ABSTRACT

 In this study, two sound absorption composite panels were developed using agro waste materials. The first panel was produced using combination of coconut coir fibre, shredded office paper with gypsum as the binder. The second one was developed using rice straw, saw dust and urea formaldehyde as binder. The percentage composition of coconut with shredded paper and rice straw with sawdust were varied at different ratios of 100:10, 75:25, 50:50 and 75:25 to study the influence of varied composition on acoustic properties. The various composite mixture were thoroughly mixed and poured into a mould of 120x120x50 mm. They were further compacted and allowed to cure for 5 hours before subjecting to thermal treatment for 12 hours. The developed composite samples were tested for density, sound absorption coefficients and acoustic impedance. The results obtained showed that the combination of coconut fibre showed absorption coefficients values ranging from (0.9-0.52) and (0.22-0.29) for noise reduction coefficient. In the composite of rice straw with saw dust, corresponding values ranging from (0.13-0.46) and (0.16-0.23) were obtained. The acoustic impedance values ranging from 1.2-1.3 xl 6 kgm2s' and 0.9-1.1 x106kgm2s' were obtained for the previous and later respectively. Higher density values of (325-360) kgm2and (250-310) kgm2were obtained for the respective samples. It was concluded that the developed samples could be utilized for noise absorption in power houses, classroom and automobiles.