Evaluation of rheological and aging behavior of modified asphalt based on activation energy of viscous flow

Abstract

Styrene–butadiene–styrene (SBS) is one of the most widely used polymer modifiers for the improvement of the durability of asphalt pavement. SBS functionalization can improve the low-and high-temperature performance and aging resistance of asphalt binders. This paper systematically explores the feasibility of the activation energy of viscous flow (Ea) in evaluating the rheological and aging behavior of functionalized SBS-modified asphalt binders, including SBS-, styrene–ethylene/butylene–styrene (SEBS)-, SEBS-grafted maleic anhydride (MAH)-, and SBS/organic montmorillonite (OMMT) nanocomposites- modified asphalts (SBS-A, SEBS-A, MAH-A, and OSBS-A for short). The Ea values of different functionalized materials were calculated by Arrhenius equation based on Dynamic Shear Rheometer (DSR) and Rotational Viscosimeter (RV) tests, which means that the viscous flow behavior were analyzed at different temperature ranges. Ea based on RV test, the rutting factor and rutting factor aging index came to the same conclusion, that is, SEBS-A and OSBS-A with higher Ea values (lower temperature sensitivity) show excellent rheological properties and better aging resistance, followed by SBS-A, MAH-A, and base asphalt (BA). Besides, Ea based on DSR test was higher than Ea based on RV test, which is related to physical phase (visco-elastic phase and viscous phase). From the perspective of the viscous flow behavior of the binders, Ea based on RV test provides scientific and effective methods for probing the effect of SBS functionalization and designing high capability materials for pavement.