Performance Evaluation of Polymer-Modified Binder Containing Reclaimed Asphalt Pavement Using Multiple Stress Creep Recovery and Linear Amplitude Sweep Tests

The present study evaluates the effects of reclaimed asphalt pavement (RAP) binders collected from two different sources (RAP-A and RAP-S) on Superpave performance grade (PG), rutting, and fatigue performance of a polymer-modified binder (PMB). Preliminary rheological investigations on both extracted RAP binders revealed that RAP-A had stiffer binder than RAP-S binder. The PMB was blended with 0, 15, 25, and 40% of RAP-A and RAP-S binders. Superpave PG was determined based on dynamic shear rheometer and bending beam rheometer tests. The rutting and fatigue performance of PMB with varying percentages of RAP binders were evaluated using multiple stress creep recovery and linear amplitude sweep (LAS) tests, respectively. The results showed that the high-temperature PG of PMB bumped by one grade interval; however, low-temperature PG remained unaltered. Although the addition of both RAP binders resulted in a similar PG, their rutting and fatigue performance were found to be significantly different. This showed that same PG of binder may not necessarily have similar performance. Although the addition of RAP binder to PMB increased the stress sensitivity of the PMB-RAP binder blend, the stress sensitivity remained well within the critical limit. The result from the LAS test showed that the addition of RAP binder may adversely affect fatigue resistivity of PMB. Overall, change in performance of PMB was found to be dependent on nature, source, and quantity of RAP binder.