Experimental investigation on the pull-out behaviour, including the withdrawal capacity, slip stiffness and interfacial shear stress, of axially loaded screwed-in threaded rod embedded in cross laminated timber (CLT) was conducted. Specimens with varying embedment length and different number of threaded rods were tested in this study. To prevent premature splitting failure of timber, some specimens were reinforced in the direction perpendicular to the timber grain with self-tapping screws. Test results showed that the screwed-in threaded rod connections exhibited good pull-out behaviour with high withdrawal capacity and slip stiffness. Within a certain range, the withdrawal capacity increases considerably with the increase of embedment length, while the average interfacial shear stress shows the opposite tendency. The self-tapping screws played an important role on reducing the splitting of the timber and improving the withdrawal capacity and slip stiffness of the screwed-in threaded rod. Additionally, for the specimens with self-tapping screw reinforcements, the improvement of withdrawal capacity and stiffness when increasing the number of threaded rods are much more obvious than that of the specimens without the self-tapping screws, due to the change of failure modes.

To evaluate the static and seismic behaviour of glulam beam-to-column connections with screwed-in threaded rods, nine specimens grouped in three were tested under both monotonic and reversed cyclic loads. The failure modes, moment resistance, initial rotation stiffness, ductility, and energy dissipation capacity of the developed connections were investigated. The results indicated that the developed beam-to-column connections showed superior structural performance. Furthermore, with the introduction of a steel bracket, the hybrid screwed-in threaded rod connection features larger stiffness, higher load-carrying capacity, remarkable ductility, and better energy dissipation capacity. The main failure modes included the yielding of steel brackets, as well as the yielding or rupture of the threaded rods, which indicated a ductile behaviour. The connection specimens with steel columns showed larger stiffness than those with glulam columns, which is reasonable for the bigger compressive deformation of glulam columns.