Analysis of Finger-Joints in Glass Fiber-Reinforced Polymer (GFRP) Composite Glued Laminated Timber Beams
The objective of this paper was to evaluate the effect of finger-joint reinforcement on the bending strength and stiffness of glulam beams made from high-density Eucalyptus spp. glued with resorcinol-formaldehyde adhesive. Six glulam beams were tested: three reinforced with glass fiber-reinforced polymer (GFRP) and three unreinforced for comparison. The GFRP was placed between the last two laminates and at the bottom edge of the glulam only in the finger-joint position. The stiffness and strength of glulam beams were evaluated using static bending tests, which showed that the use of GFRP reinforcement resulted in a gain of more than 100% in average ultimate bending moment and about 10% in average bending stiffness. To calculate the theoretical bending stiffness and normal stresses, a theoretical analysis of beam bending was performed using the transformed section method, which showed agreement with the experimental results.