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.
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Anisotropic and Inhomogeneous Structures with Fast Synthetic Aperture Methods”, Proceedings of the
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pages, 2012.
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by Synthetic Aperture Focusing Technique”, Journal of Materials in Civil Engineering (JMCE), ASCE
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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
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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.