Experimental Characterization of Timber Floors Strengthened by in-Plane Improvement Techniques

The rehabilitation of existing timber floors in seismic area should take into account the possibility to use both traditional and more modern materials and techniques. An extensive experimental program carried out at the University of Padova concerned full-scale wooden floors segments strengthened through the application of several solutions, belonging to the following three main categories: planks overlapping, diagonals, and nets. In detail, the following techniques were considered: single and double planking with an orientation of ±45° having different thicknesses; steel, CFRP, SRP or wooden diagonals; natural fibre (hemp) composites applied as nets with resin or vinyl glue; wooden nets applied with hardwood pins and screws. The study is aimed at characterizing the behaviour of strengthened floors for the selection of the most suitable solutions applicable in existing buildings, which are able to provide proper in-plane stiffness for seismic load distribution among bearing walls. The test set-up was designed and realized on purpose to simulate the in-plane shear behaviour of timber floors. The experimental results and the comparison between unreinforced and strengthened floors under monotonic shear load are presented in the paper.