TY - GEN A1 - Maierhofer, Christiane A1 - Wöstmann, Jens A1 - Trela, Christiane A1 - Röllig, Mathias ED - L. Binda, ED - M. di Prisco, ED - R. Felicetti, T1 - Investigation of moisture content and distribution with radar and active thermography T2 - 1st International RILEM Conference, on Site Assessment of Concrete, Masonry and Timber Structures (SACoMaTiS 2008) CY - Varenna, Italy DA - 2008-09-01 KW - Radar KW - Active thermography KW - Non-destructive testing KW - Moisture KW - Masonry PY - 2008 SN - 978-2-35158-062-2 VL - 1 IS - PRO 59 SP - 411 EP - 420 PB - RILEM Publications AN - OPUS4-18032 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wendrich, Astrid A1 - Trela, Christiane A1 - Krause, Martin A1 - Maierhofer, Christiane A1 - Wöstmann, Jens A1 - Milmann, Boris ED - Mazal, P. T1 - Application of ultrasonic and radar tomography for the investigation of the internal structure of masonry T2 - 3rd International Workshop of NDT Experts CY - Prague, Czech Republic DA - 2005-10-10 KW - Masonry KW - Tomography KW - Ultrasonic KW - Radar KW - Non-destructive testing PY - 2005 SN - 80-2142996-8 SP - 299 EP - 313 PB - Univ. of Technology CY - Brno AN - OPUS4-12273 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wendrich, Astrid A1 - Trela, Christiane A1 - Krause, Martin A1 - Maierhofer, Christiane A1 - Effner, Ute A1 - Wöstmann, Jens T1 - Location of voids in masonry structures by using radar and ultrasonic traveltime tomography T2 - 9th European Conference on NDT CY - Berlin, Germany DA - 2006-09-25 PY - 2006 SN - 3-931381-86-2 SP - 1(?) EP - 6(?) PB - European Federation for Non-Destructive Testing CY - Berlin AN - OPUS4-14015 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kind, Thomas A1 - Trela, Christiane A1 - Schubert, Marcus A1 - Wöstmann, Jens ED - Lambot, S. ED - Giannopoulos, A. ED - Pajewski, L. ED - André, F. ED - Slob, E. ED - Craeye, C. T1 - Aggregates scattering of GPR waves in concrete N2 - Time slices of very dense GPR measurements carried out at concrete with a real point distance of less than 10 mm in x and y direction show weak reflection patterns besides the strong reflections of reinforcements. A repetition of these measurements with the same local geometrical precision at the same specimen shows the same reflection pattem. We suppose that the heterogeneity of concrete given by aggregates (e.g. gravel, broken granite) causes local weak Scattering of the GPR waves and leads to reflection patterns in the GPR data. These reflection patterns can be explained by a Superposition of multiple scatterings of single aggregates. So far these reflection patterns have been not recognized in Standard time slices due to the large spacing (> 5 cm) between single profiles and because of the interpolation between the profiles. We investigate the characteristics of the volume scattering effects, caused by aggregates, at concrete blocks with two different grading curves. In a more general investigation we study the volume scattering of aggregates by using wooden boxes filled with only typical aggregates and an included defined reflector (metal plate). The thickness of the aggregate layer above the metal plate was varied between 20 cm and 40 cm. With a very dense measuring grid at the surface we are able to calculate the effective volume scattering and to analyze the distribution of the reflection amplitude of the included metal plate for different aggregate set-ups. Results of this study confirm that the weak reflection patterns in concrete can be explained by aggregate scattering and have a direct correlation to the penetration depth of GPR in concrete. T2 - GPR 2014 - 15th International conference on ground penetrating radar CY - Brussels, Belgium DA - 30.06.2014 KW - Aggregates KW - Volume scattering PY - 2014 UR - http://sites.uclouvain.be/GPR2014 SP - 933 EP - 938 AN - OPUS4-34576 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert A1 - Kind, Thomas A1 - Krause, Martin A1 - Schulze, S. A1 - Taffe, A. A1 - Trela, Christiane A1 - Wöstmann, Jens T1 - Praktische Anwendung zerstörungsfreier Prüfverfahren an Brücken N2 - Die drei Beispiele zerstörungsfreier Prüfungen an Spannbetonbrücken zeigen unterschiedliche Problemstellungen und deren Lösung mit unterschiedlichen Ansätzen. Allen drei Beispielen gemeinsam ist die Verwendung kommerzieller Geräte. Diese werden von verschiedenen Anbietern bereitgestellt. Eine weitere Gemeinsamkeit ist, dass die Grundgeräte durch zusätzliche Maßnahmen ergänzt. Erst dann ist der gewünschte Untersuchungserfolg sicher gestellt. Im ersten Beispiel wurde die vom Auftraggeber geforderte Präzision dadurch erreicht, dass systematische Voruntersuchungen stattfanden. Die Übertragung der Lokalisierung direkt auf die Betonoberfläche stellte sicher, dass keinen Informationsverluste an die nachfolgenden Aufgaben auftraten. Das zweite Beispiel zeigt den Nutzen von Automatisierung und Kombination von Verfahren. Damit können dem Auftraggeber die notwendigen Angaben über Einbauteile mit großer Detaitreue und leicht verständlicher Visualisierung aufbereitet werden. Der abschließende Bericht zeigt, wie vorhandene Auswertungen sinnvoll durch noch in der Forschung befindliche Ansätze bereichert werden. Insgesamt ist die zerstörungsfreie Prüfung in der Lage, an Brücken preisrelevante Fragestellungen zu lösen. Voraussetzung hierfür ist eine sorgfältig geplante Vorgehensweise und ein sicheres Verständnis der Grundlage der eingesetzten Geräte und Auswertungsschritte. T2 - 1. Brückenkolloquium - Beurteilung, Ertüchtigung und Instandsetzung von Brücken CY - Ostfildern/Stuttgart, Germany DA - 24.06.2014 PY - 2014 SP - Paper 00_08, 1 EP - 8 AN - OPUS4-31032 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trela, Christiane T1 - Vergleich von Radarmessungen in Reflexion und Transmission zur Detektierbarkeit von Lufteinschlüssen in Betonbauteilen T2 - Bauwerksdiagnose 2014 CY - Berlin, Germany DA - 2014-02-13 PY - 2014 AN - OPUS4-30654 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trela, Christiane T1 - Systematische Radaruntersuchungen zum Auffinden von Strukturschwächen in Betonbauteilen T2 - DGZfP-Jahrestagung CY - Potsdam, Germany DA - 2014-05-26 PY - 2014 N1 - Geburtsname von Klee, Martin: Günther, M. - Birth name of Klee, Martin: Günther, M. AN - OPUS4-30804 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trela, Christiane A1 - Kind, Thomas A1 - Schubert, Marcus A1 - Klee, Martin ED - Lambot, S. ED - Giannopoulos, A. ED - Pajewski, L. ED - André, F. ED - Slob, E. ED - Craeye, C. T1 - Detection of weak scatterers in reinforced concrete structures N2 - GPR surveys on concrete structures like bridges, dccks and buildings are succcssfully applied to detect and localize construction elements mostly madc of metal. Dcfects like air voids behind rebars in incompletely compacted concrete still represent major challenges due to thcir weak reflcction amplitudes. In a systcmatic study at a concrete test specimen with vcrtical rebars and simulated air voids of different size and depth, the effects of different GPR data acquisition Parameters like antenna frcqucncies (1.2 up to 2.6 GHz) and antenna orientation on the quality of imaging of thcsc air voids wcre investigated. Vcry dense measurements with high Position accuracy were carried out using an automated scanning System. Despite the strong shadowing and disturbing interference effccts of the reinforccmcnt and the associated strong rcflections, the weak scatterers can still be identified to a ccrtain depth using appropriate antenna configurations. Measurements with the antenna orientation perpendicular to the rebars of 1.2 to 2.0 GHz give the best results. Pre- and postprocessing steps like filtering, gain, 3D SAFT (Synthetic Apcrture Focusing Technique) rcconstruction and somc adapted visualization options were properly applied to improve the imaging results of thcsc weak scatterers. T2 - GPR 2014 - 15th International conference on ground penetrating radar CY - Brussels, Belgium DA - 30.06.2014 KW - Radarmessungen KW - Automatisierung KW - Strukturerkennung KW - Stahlbeton KW - Reflection profiling KW - Data processing KW - SAFT reconstruction and visualisation of NDT-datasets PY - 2014 N1 - Geburtsname von Klee, Martin: Günther, M. - Birth name of Klee, Martin: Günther, M. SP - 904 EP - 910 AN - OPUS4-31168 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trela, Christiane T1 - Detection of Weak Scatterers in Reinforced Concrete Structures T2 - Ground Penetrating Radar (GPR) Conference 2014 CY - Brussels, Belgium DA - 2014-06-30 PY - 2014 N1 - Geburtsname von Klee, Martin: Günther, M. - Birth name of Klee, Martin: Günther, M. AN - OPUS4-31089 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kind, Thomas A1 - Wöstmann, Jens A1 - Feistkorn, Sascha A1 - Trela, Christiane ED - Meßinger, Jens T1 - Radar in der Baupraxis: Lokalisierung von zweilagig vorgespannter Bewehrung in Beton N2 - Die Ermittlung der genauen Bewehrungslage ist von großem Interesse bei der Instandsetzung und Ertüchtigung von Stahlbetonbauwerken. Denn nur wenn die Lage der für die Standsicherheit wichtigen Bewehrung bekannt ist, können Kernbohrungen oder Sägearbeiten schadensfrei durchgeführt werden. Das Bodenradar als zerstörungsfreie Methode ist wegen des einfachen Verfahrens der Antenne entlang einer Messspur für eine solche Aufgabenstellung sehr gut geeignet. Die Anwendung kann aber eingeschränkt werden, wenn die gesuchte Bewehrung zu tief liegt oder durch eine davor liegende Bewehrung abgeschattet wird. Bei der Ortung mehrlagiger Bewehrung ist es wichtig, einen mehrstufigen und effizienten Messplan zu erstellen, der den Aufwand auf einem vertretbaren Maß beschränkt und die Möglichkeit bietet, beim Erreichen der Verfahrensgrenzen rechtzeitig die Untersuchung abzubrechen. Am Beispiel einer Stahlbetonbrücke, die nachträglich mit externen Spanngliedern versehen wurde, wird das Vorgehen beim Orten von mehrlagiger Bewehrung gezeigt. T2 - Georadar - Erfahrungen und Perspektiven CY - Freiberg, Germany DA - 24.09.2009 KW - Radar KW - Zerstörungsfreie Prüfung KW - Stahlbeton PY - 2010 SN - 0947-1944 VL - I SP - 1 EP - 6 PB - Dt. Geophysikalische Ges. CY - Potsdam AN - OPUS4-39827 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trela, Christiane T1 - Ground penetrating radar in reflection vs transmission mode for void detection in concrete structures N2 - The concreting of prefabricated concrete structures can lead to insufficient bonding or even to remaining cavities. Honeycombs (aggregate clusters without cement) represent potential weakening of the structure and need to be detected non-destructively. In our study we tested the capability of ground penetrating radar (GPR) techniques for this purpose. We applied GPR in reflection mode and zero-offset profiling (ZOP) transmission mode on a precast concrete twin wall with built-in honeycombs. GPR measurements were performed as two channel measurement with ground coupled antennas with centre frequencies of 1.5 GHz and 2.6 GHz mounted to an automated scanner system. Our findings show that ZOP transmission measurements are a more efficient method to detect voids in reinforced concrete structures compared to reflection mode measurements. This holds for both the effort needed for the measurement and the evaluation as well as the validity of the data. Honeycombs (basically representing voids) are usually characterized by strongly reduced amplitudes and earlier arrivals of the transmitted wave. T2 - International Symposium Non-Destructive Tesing in Civil Engineering (NDT-CE 2015) CY - Berlin, Germany DA - 15.09.2015 KW - Void detection KW - Ground penetrating radar KW - Reflection KW - Transmission KW - Reinforced concrete KW - Prefabricated wall PY - 2015 AN - OPUS4-40005 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trela, Christiane A1 - Kind, Thomas A1 - Schubert, Marcus T1 - Detection of air voids in concrete by radar in transmission mode N2 - Air voids in concrete like honeycombs are one of the major concerns regarding quality assurance for the construction of infrastructure buildings like bridges or tunnels. This paper shows that voids in reinforced concrete walls or slabs can be detected by two standard ground coupled GPR antennas in transmission mode using a two-side zero-offset profiling configuration like in borehole radar applications. For the detection of voids only the amplitudes of the direct wave in transmission mode are evaluated. Even when the depth of the void can not be detected in this configuration, the major advantage of the zero-offset profiling in transmission mode is a lower interference with the surrounding reinforcement compared to a regular one-side reflection profiling. The capability of the two-side zero-offset profiling is demonstrated on a test specimen with a set of polystyrene balls of two different sizes representing voids like honeycombs in concrete. GPR measurements are realized by an automated scanning system in order to allow for a synchronous movement of the antennas. In transmission mode voids can be detected at greater depths compared to reflection mode, since the travel path of the direct wave is half as long. Another characteristic of the transmission mode is that the direct wave through the air voids is faster and arrives earlier than the direct wave in the surrounding concrete. Hence it can be separated from the strong reflection of the reinforcement. Finally the measurements in transmission mode are less sensitive to the antenna frequency and polarization than in reflection mode. T2 - IWAGPR 2015 - 8th International workshop on advanced ground penetrating radar CY - Firenze, Italy DA - 07.07.2015 KW - Radar KW - Zerstörungsfreie Prüfung KW - Ground penetrating radar KW - Transmission KW - Reinforced concrete KW - Honeycombs KW - Void detection KW - First arrival PY - 2015 SN - 978-1-4799-6495-6 DO - https://doi.org/10.1109/IWAGPR.2015.7292650 AN - OPUS4-34678 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Trela, Christiane A1 - Wöstmann, Jens A1 - Kruschwitz, Sabine ED - Carlos Brebbia, T1 - Contribution of radar measurements to the inspection and condition assessment of railway bridges - case study at a historic masonry arch bridge in Olesnica/Poland N2 - Ground Penetration Radar (GPR) as a non-destructive (NDT)-method can be applied to obtain detailed information about the inner structure and condition of bridges without damaging the structure. In this paper the capabilities and limitations of the application of the fast inspection technique GPR will be demonstrated. In addition to GPR investigations, geoelectrical measurements, coring and petrophysical investigations have been carried out. The investigated railway bridge in Olesnica is a typical European masonry arch bridge (age, construction and span length). It shows typical damage to the masonry arches such as increasing salt concentration, destruction, material losses and longitudinal cracks. Radar measurements were carried out with two main objectives: (1) Identification of basic geometric dimensions of the bridge and identification of construction details; (2) Evaluation of the condition of the masonry, such as mechanical damage (e.g. cracks) or variation of the moisture content. Radar antennas of different frequencies (having different penetration depths) have been used to estimate the thickness of the walls. Because of the high attenuation in the inner masonry structure the measurements have not produced satisfying results, but the radar measurements have been successfully applied to investigate the moisture distribution in the masonry. These results have been verified by coring and through geoelectrical measurements. Cracks were studied at two testing areas at one wing wall of the bridge using an automatic 2D radar scanning system. The radar data were processed using advanced data processing tools like FT-SAFT reconstruction and data fusion. The processing sequence allowed the creation of high-resolution depth sections (C-Scans). KW - Ground Penetration Radar KW - Spectral induced polarization KW - Coring KW - Railway bridge KW - Non-destructive testing method KW - Condition assessment PY - 2008 SN - 978-1-84564-106-1 DO - https://doi.org/10.2495/HPSM080541 SN - 1743-3509 VL - 97 SP - 535 EP - 544 PB - WIT Press CY - Ashurst, Southampton, UK AN - OPUS4-17745 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Bien, J. A1 - Kaminski, T. A1 - Trela, Christiane ED - Hyun-Moo Koh, ED - Dan M. Frangopol, T1 - Numerical analysis of old masonry bridges supported by field tests T2 - Bridge Maintenance, Safety, Management, Health Monitoring and Informatics - IABMAS 2008 CY - Seoul, South Korea DA - 2008-07-13 PY - 2008 SN - 978-0-415-46844-2 SP - 2384 EP - 2391 PB - CRC Press CY - Boca Raton AN - OPUS4-17749 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Paasche, H. A1 - Wendrich, Astrid A1 - Tronicke, J. A1 - Trela, Christiane T1 - Detecting voids in masonry by cooperatively inverting P-wave and georadar traveltimes N2 - Collecting different geophysical data sets at the same object and site offers the opportunity to reduce uncertainties and ambiguities in data analysis and interpretation. To be effective, the different available data sets should be linked during the model-generation process, e.g. by cooperative inversion. In this study, we apply a recently developed zonal cooperative inversion approach based on fuzzy c-means cluster analysis to a non-destructive testing experiment. After briefly reviewing the fundamentals of the inversion strategy, we present a synthetic study investigating the potential of the method to detect air-filled voids in masonry by using ultrasonic and georadar traveltime data. Then, we present and discuss laboratory experiments including the results of cooperatively inverted ultrasonic and georadar traveltimes collected at a masonry test specimen. The geometry of the specimen is known and is thus an ideal test object for a first-time real application of the novel zonal cooperative inversion procedure. Compared to the results of separate inversions of ultrasonic and georadar traveltimes, the zonal cooperative inversion allows for an improved delineation of the size and position of the cavities. The P-wave and georadar velocities determined for the model regions corresponding to the cavities are also improved. KW - Non-destructive testing KW - Tomography KW - Traveltime KW - Cooperative inversion KW - Cluster analysis PY - 2008 DO - https://doi.org/10.1088/1742-2132/5/3/002 SN - 1742-2132 VL - 5 SP - 256 EP - 267 PB - IOP Publ. CY - Bristol AN - OPUS4-18815 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Trela, Christiane A1 - Gil, Magdalena ED - Meßinger, J. T1 - Bodenuntersuchungen mit Georadar zum Auffinden von Grenzsteinen KW - Bodenuntersuchung KW - Georadar KW - Grenzsteine KW - Radar PY - 2010 SN - 0947-1944 VL - I SP - 7 EP - 14 PB - Dt. Geophysikalische Ges. CY - Potsdam AN - OPUS4-21836 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trela, Christiane T1 - Ergebnisse aus dem Teilprojekt der BAM: Bodenuntersuchungen mit Georadar zum Auffinden von Grenzsteinen T2 - Radar-Rundtischgespräch an der TU Bergakademie Freiberg, Institut für Geophysik CY - Freiberg, Germany DA - 2009-09-24 PY - 2009 AN - OPUS4-20120 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cruz, P.J.S. A1 - Topczewski, L. A1 - Fernandes, F.M. A1 - Trela, Christiane A1 - Lourenco, P.B. T1 - Application of radar techniques to the verification of design plans and the detection of defects in concrete bridges N2 - Non-destructive tests (NDT) are an essential tool used in special inspections to gather detailed information about the condition of a bridge. The inspection of bridge decks is a critical task, and, currently, can be successfully carried out using a wide range of NDT techniques. Nevertheless, some of these techniques are excessively expensive and time consuming. One of these techniques, the ground penetrating radar (GPR), has been used for some decades in the non-destructive inspection and diagnosis of concrete bridges. GPR is useful to find general information about the true position of reinforcement and tendon ducts, and check the quality of the construction and materials. A significant number of reinforced and prestressed concrete bridges are deteriorating at a rapid rate and need to be repaired and strengthened. During these rehabilitation processes, designers are often faced with a lack of original design plans and unawareness of the real position of reinforcement and tendon ducts. In this paper, three case studies of the use of GPR techniques for the inspection of concrete bridges are presented and analysed. The main aim of this research is to show the strong need and usefulness of these techniques, which can provide non-visible information about structural geometry and integrity required for strengthening and rehabilitation purposes. KW - Non-destructive tests KW - Ground penetrating radar KW - Tomography KW - Bridge condition assessment KW - Detection of defects PY - 2010 DO - https://doi.org/10.1080/15732470701778506 SN - 1573-2479 SN - 1744-8980 VL - 6 IS - 4 SP - 395 EP - 407 PB - Taylor & Francis CY - London AN - OPUS4-20144 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kind, Thomas A1 - Feistkorn, Sascha A1 - Trela, Christiane A1 - Wöstmann, Jens T1 - Impulsradar für schadensfreie Kernbohrungen an Spannbetonbrücken N2 - Der Bedarf an Kernbohrungen in Stahlbetonbauwerken ist in den letzten Jahren durch die steigende Anzahl von Instandsetzungen und Ertüchtigungen unterschiedlicher Stahlbetonbauten stark gewachsen. Für die Durchführung einer Kernbohrung ist die Kenntnis der genauen Lage der vorgespannten Bewehrung notwendig, um diese für die Statik wichtigen Elemente nicht zu beschädigen. Das methodische Vorgehen für die schadensfreie Durchführung von Kernbohrungen wird am Beispiel einer ca. 1 m dicken Hohlkastenseitenwand der Karl-Carstens Brücke in Bremen gezeigt. Nach der Darstellung der Ausgangslage und der Aufgabenstellung werden die Schritte beschrieben, die zu einer erfolgreichen Durchführung der Aufgaben erforderlich waren. Hierbei steht die planmäßige Anwendung der zerstörungsfreien Untersuchungsmethode Impulsradar im Vordergrund. Das Vorgehen gliedert sich in vier Schritte: - Zunächst wurde eine Voruntersuchung durchgeführt, um festzustellen, ob sich die vorgespannte Bewehrung in den erwarteten Tiefen von bis zu 50 cm und unter den vorhandenen Bedingungen der Hohlkastenseitenwände mit dem Impulsradar detektieren lässt. - Nach der erfolgreichen Voruntersuchung wurden im zweiten Schritt die Bereiche der geplanten Kernbohrungen großflächig mit dem Impulsradar untersucht. - Anschließend konnte anhand der Messdaten die Lage der Bewehrung ermittelt und in einen Plan eingezeichnet werden, der im Maßstab 1:1 ausgedruckt wurde. Dieser Plan wurde positionsrichtig auf die Oberfläche der Hohlkastenwand geklebt. - Im letzten Schritt wurden dann gezielte Test- und Suchbohrungen durchgeführt, denen die eigentlichen Kernbohrungen folgten. Mit der im Plan dargestellte Bewehrungslage war die Voraussetzung für schadensfreies Bohren gegeben. So konnten die Kernbohrungen durchgeführt werden, ohne die vorgespannte Bewehrung zu beschädigen. KW - Zerstörungsfreie Prüfung KW - Impulsradar KW - Stahlbetonbrücke KW - Ertüchtigung KW - Kernbohrung KW - Schubnadeln KW - Spannglieder PY - 2009 DO - https://doi.org/10.1002/best.200900060 SN - 0005-9900 SN - 1437-1006 VL - 104 IS - 12 SP - 876 EP - 881 PB - Ernst CY - Berlin AN - OPUS4-20657 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trela, Christiane T1 - Application of ultrasonic and radar tomography for the investigation of the internal structure of masonry T2 - IIIrd Workshop of "NDT in Progress" CY - Prague, Czech Republic DA - 2005-10-10 PY - 2005 AN - OPUS4-11977 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trela, Christiane T1 - Radartomografie zur Strukturuntersuchung an Betonbauteilen T2 - 6. Radarrundtischgespräch an der TU Freiberg im Institut für Geophysik CY - Freiberg, Germany DA - 2005-09-29 PY - 2005 AN - OPUS4-11071 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -