ULTRASONIC SIGNAL-PROCESSING TECHNIQUES FOR THE MEASUREMENT OF DAMAGE GROWTH IN STRUCTURAL-MATERIALS

In recent years, the ultrasonic signal-processing technique, which has been enormously successful in material testing, has found few applications in the analysis of concrete damage because of the heterogeneous nature of this material. In the present study, frequency-domain analysis of the ultrasonic signals, based on the Segmented Chirp Z-Transform, has been used to both detect and monitor the crack growth in structural materials. In comparison with the usual methods of pulse velocity or attenuation measurement, a very sensitive and accurate testing method was obtained. The experimental setup is described and the preliminary results, relating to uniaxial compression tests carried out on cubic concrete specimens and bricks, discussed.