Article of RILEM TC 278-CHA: evaluation of self-healing properties of asphalt binders—outcomes and challenges

This paper describes part of the activities conducted by RILEM Technical Committee 278-CHA (Crack-Healing of Asphalt Pavement Materials) Task Group 2a. The main objective of the TG2a was to explore and evaluate the experimental methods and criteria for the assessment of self-healing of asphalt binders. The work was developed in two phases. In the first phase, various existing healing test protocols were scrutinized, encompassing time-sweeps with single rest periods (TS-SRP), time-sweeps with multiple rest periods (TS-MRP), and linear amplitude sweeps with rest periods LASH). The protocols were evaluated and compared across different laboratories. The outcomes of interlaboratory testing led to the selection of the LASH-based approach. However, it was acknowledged that new insights and modifications were necessary due to the possible occurrence of biasing effects during the amplitude sweep. Such issues were addressed in the second phase of research, in which a modified LASH-based procedure underwent further investigation using various methods for data analysis, including approaches based on dissipated energy and the viscoelastic continuum damage model.