Ultrasonic wave propagation in deteriorated concrete structures was studied numerically and experimentally. Ultrasonic single-side access immersion pulse-echo and diffuse field measurements were performed in deteriorated concrete structures at 0.5 MHz center frequency. Numerically and experimentally it is shown that the undamaged layer thickness in a deteriorated concrete structure is measurable using pulse-echo measurements when the deterioration depth is larger than the wavelength. The signal overlapping, which occurs in the thin deteriorated layers, can be overcome using diffuse field measurements or a pattern matching technique. The ultrasonic experimental data were shown to be in good agreement with the widely used phenolphthalein test for concrete degradation.
Demcenko, A., Visser, R., & Akkerman, R. (2016). Ultrasonic measurements of undamaged concrete layer thickness in a deteriorated concrete structure. NDT & E international, 77, 63-72. https://doi.org/10.1016/j.ndteint.2015.09.005