Behaviour of embedded H-profile balcony-to-slab connection

Abstract

This paper investigates experimentally and numerically the behaviour of a balcony-to-slab connection made by an H-profile embedded in the concrete slab. A large-scale test was performed on a specimen of the connection system in order to determine the moment-bearing capacity, the deformation behaviour, the cracking patterns, the distribution of the bending moment along the axis of the embedded steel H-profile as well as the failure mode of the connection system. The test results showed that the failure mode was governed by the concrete shear of the slab. In addition, a 3D finite element model of the experimental test was also carried out and successfully validated against the experimental results. For a practical design of the connection system, a model based on Timoshenko beam on elastic foundation (BEF) was investigated and verified against the results obtained from the validated FE model. The Winkler modulus of the BEF model was determined by considering the local deformation of the concrete based on a strut-and-tie model. The results demonstrate that the BEF model with this value of the Winkler modulus provides a conservative estimation of the shear and bending forces applied to both the embedded H-profile and the concrete cross-sections. This method is a first tentative design basis using linear elastic theory for such a system.