Research progress on short-term mechanical properties of FRP bars and FRP-reinforced concrete beams

Fiber reinforced polymer (FRP) bars have been increasingly recognized in the field of civil engineering due to their advantages of light weight, high strength and excellent durability. FRP bars can replace steel bars in concrete beams and effectively improve the durability of beams. In this paper, the literature relevant to the short-term mechanical properties of FRP bars and FRP-reinforced concrete beams was reviewed based on previous studies and practical engineering application. Firstly, the mechanical properties of FRP bars were reviewed. Different types of fibers or steel and fibers can be combined to obtain hybrid fiber reinforced polymer (HFRP) or steel-fiber composite bars (SFCB) with excellent mechanical performance, respectively. The bond performance and bond-slip model between FRP bars and concrete were discussed. Several common bond-slip models were usually used to study the bond performance between carbon fiber-reinforced polymer (CFRP) bars or glass fiber-reinforced polymer (GFRP) bars and concrete, but changing the type of FRP bars will lead to larger dispersion. Then, the experimental studies, theoretical calculation methods and finite element simulation methods of flexural/shear behavior of FRP-reinforced concrete beams were presented. Finally, their applications in practical engineering were discussed and the prospects of further research were proposed. It is pointed out that FRP-reinforced ultra-high performance concrete (UHPC) beams, FRP-reinforced geopolymer concrete (GPC) beams, engineered cementitious composites (ECC)-FRP-reinforced concrete beams, prestressed FRP-reinforced concrete beams and steel/FRP hybrid-reinforced concrete beams can effectively improve the deformation resistance and poor ductility of pure FRP-reinforced concrete beams.