The development of a method for crack-depth estimation in concrete by the electric response parameters to pulse mechanical excitation

A method is proposed for contactless testing of cracks in concrete by the electric response parameters to pulse mechanical excitation. Theoretical research is conducted on the electric response to pulsed elastic impact of the material with piezoelectric quartz inclusions. Numerical results are confirmed by experimental research on concrete samples. It is shown that the presence and growth of a crack in concrete lead to a change in measured electrical signal frequency response. Increase in crack depth leads to a shift of dominant spectral peaks to the lower-frequency region and decreases the cross-correlation coefficient between spectra from the sample containing defects and a solid sample. (paper)