The invention relates to the technical field of concrete detection, in particular to a concrete protective layer void detection method and
system based on a detachable piezoelectric
ceramic sensor and an electromechanical impedance
resonance technology. The detection method comprises the following steps: temporarily fixing a detachable piezoelectric
ceramic sensor on a detection point on the surface of a concrete structure; applying an alternating-current sweep-frequency
voltage to excite the piezoelectric
ceramic sensor, and obtaining an electromechanical impedance
signal frequency spectrum; the electromechanical impedance
signal frequency spectrum is analyzed, the frequency of a local defect
formant is obtained, and according to the frequency of the local defect
formant, geometric parameters of a void area are estimated through a
defect size and frequency relation model; and moving the sensor and repeatedly detecting other detection points. The detection method has high efficiency and flexibility, and detection can be realized in any environment; the single-point detection speed is high, the efficiency is high,
baseline data is not needed for detection, the anti-interference performance is high, and rapid positioning and quantitative evaluation of void damage can be achieved.