Multi-scale analysis of damping characteristics of dry mixed rubberized porous asphalt mixtures for tire-pavement noise reduction

Abstract

Waste rubber particles have the potential to enhance the damping performance of asphalt pavement. However, there is a scarcity of research on the mechanism of the influence of rubber particles on the damping characteristics of asphalt mixtures. The purpose of the paper is to explore the influence of rubber particles on the damping characteristics, and reveal the noise-damping mechanism of dry mixed rubberized porous asphalt mixture (RPAM). The dynamic modulus test based on UTM was used to characterize the dynamic stiffness characteristics and energy dissipation capacity of RPAM. The self-made free vibration-damping test was applied to evaluate the damping properties of RPAM. X-ray Computed Tomography (CT) was used to scan the specimens of RPAM, and image analysis techniques were established to study the distribution characteristics of rubber particles. The correlation between the distribution characteristics of rubber particles and damping properties was constructed to explore the damping mechanism of the RPAM. The results showed that with the increase of rubber particle content, the stiffness of RPAM decreases. From an energy perspective, RPAM with more rubber particles has a stronger energy dissipation ability, resulting in better damping properties. From a microscopic perspective, RPAM with more rubber particles has a larger proportion of effective rubber particles, which are key to improving damping properties. It is worth noting that the rubber particle content should not exceed 3% to meet the requirements of pavement performance. The findings offer practical guidelines for the design of low noise pavement.