Evaluating the Effects of Sasobit on Characterization and Workability of Asphalt Mixes Containing Reclaimed Asphalt

Use of Reclaimed Asphalt Pavement in HMA is beneficial by reduction of initial costs. But the higher stiffness of aged binder may lead to workability issues in the field، therefore use of large percentages of RAP impacts the HMA properties. Utilizing Sasobit is a solution to use more RAP at a relatively lower temperature in HMA mixes. This study investigates the effects of 2 percent Sasobit on the reduction of compaction temperature by measuring low shear viscosity and workability of mixtures containing RAP binder. Low and intermediate temperature properties of RAP binder using mix designs were compared to properties of artificially aged binders. Virgin binder was aged in PAV to make artificial RAP binder. Comparison between physical parameters of RAP binder and binder aged in PAV was done and it was found that about 40 hours is sufficient for simulating the aging of RAP binder and making artificially aged binder. Results of this study on artificial RAP show that utilizing Sasobit is a feasible way to make HMA which contain 25% RAP. Utilizing RAP and Sasobit together in a HMA project would lead to select softer virgin asphalt binder with a lower performance grade.