Cairo University

MTPR Journal

 

MEASUREMENT OF SOUND REDUCTION INDEX OF LIGHTWEIGHT PARTITIONS USING TWO- ROOM AND VIBRATION VELOCITY METHODS

2016-12-17
A.M.Shehap1, Abd ElFattah A Mahmoud2, Hatem Kh. Mohamed3*
1 Department of Physics, Faculty of Science, Cairo University
2,3 National Institute for Standards (NIS)

Vol./Issue: 16 , id: 237

Noise pollution has become another deleterious outcome of modern civilization. Nowadays, the usage of lightweight partitions in various wall and floor structures increases due to its advantages over traditional masonry partitions since they are easy to install and it can achieve the sound insulation requirements with low cost and low overall surface weight. Airborne sound insulation is the most important physical quantity defining the acoustical quality of buildings. In this paper, a comparison between two-room method that described by ISO 140-3 and vibration velocity method (not standardized) for measuring sound reduction index (SRI) of single and double leaf plywood and gypsum board lightweight partitions are presented. Regarding to double leaf partitions, measurements were carried out with the leaves separated by 50, 100 mm air gap. Space between the leaves was filled with a layer of either Rockwool or polyurethane in order to show the effect of cavity absorption on the sound reduction index behavior. From the results it is shown that, the SRI of gypsum board increased by 5-6 dB over plywood and it is also shown that a good agreement between the two mentioned methods except at high frequencies.