Improved three-dimensional discrete modeling method and anti-cracking properties of asphalt mixture

Abstract

To explore the low-temperature cracking of asphalt composite’s materials, this study used the three-dimensional module in the particle flow code (PFC3D), from which a three-dimensional numerical model of the Marshall split specimen and a three-point trabecular bending specimen was established. Second, the different contacts inside the model and parameter selection were defined, which resulted in splitting-test and bending-test simulation results for AC-13 and SMA-13 in the five temperature ranges of −15 °C, −10 °C, 0 °C, 10 °C and 15 °C. Finally, indoor trial verification simulation results were obtained, and the average error of the stiffness modulus was within 10%, so model reliability was verified. The simulation results show that the contact fracture of the aggregate, and the asphalt mastic is the chief cause of cracking. The contact between the aggregates is the maximum intensity of the pitch mixture, and the contact between the asphalt mastic and the aggregate contributes more than 90% of the asphalt mixture’s bending strength. Whether it is a splitting-power modulus or bending-power modulus, the value for AC-13 is larger than it is for SMA-13, indicating that AC-13 anti-crack performance is better than that of SMA-13. The study’s results provide a theoretical basis for the design of asphalt pavement materials.