Development of Stress Sweep Rutting (SSR) test for permanent deformation characterization of asphalt mixture

- Developing a Stress Sweep Rutting (SSR) test method to calibrate a permanent deformation model, shift model.
- Evaluation of effect of temperature, deviatoric stress, load time, and rest period on permanent deformation.
- Use of actuator displacement to collect the permanent strain data.
- Comparisons of rut-depth predictions from the original TSS and the SSR methods using the LVECD program.

The goal of this work is to develop a simple rutting test method, referred to as the Stress Sweep Rutting (SSR) test, which can be used to calibrate a permanent deformation model, known as the shift model, of asphalt mixtures. The effect of each shift model parameter, i.e., temperature, deviatoric stress, load time, and rest period, on permanent deformation has been explored and evaluated in an effort to minimize the test requirements of the rutting characterization. The accuracy of the SSR test method was evaluated using the Layered ViscoElastic pavement analysis for Critical Distresses (LVECD) program by predicting the permanent deformation and compared to the Triaxial Stress Sweep (TSS) method, which was originally developed to calibrate the shift model. The rut depths predicted from the SSR and TSS method using the LVECD program are in close agreement, thereby verifying the SSR test method.