Shearing Properties Of FRP Bars-Basalt Fiber Reinforced Concrete Beams

With the extensive application of concrete structure in civil engineering,the problem that the durability of traditional reinforced concrete structures declines in use process has become increasingly prominent.Compared with the steel bar,fiber reinforced polymer bar(FRP)has the advantages of light weight,high strength,strong corrosion resistance,good fatigue resistance and others.It has a broad application prospect in civil engineering that to use FRP bar substitute steel bar,which can fundamentally solve the problem of steel corrosion.Due to the poor plastic deformation capacity and the low elastic modulus,FRP reinforced concrete structure compared to the reinforced concrete structure has significant differences on the mechanical performance aspect.And the shear failure has obvious brittle failure characteristics,which are small ductility and not obvious omen.Therefore,it is very important to improve the shear behavior of FRP reinforced concrete structure.Fiber reinforced concrete has excellent mechanical properties.Fiber can improve the effect of crack resistance and toughness,thus to enhance the ductility of concrete structure.It has great research value and practical engineering significance that using fiber to improve the mechanical properties of FRP reinforced concrete structure and to study the shear strength of FRP barsfiber reinforced concrete structure.In this paper,the mechanical properties of basalt fiber reinforced concrete with different water cement ratios(0.51,0.45,0.39)and different fiber volume content(0%,0.1%,0.2%,0.3%)were tested.Through the experiments of cube compressive strength,prism compressive strength and cube splitting tensile strength with 12 groups of basalt fiber reinforced concrete,to analyze the influence of basalt fiber on the mechanical properties of concrete and fit the concrete compression constitutive equation according to the stress-strain test curve.According to the obtained test results,ABAQUS is used to simulate the reinforced concrete beams,FRP bars-ordinary concrete beams and FRP bars-fiber reinforced concrete beams under concentrated load.By fiber volume ratio,longitudinal reinforcement ratio,stirrup ratio and shear span ratio as variables to analyze the variation of ultimate load and the corresponding deflection of beams.The truss-arch model is used to establish the theoretical calculation formula of shear capacity of FRP bars-fiber reinforced concrete beams.Then according to the comparison between the calculated value and the simulated value,the results provide some reference and theoretical guidance for the practical engineering design of FRP bars-fiber reinforced concrete beams.