Airborne Sound Insulation of Beam and Block Floors: Direct and Flanking Transmission

Abstract

Beam and block floors are commonly used as separating floors between dwellings. Measurements of the dynamic properties of these floors indicate that beam and block floors are highly orthotropic, and do not act as infinite plates in terms of their driving-point mobility. Transmission suite measurements of beam and block floors with or without a screed show that these floors do not achieve the same level of airborne sound insulation as a homogeneous isotropic concrete slab floor. Significant differences were found in the flanking transmission between masonry walls when coupled to a beam and block floor at a T-junction in comparison with homogeneous concrete slab floors. Vibration measurements indicate that at frequencies below 500Hz, flanking transmission along masonry flanking walls past beam and block floors is significantly higher than with homogeneous concrete slab floors of similar surface density.