Study on sound absorption characteristic of porous asphalt mixture based on macroscale and mesoscale analysis

Abstract

To explore the sound absorption characteristics of porous asphalt mixture, the effects of macroscopic parameters of asphalt mixture on sound absorption coefficient (SAC) were studied by the sound absorption coefficient test, and the mesoscopic void structure was investigated by industrial computed tomography (CT) and three-dimensional (3D) reconstruction techniques. The results show that the SAC can be increased by increasing the porosity or thickness and reducing the NMAS. The increase of porosity and the decrease of pavement thickness can better absorb high frequency noise (above 1000 Hz). Through the grey correlation analysis, it can be seen that the SAC of porous asphalt mixture is most affected by the porosity. There is a strong linear relationship between the microscopic void characteristic of porous asphalt mixture and the peak and mean value of SAC.