APPROACHES FOR THE GENERATION OF STRESS WAVES IN CONCRETE

This paper reviews several existing, as well as potential, stress-wave -generating techniques for concrete. The generating techniques under s tudy include standard ultrasonic pulse generators, high-energy ultraso nic toneburst systems, and simple impact. In addition, the use of lase r sources and ultrasonic lithotripters are proposed. The novelty of th is review is that the methods are analyzed considering applications to existing concrete NDE methods. The strengths and weaknesses of each g eneration technique are discussed. Some of the methods are demonstrate d through laboratory tests on a variety of specimen types. A descripti on of each technique and conclusions concerning the appropriateness of each technique are also made.