Road performance and noise reduction characteristics of dense graded dry-process rubberised asphalt mixture

Abstract

Waste tire rubber particles have potential to improve the road durability and reduce road noise. However, the current research on the influencing factors and noise reduction mechanisms of rubber asphalt mixtures' noise reduction performance is not very in-depth, which hinders the balanced design of low-noise road performance and noise reduction function. This research aims to investigate the effects of dry-process rubber particle addition on the road performance and noise reduction capabilities of asphalt mixtures, clarifying the road performance enhancement and noise reduction mechanism of dry-process rubber asphalt mixtures. This study initially evaluated the high- and low-temperature performance, water stability, and fatigue performance of Stone Matrix Asphalt (SMA) mixtures with varying rubber particle contents (0 %, 1 %, 1.5 %, and 2 %) prepared using the dry -process, and clarified the modification mechanism of dry-process rubber particles from a microscopic perspective. Furthermore, explored the trend of damping characteristics of asphalt mixtures with rubber particle content through dynamic modulus tests. The dry-process rubberised asphalt mixtures sound absorption and noise reduction performance were analyzed through tire/road noise test and absorption coefficient detection. The results show that the road performance of asphalt mixture first improves and then decreases with the increase of rubber particles content. The optimal road performance of asphalt mixture is achieved when the rubber content is 1.5 %. The formed semi continuous phase network structure between rubber particles and asphalt can enhance the structural strength of asphalt mixtures, thereby improving its road performance. Rubber particles enhance the sound absorption and damping capabilities of asphalt mixtures, improving their noise-reduction performance. The 1.5 %RSMA (SMA mixture with 1.5 wt% rubber particles by aggregate) can reduce noise to 3 dB(A) compared to the 0 %RSMA mixture, and road noise levels are correlated with vehicle speed and rainwater blockage.