Optimization of Mechanical and Acoustic Performance of Timber Floors

In the paper, the results of an experimental study aimed at evaluating the mutual influence among the intervention techniques normally employed to improve separately the acoustic or the in-plane mechanical performance of timber floors are provided. The superimposition of planks having different thickness and arrangement or connections is usually considered to improve the in-plane stiffness of floors, especially in case of interventions on existing buildings in seismic zone, to take into account, if possible, also preservation criteria. On the other hand, the improvement of acoustic comfort is addressed to the use of specific noise-abating materials, like insulating fibre-boards or sheathings, whose contribution, in terms of mechanical stiffness/strength is often neglected. This work proposes a combined interpretation of the two abovementioned requirements, through the characterization of the main parameters governing the physical and mechanical phenomena. The first results obtained on simple mono-directional full-scale specimens of floors are presented; seven combinations among various solutions of boards and noise-abating materials are compared, first from a mechanical and subsequently acoustic point of view. The results allowed identifying the solution, which was able to optimize at best both the mechanical and acoustic requirements, to be proposed for the intervention on existing timber floors.