Existing projects can be repaired by excavation of failure areas or just by filling potholes.
Excavation of failure areas requires removing the soft or failed material and replacing it with a more stable material. Each area is different however 18″ of excavation is not uncommon in this area. It is then filled with a larger rock and base to bring back to the original base level and the surface is then added to bring it level with the surface being matched. Premix or cold mix is used to fill potholes or failure areas that have occurred in the surface. A lighter oil is used to mix it and it can be used cold or for a longer period of time. Holes should be cleaned of all unconsolidated material and sprayed with oil to provide a bonding surface. The mix is then added and rolled to compact in place.