Research On Flexural Performance Of SFCB Reinforced Concrete Beams Under Coupling Effect Of Load And Chloride Corrosion

The performance of reinforced concrete structures in harsh environments will deteriorate,resulting in reduced durability.By using Steel-FRP composite bars instead of common steel bars that are easily corroded,SCFB concrete beams with good durability are formed.This paper designs and manufactures SFCB concrete beams corroded by chloride corrosion and SFCB concrete beams coupled by the load and chloride corrosion.The research is carried out from the following aspects.The research results provide reference and basis for further research on the durability of SFCB concrete beams in the future(1)Through the effect of chloride corrosion and the coupling effect of load and chloride corrosion,the yield strength and ultimate tensile strength of the three kinds of SFCBs subjected to the tensile test are measured,and the yield strain and ultimate tensile strain are also calculated.the datum are fitted to expressions about erosion time and stress level.(2)Through the static bending test of the designed twenty chloride corrosion SFCB concrete beams and twenty-four SFCB concrete beams under the coupling effect of load and chloride corrosion,the effects of different erosion times and bending load levels on the SFCB concrete beams were studied Influence of bearing capacity,deflection and crack width.(3)Based on the material constitution,plane section assumption and test phenomenon,the failure mode of suitable reinforcement is analyzed specifically.Two equilibrium reinforcement ratios are given and the calculation formulas for the ultimate load of the SFCB concrete beam are derived;the calculation formulas for the deflection and maximum crack width of the SFCB reinforced concrete beam under short-term load are given;the curvature ductility coefficient is given;the theory The calculation results of the formula are compared with the experimental values to verify the rationality of the theoretical formula.(4)Based on the concrete strength degradation model,the SFCB concrete beam flexural capacity degradation model is given.The reliability analysis of the SFCB concrete beam is carried out using the JC method,and the reliability index is calculated,and the influence of different load effects on the curved beam is analyzed.(5)According to the deduced calculation formula of flexural bearing capacity,crack width and deflection of SFCB concrete beams,corresponding degradation models of SFCB concrete beams are given.the service life of SFCB concrete beams is 35 years under normal use limit state.The high load effect has a significant impact on the durability reliability index After a period of service,the reliability index of the SFCB concrete beam decreases faster.