Investigation of the Sound Absorptivity of Portland Cement Concretes

Abstract

Coefficients of absorption were determined by the reverberation method, both instrumentally and with the ear. The samples were special types of concretes, ranging from dense, heavy mixes using standard aggregates to light, porous ones having varying proportions of cement, sand and light weight aggregates, such as cinders and haydite. The results show that porous materials absorb sound, but dense materials with small porosity are not efficient in absorbing sound. Haydite and cinder concrete constructions proved to possess effective sound-absorbing values; sandstone and limestone products were not so good, but most of the specimens are more sound absorbent than the usual hard plasters and cements so that these new products can be used advantageously in buildings to reduce noise.