TY - CONF A1 - Klewe, Tim A1 - Strangfeld, Christoph A1 - Ritzer, Tobias A1 - Kruschwitz, Sabine T1 - Nondestructive determination of moisture damage in layered building floors N2 - In this ongoing research project, we study the influence of moisture damage on Ground Penetrating Radar (GPR) in different floor constructions. For this purpose, a measurement setup with interchangeable layers is developed to vary the screed material (cement or anhydrite) and insulation material (glass wool, perlite, expanded and extruded polystyrene), as well as the respective layer thickness. The evaluation of the 2 GHz common-offset radar measurements is focused on the extraction of distinctive signal features that can be used to classify the underlying case of damage without any further information about the hidden materials or layer thicknesses. In the collected dataset, we analyze the horizontal distribution of A-scan features in corresponding B-scans to detect water in the insulation layer. Furthermore, possible combinations of these features are investigated with the use of multivariate data analysis and machine learning (logistic regression) in order to evaluate the mutual dependencies. In this study, the combination of an amplitude- and frequency-based feature achieved an accuracy of 93.2 % and performed best to detect a damage in floor insulations. T2 - 18th International Conference on Ground Penetrating Radar CY - Meeting was canceled DA - 14.07.2020 KW - Radar KW - Feuchte KW - Moisture KW - Building floors PY - 2020 DO - https://doi.org/10.1190/gpr2020-045.1 SN - 2159-6832 SP - 164 EP - 167 AN - OPUS4-51575 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klewe, Tim A1 - Völker, Tobias A1 - Götz, J. A1 - Landmann, M. A1 - Wilsch, Gerd A1 - Kruschwitz, Sabine T1 - Sorting of construction and demolition waste by combining LIBS with NIR spectroscopy N2 - In a joint project of partners from industry and research, the automated recycling of construction and demolition waste (CDW) is investigated and tested by combing laser-induced breakdown spectroscopy (LIBS) and near-infrared (NIR) spectroscopy. Joint processing of information (data fusion) is expected to significantly improve the sorting quality of various materials like concrete, main masonry building materials, organic components, etc., and may enable the detection and separation of impurities such as SO3-cotaining building materials (gypsum, aerated concrete, etc.). The project focuses primarily on the Berlin site to analyze the entire value chain, minimize economic/technological barriers and obstacles at the cluster level, and sustainably increase recovery and recycling rates. First measurements with LIBS and NIR spectroscopy show promising results in distinguishing various material types and indicate the potential for a successful combination. In addition, X-ray fluorescence (XRF) spectroscopy is being performed to obtain more information about the quantitative elemental composition of the different building materials. Future work will apply the developed sorting methodology in a fully automated measurement setup with CDW on a conveyor belt. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - LIBS KW - NDT KW - Circular economy KW - Recycling KW - Material classification PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-555531 UR - http://www.ndt.net/?id=27220 VL - 2022/09 SP - 1 EP - 9 PB - NDT.net CY - Bad Breisig AN - OPUS4-55553 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klewe, Tim A1 - Völker, Tobias A1 - Landmann, Mirko A1 - Wilsch, Gerd A1 - Kruschwitz, Sabine T1 - Laser-based sorting of construction and demolition waste for the circular economy N2 - Closed material cycles and unmixed material fractions are required to achieve high recovery and recycling rates in the building industry. The growing diversity of construction and demolition waste is leading to increasing difficulties in separating the individual materials. Manual sorting involves many risks and dangers for the executing staff and is merely based on obvious, visually detectable differences for separation. An automated, sensor-based sorting of these building materials could complement or replace this practice to improve processing speed, recycling rates, sorting quality, and prevailing health conditions. A joint project of partners from industry and research institutions approaches this task by investigating and testing the combination of laser-induced breakdown spectroscopy (LIBS) and visual (VIS)/ near-infrared (NIR) spectroscopy. Joint processing of information (data fusion) is expected to significantly improve the sorting quality of various materials like concrete, main masonry building materials, organic components, etc., and may enable the detection and separation of impurities such as SO3-containing building materials (gypsum, aerated concrete, etc.). Focusing on Berlin as an example, the entire value chain will be analyzed to minimize economic/technological barriers and obstacles at the cluster level and to sustainably increase recovery and recycling rates. First LIBS measurements show promising results in distinguishing various material types. A meaningful validation shall be achieved with further practical samples. Future works will investigate the combination of LIBS and VIS/NIR spectroscopy in a fully automated measurement setup with conveyor belt speeds of 3 m/s. T2 - 6th fib Congress 2022 CY - Oslo, Norway DA - 12.06.2022 KW - LIBS KW - Data fusion KW - Circular economy KW - Recycling KW - Material classification PY - 2022 SP - 1 EP - 7 AN - OPUS4-55555 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd A1 - Völker, Tobias A1 - Klewe, Tim A1 - Kruschwitz, Sabine T1 - Laser Induced Breakdown Spectroscopy – A Tool for Imaging the Chemical Composition of Concrete N2 - One of the most common causes of damage is the ingress of harmful ions into the concrete, which can lead to deterioration processes and affect structural performance. Therefore, the increasingly aging infrastructure is regularly inspected to assess durability. Regular chemical analysis can be useful to determine the extent and evolution of ion ingress and to intervene in a timely manner. This could prove more economical than extensive repairs for major damage, particularly for critical infrastructure. In addition to already established elemental analysis techniques in civil engineering such as potentiometric titration or X-ray fluorescence analysis, laser-induced breakdown spectroscopy (LIBS) can provide further important complementary information and benefits. The possibilities of LIBS are demonstrated using the example of a drill core taken from a parking garage. T2 - 6th International Conference on Concrete Repair, Rehabilitation and Retrofitting CY - Kapstadt, South Africa DA - 03.10.2022 KW - LIBS KW - Concrete KW - Chlorine PY - 2022 UR - https://iccrrr2022.org/downloads SP - 126 EP - 127 AN - OPUS4-56062 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd A1 - Völker, Tobias A1 - Klewe, Tim A1 - Kruschwitz, Sabine T1 - Laser-induced breakdown spectroscopy to investigate the chemical composition of concrete N2 - Laser-induced breakdown spectroscopy (LIBS) is a spectroscopic method for the analysis of the chemical composition of sample materials. Generally, the measurement of all elements of the periodic table is possible. In particular, light elements such as H, Li, Be, S, C, O, N and halogens can be measured. Calibration with matrix-matching standards allows the quantification of element concentrations. In combination with scanner systems, the two-dimensional element distribution can be determined. Even rough surfaces can be measured by online adjustment of the laser focus. LIBS can also be used on-site with mobile systems. Hand-held systems are available for point measurements. Common applications include the investigation of material deterioration due to the ingress of harmful ions and their interaction in porous building materials. Due to the high spatial resolution of LIBS and the consideration of the heterogeneity of concrete, the determination of precise input parameters for simulation and modelling of the remaining lifetime of a structure is possible. In addition to the identification of materials, it is also possible to assess the composition for example of hardened concrete, which involves the cement or aggregate type used. Other important fields of application are the detection of environmentally hazardous elements or the material classification for sorting heterogeneous material waste streams during dismantling. Non-contact NDT for “difficult to assess” structures as an example application through safety glass or in combination with robotics and automation are also possible. In this work, an overview of LIBS investigations on concrete is given based on exemplary laboratory and on-site applications. T2 - NDE NucCon 2023 CY - Espoo, Finland DA - 25.01.2023 KW - LIBS KW - Concrete KW - Chemical analysis PY - 2023 UR - https://www.aalto.fi/en/nde-nuccon-2023 SP - 351 EP - 359 AN - OPUS4-57303 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Munsch, Sarah Mandy A1 - Klewe, Tim A1 - Schumacher, K. A1 - Telong, Melissa A1 - Grobla, Lili A1 - Völker, C. A1 - Yared, K. A1 - Kruschwitz, Sabine ED - Rogge, Andreas ED - Meng, Birgit T1 - Anwendung von KI für die Materialoptimierung im Bauwesen N2 - Diese Arbeit untersucht den Einsatz von Künstlicher Intelligenz (KI) in der Materialentwicklung für Beton, mit einem Fokus auf Karbonatisierungswiderstand, CO₂-Reduktion und Kostenoptimierung. Das KI-Tool SLAMD, das auf inverses Materialdesign setzt, konnte in Studien die Entwicklungszeit für Betonmischungen um bis zu 80 % verkürzen. Durch die Integration zusätzlicher 1H-Kernspinresonanz-Daten wurde der Prozess um weitere 40 % beschleunigt. Insgesamt zeigt sich, dass der Einsatz von KI die Effizienz und Nachhaltigkeit in der Materialentwicklung signifikant steigern kann. T2 - 11. Jahrestagung des DAfStb mit 63. Forschungskolloquium der BAM Green Intelligent Building CY - Berlin, Germany DA - 16.10.2024 KW - Künstliche Intelligenz (KI) KW - Materialoptimierung KW - Bauwesen PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-612949 SN - 978-3-9818564-7-7 SP - 192 EP - 200 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-61294 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klewe, Tim A1 - Strangfeld, Christoph A1 - Ritzer, Tobias A1 - Kruschwitz, Sabine ED - Littmann, K. T1 - Zerstörungsfreie Lokalisierung von Flüssigwasser in Fußböden durch Kombination von Radar und Neutronensonde N2 - Das Neutronensondenverfahren wird bereits seit vielen Jahren erfolgreich zur Eingrenzung und Quantifizierung auftretender Feuchteschäden an Fußböden eingesetzt. Hierzu bedarf es jedoch einer Vielzahl zerstörender Sondierungsbohrungen, welche die gewonnenen Messdaten kalibrieren und eine Tiefenzuordnung des Flüssigwassers zulassen. Dadurch entsteht ein zeitlicher und finanzieller Aufwand, der durch den parallelen Einsatz des elektromagnetischen Radarverfahrens vermieden werden könnte. Mit seiner hohen Sensitivität für Wasser bietet diese Messmethode die Möglichkeit der vertikalen Lokalisierung von Feuchte, was zu einer automatisierten Klassifizierung typischer Schadensfälle beitragen soll. In einem laufenden Forschungsvorhaben werden in systematischen Laborstudien gängige Schadensfälle an häufig anzutreffenden Fußbodenaufbauten simuliert und deren Einfluss auf die genannten Verfahren untersucht. Hierbei kommen Zement- und Anhydritestriche, sowie unterschiedliche Dämmmaterialen mit variierenden Schichtdicken zum Einsatz. Wesentlicher Bestandteil der Auswertung ist die Extraktion signifikanter Signalmerkmale des Radarverfahrens, welche Rückschlüsse auf den Schadensfall und ggf. die Wassermenge zulassen. Weiterführend sollen die Kombinationsmöglichkeiten der verschiedenen Signalmerkmale und der Neutronensondendaten durch Methoden der multivariaten Datenauswertung und des maschinellen Lernens geprüft werden. Die Unabhängigkeit gegenüber wechselnden Schichtdicken und Materialien steht hierbei besonders im Fokus und soll anhand der erzielten Ergebnisse evaluiert werden. T2 - 10. Kolloquium Industrieböden - Fachtagung über stark beanspruchte Bodenkonstruktionen CY - Esslingen, Germany DA - 03.03.2020 KW - Radar KW - Feuchte KW - Neutronensonde PY - 2020 SN - ISBN 978-3-8169-8505-1 (ePDF) SN - ISBN 978-3-8169-3505-6 (Print) SP - 179 EP - 185 PB - Expert Verlag CY - Tübingen AN - OPUS4-50589 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -