Abstract
Under climatic conditions such as high temperature plus ultraviolet radiation and water, the mechanical properties of asphalt pavement will be significantly attenuated. Present research mainly focused on thermal oxidation and ultraviolet radiation aging, and there were many controversies about the effect of water on the aging performance of asphalt. In addition, the relationship between the aging behavior of asphalt under complex environments and the standard PAV test needs to be further clarified. This research comprehensively evaluated the rheological properties, microscopy, and functional group of matrix asphalt, SBS, and high viscosity modified asphalt under different climatic conditions. Compared with thermal oxidation aging, daily exposure to UV radiation can increase the aging degree of matrix and modified asphalt by about 5 % and 1.5 %, respectively. Compared with thermal oxidation aging, the presence of water and the coupling effect of UV and water can reduce the aging degree of asphalt by 3.5 % and 2.6 %, respectively. After 5 days of thermal oxidation and UV coupling, the aging degree was close to or even greater than that of the PAV experiment. Asphalt aging caused an upward shift in the complex modulus master curve, and a downward shift in the phase angle master curve of matrix asphalt and high viscosity modified asphalt. Due to the synergistic effects of hardening and polymer degradation, the phase angle master curve of SBS modified asphalt showed an upward trend in the low frequency range. Under the influence of climatic conditions, the polymer of asphalt would degrade, the particle size of the polymer phase decreased, and the brightness of fluorescent image became darker. The rich polymer phase structure of high viscosity modified asphalt enabled it to maintain excellent mechanical properties even after long-term aging.
Published Version
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