Mechanical Behaviour Investigation for the Timber-UHPC Shear Connector in 3D Printed Concrete Based Composite Beam

3D concrete printing technology has emerged as an innovative solution for various construction projects, including homes, architectural features, and construction projects from wells to walls. This study proposes a novel 3D printed concrete (3DPC)-Timber composite beam that does not rely on reinforcement. The connection between the 3DPC slab and timber is achieved using a notch shear connector filled with Ultra-High-Performance Concrete (UHPC). To investigate the shear behavior of the UHPC-timber connections in 3D-printed concrete-based composite structures, notch shear connectors with different number of screws (the notch connection without screw, one screw embedded into the notch connection and two screw embedded into the notch connection) are investigated and analysed through using push-out tests. The experimental results showed that the screw has a significant impact on load-carrying capacity, shear stiffness and ductility. The rectangular notch combined to two screws exhibits highest shear capacity, shear stiffness and ductility.