The LAUS: First Applications of a New System for Ultrasonic Imaging of Very Concrete Structures
Conference: Publication Date: 27 August 2018Testing Method:
The LAUS (Large Aperture Ultrasonic System) has been developed to image very thick concrete structures, which are not accessible for commercial systems. The device and the corresponding software is the result of joint research of BAM, an ultrasonic instrument manufacturer and University of Kassel, Germany. It consists of 12 separate arrays of 32 point-contact shear wave transducers each, which can be deployed in flexible configurations. Each array is combined with battery and transmitter, receiver and wireless communication electronics.
Three case histories are presented. First the system was deployed on a 5-m thick heavily reinforced foundation slab. The reflection of the slab’s bottom was imaged clearly. In addition, a multiple reflection was registered, thus giving hope that even thicker elements might be imaged by the instrument. Second, the LAUS was used to investigate a massive bridge girder where a heavy rainstorm during concreting had led to imperfections that were visible after removing the formwork was removed. The LAUS could image tendon ducts in 1.8m depth and the backwall closely behind them. Some limited areas showed blurred reflections and were checked by drill holes; these areas were affected by diffuse damage which could be repaired by injections. Third, a large retaining wall was checked for thickness.
Meanwhile, the LAUS has been used in underground waste deposits (nuclear and other) for quality assurance of sealing plugs. A confirmed penetration depth of about 7 m has been reached.
- Schickert, M., and M. Krause. “Ultrasonic techniques for evaluation of reinforced concrete structures”. In: Ch. Maierhofer, H.-W. Reinhardt, G. Doman (eds.); Non-destructive evaluation of reinforced concrete structures, Woodhead Publishing Limited, Cambridge, Part II.22, pp. 490-530 (2010)
- Krause, M. “Localization of grouting faults in post tensioned concrete structures”. In: D. Breysse (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, Springer (2012) Chap. 6, pp. 263-304
- Wiggenhauser, H., und E. Niederleithinger. „Innovative Ultrasonic Techniques for Inspection and Monitoring of Large Concrete Structures“. Herausgegeben von V. L’Hostis und R. Gens. EPJ Web of Conferences 56 (2013): 04004. https://doi.org/10.1051/epjconf/20135604004.
- Wiggenhauser, H., A. Samokrutov, K. Mayer, M. Krause, S. Alekhin, und V. Elkin. „Large Aperture Ultrasonic System for Testing Thick Concrete Structures“. Journal of Infrastructure Systems, Juni 2016, B4016004. https://doi.org/10.1061/(ASCE)IS.1943-555X.0000314.
- Wiggenhauser, H., E. Niederleithinger, und B. Milmann. „Zerstörungsfreie Ultraschallprüfung dicker und hochbewehrter Betonbauteile“. Bautechnik 94, Nr. 10 (2017): 682– 88. https://doi.org/10.1002/bate.201700040.
- Wiggenhauser, H., M. Behrens, D. Moser, R. M. Moryson, S. Pudovikov and H.-G. Herrmann. „Nondestructive assessment of retaining wall of former coal mine plant: Zerstörungsfreie Prüfung der Stützmauer einer ehemaligen Kohlegrube“. Mauerwerk 22, Nr. 3 ( 2018): 175–86. https://doi.org/10.1002/dama.201700021.
- Moser, D., H. Wiggenhauser, H.-G. Herrmann, M. Behrens, and R. Moryson, S. Pudovikov. “ Nondestructive Evaluation of a retaining wall of former coal mine plant”. SME/NDT-CE 2018.
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