Bonded-in GFRP rods for the repair of glued laminated timber

This paper describes an experimental test programme whereby the use of adhesively bonded-in glass fibre reinforced polymer (GFRP) rods were examined for the reinforcement and repair of artificially fractured glued laminated timber beams. The reinforcement technology was initially tested on control undamaged beams whereby it was seen that the geometrical arrangement of the groove influenced the mechanical performance of the beams. The mechanical behaviour of artificially fractured and fracture repaired beams was subsequently examined. By using practical percentages of reinforcement, strategically located at the soffit of fractured beams, it was seen that the stiffness of the beams can be satisfactorily restored to its original state. Furthermore, a significant increase in ultimate moment capacity can be achieved with the use of these materials. No premature bond failures were recorded while undertaking the testing. The paper also discusses the development of a 3-dimensional finite element model which incorporates anisotropic plasticity theory. The results from the model agree with the experimental testing by demonstrating the performance of the composite system can be enhanced by improving the geometry of the routed out grooves in which the reinforcement is placed. The model also predicted with good accuracy the stiffness of the beams as well as the nonlinear behaviour of the reinforced beams and is a useful tool for further optimisation of the repair system.