Effects of clogging and cleaning on sound absorption performance of rubberized porous asphalt mixture

The rubberized porous asphalt mixture (RPAM) has both the sound absorption capacity of air voids and the damping performance of rubber particles, which is a high-potential noise reduction pavement. However, the air voids are inevitably subjected to clogging, resulting in insufficient sound absorption performance. Moreover, it is not clear whether a large amount of rubber particles exacerbates the attenuation of sound absorption performance. Therefore, the purpose of the paper was to explore the attenuation law of sound absorption performance of RPAM under the action of multiple clogging cycles, and then optimise the preparation parameters to improve noise reduction durability. Constant head permeability test was carried out to simulate the clogging process, and manual and high-pressure washing were used to clean the clogged samples. The results showed that the attenuation process of sound absorption coefficient conformed to exponential function. The interconnected air voids were mainly clogged in the fast attenuation phase, and the open voids were clogged in the slow attenuation phase. It was more efficient to clean samples completely clogged than to clean samples clogged for three cycles. More importantly, rubber particles accelerated the attenuation of sound absorption performance during the clogging process. However, the noise reduction durability of RPAM optimised by orthogonal test was significantly improved, even better than that of porous asphalt mixture without rubber particles.