Covering Thickness and Diameter Measurement of Reinforcing Bars by Eddy Current Testing Using Neural Network

Techniques for determining the covering thickness and diameter of reinforcing bars are needed in the evaluation of the existing strength of reinforced concrete structures. When eddy current testing is used with a relatively high test frequency, the covering thickness and diameter of the rebar can be determined simultaneously using relations between amplitude versus covering thickness and phase versus diameter. Neural networks were employed to estimate covering and diameter of rebar in this study. The phase waveform of the eddy signal generated by scanning the test coil along the surface of concrete was used for input data for the neural network.