New Method for Pavement Rutting Prediction

In recent years, pavement rutting rate has increased significantly due to constant traffic intensity increment. These solicitations affect the bituminous layers that can quickly attain their permanent deformation limit resistance. This phenomenon can lead to a pavement depression, located in the tyre-road contact surface. The purpose of this paper is to present a methodology to estimate the rutting of bituminous pavements and to predict the rutting risk considering the bituminous mix rutting resistance characteristics obtained with the LPC traffic simulator, and taking into account the traffic and environmental characteristics. The traffic characteristics are represented by the total heavy traffic expressed in equivalent single axle loads (ESAL) passed on the pavement during the service period, and the heavy vehicles speed on the considered section. The environmental characteristic is represented by the pavement temperature at 2 cm depth. The developed model starts from the widely used empirical rutting formula and its experimentally determined coefficients. The general concept of the model is to start from this generalised rutting formula and to apply it to the real rutting behaviour occurring in pavements. For this purpose, observations and material analysis of eleven in place pavements were made. The model was calibrated using eleven bituminous mixes and verified introducing the characteristics of four in place bituminous mixes not considered in the initial calibration phase. The developed model gives rut depth values after having determined material and site characteristics and presents a good correlation coefficient with very satisfactory results in its verification phase with additional materials.