Measurement on the fatigue-healing performance of SARAs fractions in bitumen and its characterization by molecular simulations

Xu, Haiqin; Wu, Shaopeng; Chen, Anqi; Zou, Yingxue; Airey, Gordon; Wang, Haopeng; Zhang, Hanyu

Abstract

The objective of this research was to investigate the healing characteristics of bitumen through the assessment of fatigue-healing performance of SARAs fractions and its characterization at the molecular level with SARAs fractions as the intermediate. Firstly, the flow behaviors and fatigue-healing performance of fractions were characterized by rheometer. Then, the diffusion systems were constructed and the diffusion with preset cracks was carried out, the evaluation of which was identified by density distribution, relative concentration in crack region, mean square displacement and interaction effect. The results indicate that aromatics exhibit the closest similarity to original bitumen in flowing behavior, which also reflected in the healing performance. The healing performance of resins and asphaltenes are extremely limited while that of saturates was comparable to fluid. Molecular simulation was further supporting to investigate the healing process. A platform period was found in the healing period when the molecules would move to seek the lowest energy state which was considered as healing in the alternative perspective. During the period, heavy components were more difficult to traverse while weak interaction between light components would shorten the period and identify the lowest energy state more easily, thereby greatly affecting the healing performance of fractions. Furthermore, heavy components are analogous to anchor points, among which resins were more readily aggregated and asphaltenes were relatively dispersed, while light components diffuse flexibly within them. The diffusion has the potential to drive the movement of heavy components which also kept the capture of other components, ultimately resulting in the formation of a stable healing state. The outcome with a discernible interaction effect would be important theoretical significance for the refinement of bitumen of better healing performance and the potential to influence the development of rejuvenators.

Citation

Xu, H., Wu, S., Chen, A., Zou, Y., Airey, G., Wang, H., & Zhang, H. (2024). Measurement on the fatigue-healing performance of SARAs fractions in bitumen and its characterization by molecular simulations. Journal of Molecular Liquids, 412, Article 125850. https://doi.org/10.1016/j.molliq.2024.125850

• Journal Article Type: Article
• Acceptance Date: Aug 23, 2024
• Online Publication Date: Aug 26, 2024
• Publication Date: Oct 15, 2024
• Deposit Date: Sep 2, 2024
• Publicly Available Date: Aug 27, 2025
• Journal: Journal of Molecular Liquids
• Print ISSN: 0167-7322
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 412
• Article Number: 125850
• DOI: https://doi.org/10.1016/j.molliq.2024.125850
• Public URL: https://nottingham-repository.worktribe.com/output/38913864
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0167732224019093?via%3Dihub