Assessment of Residual Life of concrete structures affected by reinforcement corrosion

The corrosion process in reinforced concrete structures, exposed to marine or industrial environments, causes the appearance and growth of cracks. As a consequence, this produces a slow degradation of the material physical properties, steel fragilization and a decrease of the bond strength and steel reinforcements, cross section, affecting its static and dynamic behavior.In the second half of the twentieth century, the importance of constructions’ service life was noticed, so different techniques have been developed to predict the Residual Life of existing structures, in order to increase it. This situation has a significant economic impact on society.This paper presents a non-destructive technique to predict the Residual Life of reinforced concrete beams having different cracking levels, as results of steel reinforcement corrosion, considering the variation produced in the dynamic behavior, through the variation of the first natural vibration frequency.The reinforcement corrosion is an electrochemical process that can be quantified by measuring the intensity of the current on the concrete surface. In this paper, to simulate the corrosion process, a current is externally applied to the studied structure reinforcement and then crack widths and vibration natural frequencies are measured. Based on these measurements a mathematical model is proposed to predict structure remaining life.