Characteristic Evolution of GO/SBS-Modified Asphalt during Aging

Styrene-butadiene-styrene (SBS)-modified asphalt has been widely used in high-grade pavement due to its excellent road performance. However, environmental factors will lead to continuous deterioration of SBS-modified asphalt; thus, it is difficult for asphalt pavement to meet the demands of long-term service. In recent years, graphene oxide (GO) has attracted the attention of scholars due to its excellent compatibility and modification effect when used as an asphalt modifier. Based on previous studies, this study explored the characteristic evolution of GO/SBS composite-modified asphalt during aging. To achieve this goal, GO and the SBS polymer were blended to prepare GO/SBS composite, which was then used to prepare the modified asphalt. Pure SBS and the GO/SBS composite were investigated by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), and thermogravimetry (TG). In addition, the GO/SBS-modified asphalt and SBS-modified asphalt were studied by FTIR, fluorescence microscope (FM), dynamic shear oscillatory (DSR) test, and multiple-stress creep recovery (MSCR) test. The results indicated that the incorporation of GO inhibited the deterioration of the asphalt binder and relieved the degradation of the SBS modifier during the thermo-oxidative aging and photo-oxidative aging processes. Based on the results extracted from the curves of the original samples in the FTIR analysis, it was concluded that GO was combined by physical blending in SBS and SBS-modified asphalt. The TG test results verified that the GO powder could ameliorate the thermal stability of SBS. Moreover, GO improved the antirutting performance of the original SBS-modified asphalt, while the GO/SBS-modified asphalt had relatively poorer antirutting performance compared to the SBS-modified asphalt after the same aging tests. The reason was that the increment of antirutting performance of asphalt binder by aging process was inhibited by GO.