The airborne sound insulation performance of cross-laminated bamboo and timber (CLBT) and cross-laminated timber (CLT) wall panels

Abstract

The growing application of timber and bamboo in construction applications makes it important to investigate their acoustic properties. This study conducted a comparative experimental investigation of the airborne sound insulation performance of Cross-Laminated Timber (CLT) and a novel composite, Cross-Laminated Bamboo and Timber (CLBT), wall panels. A total of 10 fullscale wall specimens, including basic designs and upgrades with lining systems, were tested in accordance with ISO 140-3. The results demonstrate that structural optimization using multi-layer linings is effective for sound insulation performance for both CLT and CLBT walls. The optimal CLT wall achieved an Rw of 47 dB with consistent spectrum-adjusted values, meeting high acoustic standards. The optimized CLBT wall reached an Rw of 45 dB, which can meet the acoustic requirements of most conventional buildings, but its low-frequency sound insulation performance is insufficient (Rw+Ctr=39 dB). This study demonstrates that using a multi-layer composite structure, integrating porous materials, high-density reflective layers, and elastic flanking transmission control elements, is key to achieving good sound insulation performance across the full frequency range. Furthermore, CLBT walls can achieve comparable sound insulation performance to CLT walls with proper design, meeting the acoustic requirements for many conventional buildings.