A rational and mechanics-based equation is proposed for the prediction of
shear strength of reinforced concrete beams without web reinforcement.
This prediction is based on basic shear transfer mechanisms, a modified
Bazant's size effect law, and numerous published experimental data,
including high-strength concrete beams with compressive strengths of concrete
up to 100 MPa (14,500 psi). Comparisons with experimental data
indicate that the proposed equation estimates properly the effects of primary
factors, such as concrete strength, longitudinal steel ratio, shear
span-to-depth ratio, and effective depth. It is shown that the proposed
equation is considered to be better than the other equations compared in
this study with respect to accuracy and estimation of primary factors. A
simplified design equation is also derived within the limited range of effective
depth for practical purposes.