TY - CONF A1 - Wiggenhauser, Herbert T1 - Validation process T2 - Transportation Research Board (TRB) 87th Annual Meeting, Commitee AFF40 CY - Washington, D.C., USA DA - 2008-01-13 PY - 2008 AN - OPUS4-16596 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - Imaging ultrasound on concrete T2 - Transportation Research Board (TRB) 87th Annual Meeting, Commitee AFF40 CY - Washington, D.C., USA DA - 2008-01-13 PY - 2008 AN - OPUS4-16597 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - Horstwalde center for validation, training and research in NDT in civil engineering T2 - Transportation Research Board (TRB) 87th Annual Meeting, Commitee AFF40(1) CY - Washington, D.C., USA DA - 2008-01-13 PY - 2008 AN - OPUS4-16598 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - NDT and its application in civil engineering T2 - CBRI Seminar CY - Roorkee, India DA - 2007-02-07 PY - 2007 AN - OPUS4-16553 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - NDT in civil engineering T2 - CBRI Seminar CY - Roorkee, India DA - 2007-02-02 PY - 2007 AN - OPUS4-16554 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - Bridge testing using combined NDT methods T2 - IGCAR CY - Kalpakkam, India DA - 2007-02-23 PY - 2007 AN - OPUS4-16555 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - NDT activities of HW Reinhardt - a short summary T2 - ACM-Tagung (Ehrenkolloqium) zu Ehren Herrn Reinhardt an der Universität Stuttgart CY - Stuttgart, Germany DA - 2007-07-23 PY - 2007 AN - OPUS4-16556 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - Automated NDE of post-tensioned concrete bridges T2 - LTBP Workshop an der EMPA CY - Zurich, Switzerland DA - 2007-09-11 PY - 2007 AN - OPUS4-16557 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - Automated NDE of post-tensioned concrete bridges T2 - Seminar University Chengdu CY - Chengdu, China DA - 2007-09-17 PY - 2007 AN - OPUS4-16558 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - Automated NDE of post-tensioned concrete bridges T2 - Workshop Railway Organisation CY - Xining, China DA - 2007-09-19 PY - 2007 AN - OPUS4-16559 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shokouhi, Parisa A1 - Feldmann, Rüdiger A1 - Wiggenhauser, Herbert T1 - Stress-Dependency of Sonic Velocity in Concrete under Unaxial Load KW - Design KW - Public Transportation and Ferries KW - Safety PY - 2008 IS - CD-ROM (Paper 08-1450 / Session 568) SP - 1 EP - 15 PB - TRB CY - Washington, DC AN - OPUS4-16650 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - Alkali transport in concrete measured with LIBS T2 - ACI Fall Convention, ACI Commitee 228 CY - Fajardo, Puerto Rico DA - 2007-10-14 PY - 2007 AN - OPUS4-16664 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - Alkali transport in concrete measured with LIBS T2 - Transportation Research Board (TRB) 2008, Committee AFN010 CY - Washington, D.C., USA DA - 2008-01-13 PY - 2008 AN - OPUS4-16665 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - NDT-CE Challenges and Lessons learned T2 - SIBTEST 2011, NDT-Workshop CY - Gorny, Altai Krai, Russia DA - 2011-07-25 PY - 2011 AN - OPUS4-24721 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Alver, Ninel A1 - Wiggenhauser, Herbert T1 - Modified SIBIE procedure for ungrouted tendon ducts applied to scanning impact-echo N2 - The impact-echo method has been successfully applied to identify defects inside concrete. In addition, to detect ungrouted tendon ducts in a large concrete slab, a scanning impact-echo technique is developed. However, since resonant frequencies in the spectrum responsible for the travel paths via defects are only taken into account, the method could lead to erroneous results due to complicated spectra obtained in the tests. Consequently, Stack Imaging of spectral amplitudes Based on Impact-Echo (SIBIE) procedure has been developed to improve the data interpretation. Conventionally, SIBIE is applied to a single measurement data and a point information of defects is obtained at the area, where the impact test is performed. In this study, SIBIE is applied to scanning impact-echo data. Locations of ungrouted tendon ducts embedded in a large concrete specimen are investigated. In order to visualize the whole cross-section tested, the SIBIE analysis is modified, introducing an elliptical integration mode. It is demonstrated that ungrouted tendon ducts are successfully located by the modified SIBIE analysis, whereas results of the conventional B-scan analysis are not so good as the modified SIBIE analysis. KW - Impact echo KW - Scanning procedure KW - SIBIE PY - 2010 DO - https://doi.org/10.1016/j.conbuildmat.2010.05.012 SN - 0950-0618 VL - 24 IS - 12 SP - 2388 EP - 2392 PB - Elsevier Science CY - Amsterdam AN - OPUS4-23961 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - Zerstörungsfreie Prüfung im Bauwesen - 3 Fallstudien: - Automatisierte Prüfung großer Flächen - Bestimmung von Spanngliedlagen - Untersuchungen an der Florisdorfer Brücke T2 - FSV Seminar Brückenprüfer - Erfahrungsaustausch CY - Vienna, Austria DA - 2011-11-22 PY - 2011 AN - OPUS4-24774 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - Non-Destructive Testing in Civil Engineering T2 - SVTI-Workshop "ZfP für Betonbauteile in Kernkraftwerken" CY - Zurich, Switzerland DA - 2011-11-16 PY - 2011 AN - OPUS4-24895 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shokouhi, Parisa A1 - Wöstmann, Jens A1 - Schneider, Gerhard A1 - Milmann, Boris A1 - Taffe, Alexander A1 - Wiggenhauser, Herbert T1 - Nondestructive detection of delamination in concrete slabs - multiple-method investigation N2 - The delamination of concrete slabs is the separation along a plane roughly parallel to, and generally near, the surface. Corrosion-induced delamination is a common problem in old concrete bridge decks. If undetected, delaminations could expand, reach the surface, and result in spalling. Early detection of delamination is necessary for planning timely repairs that prevent costly deck replacement projects. Most bridge owners rely on routine visual and traditional surveys of bridge deck conditions. These surveys are highly subjective and can locate only large shallow delaminated zones. Several nondestructive testing (NDT) techniques have recently been employed for bridge deck evaluation to obtain more objective and comprehensive assessment. The reliability of applicable methods needs to be established before a greater role for NDT in routine inspections can be encouraged. This paper presents a validation study aimed at evaluating the effectiveness of three NDT techniques, namely impact echo, ultrasound (US) echo, and US linear array, in detection of delamination. This study is unique because the subject test specimens were deteriorated bridge deck segments preserved from the demolition of a prestressed box girder bridge. The results of the tests conducted on one of the specimens are presented and discussed here: impact echo provided satisfactory overall assessment, but the individual results were often difficult to interpret; US echo detected deep delaminations but not shallow ones; and US linear array located the extent of deep delaminations and provided indications of shallow ones. KW - Delamination KW - Concrete KW - Ultrasonic testing KW - Impact echo KW - Scanning PY - 2011 DO - https://doi.org/10.3141/2251-11 SN - 0361-1981 VL - 2251 SP - 103 EP - 113 PB - National Research Council CY - Washington, DC AN - OPUS4-25552 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - ZfP im Bauwesen oder Wo ist der Fortschritt? T2 - Kolloquium für Gerd Dobmann, FhG IZFP Saarbrücken CY - Saarbrücken, Germany DA - 2012-02-14 PY - 2012 AN - OPUS4-25480 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lai Wai-Lok, Wallace A1 - Kind, Thomas A1 - Wiggenhauser, Herbert T1 - Using ground penetrating radar and time-frequency analysis to characterize construction materials N2 - For decades, applications of nondestructive evaluation-civil engineering (NDE-CE) focus on object identifications (such as steel bars, tendon ducts and backwall reflections) in infrastructures. Because of the advantage of efficient visualization of internal structure, utilization of these methods can probably be extended to material characterization (MC) of aging and adversely exposed infrastructures. However, two factors yield a big gap between NDE and MC. First, for the ease of visualization, the primary focus of NDE-signal processing is object identification, which usually alters the originality of the signal. Second, there is lack of relationship and inverse models bridging the NDE-derived and conventional material properties compared to other disciplines of science, such as geophysics. These disadvantages make laboratory and field-scale NDE-MC still a far-reaching holy grail and is possibly the greatest hurdle to be regularly adopted in CE structures. This paper attempts to address this gap from object identification to MC using ground penetrating radar (GPR) as one of the most frequently used NDE-CE methods, and signal processing with joint time–frequency domain (JTFA) analysis. Three examples of material property characterization regarding the individual effects of steel bar corrosion in concrete, hydration and moisture content distribution of construction materials are given. KW - Ground penetrating radar KW - Time-frequency analysis KW - Construction materials KW - Short time fourier transform PY - 2011 DO - https://doi.org/10.1016/j.ndteint.2010.10.002 SN - 0963-8695 VL - 44 IS - 1 SP - 111 EP - 120 PB - Butterworth-Heinemann CY - Oxford AN - OPUS4-26288 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lai Wai-Lok, Wallace A1 - Kind, Thomas A1 - Wiggenhauser, Herbert T1 - Frequency-dependent dispersion of high-frequency ground penetrating radar wave in concrete N2 - This paper studies the dielectric dispersion of high frequency radar wave in concrete in early-aged and hardened concrete specimens. Frequency-dependent spectra of phase velocity ν(ω) were measured to deduce the spectra of real part of dielectric permittivity ε'(ω). The dispersion was measured by three high nominal ground penetrating radar frequencies (1.5, 1.6 and 2.6 GHz), experimenting on two steel bars with concrete cover 50 and 100 mm. It was found that ν(ω) and ε'(ω) dispersed at lower frequency, but became stable at high frequency regions, which agrees with the classical GPR plateau. The same frequency components at different nominal antenna frequencies show a close range of ν(ω) and ε'(ω) in concrete of different ages. The results in this paper warrant further investigation of using GPR wave to study material properties. KW - Frequency-dependent dielectric dispersion KW - Ground penetrating radar (GPR) KW - Phase velocity KW - Real part of dielectric permittivity KW - Concrete PY - 2011 DO - https://doi.org/10.1016/j.ndteint.2010.12.004 SN - 0963-8695 VL - 44 IS - 3 SP - 267 EP - 273 PB - Butterworth-Heinemann CY - Oxford AN - OPUS4-26289 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lai Wai-Lok, Wallace A1 - Kind, Thomas A1 - Stoppel, Markus A1 - Wiggenhauser, Herbert T1 - Measurement of accelerated steel corrosion in concrete using ground-penetrating radar and a modified half-cell potential method N2 - A new approach is presented to evaluate corrosion of steel bars in concrete by 1.5- and 2.6-GHz ground-penetrating radar (GPR) and a modified half-cell potential method. Changes in time-lapsed travel times, amplitudes, and peak frequencies that are associated with short-time Fourier transform spectrograms of the bar reflections were continuously measured. The year-long corrosion process of the reinforcement bar rapidly accelerated within a few days by impressing direct current across a pair of embedded reinforcement bars, which served as the anode and cathode. When corrosion started, the travel times, amplitudes, and frequency spectra of the bar reflection changed. The results were analyzed by dividing the material's response into three phases (NaCl contamination, depassivation, and corrosion). The writers attribute the phenomena of the first two phases to the ionic conduction and interfacial polarization effect, described in the low-frequency regime of complex dielectric permittivity outlined in the Maxwell-Wagner effect. The remaining phase corresponds with the appearance of large and multiple interfaces among steel, concrete, corrosion product, and cracks, in addition to the upward movement of the corrosion product to the concrete surface that intercepts wider radar footprints. The findings, based on time lapse measurements, provide a basis to further apply the GPR technique to spatial measurements in laboratory and field studies. KW - Accelerated steel corrosion in concrete KW - Ground-penetrating radar KW - Short-time Fourier transform KW - Half-cell potential PY - 2013 DO - https://doi.org/10.1061/(ASCE)IS.1943-555X.0000083 SN - 1076-0342 SN - 1943-555X IS - June SP - 205 EP - 220 CY - New York, NY AN - OPUS4-28851 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - Nondestructive Evaluation of Steel-Concrete Mockups T2 - 10th International Conference on NDE in Relation to Structural Integrity for Nuclear and Pressurized Components CY - Cannes, France DA - 2013-10-01 PY - 2013 AN - OPUS4-29184 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - Borehole based methods for length determination of existing piles, State of the Art of NDE Protocols for Bridge Management, Multi-probe ultrasonics testing for detection of delamination in concrete bridge decks T2 - NDT Workshop CY - Lansing, MI, USA DA - 2013-03-28 PY - 2013 AN - OPUS4-28077 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -