Effect of different factors on sound absorption property of porous concrete

As a functional pavement material with a large number of pores, porous concrete (PC) pavement exhibits a good sound absorption performance. Limited experimental studies focused on the effects of aggregate size, cement to aggregate ratio, and pavement thickness of porous concrete on its sound absorption in a wide range of sound frequencies. Besides, the effects of temperature and humidity on the sound absorption performance of porous concrete are still unclear. In this study, one hundred and thirty-five samples of porous concrete were prepared that consist of three aggregate gradations, three cement to aggregate (C/A) ratios and three thicknesses to investigate the sound absorption property of porous concrete considering the effects of temperature and humidity. These samples were tested at different temperatures (-10, 5, 20, 35 and 50 degrees C) and with different humidity (dry, inundated and saturated) using impedance tubes method with varied sound frequencies (200-2000 Hz). The results demonstrated that: under the same conditions, the sound absorption property of porous concrete decreases with the increase of aggregate size and cement to aggregate ratio, and increases with the increase of thickness. In addition, the temperature and presence of water have significant effects on the sound absorption property of porous concrete.