Investigation of the moisture damage and the erosion depth on asphalt

• Published in: Construction & building materials 2023-03, Vol.369, p.130503, Article 130503
• Main Authors: Zou, Yingxue, Xu, Haiqin, Xu, Shi, Chen, Anqi, Wu, Shaopeng, Amirkhanian, Serji, Wan, Pei, Gao, Xiang
• Format: Article
• Language: English
• Subjects: Adhesion property; Asphalt; Diffusion coefficient; Erosion depth; Moisture damage; Rheological property
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2023.130503

•Asphalt samples were immersed for different periods up to 504 h.•The chemical structure, rheological property and adhesion property were studied.•The erosion process was monitored at different depth.•The relation between erosion depth and period is shown in three stages.•The moisture erosion process is found to be cyclical. Moisture erosion is one of the key factors leading to asphalt pavement damage, and the erosion depth indicates the moisture damage level but it is usually neglected. In order to study the moisture erosion and the erosion depth, this study characterized the chemical structure, rheological property and adhesion property of asphalt at different depths after immersion for different periods. To further explore the diffusion mechanism of eroded asphalt, a Log-log numerical model was established based on the Fick’s second law to calculate the diffusion coefficient throughout the depth. The results indicate that it takes just four hours for water to penetrate a 25 μm asphalt film. The relation between erosion depth and immersion period presents three stages, and the process can be fitted with a polynomial model. At the macroscopic level, there is a lag between the changes in adhesion property with chemical structure and rheological property. Additionally, the periodicity of moisture erosion process was verified by the calculation of diffusion factor. In summary, the diffusion mechanism of eroded asphalt by moisture can provide a theoretical basis for the development of laboratory moisture erosion test specification, thus avoiding the waste of raw materials.