Multiscale investigation of waste soybean oil rejuvenated asphalt binder utilising experimental methodologies and molecular dynamics simulations

ABSTRACT

To demonstrate the rejuvenation effect of waste soybean oil (WSO) on aged asphalt binder (AB) and realise the efficient combination of laboratory evaluation and numerical simulation. The rheological properties and molecular dynamics simulation of WSO rejuvenated binders were investigated. The results demonstrated that the WSO provided sufficient light components in the AB and reduced the stiffness. The WSO rejuvenated binders were transformed into a sol–gel structure, this resulted in excellent rheological properties. The WSO improved the anti-fatigue performance of rejuvenated binders. The WSO provided sufficient aromatics and a small amount of saturates for the AB. The blending mechanism of WSO and AB was physical blending. The atomic force microscopy micromorphology images showed that the bee-like structure of WSO rejuvenated binders was reduced in quantity compared with that of AB. The dosages of 3–6 wt% of AB content was determined to be the optimum content of WSO. The molecular dynamics results indicated that as the amount of WSO increased, the total volume and the occupied volume increased, while the free volume decreased. The volume fusion parameters increased significantly with an increase in the WSO content. This showed that WSO effectively improved the diffusion capacity of rejuvenated binders.

KEYWORDS:

• Rejuvenated binders
• waste soybean oil
• molecular dynamics simulation
• rheological properties
• microstructure characterisation

Acknowledgements

Ke Shi: data curation, writing-original draft, writing-review, and editing. Feng Ma: funding acquisition, resources, supervision, writing-review, and editing. Jenny Liu: writing-original draft, writing-review, and editing. Ruimeng Song: writing, review, and editing. Zhen Fu: funding acquisition, resources, writing-review, and editing. Jiasheng Dai: writing, review, and editing. Chen Li: writing, review, and editing. Yalu Wen: writing, reviewing, and editing.

Disclosure statement

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

Additional information

Funding

This work was supported by the National Key R&D Program of China [grant number 2018YFB1600200], the National Natural Science Foundation of China [grant number 52038001], and the Scientific and Technological Project in Shaanxi Province [2022KW-37].