The effect of moisture content on sound absorption of expanded perlite plates

• Published in: Building and environment Vol. 40; no. 3; pp. 311 - 318
• Main Authors: Yilmazer, Semiha, Ozdeniz, Mesut B.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2005
• Subjects: Acoustics; Building materials; Perlite; Sound absorption coefficient; Sound absorption coefficient; Acoustics; Building materials; Perlite
• ISSN: 0360-1323; 1873-684X
• DOI: 10.1016/j.buildenv.2004.07.004

Expanded perlite is a porous, lightweight, fire resistant and moisture retaining material with sound and thermal insulation properties. In this research, acoustical behaviour of plates made of expanded perlite was studied experimentally. Since these plates are used for sound absorption, the acoustical parameter selected for this study is “sound absorption coefficient”. Preliminary experiments indicated that moisture reduced the sound absorption coefficient on plates and there is not much significant difference between the dry and 50% humid conditions. However, there is a significant difference in acoustical properties for the 50–95% humid conditions. Thus, this interval was studied in detail. A number of expanded perlite plates having different mixtures were prepared and tested. It was observed that, coating the expanded perlite particles with sodium silicate increased the moisture resistance, and the addition of mineral fibres into the mixtures increased the strength and sound absorption coefficient of the plates.