TY - CONF A1 - Niederleithinger, Ernst T1 - Condition monitoring for lifetime extension of interim storage facilities N2 - The German interim nuclear storage facilities are designed for a 50 year service life and 40-year operating period. They will be needed much longer, as a final repository will not be available until 2050 at the earliest. The objective of ZuMoBau-ZL is to develop a suitable condition assessment and monitoring concept suitable for the structures in interim storage facilities, including life prediction models, with which the remaining service life can be predicted, verified, and monitored as realistically as possible. T2 - IAEA ICARST 2025 CY - Vienna, Austria DA - 07.04.2025 KW - Nuclear waste KW - Interim storage KW - Liefetime extension KW - Reinforced concrete PY - 2025 AN - OPUS4-62984 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Skłodowska, Anna A1 - Coronel Subia, Hernan Alejandro A1 - Inzunza Araya, Ernesto A1 - Niederleithinger, Ernst T1 - Influence of velocity changes on acoustic emission monitoring of masonry walls under diagonal compression load N2 - Acoustic emission (AE) is a highly sensitive, non-destructive method which has great potential in damage event detection and assessment in masonry structures exposed to e.g., seismic loads. However, the highly heterogenous nature of the masonry structures and their low densities cause high attenuation and distortion of the signal. Localization of the AE events is challenging because the AE waves propagate through various masonry constituents (i.e., bricks and mortar joints) at different velocities. We present an attempt to locate the sources of AE events from the signals recorded during the diagonal compression loading, and analyze the influence of different wave velocities on its accuracy. T2 - 36th Conference of the European Working Group on Acoustic Emission CY - Potsdam, Germany DA - 18.09.2024 KW - Acoustic emission KW - Masonry KW - Compression test PY - 2024 AN - OPUS4-61689 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Skłodowska, Anna A1 - Lay, Vera A1 - Baensch, Franziska A1 - Niederleithinger, Ernst A1 - Kühne, Hans-Carsten T1 - Microseismicity monitoring in materials for nuclear waste storage repositories N2 - One of the major tasks in nuclear waste management is to design safe and reliable sealing structures for radioactive waste repositories. Particularly for salt as a host rock, engineered barrier systems for underground waste disposal must be constructed of well-understood (cementitious) materials that will sustain environmental conditions and ensure high durability. Within the SealWasteSafe project, we studied two materials with a potential for sealing structures for nuclear waste repositories: an innovative alkali-activated material (AAM) and standard salt concrete (SC). To analyze the development of microstructural changes within the materials, we monitored microseismicity (aka acoustic emission monitoring) occurring during the hardening and setting period in two 340-liter-cubic specimens for up to ~250 days. The monitoring results showed, that in the first 61 days, fewer events occurred in AAM compared to SC. After this time the number of events in AAM sharply increased and significantly exceeded those observed in SC. However, the source localization analysis revealed that the increase of microseismicity in AAM material was not related to the formation of macro-cracks within the material but was mainly caused by the surface effects. Accompanying analysis of the test specimens with additional methods (such as e.g., X-ray CT) proved that no macro-cracks were observed inside the AAM specimen. Further analysis in the time and frequency domains helped to characterize the tested materials and to estimate their potential to be used for engineered barriers in nuclear waste repositories. Overall, our study shows the potential of microseismicity monitoring for feasibility studies and quality assurance in a broad range of applications, also in structural health monitoring. T2 - 84. Jahrestagung der Deutschen Geophysikalischen Gesellschaft CY - Jena, Germany DA - 10.03.2024 KW - Microseismicity KW - Nuclear waste repositories KW - Acoustic emission KW - SealWasteSafe project KW - Salt rock KW - Alkali-activated materia PY - 2024 AN - OPUS4-60549 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maack, Stefan A1 - Niederleithinger, Ernst T1 - Low frequency ultrasonic dataset for comparison and validation of signal processing and imaging techniques in civil engineering N2 - The evaluation of technical components and materials in terms of condition and quality with the aid of non-destructive testing methods plays an outstanding role both in industrial serial production and in the individual assessment of components. The ultrasonic echo method is used for a wide variety of testing tasks, such as measuring the thickness of a component. At the Bundesanstalt für Materialforschung und -prüfung (BAM) in Berlin, test methods are developed and their performance is demonstrated. For this purpose, references such as materials, test procedures or data sets are generated, which are used to evaluate these developed test methods. An important component of these references are data sets that are created according to the BAM Data Policy and made available to the scientific community and users of test methods in practice on the basis of the FAIR principles (Findability, Accessibility, Interoperability, and Reuse). T2 - The International Symposium on Nondestructive Testing in Civil Engineering (NDT-CE) 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Reference data KW - Non destructive testing and evaluation KW - Ultrasonic KW - Civil engineering PY - 2022 AN - OPUS4-58440 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Imani, A. A1 - Niederleithinger, Ernst T1 - Nondestructive Evaluation of Bridges without Structural Plans for Load Rating Purposes N2 - According to the NBI database, more than 21,000 in-service U.S. bridges lack sufficient structural documentation necessary for analytical load rating. Among these are a significant proportion of older prestressed concrete bridges. Given the lack of documentation on the reinforcing layout, such structures cannot be load rated analytically and are often subject to engineering judgement as the basis for rating. Otherwise, the typical approach for load rating such bridges is to conduct costly proof load testing and destructive probing together with making conservative assumptions. Therefore, any improvement to current practices will benefit DOTs and taxpayers alike. Accurately reconstructed 3D images of the girders to reflect the internal reinforcement could mitigate the need for costly, if not impractical, destructive testing and proof load testing, and help reduce dependency on conservative assumptions. This study examines a comprehensive NDE approach using ultrasonic tomography and GPR to aid in gathering structural information for load rating purposes. Different types of AASHTO and hollow core girders were tested. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Ultrasound KW - Radar KW - Bridges KW - Load rating PY - 2022 AN - OPUS4-56356 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lay, Vera A1 - Niederleithinger, Ernst A1 - Köpp, Christan T1 - Monitoring and digital tools for pre-disposal handling of cemented wastes N2 - Multifaceted developments for pre-disposal management of low and intermediate level radioactive waste are undertaken in the EC funded project PREDIS. In work package 7, innovations in cemented waste handling and pre-disposal storage are advanced by testing and evaluating. To provide better means for safe and effective monitoring of cemented waste packages including prediction tools to assess the future integrity development during pre-disposal activities, several monitoring and digital tools are evaluated and improved. Both safety enhancement (e. g. less exposure of testing personnel) and cost effectiveness are part of the intended impact. Current methods to pack, store, and monitor cemented wastes are identified, analysed and improved. Innovative integrity testing and monitoring techniques applied to evaluate and demonstrate package and storage quality assurance are further developed. The work includes but is not limited to inspection methods such as muon imaging, wireless sensors integrated into waste packages as well as external package and facility monitoring such as remote fiber optical sensors. The sensors applied will go beyond radiation monitoring and include proxy parameters important for long term integrity assessment (e. g. internal pressure). The measured data will be used in digital twins of the packages for specific simulations (geochemical, integrity) providing a prediction of future behaviour. Machine Learning techniques trained by the characterization of older packages will help to connect the models to the actual data. As data handling, processing and fusion are crucial for both the monitoring and the digital twin model, all data (measured and simulated) will be collected in a joint data base and connected to a decision framework. Finally, the implementation of the improved techniques will be tested at actual facilities. An overview about various relevant tools, their interconnections, and first research results will be shown. T2 - 9th IGD-TP Symposium CY - Zurich, Switzerland DA - 20.09.2022 KW - Predis KW - Monitoring KW - Sensors KW - Simulation KW - Digital twin PY - 2022 AN - OPUS4-55827 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Ultraschallprüfung von Verschlussbauwerken im Salinar N2 - Zu jedem Endlager gehört die Entwicklung eines Verschlusskonzept. Im Endlager Morsleben und an anderer Stelle werden in Abhängigkeit vom Wirtsgestein verschiedene Materialien und Bauweisen für Streckenverschlüsse entwickelt und in großem Maßstab erprobt. Hierzu gehören auch Maßnahmen der Qualitätssicherung, die Informationen über Ausführung und Zustand der Versuchsbauwerke liefern. Hierzu werden von der Bundesanstalt für Materialforschung und -prüfung (BAM) für verschiedene Forschungsvorhaben und Prüfaufträge Methoden und Geräte getestet, verbessert und vor Ort unter Tage eingesetzt Die hier beschriebenen Verfahren lassen sich auch zu Untersuchungen im Wirtsgestein anwenden. T2 - Tage der Standortauswahl CY - Freiberg/S., Germany DA - 11.02.2021 KW - Endlager KW - Verschlussbauwerke KW - Qualitätssicherung KW - Ultraschall PY - 2021 AN - OPUS4-54166 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Digital tools for cemented waste package and facility monitoring and prediction N2 - To provide better means for a safe and effective monitoring of cemented waste packages including prediction tools to assess the future integrity development during pre-disposal activities, several digital tools are evaluated and improved in the frame of the EC funded project PREDIS. Safety enhancement (e. g. less exposure of testing personnel) and cost effectiveness are part of the intended impact. The work includes but is not limited to inspection methods such as muon imaging, wireless sensors integrated into waste packages as well as external package and facility monitoring such as remote fiber optical sensors. The sensors applied will go beyond radiation monitoring and include proxy parameters important for long term integrity assessment (e. g. internal pressure). Sensors will also be made cost effective to allow the installation of much more sensors compared to current practice. The measured data will be used in digital twins of the packages for specific simulations (geochemical, integrity) providing a prediction of future behavior. Machine Learning techniques trained by the characterization of older packages will help to connect the models to the actual data. All data (measured and simulated) will be collected in a joint data base and connected to a decision framework to be used at actual facilities. The paper includes detailed information about the various tools under consideration, their connection and first results of our research. T2 - International Conference on Radioactive Waste Management: Solutions for a Sustainable Future CY - Vienna, Austria DA - 01.11.2021 KW - Radioactive waste disposal KW - Monitoring KW - Cemented waste PY - 2021 AN - OPUS4-54163 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Ultrasonic monitoring of full-scale load experiments N2 - Previous work has shown that ultrasonic monitoring using externally applied or embedded transducers and imaging methods based on coda wave interferometry are able to detect subtle changes in concrete elements. In this study, a limited number of embedded transducers has been used to monitor changes in several 12 m long two-span concrete beams subjected to point or linear loads until failure. The ultrasonic results showed the high sensitivity to stress changes and the nonlinear character of the associated effects. However, the ultrasonic features showed a very good correlation to several conventional monitoring parameters. For higher loads (significant amount of cracking), the technique had to be modified to cope with large wave velocity variations and high decorrelation compared to the reference signal. Using a very simple imaging procedure, the 2D stress field inside the beam has been visualized including inhomogeneities and artifact at places where cracking occurred at higher loads. The technique has the potential to be included in real time monitoring systems. T2 - ASNT SMT/NDT-CE 2018 CY - New Brunswick, NJ, USA DA - 27.8.2018 KW - Concrete KW - Monitoring KW - Ultrasound KW - Coda wave interferometry PY - 2018 AN - OPUS4-45827 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Coelho Lima, Isabela A1 - Grohmann, Maria A1 - Niederleithinger, Ernst T1 - Alternative imaging conditions for reverse-time migration N2 - Poster on the evaluation of several imaging conditions for reverse time migration, applied to ultrasonic echo data, tested with synthetic (simulated) dat and real data from a polyamide model. T2 - Jahrestagung der Deutschen geophysikalischen Gesellschaft CY - Leoben, Austria DA - 12.2.2018 KW - Ultrasound KW - Reverse time migration KW - Imaging condition KW - Concrete KW - Polyamide PY - 2018 AN - OPUS4-44583 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -