抄録
A new nondestructive testing technique for delamination defects in concrete structures was developed based on the lock-in measurement of surface temperature under the application of periodical light heating. Experimental study was made on the applicability to the detection of artificial delamination defects in concrete blocks. Images of the distribution of temperature amplitude and phase delay were taken by the lock-in thermography, synchronized to the reference signal of the light dimmer operation. It was found that the location and size of the delamination defects can be estimated by the contrast change in the phase delay images. The depth of the defects can be estimated from the relationship between phase delay and heating period.
