Examination of the effect of air gaps on impact sound insulation performance of dry-type double floor system

The dry-type double floor system is a floor finishing structure widely installed for apartments and offices in Japan. However, after installing the double floor system, it is found that the impact sound insulation performance using a heavy-weight impact source is usually reduced due to the resonance of the air layer between the floor panels and the concrete slab. To reduce this adverse effect, small air gaps are set between the floor panels and the surrounding walls. In this paper, an experimental study is conducted firstly. A small specimen including particle board, support legs and air gaps is made to examine the effect of air gaps experimentally. Then, the air gaps are built as a Maxwell model considering that the air gaps act as the orifice of air spring. The theoretical analysis is conducted to explain the mechanism of impact sound insulation of the double floor system with or without air gaps. Finally, a parametric study is conducted to investigate the effect of air gaps with different dimensions on the impact sound insulation performance of the double floor system.