ABSTRACT

The present state of technology of an ultrasonic pulse echo method to study the structural geometry of concrete members is discussed. Separate transmitting and receiving transducers are used and the reflected signals are recorded by a synthetic aperture focusing technique. The reflected and scattered waves in the test specimen are analysed by means of specific recon- struction algorithms. A laser vibrometer is used as the ultrasonic sensor to be able to record and process a huge number of records. The application of this method for measuring the thick- ness of concrete and for analysing tendon ducts is discussed.

Table of contents |Fulltext|

1. Introduction
2. Synthetic aperture principle in bistatic configuration of transducers
3. Thickness measurement
4. Examination of tendon ducts
5. Summary and outlook
6. Acknowledgements
7. References

Author

Dr M Krause, Dr H Wiggenhauser
Federal Institute for Materials Research and Testing
Department Safety of Structures
Laboratory Non-Destructive Testing in Civil Engineering
12200 Berlin
Germany
The Paper was presented on the UTonline Application Workshop in May '97.
The Paper was first published in the Conference Proceedings of The British Institute of Non-Destructive Testing International Conference "NDT in Civil Engineering", 8-11 April 1997, The University of Liverpool, UK, published by The British Institute of Non-Destructive Testing, ISBN 0 903132 23 0, Volumes 1 and 2.