抄録
An effective non-destructive inspection is strongly desired for cracks and air-gaps in reinfoced conceretes in recent years. An ordinary inspection for reinforced concrete has often been done with an electromagnetic wave (radar). But, B-mode image of the received signals having been used, the detection of the abnormalities has not been successfully achieved. This is because the reflected wave from the reinforcing bars is quite larger than those from cracks and air-gaps and inspectors have tried to judge the abnormalities only by seeing the B-mode image.
The present paper provides an accurate and a reliable inspection method which detects the abnormalities in reinforced concrete using the signal propagation model that the author previouusly proposed. For applying the signal propagation model, the paper proposes a preprocessing method for the received signal to reduce the influence from reinforcing bars. Experimental results will show that, in addition to a reliable detection of crack, depth of the crack and the thicknesses of various media constituting the reinforced concrete structure are accurately measured.
