Behavior of Large-Scale Reinforced Concrete Beams with Minimum Shear Reinforcement

Research has indicated that as the depth of a beam increases, a decrease in the shear strength of the section can be expected. This trend has often been termed a size effect. Testing of specimens unreinforced in shear has also demonstrated that it is possible for the shear strength to fall below that commonly assumed in design. Most sections, however, contain at least minimum transverse reinforcement as required by the building code. Therefore, it is important to understand the behavior of these structures as they may also be affected by a size effect. Two duplicate large-scale beams containing minimum shear reinforcement were tested. The tests were conducted to investigate the effect of size on the shear strength provided by the concrete as well the shear strength provided by the transverse reinforcement. The specimens were subjected to constant shear, and the test results were analyzed. Based on these analyses, conclusions and concerns regarding the shear strength of transversely reinforced sections are presented.