The effect of lerak foam and kapok as a silencer on lightweight concrete

Abstract

Lerak Foam is Foam produced by Lerak fruit mixed with water. This Foam is very suitable as an air cavity enhancer in lightweight concrete. Kapok is a natural material commonly used as pillows, mattresses and stuffed toys. Kapok with fine fibers and easily formed in a concrete mixture is expected to reduce noise. The purpose of this study is to reduce the noise of concrete materials by adding Lerak Foam and Kapok. This research was conducted in the Concrete Laboratory University of Jember, by making a sample of 40 cm x 40 cm x 40 cm concrete box with a thickness variation of 3 cm and 7 cm. This study intend to compare the value of noise reduction and transmission loss from the concrete specimen model with the addition of 100cc Lerak Foam and Kapok with 0%, 1.5%, 2.5%, 3.5% and 5% from the weight of concrete. The different values can be found by giving a noise gauge inside from the concrete box. The level of noise reduction is affected by the thickness of concrete. The level of noise reduction will increase as much as the addition of Kapok Fibers in concrete mixtures.