Investigation on Self-Healing Behavior of Asphalt Binder Using a Six-Fraction Molecular Model

The service life of asphalt pavement is influenced by many factors, of which the properties of asphalt binder are the most important. The self-healing properties of asphalt binder counteract the progression of fatigue and have been studied using experiments and molecular dynamics (MD) simulations by numerous researchers to ultimately extend the service life of asphalt pavements. In this paper, asphalt binder is separated into six fractions (saturates, monoaromatics, diaromatics, polyaromatics, resins, and asphaltenes). Then a six-fraction model of asphalt binder is created and employed to investigate the self-healing behavior of asphalt binder. The effect of crack width, temperature, and state of molecular aggregation, as well as aggregate on the self-healing process of asphalt binder is studied on a microscale by means of MD simulations. The results show that these factors have influences on the self-healing behavior of asphalt binder; in addition, graphene is found to exhibit some positive impacts on the self-healing process of asphalt binder.