New Nondestructive Test Technique and Their Developing Trend in Concrete Beam Detection

Three kinds of new NDT techniques have been developed.In this paper the development and application of nondestructive test technique at home and abroad in concrete beam are presented .The first type of NDT methods are based on the mechanical principle of stress wave propagation,such as impactecho method,spectral analysis of surface wave method,acoustic emission technique and ultrasonic pulse method etc.The second type is the electromagnetic wave propagationbased NDT methods,taking ground penetrating radar as an example.The third type of NDT method makes use of radiography as the medium of detection,for instance,infrared thermography and computerized tomography etc.In terms of practical experience,these techniques play an important role in increasing the accuracy and speed of many NDT investigations.