We had some nasty frost upheavals this year and when combined with last year's amount of rain, the ground under my blacktop driveway in one area has managed to sink and cause breakage of the blacktop. It looks like it's a sizable area about 5 ft long by about 2 feet wide - I can bust it out with my FEL and fill it - but I'm wondering what people might suggest to make a more permanent fix.. Should I have someone come in, cut it out, and repair it? What might you suggest?
If this large pothole was cause by frost heaving it will again heave next year and destroy any fix you have put in place.
For frost heaves to develop they need water and the soil must have the proper permuability and porosity to allow capilllary action to bring up water into the freezing zone and allow the ice lenzes to form.
To fix properly either the source of water must be eliminated or the soil replaced to below the frost line with a materiall that does not support capillary action.
Consider these thoughts before spending large amounts of money on resurfacing.
Thanks, Egon. What you're advocating then is to dig the hole section out - replace the rock underneath, and then have them put a blacktop section back in. I'll have to check with the local blacktop paving contractors to find out what it would take to do that.
It sure is. Every summer the highways department has crews out sealing cracks in the pavement. This prevents the water from getting into the subbase, softening it and allowing the traffic to break out a pot hole. In essance, the subbase provides the stength while the asphalt seals it from the elements.
But remember water from a crack is not the same as a frost heave. A frost heave obtains it's water from below by capilliary action.