Laboratory Evaluation of Sound Absorption Characteristics of Pervious Concrete Pavement Materials

Abstract

This paper describes a laboratory study on the sound absorption characteristics of clogged and unclogged pervious concrete (PC) pavement materials compared with those of porous asphalt (PA) mixtures and those of conventional dense-graded asphalt and portland cement concrete pavement materials. Examined in this study were the effects of the mixtures’ initial porosity on their sound absorption characteristics and how these characteristics were affected by subsequent clogging of the mixtures. Four porosity levels of PC and PA were studied: 10%, 15%, 20%, and 25%. The mixtures with 20% porosity were tested for the effects of clogging. The test results showed that the shapes of sound absorption spectra of PC and PA materials were similar displayed high sound absorption values within the frequency range of 250 to 1,000 Hz. However, for all four porosity levels studied, the PC materials produced about 0.1 or 20% higher sound absorption coefficient values throughout the entire measured frequency range from 100 to 2,500 Hz. The same order of magnitude of differences in the sound absorption values between PC and PA was also observed in their clogged states. The finding that PC exhibits a better sound absorption capability than PA is of practical significance. The results of this study also demonstrate that laboratory testing of sound absorption can be employed to provide a useful indicative assessment of the noise reduction properties of porous pavement materials without the need for full-scale field testing.