Rheological Evaluation of Warm Mix and Anti-Stripping Additives Modified Performance Grade Binders

This study evaluated the effects of a warm mix asphalt (WMA) additive, Sasobit®, and a liquid anti-stripping agent, AD-here® HP Plus, onthe rheological properties of a selected performance grade binder (PG 64-22) as per Superpave® specifications. The optimum dosage (mass) of Sasobit®was found to be 1.5%, which was expected to reduce the mixing and the high PG temperatures by 9oC and 4.5oC, respectively. Sasobit® was also found to decrease the fatigue resistance and low temperature resistance of the base binder to some extent. Furthermore, a reduced rolling thin film oven (RTFO) temperature was expected to exhibit significant reduction in the rut resistance of the WMA. While anti-stripping agent was expected to reduce the rutting resistance, it was anticipated to increase low temperature resistance of the WMA. The findings of this study are expected to enhance rheological database and help in implementing WMA mixes in Oklahoma and elsewhere.