Rheological evaluation of shortand long-term performance for warm mix asphalt (WMA) binders

Abstract

Warm-mix asphalt (WMA) additives are environmentally friendly and cost-effective products that lower the viscosity of bituminous binders to allow reduction of mixing and compaction temperatures in asphalt mix production. In this study, two WMA additives were used; Sasobit and Advera. Both were mixed in the lab with unmodified 60/70 Pen and modified PG 76-22 binders. Strain oscillation and viscosity measurement tests were performed to determine the rheological properties of the binder with and without WMA additives. Different ageing processes were performed in this study; half and full short-term ageing using the Rolling Thin Film Oven (RTFO) procedure, and long-term ageing using the Pressurized Ageing Vessel (PAV) procedure. Test results have shown that the addition of Sasobit increased the stiffness of both binders and changed PG grade by one unit up (6 C PG grade). Also, Sasobit presented better rutting resistance in modified and unmodified binders than Advera, while both WMA additives decreased the fatigue cracking resistance. Multiple Stress Creep Recovery (MSCR) test was also conducted on both unaged and RTFO aged binders. Modified binder.