Performance evaluation of accelerated corrosion techniques using electrochemical measurements and acoustic emission parameters

One of the major causes for deterioration of reinforced concrete (RC) structures is corrosion of steel reinforcement and subsequent cracking of concrete. The natural corrosion process is usually slow and takes a long time to initiate. Hence to enable corrosion and health monitoring of RC elements, the specimens are usually subjected to accelerated corrosion. This push for speed becomes a cause for problems such as difference in electrochemistry at the surface of steel rebar in concrete due to difference in various accelerated corrosion techniques as identified by some of the researchers in literature. The present experimental work investigates the effectiveness of three different accelerated corrosion techniques namely alternate drying - wetting process, admixed chloride diffusion method and impressed current technique based on electrochemical and acoustic emission measurements. From the research it was found that alternate drying - wetting process and impressed current technique are more suitable than admixed chloride diffusion method. Further, there was no prominenteffect of specific accelerated corrosion technique on AEmeasurements, indicating the suitability of this technique for structural health monitoring of RC structures under corrosion distress.