Non-destructive Corrosion Monitoring of Reinforced Concrete Steel Rebars in Chloride Media by Smartphone Magnetic and Analog Hall-Effect Sensors

The corrosion of reinforced concrete (RC) is a leading cause of structural failures and engineering problems in current infrastructural aspects; making corrosion monitoring of reinforcements in concrete structures highly important especially from safety point of view. Non-destructive testing (NDT) methods are useful approaches for in-situ detection and evaluation of steel corrosion in RC for monitoring time trend of corrosion of rebars. Recently, some NDT methods such as magnetic and resistive sensors as well as electrochemical monitoring methods such as electrochemical impedance spectroscopy were develop for RC rebar corrosion monitoring. This paper presents a novel approach using modern smartphones equipped with magnetic sensors and commercially available analog Hall-Effect sensors to monitor rebar corrosion within the concrete. Results showed a reasonable sensitivity of the methods to detect and monitor corrosion of rebars with time. In order to check and validate the data obtained in this study, another non-destructive electromagnetic test by a search coil connected to a LCR meter was used to monitor corrosion. The results obtained with this method were consistent with the previous methods. In other words, by using these three methods, it is possible to successfully monitor and determine the severity of corrosion.