Molecular Dynamics Simulation and Experimental Analysis of the Effect of Ultrasonic Disposal on the Compatibility of NanoAsphalt

Abstract

Based on LAMMPS molecular dynamics simulation of nano-silica(nano-SiO2) and asphalt molecular motion trajectory in the ultrasonic environment, the nano-SiO2 modified asphalt mixed model was proposed, and then the ultrasonic vibration process was simulated by the periodic displacement method. The solubility parameter and viscosity of the mixed model were simulated and calculated to reveal the compatibility changes of the modified asphalt from a microscopic perspective. Different temperatures and ultrasonic frequencies were achieved by changing the temperature parameter and the period parameter of the simple harmonic motion equation. Besides, to characterize the effect of ultrasonic vibration on the promotion of nano-SiO2-asphalt compatibility, the prepared nano-SiO2 modified asphalt was subjected to viscosity testing through viscosity change. The results show that the simulation could accurately predict the experimental phenomena, and the molecular simulation can be used as an effective method to study the properties of asphalt materials. The compatibility of nano-SiO2 and asphalt is positively correlated with ultrasonic temperature and ultrasonic frequency to some extent. The compatibility effect is best at 130 °C, 40 KHz. When the ultrasound frequency exceeds a certain value, the effect of promoting compatibility is not obvious.