Influence of void content on noise reduction characteristics of different asphalt mixtures using meso-structural analysis

In order to study the noise reduction behavior of asphalt pavements with different void contents, a two-dimensional (2D) level acoustic-structure coupled sound absorption model was constructed. The sound absorption effects of asphalt mixtures with different void ratios were qualitatively analyzed, and the variation law of their absorption coefficients was obtained. At the same time, the influence of void characteristics on noise reduction was analyzed using the meso-structure. The results show that: with the increase of the void ratio of asphalt mixture, the total area of voids in the specimen section increases; the number of voids in the specimen section decreases, while the average equivalent diameter of the voids increases; the fractal dimension of the voids in the section increases; the anti-dispersion ability and noise reduction effect of the asphalt mixture increase. The prediction model of sound absorption coefficient established in the study could predict the sound absorption coefficient of asphalt mixture, which provides a reference for practical application.