Non-Destructive Assessment of Rebar Corrosion Based on Equivalent Structural Parameters Using Peizo-Transducers

Occurrence of corrosion in rebars of reinforced concrete (RC) structures is a common problem faced by the ageing infrastructure across the world. This article presents a newly developed approach for detecting and quantifying corrosion of steel bars utilizing a piezoelectric ceramic (PZT) patch surfacebonded on the rebars employing equivalent structural parameters using the electro-mechanical impedance (EMI) technique. This technique utilizes the electromechanical coupling property of piezoelectric materials for a damage diagnosis. Through tests on three steel rebars, empherical relations are derived to relate the corrosion-induced mass and stiffness loss to the loss in the equivalent mass and stiffness identified by the PZT patch. The equivalent mass loss and stiffness loss correlate well with the actual mass loss and stiffness loss and, provide an alternative corrosion assessment paradigm suitable for diagnosing corrosion in steel rebars. The model-based corrosion assessment presented can be utilized for real-life steel structures.