Review on the diffusive and interfacial performance of bituminous materials: From a perspective of molecular dynamics simulation

Abstract

The cohesive and adhesive performances of bituminous materials significantly affect the service life of asphalt pavement. The molecular dynamics (MD) simulation method has been proved as an effective tool to predict the thermodynamics parameters of different multisubstance and multi-phase bitumen models during different diffusion, self-healing, and interfacial interaction processes. This paper aims to comprehensively review the application cases of MD simulations on dynamic and interfacial bitumen systems. The diffusion behaviors of oxygen, moisture, and rejuvenator molecules in the bitumen matrix could be illustrated from MD simulations considering the influence of temperature, pressure, and humidity. Moreover, molecular mobility and distribution of bitumen molecules on the aggregate surface remarkably influenced the interfacial bonding level and moisture sensitivity. In addition, the molecularscale mechanism and evaluation indices for the self-healing potential of bitumen models were reviewed. Further, the representative bitumen-(moisture)-aggregate interfacial models, the corresponding evaluation parameters, and influence factors for the adhesive bonding strength in MD simulations were overviewed. Besides, the effects of bitumen components, aggregate type, moisture invasion, temperature variation, and pull-off tension rate on the adhesion performance of bitumen-aggregate models were summarized and discussed. This review can help us fundamentally understand the dynamic diffusion, self-healing behaviors, and interfacial characteristics of bitumen models at the atomic level and develop more potential functions of MD simulations in addressing the scientific issues of sustainable bituminous materials.