Repair of timber beams using epoxy resin

Abstract

Timber beams and elements are susceptible to attacks that negatively impact a structure's physical and aesthetical properties. In recent times, the repair of old timber structures has regained popularity. However, little literature is available to help understand the mechanical properties of the different types of available repairs. The most popular method among designers is reinforcing timber beam ends with steel plates. However, this method may not be the most efficient, especially from an aesthetic point of view. Therefore, this study aims to better understand resin reinforcing systems, particularly focusing on two repair methods and two resin materials. By making use of experimental testing, as well as analytical results, the mechanical properties of nine C24 timber beams were assessed. Three of the nine beams were kept unrepaired, while another three were repaired from the top using one resin material and the last three were repaired from the side using another technique. All the beams were repaired using GFRP rods. Experimental tests were also done on two different resin sample group; one group being TG6 samples, while the other being RSA samples, such that the mechanical properties of the two resin materials could be investigated, as well as the behaviour of the resin with GFRP rods on their own. The repaired timber beams and the reinforced resin samples significantly increased their flexural properties. However, the fracture mechanisms in the repaired beams were not different from the fracture mechanisms of the natural beams. The experimental results were also compared with the obtained theoretical results, where a significant increase could be observed in the experimental results of all the beam and resin groups. Thus, this research provides a better guideline for designers when undertaking such repair projects.