Research And Finite Element Analysis On Bond Behavior Of Main Reinforcement Considering Stirrup Corrosion And Continuous Load

Excellent bond performance between reinforced concrete is the premise of reinforced concrete structure to play a good mechanical performance.As the service life of the structure increases,due to the carbonation of concrete and chloride ion erosion,the reinforcement will rust.The corrosion of reinforcement will lead to the degradation of bond performance between reinforcement and concrete,which has a serious negative impact on the bearing capacity and durability of the structure.In practical engineering,the structure is often corroded under load.The coupling effect of load and corrosion has different influence on the bond performance from that of single factor.Based on the pull-out test,this paper studies the influence of stirrup corrosion,stirrup spacing and continuous load on the bond performance of reinforced concrete.At the same time,it compares and demonstrates with the finite element simulation analysis,the main research contents are as follows:(1)Based on the pull-out test of reinforced concrete specimens,the changing characteristics and rules of bond slip relationship of reinforced concrete under the coupling effect of stirrup corrosion rate,sustained load and stirrup spacing are studied.Based on the test data in this paper and the research results of previous scholars,the empirical formula of ultimate bond strength affected by multiple factors is proposed,the corresponding bond slip constitutive relation is established.(2)Based on the pull-out test in this paper,three-dimensional pull-out solid models were established by ABAQUS finite element software to analyze the influence of stirrup spacing,stirrup corrosion rate and sustained load on the bond slip performance.and the simulation results are compared with the test results.The stress distribution of longitudinal reinforcement,stirrup and concrete during pull-out test is obtained.(3)Based on the bond slip constitutive model obtained from pull-out test in this paper,the relevant test data of RC beams with stirrup corrosion in literature are introduced,and the influence of bond slip constitutive model considering stirrup corrosion and load coupling effect on the shear performance of RC beams is explored through ABAQUS finite element software,At the same time,considering the effect of longitudinal reinforcement corrosion,a more realistic finite element model of corroded beams is established.On this basis,the parameters of longitudinal reinforcement diameter and concrete strength are analyzed to explore the change of mechanical properties of RC beam after parameter transformation,so as to provide reference and guidance for engineering practice.