Screw reinforcement on beam-to-column dowel-type connection

This study used self-tapping screws with partial threads on the point end to reinforce beam-to-column moment resisting connections. The mechanical properties of the timber-steel-timber connection were significantly improved compared to unreinforced connections. A preliminary calculation method is applied to predict the characteristic moment-resisting capacity of the unreinforced connection. The prediction is shown to be conservative. In the experiments, with a small gap in between, the two timber members in the connection started to bear on each other which shifted the centre of rotation of the connection and caused excessive tensile stresses perpendicular to the grain in the lower part of the connection. The location of the self-tapping screw regarding the design of the connections is addressed.