Effects of corrosion on linear and nonlinear elastic properties of reinforced concrete

Cracks induced by rebar corrosion are among the most important causes of performance deterioration in reinforced concrete elements. Even though several methods have been developed to detect the amount and location of corrosion-induced cracks, the sensitivity to small closed cracks located well below the concrete surface is still an issue to be faced. In this paper, we show the high sensitivity of nonlinear ultrasonic measurements performed using the Scaling Subtraction Method to point out that, under certain conditions, nonlinear indicators might prove to be very efficient and suitable to identify small variations in the element microstructure, such as those due to corrosion crack initiation.