Shear Capacity Evaluation of RC Beams with FRP Stirrups Based on Beam and Arch Actions

This study proposes a new evaluation method for shear capacity of RC beams with FRP stirrups based on beam and arch actions. The method introduces an integrated relationship between the applied shear force, the shear resistances and the stress conditions of concrete and stirrups within shear span, which enables systematic evaluation corresponding to several shear failure modes. In this paper, after introducing the concept of the new evaluation method, analytical programs regarding the beam and arch actions in RC beams with FRP stirrups are presented. Based on the results, theoretical and empirical equations are formulated for each component of the integrated relationship. The relationship is incorporated into an iteration process to determine shear capacity, defined as the shear force at which stress of either concrete or stirrups reaches the material strength. From comparisons to experimental and analytical results, the proposed method demonstrates improved accuracy to estimate the shear capacity of RC beams with FRP stirrups and provides capability to estimate the shear failure mode.