PAVEMENT EVALUATION AND DEVELOPMENT OF MAINTENANCE AND REHABILITATION STRATEGIES FOR ILLINOIS TOLLWAY EAST-WEST EXTENSION

The procedures used in the field evaluation and development of maintenance and rehabilitation strategies for the Illinois Tollway Authority's 70-mi, four-lane East-West Extension are presented. The extension consists of 14-in. portland cement concrete (PCC) placed directly on the silty clay subgrade with random joint spacing varying between 12 and 17 ft. Although the pavement is only 17 years old, it is experiencing rapid decrease in serviceability. The field evaluation consisted of a visual condition survey, nondestructive deflection testing including void detection and transverse joint load transfer efficiencies, coring, soil evaluation, determination of slab and soil properties, and petrographic analysis of the PCC. After the pavement evaluation was completed, several maintenance and rehabilitation strategies were developed for different life expectancies varying from 2 to 20 years. All of the strategies were evaluated using EXPEAR (EXpert system for Pavement Evaluation And Rehabilitation).