Laboratory Assessment of Deteriorating Performance of Nano Hydrophobic Silane Silica Modified Asphalt in Spring-Thaw Season

In the seasonal frozen regions, freeze-thaw (F-T) damage is the main pavement damage, causing a variety of poor conditions in bitumen pavement, such as cracks, pits, potholes, and slush. In previous studies, we evaluated the effect of nano hydrophobic silane silica (NHSS) on the degradation of asphalt mixture under F-T cycles, and established the damage model of NHSS modified asphalt mixture in spring-thawing season. To gain more understanding of the influence of NHSS on asphalt in spring-thawing season, NHSS modified asphalt was systematically analyzed under F-T aging process in this study. The main research objective of this paper was to investigate the deteriorating properties of NHSS modified asphalt under Freeze-thaw aging process. Within this article, the physicochemical characteristics of NHSS modified asphalt were determined by using various laboratory tests, which included basic property test, dynamic shear rheometer test (DSR), Fourier transform infrared spectroscopy test (FTIR) and thermogravimetric analysis (TGA). The results showed that the incorporation of NHSS could inhibit the F-T aging process of asphalt. Moreover, the chemical composition and thermal stability of asphalt under F-T aging process was analyzed through FITR and TGA test parameters. The results illustrated that the sulfoxide functional groups content index was more suitable for evaluating the aging degree of asphalt in the spring-thawing season and the F-T aging process had a great impact on the thermal property of NHSS modified asphalt.