Novel Approach for the Characterization of the Rutting Performance of Pavement Foundations: Fid-Bau Portal

Novel Approach for the Characterization of the Rutting Performance of Pavement Foundations

R. S. Ashtiani / B. Tseng

Permanent deformation within the unbound granular is a predominant feature that results in the degradation and loss of serviceability to the pavement structure as the passage of traffic wheel loads accumulate. Proper characterization of the multi-layer structures is necessary to improve the rutting performance by mechanistically identifying the factors that contribute to the progression of plastic deformations. A consequence of ignoring these features results in the underestimation of the rutting potential, which amounts to premature failure. Current rutting models fail to incorporate factors such as moisture state, gradation, and stress-paths which are paramount to proper characterization of base and sub-base layers. Analysis of the deformation induced by dynamic loads under a controlled laboratory environment can provide valuable information regarding the pavement responses to variations in permanent deformation factors. Therefore, the studies focus in the development of a framework, which successfully acknowledges the permanent deformation components in a synergistic manner. A comprehensive laboratory experiment consisting of a limestone source incorporating three different gradations, three different moisture states, and three different stress paths were considered in this study. The material was then molded into cylindrical samples, which were in turn subjected to various constant confining pressure stress path test to analyze how the parameters affect the rutting potential of laboratory specimen. Valuable understandings were obtained from the analysis regarding the rutting sensitivity and dissipated strain energy of the unbound granular layers subjected to variations in the stress, amount of fines content, and moisture content in the repeated dynamic loading tests.