Development of a mid-depth profile monitoring system for accelerated pavement testing

•A system was developed to measure the flexible pavement layer deformation, and incorporated into APT facility.•The developed MPMS is able to automatically measure the evolution of layer deformation with high accuracy.•The MPMS was validated based on the agreement with previous studies.•Only around 10% of rutting occurred in subgrade for full depth flexible pavement.•Most of rutting occurred within the top two asphalt layers. This study presents the development of a new mid-depth profile monitoring system (MPMS) to investigate the rutting behavior of full-depth asphalt pavements. The scope incorporates an experimental study that uses a full-scale accelerated pavement testing (APT) facility. Two different thicknesses of full-depth asphalt pavements were constructed in the Indiana accelerated pavement-testing facility. A laser profile scanning system was designed to reconstruct the transverse profiles at each pavement layer interface throughout the process of accelerated pavement deterioration. The contribution of each pavement structural layer to the total rut depth and the evolution of layer deformation were determined. The developed system provides reasonable results with a high accuracy level based on the findings. First, the measured rutting curves at each layer interface agree well with the theoretical characteristics of rutting evolution and clearly exhibit the primary and secondary stages of rutting development. Furthermore, all the measured rutting curves have good coefficients of correlation. Second, the locations of critical rutting and the total rut depths were found to be independent of pavement thickness when the pavement is sufficiently thick, which is a finding that agrees with previous study results, the study reported the thickness threshold value to be 5.12in. (13.00cm) for their case. The results demonstrate MPMS developed in this study provides an excellent method to evaluate the rutting performance of asphalt pavements in the APT. In addition, MPMS has a potential application to in-service pavements.