Dual-Potential Capacity Model for Fiber-Reinforced Polymer-Reinforced Concrete Members Failed in Shear.

Fiber-reinforced polymer (FRP) reinforcements have been used in versatile forms in recent construction practices to enhance durability performance and, consequently, to attain longevity of concrete structures. The shear strength of FRP-reinforced concrete (FRP-RC) beams holds significant importance in structural design. However, inherent analytical uncertainty exists concerning shear in concrete members due to the distinctive material characteristics of FRP bars compared to conventional steel reinforcements, such as their low axial stiffness and bond properties. This study aims to identify the shear-resistance mechanisms developed under combined actions between concrete and FRP reinforcements. To this end, the dual-potential capacity model (DPCM) was extended to FRP-RC beam members subjected to shear and flexure, and an attempt was also made to derive a simplified method. To validate the proposed approaches, a total of 437 shear test results from RC members incorporating FRP bars were used. Findings indicate that the proposed methods can provide an acceptable level of analytical accuracy. In addition, a significant shift in the shear failure mode of FRP-RC members with no stirrups was observed from the compression zone to the cracked tension zone as the FRP reinforcement ratios increased. Conversely, when FRP stirrups were added, the shear failure mode was mostly dominated by the compression zone. [ABSTRACT FROM AUTHOR]