This rehabilitation technique is only applicable to CPCD, not CRCP. Load transfer is defined as the ability of a joint or crack to transfer wheel load from one slab to the next. Good load transfer at the joints improves the performance of CPCD, and the majority of load transfer is achieved by dowels which cross the transverse joints. Aggregate interlock is supposed to provide some load transfer; however, the effectiveness of aggregate interlock diminishes with time as concrete contracts due to drying shrinkage. Also, the contribution of aggregate interlock to the load transfer is substantially diminished during winter when the temperature is low and joint opening becomes large. To ensure adequate load transfer for the life of the pavement, dowels must be used. However, there are jointed concrete pavement sections that were built without dowels. The absence of dowels along with deficient base or subgrade support results in faulting and cracking problems at joints. Figure 10-17 shows faulting in CPCD.

The pavement shown in Figure 10-17 does not have dowel bars, and the base support was not adequate. The lack of load transfer in CPCD sections without dowels increases the dynamic wheel loading, which results in increased faulting. One of the most efficient ways to restore load transfer at the joints is dowel bar retrofit (DBR). In DBR, slots are cut, concrete removed, dowel bars inserted, repair mortar is placed in the slots, the surface finished, cured, and, most often, diamond ground. Many states have used DBR to restore old CPCD where dowels were not used and have had success. The department has developed a special specification and design standards for DBR.