Behavior of reinforced concrete haunched beams subjected to static shear loading

The final research results and interpretations of the testing of ten prototype simply supported reinforced concrete beams (eight haunched and two prismatic) designed to develop a shear failure under static loading are presented. Five beams (four haunched and one prismatic) were tested without shear reinforcement whereas the remaining five (four haunched and one prismatic) were tested with a shear reinforcement satisfying the minimum required for prismatic beams by the concrete norms of Mexico’s Federal District Code (MFDC). Test results show and confirm that haunched beams have a different behavior with respect to prismatic beams. Haunched beams favor an arching action in the haunched length as the main resisting failure mechanism. The study discusses both the deformation capacity and the shear strength mechanism of reinforced concrete haunched beams. Previous design equations proposed by other authors are reviewed, modified and upgraded taking into account the additional experimental evidence obtained in this research.