A Study on the Sound Insulation Performance of Cross Laminated Timber used in Interior Walls of Buildings

• Main Authors: Chieh-TingYang, 楊傑婷
• Other Authors: Yaw-Shyan Tsay
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/mt7b5b

碩士 === 國立成功大學 === 建築學系 === 107 === The study aimed to identify the influence of different CLT (cross laminated timber) wall structures on the sound insulation performance by designing two kinds of wall structure system, namely separating wall and partition wall upon Japan CLT and Taiwan CLT as the main research objects through which several rounds of insulation test were implemented in the NCKU Architectural Acoustics Laboratory. Simulation tools were used to predict the sound insulation performance of wall structures. Simulated data were then compared against empirical data in order to verify the reliability of simulation tools. Finally, literature and formulas were investigated so as to identify the relationships between sound transmission loss of small samples and full-size samples. As shown in empirical data, the overall sound insulation performance of double wall constructions reached Rw 50 dB, while filling glass wool and the change of airgap thickness did not bring significant influence to the performance as improvement was barely less than 2dB. Rw value of solid wall constructions also reached 50dB; the performance could be further enhanced by either increasing airgap thickness between CLT and panels or filling glass wool as ways to reduce the sound transmission loss in low frequency. Having compared the performance between Taiwan and Japan CLT single panel, similar trends in sound transmission loss of both materials were found; Japan CLT was slightly better in the low frequency performance under 250Hz. Several factors were assumed to altering both low resonance frequency and sound insulation performance, including: different tree species, a change in density, and a change in young’s modulus. As shown in the simulations, the use of empirical formula in predicting the CLT single board has yielded a more accurate result instead of using INSUL and VBA tools. However, all simulation tools displayed low predictability when viewing double wall system, in which the outcomes, calculated by the mass law formulas, resembled the actual values. In the prediction of solid wall, INSUL being manipulated in the 500~1350Hz zone has delivered the value close to the actual value, in which the fitting frequency also matched in the same position.