Evaluation of FRP-Reinforced Concrete Members without Shear Reinforcement: Analysis Using Shear Crack Propagation Theory

Determination of the maximum shear capacity of reinforced concrete (RC) beams and slabs has been a challenging task for over 100 years. Recently, the shear crack propagation theory (SCPT) was developed as a unified mechanics-based solution to determine the ultimate capacity and to explain the phenomenon of one-way shear in RC members without shear reinforcement. The proposed theory is not limited to steel-RC members and can be applied to members with nonmetallic reinforcement accounting for their material parameters and constitutive relationships. Further, the SCPT does not focus only on the ultimate state but also on the behavior during the entire loading process up to failure. In this paper, the application of the SCPT is extended to RC members with longitudinal fiber-reinforced polymer (FRP) reinforcement without stirrups for the first time. A parametric study is first presented to explore the effect of FRP bar properties on shear behavior and shear transfer mechanisms in RC beams. Subsequently, the experimental results of 44 beam tests reported in the literature are used for validation. The results showed that the SCPT provided accurate estimates of the shear strength of FRP-RC beams that compared favorably with those from current design codes.