Reinforcement of maritime pine cross-laminated timber panels by means of natural flax fibers

The present paper shows the first results of an ongoing research aimed at studying the potentiality of the combination of laminated timber and natural fibers to obtain high-performance structural elements. The experimentation conducted has involved a set of Cross Laminated Timber (CLT) panels made of maritime pine grown in Sardinia (Italy) and externally reinforced with natural flax fibers fabrics. A bending test program has been carried out on two CLT layouts, three-layers and five-layers panels, for a total of 34 specimens. Three-layers panels have been tested with single and double strip of flax fibers aiming to evaluate any difference in the rupture mechanism, capacity and stiffness. The proposed technique allows a straightforward application on the intrados of the panel, aimed at increasing its capacity and stiffness. Results show that in case of three-layers panels a significant increment of load-carrying capacity and stiffness has been achieved, whilst for five-layers panels the effectiveness of the reinforcement is negligible. Variations in the failure mechanisms of reinforced panels have been discussed.