A Study on the Crack Depth Measurements of Concrete by Tone-burst Flaw Detect Method

Recently, research on the non-destructive testing of concrete has been rapidly increasing in relation with the quality, reliability, durability, and uniformity of concrete used in architectural structures. In this paper, the most important problem is the attenuation phenomena on throughing the side of concrete by ultrasonic wave, and applied tone-burst to decrease the attenuation in minimum. As the result, the correlation between crack-depth and propagation-time, maximum-spectrum and out-amplitude, in-frequency and maximum-spectrum are found to be excellent. The coefficient of each are +0.975, +0.847, -0.718. The merit of tone-burst through this experiment is that the start of reception wave is very excellent