A high-strength ductile demountable shear connector for composite floors with precast hollow-core slab units

Abstract

A novel demountable steel yielding mechanism is proposed for use in steel concrete composite beams in conjunction with precast hollow core slab units. This is the first time in existing literature that an attempt is made to combine deconstructable systems with precast hollow core slab units. The proposed steel yielding mechanism has a unique shape which promotes a ductile force-slip behaviour and allows the facilitation of the deconstruction procedure since it is not fully embedded in the concrete slab. After deconstruction, the structural parts of the proposed demountable connection can be reused in a new building’s geometry with proper modifications. Twelve horizontal full scale push out tests were performed to investigate the physical behaviour of the novel demountable connection, to determine the force-slip curves and the failure modes. Theoretical models were developed to predict the strength of the proposed connection based on fundamental mechanics. A number of advanced non-linear numerical models were additionally developed to verify the experimental results using the Abaqus Standard software. The experimental results showed that the proposed connection had high shear resistance and very high slip capacity if properly designed. The deconstruction was implemented within the lab environment by disassembling, reusing structural components and retesting. The theoretical models based on fundamental mechanics and the FEM results can predict the strength obtained in the tests.