Multiprobe chloride sensor for in situ monitoring of reinforced concrete structures

In situ monitoring of the chloride content is one of the most important procedures in preventing and controlling chloride-induced corrosion in reinforced concrete structures. Thus, the development of chloride sensors is of paramount importance for the continuous monitoring of concrete structures. The sensors must present long lifetime and reliability and operate in a wide range of chloride concentrations.The present work aims at developing and testing a sensor based on Ag/AgCl electrodes for in situ monitoring of chloride ions in reinforced concrete structures. Although these electrodes are widely used in analytical experiments due to their sensitivity to the chloride ion, little is known on their behaviour during exposure to alkaline environments, such as those existing in concrete.The multiprobe sensor presented in this work was tested in mortar and concrete specimens, revealing good stability. The results reveal that the Ag/AgCl sensor presents good sensitivity in a wide range of chloride concentrations.