Characterization of Noise-Reducing Capacity of Pavement by Means of Surface Texture Parameters

The research objective was the evaluation of surface texture parameters of commonly applied asphalt mixtures without any special requirements regarding noise reduction on one side, and porous asphalt and thin noise-reducing asphalt on the other. The research considered three geometrically and four acoustically relevant surface texture parameters determined by an optical three-dimensional (3D) measuring device based on the strips projection principle. The mean arithmetic height was identified as the most suitable for the geometrical characterization of surface texture and showed the best correlation with the shape factor. The shape factor was recognized as an especially good acoustical properties indicator for the thin noise-reducing asphalt, which was confirmed by the close-proximity (CPX) method measurements, but was unsuitable for the porous asphalt. The considered parameters also have a potential for distinguishing different types of mixtures, providing a basis for their inclusion into the recommended specifications for the thin noise-reducing asphalt, thus contributing to the achievement of the environmentally sustainable transport.