Abstract
The problem of the durability of the concrete has been brought to the public attention by railway-related accidents. The laser ultrasonic method is expected as a method of non-destructive inspection for concrete. The laser ultrasonic method has an advantage that the sensors are no need to be contact with the specimen surface. The advantage enables the automated remote inspection. In this paper, we present results of an investigation of the relation between FFT analyzed results of the waveform measured by piezoelectric transducer and the depth of artificial defect. The results show that FFT analysis enables the waveform measured by piezoelectric transducer to be of practical use in application on non-destructive inspection of the deep-seated flaw.
