Applicability study on accelerated corrosion methods of steel bars in concrete structure

Corrosion of steel rebar results in reduction of steel yield strength,change of steel mechanical characteristics and the behavior of the bond between concrete and steel rebar.The amount of corrosion of steel rebar affects the failure mode of reinforced concrete.To study the characteristics of corroded reinforced concrete structures,it is necessary to obtain corroded specimens in a short period of time.In this paper,four electrochemical accelerated corrosion methods for steel rebars in concrete structures were designed and examined experimentally to study their applicability.The experimental results show that the soaking method evenly corroded both horizontal and vertical surfaces of steel rebars.However,under natural corrosion process,the corrosion of surfaces of steel rebars is relatively uneven and pit corrosion is more obvious.Due to theses differences,it is not suitable to study the bond-slip constitutive relationship between corroded steel bars and concrete or the load carrying capacity of corroded reinforced concrete components obtained using soaking method.Half-soaking method and surface coating method with external current can simulate the natural corrosion process better.The theoretical corrosion mass of accelerated corrosion experiment is usually higher than the experimental corrosion mass.