Grouting Defects Localized by Ultrasonic Testing Including Phase Evaluation

Grouting defects, e.g. in post-tensioned structures or piped anchors may be identified by ultrasonic imaging. Since several years experiences are carried out with false color displayed phase values, which enable distinct localization of ungrouted regions. In this contribution we report on progress in localizing grouting defects in tendon ducts, when they are only partly grouted and the unfilled part is not orientated into the direction of the measuring surface. This is frequently the case e.g. for box girder structures. During the project specimens containing different types of grouting faults are investigated in order to optimize measuring and evaluation techniques. A handheld linear array system (commercially available) is applied for fast 2D-measurement and subsequent phase sensitive 3D-imaging (new software development). In a large concrete wall specimen tendon ducts and real prestressing systems containing grouting defects were built in. The ducts are partly covered by non prestressed reinforcement bars in order to investigate its disturbing influence. These included objects were investigated afterwards with the described methods. We report on large area measuring results, which were partly verified by -radiography. In the frame of practical application results of measuring the position and extend of a blockade within a posttensioned structure are presented.

1. Mayer, K., Chinta, P., Langenberg, K.-J. and M. Krause, “Ultrasonic Imaging of Defects in Known Anisotropic and Inhomogeneous Structures with Fast Synthetic Aperture Methods”, Proceedings of the 18th World Conference on Non-Destructive Testing, Durban, South Africa, 16.-20.04.2012, CD-ROM, 10 pages, 2012. 2. Schickert, M., Krause, M. and W. Müller, “Ultrasonic Imaging of Concrete Elements Using Reconstruction by Synthetic Aperture Focusing Technique”, Journal of Materials in Civil Engineering (JMCE), ASCE Vol. 15, pp. 235-246, 2003. 3. Mayer, K., Langenberg, K.-J., Krause, M., Milmann, B. and F. Mielentz, “Characterization of Reflector Types by Phase-Sensitive Ultrasonic Data Processing and Imaging”, Journal of Nondestructive Evaluation 1-3 27, pp. 35-45, 2008. 4. Krause, M. “Localization of grouting faults in post tensioned concrete structures”, In: Breysse, D. (ed.), Non-Destructive Assessment of Concrete Structures: Reliability and Limits of Single and Combined Techniques, State-of-the-Art Report of the RILEM Technical Committee 207-INR, Chap. 6, pp. 263-304, Springer, 2012. 5. Schickert, M. and M. Krause, “Ultrasonic techniques for evaluation of reinforced concrete structures”, In: Maierhofer, Ch., Reinhardt, H.-W. and G. Dobmann (eds.); Non-destructive evaluation of reinforced concrete structures, Woodhead Publishing Limited, Cambride, Part II.22, pp. 490-530, 2010. 6. Langenberg, K.-J., Brandfaß, M., Hannemann, R., Hofmann, C., Kaczorowski, T., Kostka, J., Marklein, R., Mayer, K. and A. Pitsch, “Inverse Scattering with Acoustic, Electromagnetic, and Elastic Waves as applied in Nondestructive Evaluation”, In: Wirgin, A. (ed.); Scalar and Vector Wavefield Inverse Problems, Springer-Verlag, Wien, 2000. 7. Langenberg, K.-J., Marklein, R. und K. Mayer, „Theorethische Grundlagen der zerstörungsfreien Materialprüfung mit Ultraschall“, Oldenbourg Wissenschaftsverlag GmbH 2009, Authorized translation: “Ultrasonic Non-destructive Testing of Materials, Theoretical Foundations” CRC Press, Taylor & Francis Group, Boca Raton, 2012. 8. Mayer, K.: “Software system InterSAFT for imaging evaluation of ultrasonic measurements”, by order of Bundesanstalt für Materialforschung und -prüfung BAM, Berlin, 2008. 9. Bishko, A.V., Samokrutov, A.A. and V.G. Shevaldykin, “Ultrasonic Echo-Pulse Tomography of Concrete Using Shear Wave Low-Frequency Phased Antenna Arrays”, 17th World Conf. on NDT, 25-28 Oct. 2008, Shanghai, China, 2008. 10. Mayer, K., Langenberg, K.-J., Krause, M., Milmann, B. and F. Mielentz, “Characterization of Reflector Types by Phase-Sensitive Ultrasonic Data Processing and Imaging”, Journal of Nondestructive Evaluation 1-3, 2008.
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