Laboratory Evaluation of Short- and Long-Term Aging Resistance of Rejuvenated RAP Mixtures

Abstract

This study evaluated the aging resistance of asphalt mixtures containing various percentages of reclaimed asphalt pavement (RAP) and rejuvenators after short-term (ST) and long-term (LT) aging. To this end, rubberized waste oils (i.e., waste engine and cooking oils) and pure waste oils were used as rejuvenators in asphalt mixtures including different percentages of RAP materials (i.e., 25%, 50%, and 75% by the weight of mixtures). The rejuvenated RAP mixtures underwent ST and LT aging processes separately. Afterward, the dynamic modulus (DM) test, semicircular bending (SCB) test, and moisture sensitivity (MS) test were conducted to evaluate the mechanical properties of different samples. The outcome results showed that before exposing samples to LT aging, the efficiency of all rejuvenated mixtures’ stiffness and also their cracking resistance were close together. After applying LT aging, the mechanical properties of RAP mixtures including rubberized rejuvenators were much better than pure rejuvenators. This issue indicated that rubberized rejuvenators and, consequently, RAP mixtures containing these rejuvenators, are more aging resistant and have a superior LT performance. Additionally, there was no concern observed regarding the moisture susceptibility of rejuvenated RAP mixtures before and after applying the aging process.