Experiments were systematically carried out to give an insight into the behavior of reinforced beams, with particular reference to failure mechanisms. An experimental technique to measure dowel forces directly is developed, and experiments to investigate the important variables which affect the dowel strength are described. The analysis of results shows that in the case of beams which are reinforced against dowel failure, shear failures are accompanied by yielding of the main reinforcement. This reinforcement is unable to develop the full axial tensile force owing to the presence of the dowel shear force; this also explains the reduced neutral axis depth observed in shear failures. In beams without shear reinforcement, or in those with large stirrup spacing, failure is attributable to splitting at the level of the steel without yielding of the reinforcement.