Experimental study on floor impact sound insulation and vibration characteristics in cross laminated timber building

Efforts toward the construction of timber public buildings have been madden since the enforcement of the Act for Promotion of Use of Wood in Public Buildings (Law No. 36 of 2010 of Japan). The promotion of the use of wood can contribute to the prevention of global warming etc. As this act, a low-layer public building is supposed to attempt making to timber construction. Moreover, it is expected that the building such as apartment houses comes to be made from wooden construction. CLT (Cross laminated Timber), which had been used in Europe and North America, was standardized in JAS (Japanese Agricultural Standard) as building material, and became able to adopt it to a timber building in Japan. This paper reports the floor impact sound insulation of CLT building that CLT panels are exposed. The heavy-weight floor impact sound insulation was Lr-65 which is showed high performance for timber building. However, the light-weight floor impact sound insulation was Lr-85 which is showed low performance. Moreover, the impedance and surface vibration characteristics are investigated. The driving point impedance level was approximately 100 dB, and the rise of impedance level by the restriction of the slab edge was not seen. On the other hand, at the joint of the CLT panel, the driving point impedance level greatly decreased. About these results, it can be expected to use in a prediction of the impact sound insulation.