Pull‐out failure of headed studs close to the concrete edge

Abstract

Horizontally lying headed studs allow thin concrete slabs as a concrete flange. The shear capacity of studs close to the concrete edge is affected by splitting forces in the concrete. Due to the small edge distance of the headed studs to the concrete edge, a reduction in the capacity of the shear connection according to EN 1994-2 Annex C is required. Thereby additional geometric boundary conditions for the required length of the headed studs in the edge position are defined. In this way, a pull-out failure, which was observed in push-out tests, is prevented. These requirements for the minimum length of the headed studs can lead to comparatively long studs, which in practice are uneconomical or not feasible. Influences of load-carrying parameters such as the degree of reinforcement of the shear reinforcement or the concrete strength cannot be considered. On the basis of recent developments in the fastening technology, the possibility is created to neglect the geometric restrictions and to prove the actual tensile forces occurring in the studs. Based on new experimental and numerical investigations, in this paper the revision of these restrictions will be presented.