Characterization of Reclaimed Asphalt Pavement and Optimization in Polymer Modified Asphalt Blends: A Review

Abstract

This study reviews relevant literature on the characterization of reclaimed asphalt pavement (RAP) and its interaction with polymer modified asphalt(PMA). The study on fatigue cracking indicates that several indexes of binder performance usually decreased the tolerance to cracking of the Polymer Modified Asphalt (PMA). In another perspective, RAP binding rigidity affects the PMA binder tolerance to fatigue. The greater the rigidity of the RAP binder, the more fatigue strength the binders would provide. In addition, several researchers have demonstrated that the quality of RAP binder decreased the elastomeric response worth. It was generally found that the RAP binder effect on the PMA binder is similar to the unmodified binder effect. The resistance to rutting in the PMA binder improves and at the same time, fatigue cracking and thermal cracking are adequately minimized. Moreover, several researchers have shown that the inclusion of a RAP lowers elastomeric efficiency. In summary, RAP binding stiffness and gradation are essential features for PMA-mix designs. The review further illustrates that during the process of RAP binder characterization, the mortar testing process without the use of binder extraction is more effective than the conventional method. Also, the best measure for the evaluation of the fatigue cracking efficiency of RAP containing PMA blends does not seem to have gained any consensus among researchers as several researchers seem to have varying conclusions. Literature on Life Cycle Analysis of RAP has also been reviewed and presented.