Mohammad Rahi - Manager of R&D Department of Pasargad Oil Company, Tehran, Iran
Pouria Hajikarimi - PhD Candidate, Department of Civil & Environmental Engineering, Amirkabir University of Technology,Tehran, Iran
Sahar Maniei - R&D Department of Pasargad Oil Company, Tehran, Iran
Vahid Kheirandish - R&D Department of Pasargad Oil Company, Tehran, Iran

Asphalt binder resistance to permanent deformation at intermediate temperatures considerably affects total pavement resistance to rutting. To improve asphalt resistance to permanent deformation, researchers have used various modifiers and additives such as styrene butadiene styrene (SBS) block copolymer, styrene butadiene rubber (SBR), crumb rubber, polyposphoric acid (PPA) and natural rubber latex. In this paper the effectiveness of modification of asphalt binder by styrene-ethylene/propylene-styrene (SEPS) in order to improve asphalt binder’s resistance to permanent deformation has been investigated using two different evaluation methods: the Superpave® specification parameter, G*/sinδ, and themultiple stress creep and recovery (MSCR) test. The experiments were conducted using dynamic shear rheometer (DSR) temperature sweep test and shear creep test performed on both the neat sample and modified ones. Utilizing these two approaches, rutting resistance of modified asphalt binders are determined. The research results showed that regardless of the evaluation method, SEPS can meaningfully enhance anti-rutting performance of asphalt binder.

rutting; SEPS; temperature sweep test; MSCR test