Study on the effect of different environmental factors on the aging gradient of asphalt binder based on field aging test

ABSTRACTAging of asphalt binder is a complex natural phenomenon with significant differences under the effect of different environmental factors. The accelerated aging method commonly used in the laboratory is difficult to reproduce the field aging of asphalt binder. The purpose of this study is to reveal the effect of environmental factors on the aging gradient of asphalt binder. For this reason, a layered dissolution-peeling method was developed to recycle asphalt binder films. The gradient behaviour of field-aged asphalt binder was analysed based on rheological parameters and chemical functional groups. The results showed that the layered dissolution-peeling method achieved separation of asphalt binder at 0.1 mm level. Ultraviolet light severely contributed to the distinct aging gradient of field-aged asphalt binder. The carbonyl index of field-aged asphalt binder at 0–0.32 mm was approximately 1.73 times higher than that at 0.32–0.64 mm, 1.90 times higher than that at 0.64–0.96 mm and 2.24 times higher than that at 0.96–1.28 mm. To significantly characterise the aging behaviour of asphalt binder, the film thickness in the accelerated aging simulation test should not be more than 1 mm. The findings of the study serve as a valuable reference for accurate prediction and targeted prevention for asphalt pavements.KEYWORDS: Asphalt binderfiled agingaging gradientenvironmental factorslayered dissolution-peeling method Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis study was supported by National Key Research and Development Program of China (2022YFE0137300), National Natural Science Foundation of China (52078018), and Key Technology Research in Shandong Province - Open Competition Mechanism to Select the Best Candidates Project (2021-KJ-068).