Sound absorption capacity of garnet partial replacement in mortar

Abstract

Sound absorptive materials are generally used to counteract the undesirable effects of sound reflection in the room. The research aims to develop sound absorbent mortar with inclusion of waste materials in effort to improve the acoustic quality of the room. One method to increase the acoustic quality would be covering part of concrete wall with a new mortar which has high sound absorption. The objective of the research is to determine both non-acoustic properties and evaluate acoustic performance of mortar containing waste garnet as partial garnet aggregate replacement. Three new mortar with i) a series of garnet replacement 10 to 40% of sand to normal mortar (1 sand :3 cement), ii) a series of perlite mortar (1 cement: 4 perlite) with waste garnet replacement up to 30%, and iii) a series perlite mortar with garnet replacement and cotton fiber were developed to have such high sound absorption. Waste garnet, an industrial waste obtained from the shipyard industries were used for the purpose of greener production.. At 7 days age garnet replacing sand of 20% in normal mortar demonstrated highest average sound absorption of 0.221 which implies that the capacity of 22% in absorbing sound in room, thus not achieving the target of 0.8. The inclusion of garnet in perlite mortar and addition of cotton fiber do not posses good effect in 7 days age of mortar. However, overall, garnet increased the sound absorption of mortar.