The Improvement in the Floor Impact Noise with Changes in the Glass Transition Temperature of an SBR Latex Mortar

Abstract

It is most effective to reduce floor impact noise as close to the sound source as possible. In apartments, there are multiple layers in the floor system, from floor finishing to the structural concrete slab. Apart from the floor finishing, mortar lies at the top layer of the floor system, followed by autoclaved lightweight concrete, insulation, and the concrete slab. The present study aims to identify the reduction characteristics of light and heavy floor impact noises by changing the glass transition temperature of an SBR (styrene–butadiene rubber) latex mortar. To achieve this, structural tests were undertaken to find the appropriate mix proportions of SBR latex in the mortar, meeting the glass transition temperature based on the physical test results regarding the latex mortar. As seen in the study method and process, because this study aimed to both increase and decrease the strength compared to general mortar, a 7% mixture ratio of Tg 4 °C SBR latex was decided upon for the strength increase, while a 5% mixture ratio of Tg −16 °C SBR latex was chosen for the strength reduction. A mock-up specimen was created using the SBR latex-modified mortar according to the identified mix proportions, and the characteristics of light- and heavy-weight floor impact noises of the SBR latex-modified mortar were then examined. Comprehensive analysis of the reduction performance of the floor impact noise revealed that the Tg −16 °C SBR latex-mixed mortar showed a reduction effect of about 2–5 dB for light-weight impact noise and about 7–10 dB for heavy-weight impact noise.