EXPERIMENTAL INVESTIGATION OF CLT PANELS REINFORCED WITH GFRP BARS

When it comes to designing timber structures the limiting factors are usually stiffness properties of the engineered wood products. Stiffness requirements within the serviceability limit state (deformations and vibrations) are often the most relevant criterion for the design of timber elements subjected to bending. This paper shows an experimental study undertaken to investigate the effectiveness of glass fiber reinforced polymers (GFRP) as flexural reinforcement of cross laminated timber (CLT) panels. Five panels reinforced with GFRP bars and five unreinforced (control) panels were tested up to failure in a four-point bending configuration. Identical reinforcement arrangement in both tension and compression zones was considered in order to achieve the maximum increase in stiffness. The mechanical properties of reinforced panels are compared to those of unreinforced panels with regard to the load-deflection behaviour, failure mode, load-carrying capacity, deformability, bending stiffness values, as well as strain distribution along the panels’ depth. The experimental results demonstrated the beneficial effect of the proposed reinforcing solution in terms of strength, stiffness and ductility. No issues were evident regarding the integrity of the bond between CLT panels and GFRP bars.