LAUSR

Abstract The influence of shear rate and mixing time and, simulated long-term aging as a function of frequency and temperature on the rheological behaviour of SBS modified bitumen was evaluated from oscillatory rheology measurements. Complex shear modulus (G*) and phase angle (δ) values were measured and Master curves, Black diagrams and Cole-Cole plots constructed in an attempt to assess the effects of mixing conditions (i.e. short term aging) and long term aging on the rheological characteristics of SBS modified bitumen. Rutting (G*/sin(δ)) parameters were calculated to obtain the performance grade (PG) temperatures of each modified bitumen. It was observed that higher shear rates and longer mixing times promote oxidative aging of the SBS modified samples relative to neat bitumen and have higher activation energies for flow and temperature susceptibility. Additionally, for the same shear rate and mixing time a similar level of compatibility between SBS and bitumen is obtained.