抄録
We have been trying to improve the floor impact sound insulation of heavy-weight impact source of half PCa rectangular void slabs by making voids in the slabs to lighten the weight of slabs in spite of increasing the thickness of the slabs. However due to the resonance phenomenon of the thin concrete plates of the upper and lower parts of the voids, the rise of sound pressure at 1000Hz was recognized especially in light impact sound level, and in order to control the rise, we have made many experiments using small models of void slabs. This time we produced four types' slabs of life size models including standard rectangular voids and made experiments to confirm the effect, installing the voids to the existing floor of the collective housing. The best result was recognized in the case that the improved voids were shocked on the bare concrete and vinyl sheet finishing by the light impact source, but we could not get clear differences in the case of sound proof floorings or dry processed double floor finishing.
