This paper deals with a field investigation of impact noise of floors generated by a tapping machine in a box-frame-type reinforced concrete apartment building. The structure has three floors and eighteen apratments as shown in figures 1 and 2.
The tapping machine was set in room number 3 of apartment number 304, which is on the third floor as shown in figure 2, and noise distribution to the entire apartment building and the apartments below the noise source (304) was investigated.
The flooring materials are reinforced concrete slab, plywood, and Japanese mat. The conclusions of this field investigation are summarized as follows :
In the source room, the impact sound level generated by the tapping machine on the plywood floor was higher by a few decibels than that generated on the other two floor materials, which showed similar levels.
Impact sound on the reinforced concrete slab floor and on the plywood floor is distributed to almost the whole area of the building but impact sound on the Japanese mat is distributed to a limited part of the building.
Impact noise on reinforced concrete slab floors contains more higher-frequency components than on the other two flooring materials.
Japanese mat was the best of the three floor material tested in terms of reduction of floor impact noise.
Impact noise on plywood floors and reinforced concrete slab floors may be reduced effectively by covering the floors with an elastic surface material such as carpeting.