Advancements in Shear Resistance Prediction for Concrete Beams: A New Shear Model

The shear resistance of concrete beams has been a challenge. This study introduces an innovative shear model based on the critical crack model. By incorporating the concept of a local compression zone, the shear contribution from the upper edge of the concrete is effectively enhanced. An expression for the shear capacity of a concrete beam is derived by assuming an inclination angle for a critical crack. The optimal crack inclination angle is determined through an analysis of extreme values. To assess the reliability of the proposed methodology, the widely recognized ACI-DAfStb database was used. Comparative analyses were conducted between the calculation results obtained by the new model and those derived from the Strut-and-Tie model for deep beams and the truss model for slender beams. The positive results of these comparisons affirm the efficacy of the developed approach in enhancing the accuracy of shear behavior predictions in concrete beams.