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Abstract: Review of Current Research on Nondestructive Testing Methods for Steel Corrosion in ConcreteReturn to previous page
By John S. Popovics, University of Illinois at Urbana-Champaign, US
The corrosion of steel reinforcing bars and tendons in concrete is a principal cause of the observed degradation in the built environment and represents an important contributing factor for estimating and prolonging structural service life. Methods that detect or somehow characterize corrosion processes without damaging the material (NDT) and minimizing disruption to service are therefore important tools in the effort to sustain the concrete infrastructure. NDT methods based on electrochemical measurements, such as corrosion potentials and currents, have long been used to monitor corrosion processes. More recently however other NDT methods, based on a wide range of phenomena, have been studied and applied to characterize corrosion in concrete. In this paper, a brief historical review of electrochemical monitoring methods is presented, followed by a review and evaluation of recent research developments. The evaluated methods are organized by phenomenological bases and type of measured data, distinguishing between methods where the corrosion process itself is measured and those that measure the secondary effects and environments associated with corrosion processes. Methods based on electromagnetics, electric/magnetic fields, mechanical waves, and optics are considered here, but traditional chemical sampling methods are not. The review reveals that emerging NDT methods provide new information about corroding reinforced concrete structures; however more research development is needed to establish the ability to reliably and accurately assess the state of past and current corrosion in reinforced concrete structures.
Dr. John S. Popovics holds B.S. and M.S. degrees (Drexel University 1988 and 1990, respectively) in civil engineering, and a Ph.D. (The Pennsylvania State University 1994) in engineering science and mechanics. He has been on the faculty of the department of Civil and Environmental Engineering at the University of Illinois since January 2002. He has also held the positions of Research Assistant Professor at Northwestern University, Assistant Professor at Drexel University, Guest Scientist at the German Federal Materials Research Institute (BAM-Berlin), Visiting Professor at the Polytechnic University of Valencia in Spain and Visiting Researcher, Laboratoire Centrale des Pont et Chaussées (LCPC) in France.
Dr. Popovics is a member of the Acoustical Society of America, the American Society of Civil Engineers, the American Academy of Mechanics, and he is a named Fellow of the American Concrete Institute and the American Society for Nondestructive Testing. He participates as a voting member in five technical committees and currently serves as chair in two committees in these societies. He serves as associate editor of the Journal of Nondestructive Testing. He is affiliated with the Center for Advanced Cement-Based Materials (ACBM). Dr. Popovics was the recipient of the National Science Foundation's CAREER award (1999), the American Society of Nondestructive Testing Fellowship Award 2012 and several teaching and advising awards from the University of Illinois.