عنوان مقاله [English]
The performance properties of bitumen can be improved by using several modifiers, including: polyphosphoric acid (PPA), semi-hot asphalt mixers (WMA) and styrene butadiene rubber (SBR). The present study evaluated the effect of PPA and WMA additives on the rheological behavior of SBR modified bitumen. Modified SBR / PPA and SBR / PPA / WMA bitumen were subjected to rotational viscosity, dynamic shear rheometer, multiple stress and creep recovery (MSCR) and linear slope sweep (LAS) tests. Based on the results of MSCR test at both stress levels, modification of the base bitumen by SBR, PPA and WMA additives improves the permanent deformation performance of the main bitumen. The results of LAS test showed that the use of SBR and WMA additives improves the fatigue life of bitumen. Also, by adding PPA, the fatigue life of SBR modified bitumen is increased. While the fatigue life is longer than the original bitumen. Among warm additives, Sasobit has a better effect on increasing the performance of bitumen.