Influence of beam size, longitudinal reinforcement, and stirrup effectiveness on concrete shear strength

Research has shown that the current ACI shear design provisions provide unconservative results for large beams and beams with low levels of longitudinal reinforcement. Furthermore, recent research has indicated that some assumptions made in the current design provisions for shear reinforcement may further reduce the level of conservatism. To further explore these deficiencies, this study investigated the influence of beam size and longitudinal reinforcement ratio on the shear strength attributed to the concrete, as well as the effectiveness of stirrups in transferring shear across a diagonal crack. The experimental portion of this study tested six rectangular reinforced concrete beams. Other research data found in the literature were used to supplement the experimental data. Based on test results and a data analysis, conclusions regarding the influence of beam size, longitudinal reinforcement, and transverse reinforcement on shear strength are presented herein.