Bond Performance Test And Finite Element Analysis Of Corroded Reinforced Concrete Structure

Reinforced concrete structure is one of the most commonly used structural forms in the infrastructure industry.RC structure not only has cost advantages,but also has high structural rigidity and good cooperative performance.For the RC structure,good bonding performance is the key "foundation" for the structure to function normally.However,in the long-term service period of the RC structure,due to the corrosion of various corrosion media,especially chloride ions,the steel bars in the structure are corroded,which leads to the degradation of the structural bonding performance and the reduction of the bearing capacity,which affects the durability and service life of the structure.Therefore,the research on the degradation of the bonding performance of the structure after the corrosion of the steel bar has practical significance and engineering value.At present,the research on the influence of corrosion on the bond slip of RC structures at home and abroad mainly adopts experiments and numerical simulation analysis.In recent years,with the rapid development of computers and finite element software,numerical simulation methods have been widely used.This article is based on existing related research,from the perspective of experiment and finite element analysis,mainly to study the change law of the bonding performance of RC structure after corrosion of steel bar.The main research contents are as follows:(1)High-strength reinforced concrete pull-out specimens with different corrosion rates were obtained by means of an external DC power supply to accelerate corrosion,and a central pull-out test was conducted to study the relationship between bond strength and bond slip at low corrosion rates.Further combining the previous test data and results,a relatively complete bond stress-slip constitutive relationship is obtained.(2)The finite element software was used to perform finite element numerical simulation on the drawing specimens with different corrosion rates,and the corresponding numerical simulation results of concrete and steel bar stress and bonding stress were compared with the test results to verify the correctness of the bonding slip finite element model.(3)The finite element software is used to numerically simulate the RC beam structure under different corrosion rates.It is divided into two cases according to whether the bond slip is considered,and it is compared with the existing test results toillustrate the RC structure analysis.Therefore,the necessity and rationality of considering bond slip in the analysis of corroded RC structure are studied.(4)Adopt the method of theoretical analysis to get a numerical analysis method of indirect simulation to modify the constitutive model of steel bar.This method includes the effect of bond-slip effect on the structure and quotes the relevant tests of the pier.The data was verified,and the comparative analysis of the simulation results verified the feasibility of this method.Further analysis of the influencing factors on the rust rate,rust area,etc,found that as the rust ratio and the rust area increases,the degradation of bond performance has a greater impact on the mechanical performance of the structure.