Strategies to evaluate acoustic properties of timber hollow box floors

Abstract

The Norwegian project Woodsol aims at developing long span lightweight floors for timber buildings with increased spatial flexibility. One key element of the Woodsol system is the moment resisting frame consisting of pre-fabricated floor elements connected to continuous glulam columns. Each corner of the floor element is connected to the columns through steel connectors. The solution for floor elements is currently based on a hollow box with a resilient top floor. The construction systems shall fulfil the acoustic requirements for both commercial buildings, public buildings and apartments. The vibro-acoustic behavior and sound insulation properties shall be verified experimentally but standard building acoustic laboratory do not offer the required opening size of 8 to 10 m neither facilitate relevant flanking transmission setups. This paper presents the strategy we adopted to accomplish the task. To both assess sound transmission and estimate the flanking transmission, we planned and performed experimental investigations based on vibration measurements on a mockup. Methods within this strategy cover Experimental Modal Analyses, Integral Transform Method and Junction Transmission Measurements. The purpose and principles of the methods will be presented together with some preliminary results.