Pavement performance and modification mechanisms of asphalt binder with nano-Al₂O₃

ABSTRACT

Nanomaterials has been widely adopted in asphalt binder modification in pavement engineering. Considering the advantage of nano-Al₂O₃ in high-temperature resistance and chemical stability, this study investigated the feasibility of the nano-Al₂O₃ used in asphalt modification in terms of performances and mechanisms. The impact of the nano-Al₂O₃ content on modified asphalt binder’s pavement performance was analyzed via aging resistance, low temperature performance, high temperature performance, and bonding performance using various tests (e.g. DSR test, BBR test, RTFOT test, and BBS test). Results showed that the nano-Al₂O₃ is capable of improving base asphalt’s aging resistance, high temperature performance and bonding performance, while bringing an insignificant adverse impact on performance at low temperatures simultaneously. Moreover, modification mechanisms of the asphalt binder under the modification of nano-Al₂O₃ were revealed from a view of functional groups and molecular characteristics via Gel permeation chromatography (GPC) tests and Fourier transform infrared spectroscopy (FTIR) tests. According to the result, modification of base asphalt binder by nano-Al₂O₃ belongs to physical blended and inhibits the growth of sulfoxide groups during the aging process. Meanwhile, the nano-Al₂O₃ increases the base asphalt binder’s molecular weight based on LMS percentage, number-average and weight-average.

KEYWORDS:

• Modified asphalt binder
• nano-Al₂O₃
• pavement performance
• aging resistance
• modification mechanisms

Data availability statement

The data, models, or code generated or used during the study are proprietary or confidential in nature and can be obtained from the corresponding author upon request.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Science Foundation of the United States [grant number CMMI-0644552]; National Natural Science Foundation of China [grant number U1134206]; Yunnan Provincial Department of Transportation [grant number 7921000079]; Shangdong Expressway Co. Ltd [grant number QLTD-2019-7-FW-0036].