CPR offers a cost-effective, energy-efficient formula for maintaining an aging highway. CPR is recommended where much of the pavement slab remains in good condition with only limited areas of deterioration/loss of riding quality due to problems at joints and cracks. CPR is a total system that includes undersealing, full depth slab replacement, partial depth and spall repairs, reestablishment of load transfer at joints, grooving and grinding of pavement surface, cleaning and resealing of joints, and shoulder restoration. Full restoration will not be accomplished unless all the necessary steps that comprise the CPR system are administered. Incomplete restoration will permit further deterioration, perhaps negating all remedial action taken.
A leading cause of damage to concrete highway slabs is the development of voids or pockets beneath the slab. The prime causes of support erosion are improper drainage, edge sealing and shoulder design which allow water to flow under the slab and create washouts. Advanced subgrade failure is obvious to visual inspection, but finding the voids early while repair can be less expensive is more difficult. It is one of the tasks that must be performed before comprehensive CPR can be undertaken.
CPR is less costly than conventional resurfacing with asphalt concrete. One cost analysis shows that a full CPR program may cost only 50 to 60 percent of what a 4-inch asphalt overlay would cost.