Scan of surface-opening cracks in reinforced concrete using transient elastic waves

This study develops a method to scan the surface cracks of reinforced concr ete using transient elastic wave tests. In the tests, an impact is applied at constant intervals along one side of the crack opening, and the surface response of the concrete due to each impact is measured and recorded. Then the procedure is repeated with the source applied on the opposite side. The method of ellipse intersection is adopted to process the surface response of the concrete structure. An image is then constructed that shows the thre e-dimensional image of the crack. The image can he used to determine the lo cation of the reinforcing steel bars, the thickness of the covering, and to judge whether the crack penetrates through the rebars. Numerical examples and a model tear, are presented to verify the effectiveness of this method. (C) 2001 Elsevier Science Ltd. All rights reserved.