Assessment of Corrosion in Rebars by Impressed Current Technique

Abstract

Steel reinforcement corrosion results in premature failure of reinforced concrete (RC) structures. Corrosion is known to adversely affect the structural integrity of buildings, bridges, and other structures made up of concrete. Cracking of concrete cover due to corrosion of steel rebar in concrete is an indicator showing the end of service life of the existing RC structures. Corrosion of steel rebar embedded in concrete is a relatively time-taking process. Thus, to monitor the structural health of RC specimens, methods to accelerate corrosion are applied. In this paper, firstly impressed current technique (ICT) and then the setup are described which has been used for acceleration of corrosion of steel reinforcement. Then, different parameters of ICT procedure based on Faraday’s law are presented. ICT was utilized at different applied currents to find out the induced corrosion current. The novel comparative study of corrosion of steel bars of 20 mm diameter embedded in concrete having M30 grade at the cover of 40 and 50 mm by ICT was performed. All reinforced concrete specimens were tested for different casted and cured periods of 7, 14 and 28 days. Based on research findings, increment in the amount of mass loss of steel is not in proportion to corrosion current as suggested by Faraday’s law. Also, some other related parameters were evaluated.