Microscopic R-curve simulation study of asphalt material fracture

Abstract

Cracks can significantly influence the service life of an asphalt pavement. To study the microcracking behavior of asphalt materials, this paper utilized molecular dynamics simulation methods to simulate the tensile fracture process of asphalt materials at the microscopic level and described the fracture behavior using R-curve. Two experimental factors, temperature and loading rate, were selected to simulate the tensile fracture of virgin asphalt binder, aged asphalt binder, and SBS modified asphalt binder, and Microeconomic R-curve were constructed based on the fracture displacement and cumulative fracture energy of asphalt materials. Meanwhile, fracture energy, cohesive energy, and energy rate were used to evaluate the fracture behavior of asphalt materials. The results indicated that the micro-R curve simulated by molecular dynamics can well describe the tensile fracture behavior of asphalt. Among the fracture indicators, fracture energy and energy rate were significantly affected by the type of asphalt, while cohesive energy was significantly affected by the loading rate.