Influences Of Steel Bar Corroding On The Deforming Behaviors Of Concrete Bending And Column Members

Corrosion of reinforcement steel bar is recognized as one of the most important factors affecting durability of R.C. construction. Currently, research has mostly focused on compressive member's carrying capacity and little research is done on the stiffness of compressive member,especially of eccentric compressive column. A key project, "chlorine salt erosion environment of concrete durability design and evaluation basic theory research" (50538070) by the National Natural Science Foundation studied the pressure of corroded bending stiffness degradation bending members is expected to clear understanding of rust bent pressure component bending stiffness degradation rules. On this basis, establish rust bent pressure component bending stiffness calculation model for deteriorating, durability of concrete structure security analyses provide basis.The main works are as follows:1. Through the analysis of the corrosion bent pressure component bending stiffness of influencing factors, clear rebar corrosion caused by the rapping effect degeneration is bent pressure component rust bending stiffness of the key factors. On this basis, using analytic method to corrode the bending stiffness of pressure component deformation are analyzed in theory, and establishes the not rust and rust bent pressure component bending stiffness of calculation model.2. Design for 15 root different corrosion rate of different eccentricity concrete column components. Using the electrify rapid corrosion test, it established the corrosion component degree of rust estimation formulae. Through the loading experiment, we obtained the load test components - deflection curves. In this work, on the basis of component rebar corrosion degree of deformation performance was discussed in the paper. The results of the study indicate that when rebar corrosion rate less than 6%, reinforcement corrosion on bending stiffness of pressure component is affected very little, but when the corrosion rate more than 6%, reinforcement corrosion on bending stiffness of pressure component had significant effects.3. Based on the experimental study on institute established corrosion bent pressure component bending stiffness calculation model of the parameter inversion, we obtained the rust component stiffness computation model of the bonding degradation comprehensive influence coefficients. Through experimental results with the extensive verification of other studies, we confirmed the established hypothesis in this study corrosion that bent pressure component bending stiffness calculation model can better reflect the rust bent pressure components deformation property,4. Through the bonding degradation comprehensive effect coefficient variation analysis, when the corrosion rate is 0.04 to 0.12 and bonding degradation between changes in the comprehensive influence coefficients are roughly 1.3 to2.4, combined with the cover between changes in section rust bilge crack effectively size effect coefficient change, the results of this study in reference [28 t030] conclusions are basically the same.5. Using large commercial finite element program ANSYS, we consider corrosion caused by bonding performance degradation corrosion concrete bias component, a finite element model. Through the finite element calculation results and experimental results verified the contrast, this paper built finite element model of reliability. On this basis, through the change of corrosion rate, longitudinal reinforcement diameter, stirrup spacing related parameters on the bending stiffness of reinforced concrete bias component the sensitivity calculation and analysis.