Vibro-acoustic testing on impact sound performance of novel floating floor systems with polyurethane cushions

Abstract

Impact sound transmission in concrete slabs is a persistent challenge in building acoustics, particularly in residential and commercial environments. This study introduces a novel floating floor design utilizing polyurethane cushions of various 3D shapes and sizes to mitigate impact noise. The aim is to improve acoustic performance across a wide frequency spectrum while maintaining flexibility and practicality in installation. Two floating floor configurations — fully-filled and half-filled systems — were experimentally tested on twenty-two specimens under controlled laboratory conditions. Fully-filled systems achieved significant impact sound reductions of up to 6.8 dB, delivering consistent performance in mid to high frequencies and low frequencies when appropriately configured. In contrast, half-filled systems were effective at controlling low-frequency noise but demonstrated limitations at higher frequencies due to resonance sensitivity and variability in configurations. Parametric studies revealed that optimizing polyurethane cushion properties, such as elastic modulus and height, enhanced overall impact sound performance. Additionally, incorporating lightweight concrete layers significantly improved low-frequency insulation. Fully-filled systems consistently outperformed conventional methods, delivering comprehensive and reliable sound insulation. However, half-filled systems require further refinement for broader acoustic applications. This research highlights the critical role of cushion material properties, structural configurations, and multi-layer designs in effective impact sound control, providing a solid foundation for next-generation floating floor systems tailored to advanced acoustic insulation needs.