Kinetics-based formulation of relationship between healing and ageing of asphalt binder

ABSTRACT

Ageing and healing are both important characteristics of asphalt binder. The effect of ageing on healing is often studied, but the quantitative relationship between them is not clear. Thus, this study aims at explaining and formulating the inner relationship between healing and ageing based on a kinetics-based approach, expressed as healing and ageing activation energy, respectively. The healing activation energy is obtained based on the healing kinetics approach using recoverable strain energy (RSE). The ageing activation energy is calculated based on the kinetics-based ageing model. After that, further analysis is performed to explore the relationship between healing and ageing kinetic rates of asphalt binders, and the interpretation of the discovered relationship is proposed. The results indicate that the healing activation energy of aged asphalt binder has no big difference from the sum of ageing activation energy plus the healing activation energy of unaged asphalt binder. Define the ratio of initial temperature kinetic rate to the final temperature kinetic rate of healing/ageing as the healing/ageing rate ratio. It indicates that the product of the healing rate ratio of unaged asphalt binder and the ageing rate ratio of the same binder is close to the healing rate ratio of aged asphalt binder.

KEYWORDS:

• Asphalt binder
• ageing
• healing
• activation energy
• kinetic rates

Disclosure statement

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

Additional information

Funding

This research was supported by Zhejiang Provincial Natural Science Foundation of China [grant number LZ21E080002], National Key R&D Program of China [grant number 2019YFE0117600] and China Scholarship Council [grant number 202006320255].