Application of new ultrasound and sound generation methods for testing concrete structures

Transient stress waves offer a powerful approach for non-destructive condition evaluation of concrete structures. However, currently used stress-wave-generating techniques are limited by poor controllability and/or penetrating ability. Stress wave generation must therefore be improved so that the application of existing and new ultrasonic and sonic non-destructive testing techniques to concrete structures will be more effective. This paper first summarizes the existing, traditional stress-wave-generating techniques for testing concrete structures. A method by which electromagnetic and piezoelectric-based sources are driven by AM burst signals is then introduced, fully detailed and shown to be appropriate for concrete tests in place of traditional sources. The performance of these sources is demonstrated through the results of impact-echo tests and spectral analysis of surface waves performed on a Portland cement concrete structure.