A CRACKING MODEL FOR PLAIN JOINTED PORTLAND CEMENT CONCRETE PAVEMENTS

This paper examines the relationships between two modes of distress and performance for plain, jointed portland cement concrete without dowels at transverse contraction joints. The two modes examined are joint faulting and cracking which are major contributors to loss in serviceability for well designed and constructed pavements in California, Analysis of 500 lane miles of faulted pavement indicates that faulting is related to the number of EALs and that the type of cement-treated material influences faulting behavior. Guidelines are presented for prediction of faulting distress. Cracking analyses using finite element procedures indicate that the strength of the cement-treated layer has an important effect on fatigue life of pcc pavements. Detailed traffic analyses of 600 lane miles of pavement in the San Francisco Bay Area, considering thermal stresses and material variations, indicate that there is a collision fatigue relationship for pcc pavements when the fatigue relationship: nf = 225,000 is used. The analyses also indicate that there is little time differential between the onset of first and third stage cracking. Once 20 percent of the slabs show first stage cracking, the serviceability of the pcc pavement is terminating. Analyses indicate that this performance model is also applicable to other environments in California. The results of the study are used to illustrate the framework for a rehabilitation management system for plain, jointed pcc pavements.