Title: Kelvin Probe Array for Rapid Survey of Reinforced Concrete Corrosion
Author(s): Leonidas P. Emmenegger and Alberto A. Sagüés
Publication: Materials Journal
Appears on pages(s): 135-143
Keywords: contactless; corrosion; half-cell; Kelvin probe; potential mapping; reinforced concrete
Half-cell potential mapping is frequently used for the detection of corrosion in reinforced concrete. The procedure can be time-consuming and disruptive, partly due to the need for physical contact with the concrete surface. An alternative is presented in the form of a fast-responding, non-contacting electrode array that requires no surface pretreatment, and is suitable for mobile operation. This approach uses the vibrating Kelvin probe principle, with the electrode hovering over but not touching the concrete surface. Operation is demonstrated on an actual Florida bridge deck with a robust synchronized array as a model for lane-wide roadway scanning. The electrode-to-concrete (operating) surface gap can clear normal deck surface irregularities. Results replicated corrosion-identifying features from conventional half-cell electrode mapping without significant surface preparation or waiting for potential stabilization. The technology is promising for rapid corrosion assessment of bridges at low cost without extended lane closures.