Implementation of Resilient Modulus – CBR relationship in Mechanistic Pavement Design

Résumé

One of the most important part of mechanistic flexible pavement design, is the determination of the resilient modulus (Mr) to characterize the mechanical behaviour of road structures. Because of the complexity and cost of the test, correlations have been established to predict resilient modulus. California bearing ratio (CBR) is the most used parameter to estimate resilient modulus since this parameter is not expensive and is easy to obtain.
The objective of this paper is to implement Mr-CBR relationship in Cast3m, to verify the impact of correlations on the mechanistic design of the base course. In fact, correlations have been established based on statistical analysis. The predicted modulus is used to replace Young’s modulus representing the stiffness modulus of the base course. The Uzan model is also implemented to compare the deformations obtained by these two structures. Tridimensionnal modeling performed on six pavements structures, shows that, the deformations obtained with the pavements resilient modulus predicted is higher than pavements with Uzan model. These excesive deformations due to the use of inadequate modulus, generate damages and premature failures in pavements.