Study and monitoring of metallic reinforcement corrosion in concrete

Working Group

Tiziano Bellezze, Gabriella Roventi, Francesca Tittarelli, Giuliani Giampaolo, Annamaria Viceré, Alessandra Mobili, Chiara Giosuè, Alberto Belli
Corrosion of reinforcements in concrete structures is the main cause of their degradation as a result of their exposure in aggressive environments, such as urban and/or marine ones. Therefore, the activity of the research group in this field concerns with the study of the corrosion resistance of steel and galvanized steel reinforcements in concrete obtained with traditional cement binders and with innovative ones (“geopolymers”), which can contain suitable corrosion inhibitors. Experimental investigations are conducted by accelerated corrosion tests on laboratory specimens, which are initially cured under controlled temperature and humidity conditions and subsequently exposed to aggressive environments: immersion in chlorides-rich solutions and/or exposure in a carbonation chamber. Corrosion rate monitoring is carried out through electrochemical tests and validated at the end of each experimentation by visual observations of the rebars. Furthermore, the corrosion and/or passivation products present on the reinforcing bars are characterized in order to identify the causes of the observed corrosive phenomena and what are the optimal conditions of protection. For this purpose, the research group uses equipment such as the optical microscope, the scanning electron microscope and the RX diffractometer. Finally, to prevent the deterioration of the structures, sensors are studied and developed to monitor different parameters related to the corrosion of the reinforcing bars, such as corrosion potential, depth of carbonation or penetration of chlorides, the determination of the corrosion rate of the reinforcements and the measurement of resistivity of the tested matrices.