This study evaluates the rutting performance of asphalt binders used in the construction of the Pavement Testing Facility (11 lanes) at the Federal Highway Administration’s Turner-Fairbank Highway Research Center. The binders were either sourced directly from the asphalt plant tank during construction (“tank binders”) or extracted and recovered from asphalt mixtures sampled during construction (“recovered binders”). The researchers performed laboratory tests, including high-temperature performance grade (HTPG), multiple stress creep recovery (MSCR), and frequency sweep tests. Results from the overall binder ranking, based on analyzed outputs from all tests, showed the superior rutting performance of polymer-modified binders, followed by binders recovered from recycling agent (RA)-modified high-reclaimed asphalt pavement (RAP) mixtures, control mixtures, and the no-RAP mixture. The binder rankings based on nonrecoverable creep compliance at 3.2 kPa from the MSCR test and zero shear viscosity (ZSV) from the frequency sweep test correlated most closely with overall rankings, whereas HTPG and Shenoy parameters showed limitations in effectively classifying binders. Given the applied small strains within the linear viscoelastic region during the frequency sweep test, ZSV appeared to be the most promising viscoelastic-based parameter capable of providing robust evaluations of expected rutting resistance comparable to the MSCR test. The study further validated the effectiveness of RA modifications in accommodating elevated RAP contents while maintaining high-temperature performance comparable to control mixtures with lower RAP levels. In addition, recovered binders exhibited significantly higher expected rutting resistance than tank binders, a finding that can potentially be attributed to RAP incorporation and aging effects during production, hauling, and storage.
Abdollahi et al. (Thu,) studied this question.