Chapter 3: Local Road Planning 80 Table 3.5 Typical Pavement Distress of Portland Cement Concrete Pavements (PCCP) Distress Type Major Causes Common Repair Method B.1 Shattered Subgrade and/or base Full depth repair (slab Slabs failure, lack of dowel bars replacement) (load transfer problem), insuiffcient pavement thickness, base and subbase settlement, substandard concrete quality B.2 Scaling Over-ifnishing, improper Slurry seal, skid resis- curing, unsuitable tance treatment, AC aggregates, chemical overlay action. Substandard concreate mix B.3 Cracking: B.3.1 Corner Traiffc loads on Crack sealing, remove cracks unsupported corners, spot and replace weak subgrade/base B.3.2 Diagonal Traiffc loads on cracks unsupported slab end, subgrade settlement, pumping B.3.3 Shrinkage of concrete, Longitudinal expansive base or Full depth repair (slab cracks subgrade, loss of support replacement) from edge pumping Overload, repeated B.3.4 Transverse bending on pumping Cracks slabs, failure of foundation, shrinkage B.3.5 Crocodile Improper load transfer Cracks device, base/subgrade weakness, insuiffcient slab thickness, settlement of base