An evaluation of strength performance of the edge connections between cross-laminated timber panels reinforced with glass fiber-reinforced plastic

The strength performance of edge connections between the cross-laminated timber (CLT) panels, as currently applied to CLT construction, was compared to that of connections reinforced with glass fiber-reinforced plastic (GFRP) by means of a tensile-type shearing test. In this study, the reinforced half-lapped connection is intended to prevent CLT from coming apart due to failure of self-tapping screws (STS) by bonding GFRP sheets to connections between CLT panels. The end-distance and edge-distance of this reinforced half-lapped connection were designed to equal 5D (where D is the fastener diameter) and 4D, respectively, which is shorter than the 6D recommended by European Technical Approval (ETA). Nevertheless, the yield strength was increased by 7%, and the stiffness by 92%, compared to the non-reinforced half-lapped connection. In addition, the internal spline connections using GFRP-reinforced plywood were 57 and 36% higher than the connection made up of LVB or plywood, respectively, and the energy dissipation percentages were 400 and 76%, respectively. These results indicate that the reinforcement effect of the connection by the GFRP was very significant. On the other hand, the half-lapped connection of the larch CLT improved the strength performance as the end-distance increased, and the end-distance had a greater effect on the strength performance than the edge-distance.