Design of RC-slabs without shear reinforcement is still under debate. This applies particularly to bridge decks, which are loaded by high concentrated forces (wheel loads). New design models, for example the one in Eurocode EC2-1, show a significant lower bearing capacity than former approaches. Thus, the structural safety of existing bridges often cannot be verified. Retrofitting, however, can hardly be done. In new constructions, shear reinforcement has to be arranged, which increases the building cost significantly. Therefore, more reliable design models for shear in members without stirrups are urgently needed. To get a better understanding of the shear behaviour of RC members, intense experimental and numerical investigations had been conducted.