Repairs to Existing Bases
Resin bonded surfaces can be laid on existing concrete or asphalt surfaces on a suitable construction for expected traffic loads. Joints and cracks in concrete should be broken out (Cut) to a minimum width of 200mm and infilled with well compacted macadam base layer as indicated in previous section as per normal good practice for flexible surfacing. This does not absolve the specifier from designing a construction suitable for expected traffic and ground conditions.
Cross sectional view of cracked concrete base. Cut out to minimum 200mm wide and infilled with well compacted macadam
Note: Where macadam is used – allow 28 days to oxidise and harden (7 Day alternative can be specified)
Oil damaged asphalt driveways
Oil or fuel spills will invariably cause a breakdown of the binder and cause the affected asphalt to soften. Where this is the case, the affected tarmac must be cut back to where it is sound and infilled with replacement macadam (As per concrete crack repair example above)
Effective rainwater removal
In certain instances. A driveway may not need repair works but does have a number of ‘hollows’ or wells where water currently gathers. Where this is the case, there are a couple of options:
First it will be necessary to ‘water test’ the area and mark out where the water gathers (Use a suitable line marking spray)
Cut out and bring to level as above
Use exterior levelling compound (Cempolay ultra or equivalent) or other proprietary external ‘Hole filler’ to bring to level. Once mixed following manufactures instructions, this product is simply poured into the hollow where it will self level. Most builder’s merchants stock this product – be sure to specify EXTERNAL. Please note that certain exterior levelling compounds are NOT suitable for use on tarmac.
Either of the above options may simply ‘Move’ the water to another part of the driveway. Ultimately the water must be able to drain away. Either away from the property onto the roadway or into a suitable drain. If drainage is going to be a major issue, then consider the resin BOUND alternative
One other option to create or alter the levels and flatness of a surface is to use a site mixed ‘Fibretex’. This is a very strong ‘screed’ which can be trowelled onto a clean, power washed, sealed, dry surface.
A suitable steel, wood, brick, stone or aluminium edging should be provided to ensure neat edge detail.