Pullout Performance of Timber Joints with Glued-In Steel Rods at an Angle to the Grain

Glued-in rods in timber joints are efficient to transfer axial forces, and their pullout performances are not only related to the anchorage length, rod diameter, and glue-line thickness, but also to the angle of the rod to the grain—or the rod-to-grain angle. The limited available results on the effect of the rod-to-grain angle from literature are mostly based on the pullout tests with short anchorage lengths under the pull-compression loading, which do not correspond with the practical applications of glued-in rods. This paper explored the pullout performances of the glued-in rods with an anchorage length 10 times the rod diameter at 0° (parallel) to the grain under pull-pull loading pattern, and at 30°, 45°, 60°, and 90° (perpendicular) to the grain under pull-beam loading patterns, which are closer to practice than pull-compression loading pattern. The pullout capacity and slip modulus of timber joints with the glued-in rods parallel to the grain were greater than those at an angle to the grain. The empirical formulas were derived from the experimental results to predict the pullout capacities and slip moduli of the glued-in rods at an angle to the grain using the pullout capacity and slip modulus of the glued-in rods parallel to the grain.