ABSTRACT
Wheel tracking device is used to find the rutting susceptibility of asphalt concrete. Typically in most of these devices, like the French rutting tester and the Hamburg Wheel tracking device, the wheel follows a to-and-fro motion while subjecting the sample to a moving load. This motion is unlike what is observed in highways. It is widely known that at higher temperatures, a moving vehicle subjects the pavement to permanent deformation in the longitudinal direction in addition to the permanent deformation in the vertical direction. Thus, both the direction of wheel motion and the longitudinal component of force can affect the flow-field of the tested samples. Hence, these factors must be considered while modelling their mechanical behavior.
In this study, the influence of the direction of the wheel loading and the influence of longitudinal force on the flow-field was examined by conducting a finite element analysis on an asphalt concrete sample. Linear viscoelastic model was used to describe the mechanical behavior of asphalt concrete at 60⁰ C. A sensitivity analysis was conducted with three different coefficients of friction (0, 0.1, and 0.35), and two different modes of wheel motion (to-and-fro motion, and unidirectional motion). Preliminary analysis showed a significant difference in rut depth, for samples subjected to “to-and-fro” wheel motion, with and without longitudinal force.
