Effects of WMA additive on the rheological properties of asphalt binder and high temperature performance grade

Abstract

Sasobit additives with different dosages were added into 70# and 90# virgin asphalt binders to prepare WMA binders. The rheological properties, including G ∗ and δ, were measured by using DSR at the temperature ranging from 46°C to 70°C, and the effects of temperature, additive dosage and aging on G ∗ /sin δ, critical temperature, and H-T PG were investigated. The results indicate that WMA additive improves G ∗ but reduces δ, and the improvement on 70# virgin binder is more significant. G ∗ /sin δ exponentially decreases with the increasing temperature but linearly increases with the increasing additive dosage. Aging effect weakens the interaction between binder and additive but significantly increases the binder's viscosity; that is why G ∗ /sin δ is higher after short-term aging. In addition, the critical temperature increases with the increasing additive dosage, and the additive dosage should be more than 3% and 5% to improve H-T PG by one grade for 70# and 90# virgin binder, respectively.