Fostering a cast-in-place steel–UHPFRC connector for ductile timber–concrete composite structures: parametric study of the shear behaviour and design considerations

Abstract

Timber–concrete composite (TCC) structures provide a breakthrough solution for multi-storey buildings. Besides the importance of the connection stiffness, recent research has focused on ductile connectors. This work aims at developing an economic new cast-in-place connector to guarantee the suitable stiffness and structural ductility. A new composite connector has been developed by combining an ultra-high performance fiber reinforced concrete (UHPFRC) shell with an embedded inner steel rod. The former governs the connection stiffness, while the latter governs the connection strength and ductility. To realize a cast-in-place construction method, firstly a wide experimental investigation on the connection shear behaviour with different geometry was carried out. Secondly, the results were analyzed using Winkler’s model, which allowed to define a simplified formula. Finally, a design example of the ductile connectors is presented with emphasis on the importance of a smart design of the connection system for avoiding a brittle structural failure.