Basalt fibre reinforced polymer rods for glued connections in low grade timber

Glued-in rods offer a wide range of applications such as connecting timber sections, as reinforcement and for restoration of timber structures. The research presented in this paper focuses on their use as connectors. The pull-out capacity of glued-in Basalt fibre reinforced polymer (BFRP) rods in indigenous Sitka spruce sections was investigated. Influence on pull-out capacity of the embedded length of the bar and the end distance were determined using a pull-bending hinged test method. This pull-bending method allowed the effects of bending forces to be taken in to consideration along with axial forces in a pull-out test. An experimental programme was conducted where pull-bending tests were carried out on specimens of 12 mm diameter BFRP bars with a 2 mm glueline thickness and embedded lengths between 80 mm and 600 mm glued-in to low-grade timber with an epoxy resin. Nine repetitions of each were tested. A clear increase in pull-out strength was observed with an increasing embedded length. The longest length had a pull-out capacity 213% greater than that of the shortest embedded length. In an effort to reduce instances of failure by splitting in the timber end distance was varied. It was found that increased end distance had minimal impact upon overall pull-out capacity and that premature failure after splitting was reduced significantly.