Analysis Of Mechanical Performance Degradation Of Corroded Reinforced Concrete Columns

Concrete structures is most used in China’s current civil structure form,but due to environmental medium corrosion,serious impact on the durability of concrete. Atmospheric corrosion medium in the natural environment erode the concrete,cause carbonization of concrete,steel bar corrosion,serious situation will appear off steel rust, concrete expansion crack and spalling damage of soil degradation.These become the main phenomenon to reflect impact on the durability of concrete structure in general environment.Close to the surface of concrete reinforcement,stirrup is easier to contact corrosion environment than longitudinal reinforcement,stirrup corrosion caused by its own section decrease and mechanical performance degradation,and the corrosive also cause coating degradation and even crack,failure of the protective layer weakens the protection of the internal reinforcement,longitudinal reinforcement corrosion is more obvious,then leading to reduce the constraint function of longitudinal reinforcement and the core concrete,weaken the bearing capacity of the structure.In this paper,based on the existing experimental study,through the method of combining theoretical analysis and numerical simulation,studied the mechanical performance degradation rule of corroded reinforced concrete columns,put forward the theory formula and relevant conclusion of structure bearing capacity degeneration caused by reinforcement corrosion,provide certain theoretical reference for remaining bearing capacity evaluation and maintenance of corroded structures.This paper through the theoretical analysis of the degradation rule of corroded reinforced mechanical properties and the influence of the bearing capacity of corroded reinforced concrete column components, using appropriate corroded reinforced concrete constitutive model, the constitutive model, the steel and concrete bonding- slip constitutive model,established the ABAQUS finite element analysis of corroded reinforced concrete columncalculating model, studies the law of different mechanical properties of concrete column rebar corrosion rate of degradation. Sorting and analyzing,finite element analysis results show that:the greater the degree of reinforcement corrosion,the greater decrease of the peak stress of the peak stress and peak strain,from each group stress strain curve contrast figure show that:the greater steel corrosion ratio,the corresponding stress value of the same strain state decline(that is, the most section of the stress-strain curve down),And after the peak stress,the decline period is increasingly steep.Based on the relevant test,select appropriate constitutive model for finite element modeling,contrast test results, verify the rationality and accuracy of the simulation,the variation rule of the mechanical properties of the specimen is analyzed.put forward the formula of ultimate bearing capacity degradation under the condition of axial compression of corroded stirrups concrete column,Then further put forward the formula of the formula of ultimate bearing capacity degradation under axial compression or eccentric compression state of corroded reinforced concrete column.Under the same conditions, change of stirrup spacing and thickness of the protective layer, analysis the mechanical properties change rule of component under axial compression and eccentric compression state.