleat 2 is driven. This allows for the repair compound to envelop the head and the clear part of the body of the cleat, anchoring the cleat 2 into the ground. The head of the cleat 2 is domed and mushroom-shaped with no sharp edges, so as to avoid causing stress to the repair compound. The cleat 2 can be manually or mechanically driven into the ground.