Prediction of permanent deformation in full-scale accelerated pavement testing

The objectives of this study are to investigate the pavement response at various wheel loading conditions and to find the optimal method of analyzing that response by comparing measured and predicted rut depth among different analysis techniques. Measured deflection values under various wheel loading conditions at various wheel locations were obtained to investigate the pavement response. Four different loading conditions were applied to compare the predicted rut depth against the measured rut depth to identify the best analysis technique. Two-dimensional finite element analysis was performed to model the ability of Accelerated Pavement Testing (APT) to predict the resilient vertical strain at a critical position. Four different loading types were used to predict resilient vertical compressive strains at the middle of the pavement layers. Based on the analysis results, the accumulated rut depth is predicted at each loading cycle using the calibrated permanent deformation model of the Korean Pavement Research Program (KPRP) Interim Design Guide. The predicted rut depths were compared with the measured rut depths at three different temperatures to identify the optimal analysis method. The results indicate that the best analytical method to predict rut depths is to use measured tire contact stresses instead of the inflation pressure or the measured tire contact area.