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Buildings 2018, 8(12), 176;

Concrete Defects Sizing by Means of Ultrasonic Velocity Maps

Department of Civil and Environmental Engineering and Architecture, University of Cagliari, 09123 Cagliari, Italy
Author to whom correspondence should be addressed.
Received: 7 November 2018 / Revised: 28 November 2018 / Accepted: 4 December 2018 / Published: 7 December 2018
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The paper illustrates the results of an experimental test which intends to check the efficacy of ultrasonic testing (UT) in detecting anomalies inside concrete elements. For this purpose, UT has been carried out on a small concrete wall having different defects deliberately settled inside the wall during casting. A grid of several measurements points has been arranged on the wall surfaces and for each point the ultrasonic signal has been acquired after passing through the thickness of the wall and the propagation velocity V has been extracted and analyzed. A graphic representation of V distribution has been implemented by a map where each pixel identifies one measurement point and is representative of its neighborhood. This map highlights areas with different velocity values, and allows to visually detect areas having particularly low velocity. The matching between the low-velocity areas and the artificial defects has been analyzed, and the level of accuracy of the V map in detecting and sizing the concrete inner defects has been discussed with reference to different spacing of the grid points. Finally, some considerations regarding the choice of the most suitable measurements grid have been addressed. View Full-Text
Keywords: non-destructive testing; ultrasonic testing; concrete structures; defect sizing; velocity map non-destructive testing; ultrasonic testing; concrete structures; defect sizing; velocity map

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This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

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Concu, G.; Trulli, N. Concrete Defects Sizing by Means of Ultrasonic Velocity Maps. Buildings 2018, 8, 176.

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