Decoupling oxidation and hardening in ageing: evaluation of bitumen-stone adhesion using different experimental methods

Zhou, Lu; Airey, Gordon; Zhang, Yuqing; Wang, Chonghui

Abstract

The adhesion at the bitumen-aggregate interface critically affects asphalt pavement resistance to moisture damage and cracking and is significantly influenced by the bitumen ageing process. Coupled oxidation and hardening during ageing lead to varying results across evaluation methods. This study employs direct tensile pull-off tests at iso-temperature and iso-stiffness conditions, contact angle tests, and boiling water tests to assess bitumen-stone adhesion at different ageing levels. Results indicate oxidation and hardening have dual impacts: short-term ageing initially enhances adhesion, while prolonged ageing reduces it significantly. Polymer-modified bitumen shows improved ageing resistance due to delayed polymer degradation. Iso-temperature tests fail to clearly differentiate oxidation from hardening effects, whereas iso-stiffness tests offer more accurate assessments by excluding physical hardening. Due to interactions between chemical and physical changes in bitumen, ageing evaluations vary by indices and binder type. A comprehensive assessment combining pull-off tensile tests, surface free energy analysis, and mixture-scale evaluations is recommended.

Citation

Zhou, L., Airey, G., Zhang, Y., & Wang, C. (2025). Decoupling oxidation and hardening in ageing: evaluation of bitumen-stone adhesion using different experimental methods. Road Materials and Pavement Design, 26(Sup 1), 734-750. https://doi.org/10.1080/14680629.2025.2486525

• Journal Article Type: Article
• Acceptance Date: Mar 31, 2025
• Online Publication Date: Apr 2, 2025
• Publication Date: Apr 2, 2025
• Deposit Date: Apr 9, 2025
• Publicly Available Date: Apr 10, 2025
• Journal: Road Materials and Pavement Design
• Print ISSN: 1468-0629
• Electronic ISSN: 2164-7402
• Publisher: Taylor and Francis
• Peer Reviewed: Peer Reviewed
• Volume: 26
• Issue: Sup 1
• Pages: 734-750
• DOI: https://doi.org/10.1080/14680629.2025.2486525
• Public URL: https://nottingham-repository.worktribe.com/output/47553893
• Publisher URL: https://www.tandfonline.com/doi/full/10.1080/14680629.2025.2486525