Influence of aging on the evolution of structure, morphology and rheology of base and SBS modified bitumen

The influence of aging on the evolution of structure, morphology and rheology of base bitumen and SBS modified binders was investigated by Fourier transform infrared (FTIR), atomic force microscopy (AFM) and dynamic shear rheometer (DSR), respectively. Two laboratory simulation aging methods, named standard rolling thin film oven (RTFO) test and pressure aging vessel (PAV) test were applied in this study. The aging temperature of PAV was selected at 60 °C, which is considered to be consistent with the real high temperature within an asphalt pavement in the field. After aging, it was found that more carbonyl and sulphoxide groups but less chain segments of butadiene were available. With the oxidation of base bitumen and the degradation of SBS segments, obvious asphaltene micelles appeared in both binders, consistent with the changes of softening point and rheology of base bitumen and SBS modified binders.