ABSTRACT
The stress sweep rutting (SSR) test is a test method to characterize the resistance of asphalt mixtures to rutting using the permanent deformation shift model. This test was developed at North Carolina State University. The SSR test measures the permanent strain characteristics of asphalt mixtures as a function of deviatoric stress, loading time, and temperature. The permanent deformation shift model is based on the permanent deformation behavior of an asphalt mixture in the primary and secondary regions. The results from two SSR tests at each of the high and low temperatures are used to develop the shift model. The shift model has been implemented into the pavement performance prediction program, FlexPAVETM, to predict the permanent deformation of asphalt layers under various deviatoric stress levels, loading times, and temperatures as a function of pavement depth and time. In this paper, the SSR and FlexPAVETM model are used to show the effect of different volumetric properties on the rutting resistance of asphalt mixtures. A typical asphalt mixture in North Carolina was chosen as a case study, and the volumetric properties were changed systematically. The results state that the permanent deformation shift model can capture the effect of binder content, in-place density, and volumetric properties on the rutting behavior of asphalt mixture.
