In contrast to flexure strength, no world-wide accepted theory for determining the shear carrying capacity has been found. Therefore investigations on the shear strength of reinforced concrete elements is still present. At the beginning of this master thesis the knowledge of the shear behavior is summarized on the basis of a literature study. For this purpose, the different shear carrying mechanism and their relevant influencing parameters are explained. Due to the different structural behavior of members without and with shear reinforcement a division between these two groups is made. In the next section, the derivations of the main shear models are discussed. Since most shear models are based on the shear carrying capacity of one special mechanism, the shear theories can be classified in different categories. In chapter four a special focus lies on the development of the shear design in Austria. The different shear design methods of current and previous Austrian standards (Eurocode 2) are explained. The main part of this thesis forms the evaluation of the shear strength of selected national and international calculation models and design methods of different standards. For this purpose, comparative studies on shear databases, which were developed at the Institute for Structural Engineering at the University of Technology Vienna, were performed. Finally, the results of these analyses are summarized and interpreted in this master thesis.