engleski

Developing of the sensor for in situ monitoring of the corrosion inhibitor efficiency in concrete

Corrosion of reinforcing steel remains the most common durability problem leading to premature deterioration of reinforced concrete structures. The application of corrosion inhibitors, both as admixtures and as topical applications, is recognized as a mean of fighting reinforcement corrosion, but there is no way to accurately monitor the behaviour of the applied inhibitor on site and its effectiveness with respect to reinforcement that is not exposed to the inhibitor. Two cup-shaped sensors consisted of integrated reinforcement bars covered and conditioned with 2.5 cm of repair mortar and a counter/reference electrode. Topical silane with corrosion inhibitor was applied to the surface one of the sensor. Contact angle measurements were made prior to exposure in the salt and humidity cabinets for 1 month and impedance was measured regularly with the ReCorr QCQ instrument with customized software. Electrochemical impedance spectroscopy can explain and distinguish processes that take place at the phase boundaries and within concrete providing us with valuable information. The results show the difference of concrete barrier properties between the sensors with and without inhibitor and the state of reinforcement inside the repair mortar after being exposed to the different environment. This type of sensor can be built into the construction to act as a corrosion coupon on site and mimic the behaviour of the structure reinforcement. With this approach the efficiency and mode of action of the used corrosion inhibitor can be monitored.

corrosion ; concrete ; sensor ; in situ

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