Studies on the load-carrying behaviour of steel-to-concrete joints with headed studs for normal and shear loads

Steel and composite structures usually have interfaces to concrete walls or concrete foundations. The design and verification of the interaction between steel and concrete is challenging because the load-carrying behaviour as well as the different material properties have to be taken into account. Steel-to-concrete joints can be realised economically and with comparatively little effort by using fasteners such as headed studs for the anchorage in the concrete. Recent investigations have shown that a holistic verification of joints is possible, if the concrete failure mechanisms are integrated into the concept of the component method of steel and composite structures. This allows an economical verification that is competitive with pure concrete solutions because the load-carrying behaviour in the concrete is captured with the concrete components and the steel components of the joints do not have to be oversized to avoid failure in the concrete. The load-carrying capacity of the steel-to-concrete joints can effectively be improved by taking into account the reinforcement which allows for a significant increase of the resistance of the concrete components. By arranging the reinforcement in the area of the fasteners, it is possible to achieve a higher load-carrying capacity and, with a suitable design of the reinforcement, also a ductile behaviour of the joint. In the following article, joints are described that were studied in the dissertation (Ruopp, 2020) and were investigated with regard to the above-mentioned aspects. The article concludes with an outlook on the normative implementation.