The presence of aggregate in concrete causes considerable difficulty in performing ultrasonic measurements because of scattering of the sound waves. Conventional procedures mostly employ high-energy, low-frequency signals which are propagated from one side of the structure to the other. The usual purpose is to measure the sound velocity, from which the concrete quality can be inferred. This project aims to exploit recent progress in other research applications in order to attempt to extend both the capabilities and the convenience of ultrasonic testing of concrete. Topics being addressed include consistent and convenient transducer coupling, alternative modes of propagation such as surface waves, and signal processing to improve accuracy and sensitivity.
References
B N Pavlakovic, M J S Lowe, P Cawley, “The inspection of tendons in post-tensioned concrete using guided ultrasonic waves”, Insight, vol 41, pp. 446-452, 1999.
M D Beard, M J S Lowe, P Cawley, "Ultrasonic guided waves for the inspection of tendons and bolts",ASCE J. Mat. Civ. Eng., vol. 15, pp. 212-218, 2003.
N Ryden, M J S Lowe, "Guided wave propagation in three-layer pavement structures", J.Acoust. Soc. Am., vol. 116, pp. 2902-2913, 2004.
R Long, M J S Lowe, P Cawley, “Investigation into convenient coupling for ultrasonic transducers when inspecting concrete structures”, Review of Progress in Quantitative NDE, eds. D.O. Thompson and D.E. Chimenti, American Institute of Physics, New York, vol. 19, pp. 1677-1684, 2000.