A state-of-the-art review: Shear performance of the concrete beams reinforced with FRP bars

FRP-reinforced concrete widely used in engineering with excellent salt resistance is a potential alternative to steel-reinforced concrete in harsh environments. This paper reviews a comprehensive overview of the shear performance of the concrete beams reinforced with FRP bars on shear failure characteristics, factors affecting the shear capacity, calculation of shear capacity, shear durability, fire resistance, and future research needs. The results indicated that the low elastic modulus and the reduction of mechanical properties in the bending portion of the FRP stirrups make it difficult to limit the cracking of the concrete, resulting in an insufficient shear performance and a significant size effect of the beam. Fibers can effectively improve the post-cracking shear performance of the different types of concrete. Also, replacing FRP stirrups with FRP strips and FRP grids is a potentially feasible method to improve the mechanical properties of FRP stirrups at the bending portion. Moreover, the use of ECC, FRP grid, and TRC to strengthen and skin the bottom and sides of the beam and the application of prestressing are potential ways to reduce the size effect and improve the shear capacity. Furthermore, artificial intelligence technology and self-learning are recommended to be carried out while continuously replenishing the database dynamically to provide data support for the study of the shear resistance of concrete members reinforced with FRP bars. Finally, the quantitative relationship between material degra-dation and component mechanical performance degradation needs further research.

Automated summary

This paper provides a comprehensive review of the shear performance of FRP-reinforced concrete beams, including shear failure characteristics, factors influencing shear capacity, calculation of shear capacity, shear durability, fire resistance, and future research needs. It is found that the low elastic modulus and the reduction of mechanical properties in the bending portion of FRP stirrups hinder the cracking control of concrete and result in insufficient shear performance and a significant size effect. Fibers can effectively enhance the post-cracking shear performance of different types of concrete. Replacement of FRP stirrups with FRP strips and grids offers a potential solution to improve the mechanical properties at the bending portion. Moreover, the use of ECC, FRP grid, and TRC for strengthening and skinning the beam, as well as prestressing, are potential methods to reduce the size effect and enhance shear capacity. Additionally, the application of artificial intelligence and continuous replenishment of a dynamic database are recommended to provide data support for the study of shear resistance of FRP-reinforced concrete members. Further research is needed to investigate the quantitative relationship between material degradation and component mechanical performance degradation.