Experimental and Numerical Studies of Novel Demountable Shear Connections

Sustainable composite structures for building construction are assembled using demountable structural elements and shear connectors that can be reused and fit into the circular economy. The current research and development project, in cooperation with Budapest University of Technology and Economics and KÉSZ Group, bim.GROUP Ltd, Hungary, aims to design a novel demountable steel-concrete composite slab system for buildings. Based on the international trends and the practice of the company, new structural details were developed using precast reinforced concrete panels, embedded bolts, and through bolts – as the demountable shear connectors – with steel assemblies and mortar filling to provide better tolerances. Enhancing the tolerances means decreasing the initial slip and the stiffness reduction of the composite beam, which is the critical phenomenon of demountable composite structures. A push-out experimental program was designed and completed to study the behaviour of the developed shear connections. During the push-out tests, it was observed that the novel shear connections have proper behaviour with sufficient stiffness, resistance, and ductility. In parallel with the tests, a numerical model is developed in the ATENA program to extend the experimental study, which is the basis of the further development of the connectors. The paper presents the developed structural details and the conclusions of the push-out experimental program, with the first results of the numerical analyses.