Spalling of Continuously Reinforced Concrete Pavements

Abstract

Field investigation of continuously reinforced concrete pavements indicate the presence of delaminations at a depth of approximately 2.5 cm (1 in.) below the concrete pavement slab surface. These delaminations originate at the transverse cracks/joints and extend into the pavement from 5 to 15 cm (2 to 6 in.) and vary in width along the transverse crack. Coring of sample pavement sections indicates that spalling distress is an advanced state of these delaminations. It is assumed, given these delaminations, that spalling occurs due to stresses in the delaminated concrete layer that may be caused by wheel loads, temperature change, and the presence of moisture in the delamination. Strong evidence suggests the presence of more spalling on the downstream side (with regard to traffic flow) of the transverse cracks/joints, and that this mode of spalling is generated from shear stresses caused by a vehicle tire on the pavement. Static finite‐element analysis of the delaminated portion of a pavement slab indicates that stresses caused by a vehicle tire on the pavement can be sufficient to further extend the delaminations, thus creating spalls.