热-光-水耦合条件下SBS改性沥青老化性能与机理研究OA

SBS modified asphalt undergoes aging due to the combined influence of thermal oxidation,ul-traviolet radiation,and humidity during use.To evaluate the aging performance of SBS modified asphalt under various conditions,aging scenarios incorporating thermal oxidation,ultraviolet and humidity factors were established based on the recent climate characteristics of Guangzhou,Xi'an,and Lhasa.Infrared spectroscopy and fluorescence microscopy experiments were conducted to reveal the aging mechanism of SBS modified asphalt under these coupled aging conditions.The results show that after aging,the ductility of asphalt decreases by approximately 25%to 77%,and the softening point reduces by about 15%to 24%.Correlation analysis reveals that ultraviolet radiation has the strongest correlation with the aging process.However,under moderate humidity conditions,humidity shows the highest correlation,mainly due to the reduction in the effects of ultraviolet aging.The infrared spectrum results show a maxi-mum increase of 433.9%in the carbonyl index and 1 220%in the sulfoxide index after aging,confir-ming the previous findings.The fluorescence microstructure results further support these results.