Withdrawal strength of threaded steel rods glued with epoxy in wood

In this study, the axial strength of joints made with threaded steel rods glued in timber with epoxy is investigated. Although numerous experimental studies have investigated these joints made in glued laminated timber (glulam) from softwood, experimental data concerning tests on a whole range of hardwood species are still lacking. Thus, to evaluate the influence of timber characteristics on the behaviour of the joint, test results from different species are presented and discussed in this paper. The experimental results from samples using softwood as well as high-density hardwood glued laminated timber are compared. Diverse geometries of the joint are studied in both cases. From this experimental analysis, a formula to predict the strength of the glued-in bars is proposed. The prediction of the strength is made from two parameters that are easily quantifiable the density of the timber and the slenderness of the glued joint. This model shows a good accuracy with the test results of joints made on different species both from softwood and hardwood.