Abstract: When using nondestructive ultrasonic testing for concrete components testing is used, the amplitude is the most sensitive parameter to reflect the defects of the components. So the attenuation degree of amplitude can be the chief criterion of the components having defects when the testing process in nice coupling and consistent testing condition. In the course of ultrasonic testing, the velocity parameter is not sensitive for the little defects and the velocity will prominent descend when big defects, and the frequency parameter is also not sensitive for testing concrete defects. So using nondestructive ultrasonic testing for concrete components testing, the velocity and frequency parameter can only be the reference parameters. According to the contrast of the ultrasonic transit or non-transit crack, we can find that the ultrasonic figures have obvious difference and sometimes there will be big periods wave character when ultrasonic transit the crack. The veracity of the testing can be improved under the synthetically analysis of ultrasonic parameters’ change of ultrasonic kinematics and dynamics.

Key words: ultrasonic, nondestructive testing, concrete components, defects