TY - JOUR A1 - Wiggenhauser, Herbert A1 - Köpp, Christian A1 - Timofeev, Juri A1 - Azari, H. T1 - Controlled creating of cracks in concrete for non-destructive testing N2 - The non-destructive assessment of cracks in concrete is a common task for which non-destructive evaluation solutions have been published. Primarily, these tests have been carried out on artificial cracks that have been created by using notches instead of natural cracks. This study evaluates a procedure designed to create reproducible and controlled cracks in concrete. The procedure is based on using expanding mortar in a series of blind holes. This is done in combination with carefully aligned reinforcement to guide the direction of the crack development. The depth of the crack is also controlled by reinforcement. Crack depth varies statistically in the range of the Maximum aggregate size (16 mm) used for concrete. KW - Non-destructive testing of concrete KW - Cracks KW - Reference specimen PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-457367 UR - https://rdcu.be/4IPN DO - https://doi.org/10.1007/s10921-018-0517-x SN - 0195-9298 SN - 1573-4862 VL - 37 IS - 3 SP - 67, 1 EP - 9 PB - Springer CY - New York AN - OPUS4-45736 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wiggenhauser, Herbert A1 - Stoppel, Markus A1 - Strangfeld, Christoph T1 - BETOSCAN - Parkdeck Multisensorik - selbst fahrendes Scannersystem für Betonflächendiagnosen N2 - BETOSCAN ist eine selbst fahrende und selbst navigierende Plattform für Sensoren und Messgeräte. KW - ZfP KW - Zerstörungsfreie Prüfung KW - Multisensorik KW - Korrosionsindikation KW - Sensoren KW - Messgeräte PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-387431 SP - 1 EP - 3 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-38743 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Terzioglu, T. A1 - Karthik, M. A1 - Hurlebaus, S. A1 - Hueste, M. A1 - Maack, Stefan A1 - Wöstmann, Jens A1 - Wiggenhauser, Herbert A1 - Krause, M. A1 - Miller, P. A1 - Olson, L. T1 - Nondestructive evaluation of grout defects in internal tendons of posttensioned girders N2 - Post-tensioning systems provide safe and efficient construction solutions for long span bridges. Despite the improved grouting practices over the past decade, existing post-tensioning systems may have significant amount of grout defects, which could lead to corrosion of the strands. Condition assessment of post-tensioning systems is necessary to allow bridge owners to take timely, proactive actions to mitigate or prevent further Deterioration and unanticipated tendon failures. A detailed experimental study conducted to assess the performance of nondestructive evaluation techniques in detecting grout defects within internal tendons is presented herein. Nondestructive evaluation techniques that include Ground Penetrating Radar, Impact Echo, Ultrasonic Tomography, and Ultrasonic Echo are evaluated in terms of detecting the location and severity of fabricated grout defects in a full-scale post-tensioned U-girder mock-up specimen. While Ground Penetrating Radar can identify the location and profile of the internal tendons, particularly metal ducts due to strong reflections, this method did not provide any information about the defect conditions within the tendon. Both Impact Echo and Ultrasonic Echo techniques are effective in identifying the Location of grout defects, but could not differentiate between water, void, or compromised grout conditions. The study clearly demonstrates the need for NDE techniques that are applicable to anchorage regions, and that are capable of estimating the severity and nature of grout defects in internal tendons. KW - Zerstörungsfreie Prüfung KW - Nondestructive testing KW - Ground penetrating radar KW - Impact Echo KW - Ultrasonic tomography KW - Ultrasonic echo KW - Bridge inspection PY - 2018 UR - https://www.sciencedirect.com/science/article/pii/S0963869517305996?via%3Dihub DO - https://doi.org/10.1016/j.ndteint.2018.05.013 SN - 0963-8695 VL - 99 SP - 23 EP - 35 PB - Elsevier Ltd. AN - OPUS4-45218 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - An Ultrasound Monitoring System For Concrete Structures T2 - Istanbul Bridge Conference CY - Istanbul, Türkei DA - 2014-08-11 PY - 2014 AN - OPUS4-32998 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - An Ultrasound Monitoring System For Concrete Structures T2 - The 6th Int. Conference on Structural Health Monitoring of Intelligent Infastructure CY - Hong Kong, China DA - 2013-12-09 PY - 2013 AN - OPUS4-32999 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - Nondestructive Testing in Civil Engineering T2 - Golden Jubilee celebration of SERC Recent Advances in Structural Engineering CY - Chennai, Indien DA - 2015-05-07 PY - 2015 AN - OPUS4-33174 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolf, Julia A1 - Mielentz, Frank A1 - Milmann, Boris A1 - Helmerich, Rosemarie A1 - Köpp, Christian A1 - Wiggenhauser, Herbert A1 - Kurz, J.H. A1 - Moryson, R.M. A1 - Samokrutov, A. A1 - Alekhin, S. G. A1 - Alver, Ninel A1 - Sazak, H.Ö. T1 - An ultrasound monitoring system for concrete structures N2 - The research project "Ultrasonic Net for Concrete Monitoring (UNeCOM)" aims at developing a methodology for an embedded ultrasonic network for the condition assessment of infrastructure constructions. Civil engineering structures made of concrete, which are located in tectonically active regions or undergo special loading conditions, may require continuous monitoring. It is important to assess the condition of the building and its stability to recognise and classify the effect of a seismic event or evolving damage at early stages before failure occurs. Embedded ultrasonic sensors offer the possibility to detect changes in the material and degradation mechanisms from inside the structure in areas which are difficult or impossible to inspect otherwise. In contrast to conventional ultrasonic testing methods, where the concrete surfaces are scanned with ultrasound probes, this new approach uses sensors, which are embedded into concrete, eliminating the effect of variable coupling conditions between sensors and concrete. This method allows an integral detection of changes in the concrete structure, for example due to seismic activities, to detect mechanical impacts, as well as degradation of the material due to overloading. Such methods have great relevance especially for the monitoring of constructions like power plants, bridges, offshore structures and other structures with high technical safety requirements. The sensor network can be controlled remotely through the internet which is also being used for data transfer. The embedded sensor network is designed to monitor structural damage and concrete degradation globally with high sensitivity. T2 - Istanbul bridge conference 2014 CY - Istanbul, Turkey DA - 11.08.2014 KW - Ultrasound KW - Concrete KW - Monitoring PY - 2014 SN - 978-605-64131-6-2 SP - Paper 32, 1 EP - 9 AN - OPUS4-32028 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lai Wai-Lok, Wallace A1 - Kind, Thomas A1 - Kruschwitz, Sabine A1 - Wöstmann, Jens A1 - Wiggenhauser, Herbert T1 - Spectral absorption of spatial and temporal ground penetrating radar signals by water in construction materials N2 - This paper studies the spatial and temporal spectral absorption of reflector signals of a 1.5 GHz ground penetrating radar (GPR) during a drying process of a brickwall from initial wet to later dry state. The non-stationary GPR signals were processed with short time-Fourier transform (STFT) and wavelet transform (WT) in a novel spatial-time–frequency (STF) domain. Spatial distribution of peak frequency at the direct wave (DW) across the antenna and a backwall reflection was studied to characterize the mechanism of spectral absorption of GPR wave. Results from WT were shown to be more preferred to those from STFT because the WT offers multiple resolutions to cope with both low and high frequency components in GPR wavelets but STFT does not. In addition to the traditional GPR signal interpretation in time-domain and our previous works on time–frequency domain, the analysis method operated in the STF domain provides another possibility of material characterization by GPR in large and field scale. KW - Ground penetrating radar (GPR) KW - Short time-Fourier transform (STFT) KW - Wavelet transform (WT) KW - Spatial and temporal spectral absorption KW - Construction materials KW - Dual-polarization PY - 2014 DO - https://doi.org/10.1016/j.ndteint.2014.06.009 SN - 0963-8695 VL - 67 SP - 55 EP - 63 PB - Butterworth-Heinemann CY - Oxford AN - OPUS4-31838 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd A1 - Eichler, Thorsten A1 - Millar, Steven A1 - Wiggenhauser, Herbert T1 - Laser induced breakdown spectroscopy (LIBS) - visualization of ion transport processes in concrete N2 - Laser induced breakdown spectroscopy (LIBS) is a combination of laser ablation and optical emission spectroscopy. Due to the possibility of direct measurements on the sample surface and a minimum of sample preparation investigations of building materials can be conducted quite fast. In combination with a scanning technique (translation stage or scanning mirrors head) the element distributions are evaluated with mm resolution. Thus the heterogeneity of the material may be considered. This is a significant advantage compared to standard procedures. LIBS measurements are also time and cost saving in comparison to standard methods. The automated measurement procedures minimize the liability for errors. All elements are detectable. Results can be quantified after calibration. At BAM LIBS has been successfully applied for the investigation of distribution and transport of different ions in building materials. Quantitative measurements are performed for chlorine, sodium, potassium, sulfur, lithium and hydrogen. In addition the identification of substances and the evaluation of quantitative ratios by means of an integrated marker are possible. An overview about the principle and the possibilities of LIBS investigations of building materials is presented and typical applications are shown. The LIBS technique is close to practical application on-site. T2 - SMT 2014 - NDE/NDT for highways and bridges - Structural materials technology CY - Washington, DC, USA DA - 25.08.2014 KW - LIBS KW - Concrete KW - Alkali-silica reaction (ASR) KW - Chlorine KW - Sodium KW - Sulfur PY - 2014 SN - 978-1-57117-342-3 SP - 364 EP - 371 AN - OPUS4-31724 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schulze, S. A1 - Krause, Martin A1 - Mayer, K. A1 - Redmer, Bernhard A1 - Wiggenhauser, Herbert T1 - Grouting defects localized by ultrasonic testing including phase evaluation N2 - 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. Düring 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 y-radiography. In the frame of practical application results of measuring the position and extend of a blockade within a posttensioned structure are presen ted. T2 - SMT 2014 - NDE/NDT for highways and bridges - Structural materials technology CY - Washington, DC, USA DA - 25.08.2014 KW - Ultraschallecho-Verfahren KW - Spannbeton KW - Phasenauswertung PY - 2014 SN - 978-1-57117-342-3 SP - 321 EP - 328 AN - OPUS4-32846 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -