Study On Mechanical Properties Of Corroded Reinforcement Under Cyclic Loading

Corrosion of steel reinforcement is one of the major contributing factors to the deterioration of concrete structure durability. Reinforcement corrosion results not only mechanical deterioration of reinforcement, but also deterioration of bond between the reinforcement and concrete, which reduces the contribution of reinforcement to the concrete structures, leading to poor performance and even collapses of concrete structures. Study of the mechanical properties and bond behaviors of corroded reinforcement embedded in concrete is critical for durability evaluation of concrete structure in service. In this paper, the deterioration of mechanical properties of corroded reinforced is studied, which is basis of existing research and corroded reinforced mechanical test. Main work and achievements are listed below:(1) All the reinforcement specimens were corroded by accelerative electrochemical corrosion process. Then the specimens were loaded, which researched the mechanical properties of corroded reinforced with the variation of the corrosion rate.(2)Studies show that with the increase of the rate of corrosion, the mechanical properties of corroded reinforced is approximately reduce by linear. But the corrosion rates relatively have larger impact on the elongation, which reduces exponentially.(3) On the basis of the analysis of the test results, the paper fitted formulas of the yield strength, ultimate strength, elongation, and modulus of elasticity as the change of corrosion rates. At last, the constitutive relation of corroded reinforced was established.(4) On the basis of the constitutive relation of corroded reinforced, the paper simulated a corroded reinforced concrete beam by the finite element software ANSYS, which researched the variation of bearing capacity and stiffness variation with the corrosion rates. Then, the finite element analysis results and existing test results were analyzed to verify the feasibility of corroded reinforced constitutive relation. Finally, the paper studied the variation of the load-carrying capacity of the beam stiffness with the corrosion rate.