Materials and Structures

, Volume 38, Issue 9, pp 807–815 | Cite as

Progress in ultrasonic imaging of concrete

  • M. Schickert
Scientific Reports

Abstract

Among present non-destructive methods for concrete evaluation, ultrasonic testing uses relatively short wavelengths and therefore has particular potential for detailed assessment of concrete. Methods like SAFT (Synthetic Aperture Focusing Technique) and tomographic reconstruction are able to provide high-resolution images of concrete areas, which can be employed for tasks such as area imaging, duct localization, fault detection, and thickness measurement. This contribution is intended to give insight into some of the principles and possibilities of ultrasonic concrete imaging using SAFT and tomographic reconstruction. It thereby review progress that has been achieved at the author's institute during the last years. For SAFT reconstruction, the processing steps are explained that are necessary to obtain an image that is easy to interpret including the influence of transducers, their coupling, and image noise suppression. Quantitative evaluation of ultrasonic images enables the examination of tendon ducts for voids and the objective assessment of image quality. A field example demonstrates the possibilities of SAFT reconstruction. In a separate section, ultrasonic tomography is shown to have the capability to detect faults such as honeycombing in concrete pillars. Finally, the potential of ultrasonic imaging and remaining steps, necessary to open broad practical application are described.

Keywords

False Alarm Probability Tomographic Reconstruction Ultrasonic Imaging Concrete Element Deutsche Gesellschaft 

Résumé

Parmi les méthodes non destructives existantes pour le contrôle d'ouvrages en béton, les essais par ultrasons utilisent des longueurs d'onde relativement courtes et ont par conséquent un potentiel particulier pour une évaluation détaillée du béton. Des méthodes comme la méthode par synthèse d'ouverture, dite SAFT (Synthetic Aperture Focusing Technique), et, la reconstruction tomographique, sont capables de fournir des images due haute résolution de surfaces en béton. Ces images peuvent être utilisées pour des travaux tels, que l'imagerie de surface, localisation de conduits, détection de défauts et mesure de l'épaisseur. Cette contribution est destinée à donner un aperçu de quelques principes et possibilités de l'imagerie ultrasonique pour le béton au moyen de la méthode SAFT et de la reconstruction tomographique. L'article fait donc le point sur les progrès réalisés au cours de ces dernières années à l'institut de l'auteur. Pour la reconstruction par la méthode SAFT sont expliquées les différentes étapes nécessaires à l'obtention d'une image qui soit facile à interpréter, en incluant l'influence des transducteurs, leur couplage et la suppression du bruit de l'image Une évaluation quantitative des images ultrasoniques permet l'examen des conduits de tendons pour les cavités, et, l'évaluation objective de la qualité de l'image. Un exemple concrete montre les possibilités de reconstruction par la méthode SAFT. Dans use section séparée, la tomographie par ultrasons permet de pouvoir détecter les défauts, tels que les nids d'abeilles («honeycombing») dans des piliers de béton. Enfin, le potentiel de l'imagerie par ultrasons et les étapes restantes nécessaires à l'élargissement de son, application pratique sont décrits.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. [1]
    Krautkrämer, J. and Krautkrämer, H., ‘Ultrasonic Testing of Materials’ (Springer, New York, 1990).Google Scholar
  2. [2]
    Hillger, W. and Neisecke, J., ‘Quality control of mineral building materials by means of the novel ultrasonic pulse-echo technique’,Betonwerk+Fertigteil-Technik 59 (6) (1993) 82–89.Google Scholar
  3. [3]
    Kovalev, A.V., Kozlov, V.N., Samokrutov, A.A., Shevaldykin, V.G. and Yakovlev, N.N., ‘Puls-echo technique for concrete inspection. Interferences and spatial selection’,Defectoskopiya (2) (1990) 29–41 [in Russian].Google Scholar
  4. [4]
    Krause, M., Schickert, G., Wiggenhauser, H., Wilsch, G. and Wüstenberg, H., ‘Ultrasonic impulse-echo for non-destructive testing of concrete elements’, in ‘DGZfP-Jahrestagung, 1992’, Proceedings Fulda, April 1992 (Deutsche Gesellschaft für Zerstörungsfreie, Prüfung (DGZfP) Berlin, 1992) 214–221 [in German].Google Scholar
  5. [5]
    Schickert, M., ‘Towards SAFT-imaging in ultrasonic inspection of concrete’, in ‘Non-Destructive Testing in Civil Engineering (NDT-CE)’, Proceedings of an International Symposium, Berlin, Sept 1995 (Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP), Berlin, 1995) 411–418.Google Scholar
  6. [6]
    Schickert, M., Krause, M. and Müller, W., ‘Ultrasonic imaging of concrete elements using reconstruction by synthetic aperture focusing technique’,Journal of Materials in Civil Engineering 15 (3) (2003) 235–246.CrossRefGoogle Scholar
  7. [7]
    Schickert, M., ‘Ultrasonic tomography at concrete, elements’, in ‘DACH-Jahrestagung 2004’, Proceedings, Salzburg, May 2004 (Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP), Berlin, 2004) CD-ROM, 1–8 [in German].Google Scholar
  8. [8]
    Schickert, M., ‘Depth correction of noisy ultrasound images’, in ‘DGZfP-Jahrestagung 2003’, Proceedings, Mainz, May 2003, (Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP), Berlin, 2003), CD-ROM, 1–9 [in German].Google Scholar
  9. [9]
    Schickert, M., Schnapp, J.D., Kroggel, O. and Jansohn, R., ‘Ultrasonic testing of concrete: improved object recognition using stochastic methods’, in ‘DGZfP-Jahrestagung 2001’, Proceedings, Berlin, May 2001 (Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP), Berlin, 2001) CD-ROM,V44, w/o pagination [in German].Google Scholar
  10. [10]
    Jansohn, R., ‘Amplitude Statistics for the Assessment of Ultrasonic Echo Signals at Concrete’, Doctoral Thesis, Technical University Darmstadt, Germany (Shaker, Aachen, 2000) [in German].Google Scholar
  11. [11]
    Long, R., Lowe, M. and Cawley, P., ‘Investigation into convenient coupling for ultrasonic transducers when inspecting concrete structures’, in ‘Review of Progress in Quantitative NDE’, vol. 19 (American Institute of Physics, New York, 2000) 1677–1684.Google Scholar
  12. [12]
    Samokrutov, A.A., Kozlov, V.N. and Shevaldykin, V. G., ‘Ultrasonic defectoscopy of concrete by means of pulse-echo technique’, in ‘8th European Conference on Non-Destructive Testing (ECNDT)’, Proceedings, Barcelona, June 2002 (Spanish Society for NDT (AEND). (Madrid, 2002) CD-ROM, 1–9.Google Scholar
  13. [13]
    Kovalev, A., Rasmussen, J. and Shaw, P., ‘Ultrasonic testing of concrete structures’, in ‘8th European Conference on Non-Destructive Testing (ECNDT)’ Proceedings, Barcelona, June 2002 (Spanish Society for NDT (AEND), Madrid, 2002) CD-ROM, 1–7.Google Scholar
  14. [14]
    Krause, M., Mielentz, F., Milmann, B., Streicher, D. and Müller, W., ‘Ultrasonic imaging of concrete elements: state of the art using 2D synthetic aperture’, in ‘Non-Destructive Testing in Civil Engineering (NDT-CE)’, Proceedings of an International Symposium, Berlin, Sept. 2003 (Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP), Berlin, 2003) CD-ROM, 1–12.Google Scholar
  15. [15]
    Kozlov, V.N., Samokrutov, A.A. and Shevaldykin, V.G., ‘Thickness measurements and flaw detection in concrete using ultrasonic echo method’,Nondestr. Test. Eval. 13 (1997) 73–84.Google Scholar
  16. [16]
    Jansohn, R. and Schickert, M., ‘Objective interpretation of ultrasonic concrete images’, in ‘7th European Conference on Non-Destructive Testing (ECNDT)’, Proceedings, Copenhagen, May 1998 (7th ECNDT, Brøndby, 1998) vol. 1 808–815.Google Scholar
  17. [17]
    Schickert, M., ‘Progress in ultrasonic SAFT-imaging of concrete’, in ‘Non-Destructive Testing in Civil Engineering (NDT-CE)’, Proceedings of an International Symposium, Berlin, Sept. 2003 (Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP), Berlin, 2003) CD-ROM, 1–11.Google Scholar
  18. [18]
    Streicher, D., Schickert, M., Kroggel, O., Müller, W. and Krause, M., ‘Parameters for the quantitative assessment of ultrasonic imaging for concrete elements’, in ‘Non-Destructive Testing in Civil Engineering (NDT-CE)’, Proceedings of an International Symposium, Berlin, Sept. 2003 (Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP), Berlin, 2003) CD-ROM 1–11.Google Scholar
  19. [19]
    Kak, A.C. and Slaney, M., ‘Principles of Computerized Tomographic Imaging’ (IEEE Press, New York, 1988).MATHGoogle Scholar
  20. [20]
    Bühling, L., Schickert, M. and Tümmler, U., ‘Measurement notes’, December 2003 (unpublished).Google Scholar
  21. [21]
    Taffe, A., Gardei, A., Krause, M., Maierhofer, C. and Wiggenhauser, H., ‘Automation of non-destructive testing methods for civil engineering’,Materialprüfung 46 (7–8) (2004) 397–403 [in German].Google Scholar
  22. [22]
    Kohl, C., Krause, M., Maierhofer, C. and Wöstmann, J., ‘2D-and 3D-visualisation of NDT-data using data fusion technique’,Mater. Struct. 38 (283) (2005) 817–826.CrossRefGoogle Scholar

Copyright information

© RILEM 2005

Authors and Affiliations

  • M. Schickert
    • 1
  1. 1.Institute of Materials Testing (MFPA Weimar) at the Bauhaus-University WeimarGermany

Personalised recommendations