Effect of Non-uniform Corrosion on the mechanical properties of corroded steal bars

In order to accurately study the mechanical performance of corroded steel bars, chlorine salt drying-wetting cycles experiment for pre-cracked concrete specimens is carried on for 4 years. Based on notch depth measurement and tensile test, the non-uniform coefficient and the mechanical of corroded reinforcement from cracked concrete specimens have been researched. Following conclusions can be concluded: (1) Significant localized corrosion can be observed for reinforcement around cracked areas, slight uniform corrosion occurs for reinforcement in sound concrete; (2) The non-uniform coefficient increases with the increase of corrosion rate as the corrosion rate between 3% to 5%; (3) Based on the existing literature data, mathematical model for 16 mm diameter steel bars has been built to predict corroded rebar mechanical properties; (4) Researching the impact of the corrosion nonuniformity on the ductility of steel bar, it is indicated that the main reason which cause the plasticity reduced and the yield platform disappeared is the nonuniformity of corrosion. It leads to the tensile with eccentricity and produce the additional bending moment, thus making for the brittle fracture of corroded reinforcement.