To provide a non-destructive inspection method of a concrete structure, capable of clearly detecting the difference with a healthy part with respect to flotation, a release position or the corrosion state of a metal body, such as a reinforcing rod or a steel frame.
After the metal body is heated, the surface temperature and surface temperature distribution of the concrete structure are measured at each definite time and the temperature distribution image before several minutes of the time becoming maximum in the surface temperature is extracted; while the temperature distribution image is scanned not only to detect the maximum value of the intensities of the image on respective scanning lines, but also to detect the difference between the image intensity and maximum image intensity at a predetermined position on each of the scanning lines, and the state of the concrete structure is detected on the basis of image intensity difference.
SHIGEMATSU BUNJI
OSHITA EIKICHI
OSHITA EIKICHI