Impact of coarse aggregates on transverse crack performance in jointed concrete pavements

Environmental effects and repetitive traffic applications can lead to the d evelopment of transverse cracks in jointed concrete pavements (JCPs). Maint aining adequate aggregate interlock load transfer across these cracks is es sential for preserving the functional and structural integrity of these pav ements. The objectives of this study were to determine the effects of aggre gate type, size, and blending on the performance of transverse cracking in jointed concrete pavements. Field data collected from inservice JCPs locate d throughout southern Michigan was used to accomplish these objectives. Joi nt spacing, coarse aggregate type, shoulder type, and pavement temperature were found to have significant effects on transverse crack development, per formance, or both. The surface texture of crack faces was assessed using a promising new test method called volumetric surface texture (VST) testing. VST results provided an indication of the aggregate interlock potential of pavements containing various aggregate types. A parallel laboratory study w as conducted to study the impact of aggregate size and blending on transver se crack performance. Three performance parameters capable of mechanistical ly characterizing crack performance are discussed. A relatively simple proc edure was described for determining these parameters and evaluating crack c ondition.