Microscopic Analysis of Aging Characteristics of SBS-Modified Asphalt Based on FTIR Technology

Thermal-photo-oxidative coupled aging, anaerobic and thermal-oxidative aging testing were conducted on styrene-butadiene-styrene (SBS) type copolymer -modified asphalt at different aging temperatures. The changes in functional group index before and after aging of modified asphalt were deeply analyzed by the attenuated total reflection (ATR) method of Fourier transform infrared (FTIR) spectroscopy. The results show that the carbonyl index IC=O, the sulfoxide index IS=O, the polybutadiene index IPB, and the polystyrene index IPS can properly characterize the changes in the microscopic chemical structure of SBS-modified asphalt during aging, and can accurately quantify the degree of aging of SBS-modified asphalt at the microscopic level.