TY - JOUR A1 - von Werder, Julia A1 - Simon, Sebastian A1 - Gardei, André A1 - Fontana, P. A1 - Meng, Birgit T1 - Thermal and hydrothermal treatment of UHPC: influence of the process parameters on the phase composition of ultra-high performance concrete N2 - Several studies show that thermal and hydrothermal treatment can further improve the excellent properties of UHPC in terms of mechanical strength and durability. While for the thermal treatment the increase in strength is attributed to an intensified pozzolanic and hydraulic reaction, for the hydrothermal treatment previous studies accredited it mostly to the formation of tobermorite. In the presented study thermal and hydrothermal treatment of UHPC samples was systematically varied and the phase formation analysed related to the strength development of a reference sample cured for 28 days in water. For the thermal treatment the results show that the strength increase depends on the protection against desiccation and can be ascribed to an improved pozzolanic reaction of the siliceous fillers. To achieve a significant enhancement of strength, a pre-storage time of few days and a long dwell time at elevated temperature/pressure are required. For the hydrothermal treatment already heating the specimens up to 185 °C in saturated steam followed by an immediate cooling leads to a substantial increase in compressive strength. Pre-storage time did not affect the result as far as a minimum of several hours is guaranteed. The improved performance is due to an increase in the pozzolanic and hydraulic reaction. Surprisingly, tobermorite was only found within a very thin layer at the surface of the sample, but not in the bulk. Sulphate and aluminium stemming from the decomposition of the ettringite are bound in the newly formed phases hydroxylellestadite and hydrogarnet. KW - UHPC KW - Thermal treatment KW - Hydrothermal treatment KW - Compressive strength KW - Phase development KW - Durability KW - Tobermorite KW - Hydroxylellestadite KW - Hydrogarnet PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-523402 DO - https://doi.org/10.1617/s11527-021-01633-w SN - 1871-6873 SN - 1359-5997 VL - 54 IS - 1 SP - Article 44 PB - Springer Nature AN - OPUS4-52340 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sigrüner, M. A1 - Hüsken, Götz A1 - Pirskawetz, Stephan A1 - Herz, J. A1 - Muscat, D. A1 - Strübbe, N. T1 - Pull-out behavior of polymer fibers in concrete N2 - The bond between polymer fibers and the surrounding cementitious matrix is essential for the development of concrete reinforcement. The single fiber pull-out test (SFPT) is the standard characterization technique for testing the bond strength. However, the different phases of debonding cannot be distinguished by the SFPT. This study investigates the debonding of different polymer fibers from the surrounding cementitious matrix with a modified SFPT and proposes methods to change the SFPT setup to generate more valuable information on the debonding mechanism. The SFPT was equipped with linear variable differential transformers (LVDT), digital image correlation (DIC) and acoustic emission (AE) analysis. The results demonstrate that the modified SFPT allows a better understanding of the different phases of debonding during fiber pull-out. Furthermore, bond strength values calculated by different methods reveal that the chemical bond of the investigated polymers is not different as reported by previous studies. Deformation measurements performed using LVDTs and DIC are suitable measuring techniques to characterize the debonding mechanism in SFPT. A correlation between recorded AE and debonding phases was not found. KW - Polymer Fibres KW - Concrete KW - Pull-Out Behaviour KW - Debonding Mechanism PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-582918 DO - https://doi.org/10.1002/pol.20230264 SN - 2642-4169 SP - 1 EP - 13 PB - Wiley Periodicals, LLC. AN - OPUS4-58291 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agasty, Amit A1 - Hering, Marcus T1 - Eine Machbarkeitsstudie zur Skalierung von Sprengversuchen an Stahlbetonbauteilen N2 - Sprengversuche sind erforderlich, um Explosionsereignisse auf Grund von Unfällen oder Anschlägen zu untersuchen und um das Schutzniveau für Menschen und Anlagen in kritischen Infrastrukturen zu bewerten. Die Durchführung von Feldversuchen in großem Maßstab für komplexe Szenarien ist sehr ressourcenintensiv. Verlässliche Experimente im kleinen Maßstab sind eine vielversprechende Alternative. Die Skalierungsgesetze für die Bemessung von Stahlbetonkonstruktionen unter Explosionsbelastung sind jedoch nicht hinreichend etabliert. Die Forschungsarbeit fokussiert sich auf Stahlbetonstrukturen, die für die Standardisierung von skalierten Sprengversuchen in Frage kommen. Im Rahmen der Machbarkeitsstudie wurden auf dem TTS-Gelände Sprengversuche an Probekörpern unterschiedlicher Größe durchgeführt. Dabei wurden verschiedene horizontal gelagerte Stahlbetonplatten getestet und unterschiedlichen Explosionsbelastungen ausgesetzt. Die Sprengversuche umfassten verschiedene Messtechniken zur Quantifizierung der Explosionslast sowie des Verhaltens der Stahlbetonplatten. Die Explosionslast wurde mit bündig eingebauten piezoelektrischen Druckmessern gemessen, während Beschleunigungssensoren und flächig applizierte verteilte faseroptische Sensorik verwendet wurden, um das dynamische Verhalten der Platte unter Explosionsbelastung zu charakterisieren. Darüber hinaus wurden Schädigungsmerkmale ebenfalls mit verteilter faseroptischer Sensorik ermittelt. Die Anwendung solcher Messtechniken sowie die Nutzung verschiedener numerischer Softwaretools bieten die Möglichkeit die Skalierungsgesetze zu verifizieren bzw. anzupassen. T2 - BBK - Fachkongress Forschung für den Bevölkerungsschutz 2025 CY - Bonn, Germany DA - 05.02.2025 KW - Sprengversuch KW - Skalierung KW - Faseroptik PY - 2025 AN - OPUS4-62509 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grunewald, Thomas A1 - Grätz, Rainer A1 - Kühne, Hans-Carsten T1 - Werkzeuge zur Verwendung in explosionsgefährdeten Bereichen - Erkenntnisse zur Zündwahrscheinlichkeit von Edelstahl und NE-Metallen gegen Baustahl und Estrichbeton in Wasserstoff und Acetylen N2 - Üblicherweise werden Werkzeuge für den industriellen Einsatz aus hochlegierten Chromstählen hergestellt. Für den Einsatz in explosionsgefährdeten Bereichen werden oft Werkzeuge aus speziellen Nichteisen-Metalllegierungen (NE-Metall) verwendet. Für diese sogenannten funkenarmen Werkstoffe und deren mögliche Schlagpartner gibt es bisher keine umfassenden Untersuchungen mit Aussagen zur Zündwahrscheinlichkeit. Die TRGS 723, Abschn. 5.15, fordert den Nachweis der Funkenfreiheit der verwendeten Werkstoffpaarung. Jedoch sind Werkzeuge keine Geräte oder Schutzsysteme im Sinne der Richtlinie 2014/34/EU. Deshalb ist es nicht möglich, Werkzeuge in Übereinstimmung mit dieser Richtlinie zu zertifizieren. Der Nachweis der Erfüllung dieser Anforderungen ist durch Zertifizierungen im sogenannten "gesetzlich nicht geregelten" Bereich möglich. Die BAM bietet diese Zertifizierung für "Funkenarme Werkzeuge" im Rahmen ihres Zertifizierungsprogrammes an. Die bisherigen Ergebnisse der hier vorgestellten Untersuchung haben gezeigt, dass es keine funkenfreien, metallischen Werkzeuge (non-sparking Tools) gibt. Entscheidend ist im Hinblick auf die TRGS 723, ob zündfähige Funken entstehen oder nicht. Es ist immer die Frage, worauf die Werkzeuge im praktischen Anwendungsfall schlagen oder fallen gelassen werden können, d.h. aus welchem Material der mögliche Schlagpartner besteht. Dies können metallische Schlagpartner, aber auch Betonoberflächen sein. Unterschiedliche Kombinationen von Werkstoffen ergeben bei Schlagbeanspruchung im explosionsgefährdeten Bereich jeweils unterschiedliche Zündwahrscheinlichkeiten. Aber auch die Höhe der beim Einsatz der Werkzeuge möglichen kinetischen Schlagenergie und der Brenngas/Luft-Atmosphäre im betreffenden explosionsgefährdeten Bereich sind wichtige Einflussgrößen. KW - Mechanisch erzeugte Funken KW - Nichtelektrische Funken KW - Schlagfunken KW - Schleiffunken KW - Reibfunken KW - Funkenarmes Werkzeug KW - Funkenfreies Werkzeug KW - Nichtelektrischer Explosionsschutz KW - Non sparking tools PY - 2021 DO - https://doi.org/10.37544/2191-0073-2021-11-12-33 SN - 2191-0073 VL - 11 IS - 11-12 SP - 33 EP - 37 PB - VDI Fachmedien CY - Düsseldorf AN - OPUS4-53936 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sittner, Jonathan A1 - Götze, Jens A1 - Müller, Axel A1 - Renno, Axel D. A1 - Ziegenrücker, René A1 - Pan, Yuanming T1 - Trace element analysis and luminescence behavior of quartz in pegmatites of the Tørdal Region, Norway N2 - This publication presents a study on the mineral chemistry and luminescence properties of quartz samples from pegmatites of the Tørdal region in Norway. A total of 12 samples were analyzed using Secondary Ion Mass Spectrometry (SIMS), Electron Paramagnetic Resonance Spectroscopy (EPR), and Cathodoluminescence (CL) to gain insights into their trace element concentration and distribution as well as their luminescence behavior. The samples are characterized by different Cl emissions at 450 nm, 500 nm 650 nm and an additional shoulder at 390 nm, which is only partially visible due to the absorption of the glass optics. Of these luminescence bands, the 500 nm band is the most dominant in most samples and it is characterized by an initial blue-green luminescence, which is not stable under electron irradiation. Moreover, it is characterized by a heterogeneous distribution within the samples. This luminescence can be mostly assigned to [AlO4/M+]0 defects, with charge compensation mostly achieved by Li+. Analyses by EPR spectroscopy prove the dominance of structurally bound Al, Li, and Ti ions in the investigated samples. Further analyses using SIMS mapping demonstrate that Na and K are mainly bound to micro fractures or inclusions, suggesting a limited role in the compensation of the luminescence centers. Additionally, the SIMS mappings show that some samples contain Al-rich clusters of 10 to 20 µm in diameter, whereas other trace elements are characterized by a homogeneous distribution. These clusters correspond to bright luminescence areas in size and shape and could potentially indicate H+ compensated [AlO4/M+]0 defects. KW - Quartz KW - Trace elements KW - SIMS KW - Cathodoluminescence KW - EPR KW - Tørdal KW - Pegmatite PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-612529 DO - https://doi.org/10.1016/j.chemgeo.2024.122427 VL - 670 SP - 1 EP - 15 PB - Elsevier BV AN - OPUS4-61252 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hüsken, Götz A1 - Jeyifous, Olubunmi Anthony A1 - Schönsee, Eric A1 - Strangfeld, Christoph T1 - An assessment of the repeatability of 3D printed concrete structures N2 - Additive manufacturing of concrete structures, also known as 3D concrete printing, is a technology that received a lot of attention over the past decade due to its financial an ecological advantage as sustainable construction technology. Although several techniques and approaches demonstrate these advantages, quality control during printing is highly challenging and rarely applied and harmonized standards are not existing. Due to the continuous mixing process used in 3D concrete printing, it is impossible to exclude variations in the dry mixture or water content, and a single test sample is insufficient to be representative for the whole structure. A defect in one layer during the printing can affect the entire integrity of the whole structure. This study shows the results of an arch designed as framework structure that was printed multiple times under the same boundary conditions using an extrusion-based 3D concrete printer. Each arch was tested for its mechanical strength and load bearing behavior. The results of the mechanical testing of the printed arches are compared with material data obtained by classical tests and discussed regarding their statistical significance. T2 - Digital Concrete 2024 CY - Munich, Germany DA - 04.09.2024 KW - 3D concrete printing KW - Repeatability KW - Monitoring KW - Process control KW - Quality control PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611012 DO - https://doi.org/10.24355/dbbs.084-202408150641-0 SP - 1 EP - 9 PB - TU Braunschweig AN - OPUS4-61101 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rogge, Andreas A1 - Meng, Birgit A1 - Kühne, Hans-Carsten T1 - 63. DAfStb-Forschungskolloquium in der BAM - Green Intelligent Building N2 - Das jährlich im Herbst an wechselnden Forschungsstandorten stattfindende DAfStb-Forschungskolloquium wurde im Jahr 2024 von der BAM Bundesanstalt für Materialforschung und -prüfung in Berlin ausgerichtet. Unter der Überschrift „Green Intelligent Building“ referierten rd. 35 Vortragende in fünf Sitzungen unterschiedlicher Thematik über verschiedene betonbezogene Forschungsschwerpunkte in der BAM. Anhand der überwiegend von Doktoranden und Post-Docs dargebotenen Vorträge konnten sich die Teilnehmerinnen und Teilnehmer ein aktuelles Bild von der Qualität der wissenschaftlichen Arbeit und der hervorragenden Forschungsmöglichkeiten in der BAM machen. Durch die Vernetzung unterschiedlich ausgerichteter Fachbereiche innerhalb der BAM werden Synergie-Effekte genutzt. Analytische, baustoffliche, konstruktive, umweltorientierte und auf die Verfahrensentwicklung ausgerichtete Bereiche der BAM forschen gemeinsam zum Thema Stahlbetonbau. Es folgen ausführliche Zusammenfassungen der Tagungsinhalte. T2 - 11. Jahrestagung des DAfStb mit 63. Forschungskolloquium der BAM Green Intelligent Building CY - Berlin, Germany DA - 16.10.2024 KW - Bauteile KW - Bauwerke KW - Beton KW - Chemie der Bindemittel KW - Digitalisierung im Bauwesen KW - Green Intelligent Building KW - Innovative Technologien KW - Klimafreundliche Bindemittel KW - Ressourcenschonung PY - 2025 SN - 0005-9846 VL - 75 IS - 4 SP - 128 EP - 129 PB - concrete content UG CY - Schermbeck AN - OPUS4-63109 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jeyifous, Olubunmi Anthony T1 - Correlation of continuously measured in-line process parameters and extruded geometry in 3D concrete printing experiments N2 - Additive manufacturing of concrete structures is a novel and emerging tech-nology. Free contouring in civil engineering, which allows for entirely new designs, is a significant advantage. Although several techniques and ap-proaches demonstrate these advantages, quality control during printing is highly challenging and rarely applied. Due to the continuous mixing process used in 3D concrete printing, it is impossible to exclude variations in the dry mixture or water content, and a single test sample is insufficient to represent the whole structure. A defect in one layer during printing can affect the in-tegrity of the entire structure. Therefore, continuous and real-time process monitoring is required to record and document the printing process. At the Bundesanstalt für Materialforschung und -prüfung (BAM), a test rig for 3D concrete printing was developed to monitor the properties during the printing process. This study investigates the relationship between geometric accuracy and process parameters (pressure, pump torque, print speed, layer height, water content) in extrusion-based 3D concrete printing. Using a high-precision laser scanner, the geometric measurements of printed concrete ele-ments are evaluated in real-time. The concrete elements are printed under controlled conditions with varied process parameters. Preliminary findings indicate a significant correlation between process variables and geometric ac-curacy. T2 - Fourth RILEM International Conference on Concrete and Digital Fabrication CY - Munich, Germany DA - 04.09.2024 KW - 3D concrete printing KW - Geometric accuracy KW - Process monitoring KW - Quality control PY - 2024 DO - https://doi.org/https://doi.org/10.1007/978-3-031-70031-6_15 AN - OPUS4-61532 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seher, Julia T1 - Hydrothermalgranulate - Verwertungsmöglichkeit für Mauerwerkbruch N2 - Jährlich fallen in Deutschland etwa 75 Mio. t mineralische Bau- und Abbruchabfälle an, die eine vielfältig einsetzbare sekundäre Rohstoffquelle darstellen. Trotz hoher Verwertungsquoten werden Bau- und Abbruchabfälle zum Teil deponiert oder nur in Anwendungen mit geringen Qualitätsanforderungen eingesetzt, weil geeignete hochwertige Verwertungswege für solche sehr heterogen zusammengesetzte Körnungen mit hohem Feinanteil fehlen. Der Reststoff Mauerwerkbruch ist ein heterogenes SiO2-reiches Gemisch aus Ziegel-, Beton- und Leichtbeton-, Kalksandstein- und Porenbetonbruch sowie Putz- und Mörtelanhaftungen. Die uneinheitliche Zusammensetzung und mehr als 50 % Feinanteile durch die mechanische Aufbereitung verhindern eine unmittelbare Wiederverwertung als rezyklierte Gesteinskörnung. Eine Möglichkeit der effektiven Verwertung von Mauerwerkbruch stellt das rohstoffliche Recycling über einen hydrothermalen Stoffumwandlungsprozess dar, bei dem poröse Granulate entstehen. Aus den Eigenschaften der Hydrothermalgranulate, insbesondere ihrer Porenstruktur, ergeben sich Anwendungsmöglichkeiten als Filter- oder Speichermaterial, d. h. auch in Bereichen, die über den Bausektor hinausgehen. Hierbei können die Granulate Gesteinskörnungen natürlichen Ursprungs, z. B. Lavasand und Bims, oder aus natürlichen Rohstoffen hergestellte Körnungen, z. B. Blähtone, ersetzen. Somit wird ein Beitrag zur Schonung natürlicher Ressourcen und zur Energieeinsparung im Vergleich zur Blähtonherstellung geleistet. Ziel des ZIM-Kooperationsprojekts „HYTEGRA – Hydrothermalgranulate“ war die Entwicklung des Verfahrens zur Herstellung leichter Gesteinskörnungen durch die hydrothermale Behandlung eines Gemischs quarz- und kalkreicher Reststoffe. Als Ausgangsstoffe dienten ziegelhaltiger Mauerwerkbruch als SiO2-Träger und Papierasche aus dem Altpapierrecycling als CaO-Träger. Die vollständige Prozesskette von der mechanisch-physikalischen Aufbereitung der Reststoffe über die Formgebung der Grüngranulate bis zur hydrothermalen Härtung der Leichtgranulate wurde im Labormaßstab entwickelt und erprobt. Die Anwendung der Hydrothermalgranulate als Speichermaterial zur inneren Nachbehandlung von Beton und als Pflanzsubstrat sowie als Filtermaterial in Bodenfiltern zur Abwasserbehandlung wurde untersucht. Im Vortrag wird ein Überblick über die Ergebnisse des erfolgreich abgeschlossenen Projekts „HYTEGRA“ gegeben. T2 - Kolloquium der Leibniz-Sozietät der Wissenschaften zu Berlin: Die Energiewende 2.0 - Im Fokus: Die Stoffwirtschaft CY - Potsdam, Germany DA - 09.06.2023 KW - Mauerwerkbruch KW - Poröse Granulate KW - Rohstoffliches Recycling KW - Papierasche KW - Leichte Gesteinskörnung PY - 2023 AN - OPUS4-57639 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fiedler, Georg A1 - Hering, Marcus A1 - Schubert, T. A1 - Bracklow, F. A1 - Nerger, Deborah A1 - Hille, Falk A1 - Beckmann, B. ED - Wuttke, F. ED - Aji, H. ED - Özarmut, A. T1 - Schädigung von Stahlbetonplatten infolge eines harten Anpralls - Vergleich von halb-empirischen Methoden und experimentellen Ergebnissen N2 - Schutzbauwerke von systemkritischen Infrastruktureinrichtungen wie Betonwände und Betonbarrieren müssen Anprallereignissen oder schweren Unfällen in einem vertretbaren Maße widerstehen können. Anprallereignisse können verschiedenster Natur sein. Hierzu zählen Steinschlag, Fahrzeug- oder Flugzeuganprall oder auch Geschosseinschlag. Geschosseinschläge bzw. Bei den Anprall- oder Impaktereignissen wird zwischen hartem und weichem Anprall unterschieden, bei hartem Anprall verformt sich der Anprallkörper nicht oder nur geringfügig, bei weichem Anprall stark. In diesem Artikel werden Forschungsergebnisse zum harten Anprall auf bewehrte Stahlbetonplatten vorgestellt, welche über die letzten Jahre im Rahmen eines Kooperationsprojekts zwischen dem Institut für Massivbau (IMB) der Technischen Universität Dresden (TUD) und der Bundesanstalt für Materialforschung und -prüfung (BAM) durchgeführt wurden. Auf dem Gelände des Otto-Mohr-Labors (OML) der TUD steht hierfür ein speziell konzipierter Fallturm zur Verfügung. Der Aufbau im Fallturm lässt aktuell druckluftbeschleunigte Impaktversuche mit mittleren Anprallgeschwindigkeiten zu. Die durch Anprall geschädigten Stahlbetonplatten wurden anschließend bei der BAM mit Strahlung tomographisch untersucht. Diese Untersuchungen ermöglichen einen Blick auf die Schädigung und Rissstruktur im Inneren der Stahlbetonplatten. Ein Schwerpunkt der durchgeführten Untersuchung ist der Vergleich von Testergebnissen mit den häufig angewendeten halbempirischen Berechnungsmethoden zu den erforderlichen Wandstärken und den sich daraus ergebenden zulässigen Anprallgeschwindigkeiten. Bei diesem Vorgehen wird auch die mit analytischen Methoden abschätzbare Durchdringungsgeschwindigkeit bzw. Austrittgeschwindigkeit eines Projektils ermittelt und mit den realen Testergebnissen verglichen. Außerdem wird der Einfluss von sowohl externen als auch internen Strukturparametern auf Risse betrachtet und ein Fazit abgeleitet. Weiterhin werden laufende und zukünftige wissenschaftliche Untersuchungen zum Anprall auf Betonstrukturen am IMB und der BAM genannt. T2 - 18. D-A-CH-Tagung CY - Kiel, Germany DA - 13.09.2023 KW - Impakt KW - Harter Anprall an Stahlbetonstrukturen KW - Fallturm PY - 2023 SN - 978-3-930108-15-1 SP - 471 EP - 479 PB - Deutsche Gesellschaft für Erdbebeningenieurwesen und Baudynamik (DGEB) e.V. AN - OPUS4-58341 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seher, Julia T1 - Lightweight Aggregates - Recycling of Construction and Demolition Waste N2 - A brief introduction into the production of lightweight aggregates from construction and demolition waste and some results of the project HYTEGRA. T2 - Postdoc Symposium: BAM Focus Area Material CY - Online meeting DA - 28.04.2021 KW - Leichte Gesteinskörnung KW - Rohstoffliches Recycling KW - Reststoffe KW - Mauerwerkbruch KW - Papierasche KW - Speichermaterial PY - 2021 AN - OPUS4-52606 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - von Werder, Julia T1 - Internal sulfate resistance of concrete N2 - If the amount of sulfate within the mix design for concrete is not balanced, ettringite formation which first controls solidification continues while the concrete is hardening. Ettringite forms by reaction of sulfate contained in the cement or in some admixture with calcium aluminate (C3A) as cement component. The “late primary ettringite formation” promotes an increase in volume within the hardened concrete leading to cracks. To analyze the effect of substituting part of ordinary Portland cement (OPC) by a treated brown coal fly ash mortar bars were tested according to ASTM C452. This test method was originally developed to extrapolate from the internal to external sulfate attack and is based on the idea that by testing a concrete mixture containing sulfate the process of deterioration is accelerated because it does not have to diffuse into the concrete before reaction first. In addition to the samples prescribed in ASTM C452 further samples in the size of the German SVA procedure were tested also designed for accessing the external sulfate resistance. The results show that while the replacement of 25 % of cement by brown coal fly ash leads to length changes around the limit defined by ASTM, the substitution of 50 % cement exceeded the limit by a multiple. The progress of expansion is the very similar for the two geometries tested. In-situ XRD measurements confirmed that while for pastes made of OPC the formation of ettringite is completed after 20 hours, this is not true for the mixtures containing the brown coal fly ash. In a different study the effect of hydrothermal treatment on the phase composition of ultra-high-performance concrete was analyzed. The results show that the sulfate and aluminate resulting from the decomposition of ettringite are bound into new phases. If this binding is permanent this might allow the larger use of sulfate bearing raw materials. T2 - EuroCoalAsh 2021 Conference CY - Online meeting DA - 02.11.2021 KW - Brown coal fly ash KW - Ettringite KW - Internal sulfate resistance KW - Test methods KW - In-situ XRD KW - Hydrothermal treatment PY - 2021 AN - OPUS4-54134 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schönsee, Eric T1 - Investigations on multi-sensor data for monitoring volume flow during the printing process N2 - Extrusion based 3D concrete printing (3DCP) is a growing technology because of its high potential for automating construction and the new possibilities of design. In conventional construction methods, a sample is taken to be representative for one material batch. However, in 3DCP continuous mixing is used which results in variations during the mixing process. Therefore, one sample is not representative for the entire structure. This leads to the necessity of continuous and real-time process monitoring. This study focuses on the variations of pressure and temperature which are caused by changes in the material due to the ongoing mixing process. Changes in material, which is transported downstream, are influencing sensor signals in different positions with a time delay. In the following, the data is analysed to investigate if the changing material and the so caused change in pressure can be used to calculate volume flow. T2 - Digital Concrete 2024 CY - Munich, Germany DA - 04.09.2024 KW - Additive Manufacturing KW - In-line Monitoring KW - Volume Flow KW - Process Control PY - 2024 AN - OPUS4-61002 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weise, Frank A1 - von Werder, Julia A1 - Manninger, Tanja A1 - Maier, Bärbel A1 - Fladt, Matthias A1 - Simon, Sebastian A1 - Gardei, Andre A1 - Höhnel, Desirée A1 - Pirskawetz, Stephan A1 - Meng, Birgit T1 - A multiscale and multimethod approach to assess and mitigate concrete damage due to alkali-silica reaction N2 - Alkali-silica reaction (ASR) is a chemical reaction within concrete which can lead over time to cracking and spalling. Due to the complexity of the problem, it still causes damage to concrete constructions worldwide. The publication aims to illustrate the interdisciplinary research of the German Federal Institute for Materials Research and Testing (BAM) within the last 20 years, considering all aspects of ASR topics from the macro to the micro level. First, methods for characterization and assessment of ASR risks and reaction products used at BAM are explained and classified in the international context. Subsequently the added value of the research approach by combining different, preferably nondestructive, methods across all scales is explained using specific examples from a variety of research projects. Aspects covered range from the development of new test-setups to assess aggregate reactivity, to analysis of microstructure and reaction products using microscopical, spectroscopical and X-ray methods, to the development of a testing methodology for existing concrete pavements including in-depth analysis of the visual damage indicator and the de-icing salt input using innovative testing techniques. Finally, research regarding a novel avoidance strategy that makes use of internal hydrophobization of the concrete mix is presented. KW - Mitigation strategies KW - Concrete KW - Damage analysis KW - Alkali silica reaction KW - Road pavement KW - Accelerated testing KW - Non-destructive testing KW - Microstructure PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:101:1-2022052515100075090235 DO - https://doi.org/10.1002/adem.202101346 SN - 1527-2648 VL - 24 IS - 6 SP - 1 EP - 36 PB - Wiley-VCH CY - Weinheim AN - OPUS4-54951 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rübner, Katrin T1 - HYTEGRA - Hydrothermalgranulate - Rohstoffliches Recycling von Mauerwerkbruch N2 - Ziel des Projekts HYTEGRA ist die Herstellung leichter Gesteinskörnungen durch hydrothermale Behandlung quarz- und kalkreicher Reststoffe. Als Ausgangsstoffe dienen heterogener Mauerwerkbruch aus Bau- und Abbruchabfällen als SiO2-Träger und Papierasche aus dem Altpapierrecycling als CaO-Träger. Für beide Reststoffe besteht derzeit ein Verwertungsdefizit. Das Verfahren beruht auf der Idee des rohstofflichen Recyclings, d. h. die chemisch-mineralogischen Stoffeigenschaften werden für die hydrothermale Stoffumwandlung genutzt. Bei der Härtung der Hydrothermalgranulate bilden sich Calciumsilicathydrat-Phasen (CSH) aus der Reaktion zwischen Quarzpartikeln und Kalk im Autoklav bei 200 °C und 16 bar Sattdampf. T2 - Innovationstag Mittelstand des BMWK am 22. Juni 2022 CY - Berlin, Germany DA - 23.06.2022 KW - Mauerwerkbruch KW - Papierasche KW - Rohstoffliches Recycling KW - Leichte Gesteinskörnung KW - Bodenfilter PY - 2022 AN - OPUS4-55552 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kocherla, Amarteja T1 - Embedded Sensors for Quality Control and Structural Integrity Monitoring of Large scale 3DCP Structures N2 - Additive manufacturing of concrete structures is a novel and emerging technology. Free contouring in civil engineering, which allows for entirely new designs, is a significant advantage. Although several techniques and approaches demonstrate these advantages, quality control during printing is highly challeng-ing and rarely applied. Due to the continuous mixing process used in 3D concrete printing, it is impossible to exclude variations in the dry mixture or water content, and a single test sample is insufficient to represent the whole structure. A defect in one layer during printing can affect the integrity of the entire structure. T2 - 34th Annual Conference & Exhibition on non destructive evaluation & enabling technologies CY - Chennai, India DA - 12.12.2024 KW - Embedded sensors KW - Additive manufacturing KW - Concrete printing KW - Piezo sensors PY - 2024 AN - OPUS4-62546 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schönsee, Eric T1 - Investigations on multi-sensor data for monitoring volume flow N2 - Extrusion based 3D concrete printing (3DCP) is a growing technology because of its high potential for automating construction and the new possibilities of de-sign. In conventional construction methods, a sample is taken to be representative for one material batch. However, in 3DCP continuous mixing is used which re-sults in variations during the mixing process. Therefore, one sample is not repre-sentative for the entire structure. This leads to the necessity of continuous and re-al-time process monitoring. At the Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, a test rig is developed to allow for comprehensive monitoring of the printing process. For this purpose, sensors for torque, temperature, pressure and moisture are in-stalled into the pipe. A laser scanner is installed at the nozzle to acquire infor-mation about the geometry of the extruded material. This study focuses on the variations of pressure and temperature which are caused by changes in the material due to the ongoing mixing process. Preliminary results indicate that changes in the material properties cause changes in the sensor signals as well. These changes can be observed in various sensors with a delay, caused by material which is carried downstream. In the following, the data is ana-lysed to investigate if the changing material and the so caused change in pressure can be used to calculate volume flow. T2 - Digital Concrete 2024 CY - Munic, Germany DA - 04.09.2024 KW - 3D concrete printing KW - Monitoring KW - Pressure PY - 2024 AN - OPUS4-60997 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kühne, Hans-Carsten T1 - Die Kandelaber des Ensembles am Charlottenburger Tor N2 - Auf der Charlottenburger Brücke entstand mit dem Charlottenburger Tor und den beiden Kandelabern von 1905 bis 1908 ein repräsentatives Ensemble von Einzelbauwerken. Für die architektonische Wirkung des Charlottenburger Tores waren die beiden ca. 22 Meter hohen Kandelaber auf der Charlottenburg zugewandten Seite des Tores bedeutsam. Die Stiftung Denkmal ließ die Kandelaber seit Mai 2007 mit dem Ziel rekonstruieren, dem Tor, seiner Umgebung und der Straße des 17 Juni den historischen Gesamteindruck wiederzugeben. Im Rahmen der Rekonstruktion wurde die Grundsatzentscheidung getroffen, dass die Wiederherstellung der komplett zerstörten und auch nicht mehr in Fragmenten vorhandenen Kandelaber nicht unter Anwendung der Bautechnik von 1900 durchgeführt werden sollte. Die Zielsetzung war viel mehr, mit moderner Bautechnik die Anmutung der Kandelaber von 1903 wiederherzustellen, die in Verbindung mit anderen baulichen Elementen, wie der Charlottenburger Brücke und des Charlottenburger Tores, den historischen Gesamtkomplex bilden. T2 - Workshop Kulturguterhaltung - Vom Dampfkessel zu Nanomaterialien CY - Berlin, Germany DA - 17.11.2021 KW - Charlottenburger Tor KW - Kunststein KW - Hydrophobierung KW - Bildhauerbeton PY - 2021 VL - 3 SP - 97 EP - 105 PB - Druckerei G. Bohm CY - Berlin AN - OPUS4-57091 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogler, Nico A1 - Lindemann, Mathias A1 - Drabetzki, Philipp A1 - Kühne, Hans-Carsten T1 - Alternative pH-indicators for determination of carbonation depth on cement-based concretes N2 - The most common method for determination of the carbonation depth is the sprayed application of indicator solutions, Phenolphthalein in particular. Since the aerosols of Phenolphthalein are suspected to be carcinogenic, efforts have been intensified to use alternative indicators for the determination of carbonation depth. The subject and aim of this research paper are to examine indicator solutions from Alizarin Yellow R, Thymol Blue and a Mixed Indicator. These indicator solutions are commercially available and are not suspected to be carcinogenic. For the purpose of this research, samples previously stored under accelerated carbonation conditions (1% CO2) were examined by thermogravimetric analysis (TGA) and examination of the pH value. Additionally, the electrolytic back-titration for determination of total CO2 amount was carried out comparatively to TGA. KW - Thermal analysis KW - Accelerated carbonation KW - pH-indicators KW - Concrete PY - 2020 DO - https://doi.org/10.1016/j.cemconcomp.2020.103565 VL - 109 SP - 1 EP - 9 PB - Elsevier Ltd. AN - OPUS4-50458 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seher, Julia T1 - Hydrothermalgranulate - Verwertungsmöglichkeit für gemischten Mauerwerkbruch und Papierasche N2 - Jährlich fallen in Deutschland ca. 56 Mio. t mineralischer Bauschutt an, der eine vielfältig einsetzbare sekundäre Rohstoffquelle darstellt. Trotz hoher Verwertungsquoten werden Bau- und Abbruchabfälle zum Teil deponiert, weil geeignete und rentable Verwertungswege fehlen. Der Reststoff Mauerwerkbruch ist ein heterogenes SiO2-reiches Gemisch aus Ziegel, Beton- und Leichtbetonsteinen, Kalksandstein, Porenbeton, Putz und Mörtel. Die un-einheitliche Zusammensetzung und mehr als 50 % Feinanteile durch die mechanische Aufbereitung verhindern meist eine unmittelbare Wiederverwertung als RC-Gemisch. Eine Möglichkeit der effektiven Verwertung von Mauerwerkbruchmehlen stellt das rohstoffliche Recycling über einen hydrothermalen Stoffumwandlungsprozess dar, bei dem poröse Granulate entstehen. Aus den Granulateigenschaften, insbesondere der Porenstruktur, ergeben sich Anwendungen als Filter- oder Speichermaterial, d. h. auch in Bereichen, die über den Bausektor hinausgehen. Hierbei können die Granulate leichte Gesteinskörnungen natürlichen Ursprungs, z. B. Lavasand oder Blähtone, ersetzen und somit einen Beitrag zur Schonung natürlicher Ressourcen leisten. Im Fokus des aktuellen ZIM-Projekts HYTEGRA steht die Entwicklung eines solchen hydrothermalen Herstellungsprozesses und die umfassende Charakterisierung der hergestellten Hydrothermalgranulate. Als sekundäre Rohstoffquelle wird neben SiO2-reichem Mauerwerkbruch aus Bau- und Abbruchabfällen auch CaO-reiche Papierasche eingesetzt. Die-se Asche aus dem Altpapierrecycling weist ebenfalls ein erhebliches Verwertungsdefizit auf. Ihr Freikalk ermöglicht den Einsatz als Kalksubstitut. Die Herstellung der Hydrothermalgranulate erfolgt in einem mehrstufigen mechanischen Prozess mit abschließender hydrothermaler Behandlung. Das konventionell mechanisch aufbereitete Abbruchmaterial (RC-Gemisch < 32 mm) wird mittels Kugelmühle zu einem Mehl (< 120 µm) verarbeitet, welches im Intensivmischer unter Zugabe von Kalk und Wasser granuliert wird. Die Härtung der Grüngranulate erfolgt hydrothermal unter erhöhtem Druck in gesättigter Wasserdampfatmosphäre bei Temperaturen von etwa 200 °C. Während des Härtungsprozesses bilden sich aus Quarz (SiO2), Kalk (CaO) und Wasser Calciumsilicathydrat-Phasen, die für die benötigte Festigkeit und Porosität der Hydrothermalgranulate sorgen. Durch die Variation der Syntheseparameter Temperatur, Druck, Zeit und SiO2-CaO-Mischungsverhältnis während der hydrothermalen Härtung, aber auch durch die Prozessführung der Granulierung, wird die Variation und gezielte Einstellung der Eigenschaften der Hydrothermalgranulate ermöglicht. In Kooperation mit Industriepartnern werden die hergestellten Hydrothermalgranulate in verschiedenen Applikationsbereichen getestet, z.B. in Bodenfiltern zur Abwasserbehandlung sowie als temporärer Wasserspeicher zur inneren Nachbehandlung von hochfestem Beton und in Pflanzsubstraten. Im Tagungsbeitrag wird das Projekt HYTEGRA vorgestellt, insbesondere der hydrothermale Verwertungsweg unter Verwendung von Mauerwerkbruch und Papierasche im Labor- und Technikumsmaßstab sowie die Anwendung der hergestellten porösen Granulate als Filter- und Speichermaterial. T2 - Tagung "Aufbereitung und Recycling" 2020 CY - Online meeting DA - 12.11.2020 KW - Mauerwerkbruch KW - Papierasche KW - Rohstoffliches Recycling KW - Poröse Granulate PY - 2020 AN - OPUS4-51560 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rübner, Katrin T1 - Vom Bauschutt zur leichten Gesteinskörnung N2 - Leichte Gesteinskörnungen können ressourcenschonend aus heterogenen und feinkörnigen Bau- und Abbruchabfällen in einem mehrstufigen Prozess durch thermische oder hydrothermale Stoffumwandlung hergestellt werden. Ihre Anwendung erfolgt in Leichtbetonen und Leichtmörteln, als Schüttung im Garten und Landschaftsbau oder auch als Filter- und Speichermaterial. In zahlreichen Forschungsprojekten wurden die Herstellungsprozesse entwickelt, die Materialeigenschaften optimiert und unterschiedliche Applikationen untersucht. In diesem Beitrag wird zusammenfassend über dieser Forschungsarbeiten berichtet. T2 - 11. Jahrestagung des DAfStb mit 63. Forschungskolloquium der BAM Green Intelligent Building CY - Berlin, Germany DA - 16.10.2024 KW - Bauschutt KW - Leichte Gesteinskörnung KW - Mauerwerkbruch KW - Hydrothermalgranulat PY - 2024 AN - OPUS4-61741 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Manninger, T. A1 - von Werder, Julia A1 - Rübner, Katrin T1 - Lehmstabilisierung mittels eines Biomasseasche basierten Alkali-Aktivators und kalziniertem Ton N2 - Lehm sowie Lehmziegel sind jahrtausendealte Baustoffe, die sich durch lokale Verfügbarkeit, Umweltverträglichkeit und geringe COa-Belastung auszeichnen. Diese Eigenschaften machen sie zu Baustoffen der Zukunft. Wasserbeständigkeit ist ein wichtiger Aspekt, der beim Einsatz beachtet werden muss. Es gibt verschiedene Ansätze zur Stabilisierung, Idealerwelse sollen dabei die positiven Aspekte des Lehms, wie beispielsweise die Luftfeuchteregullerung, bewahrt werden. Zement ist hierfür nur bedingt geeignet. Als Alternative zur Stabilisierung mit Zement wurden in einer Versuchsreihe Mischungen mit calclnierten Tonen untersucht. Diese bei 600 °C auf CO2 sparende Welse erzeugten, lokal verfügbaren Rohstoffe, können mittels Alkall-Aktivierung zu einem festen „Geopolymer" vernetzt werden. Zur Aktivierung wurde eine lokal verfügbare Biomasseasche aus Hackschnitzelholz, sowie Industriell hergestelltes KOH genutzt, da das in beiden enthaltene Kalium das umweltverträglichste Alkallion Ist. In einer Versuchsreihe wurde das Verhalten des reinen Lehms mit dem stabilisierten Material verglichen. Es wurden Festigkeitswerte, Wasserlagerungsbeständigkeit und Wasserdampfdiffusionswiderstand geprüft. T2 - Internationale Baustofftagung (ibausil) CY - Weimar, Germany DA - 13.09.2023 KW - Lehmstabilisierung KW - Alkali aktivierte Bindemittel KW - Wasserbeständigkeit KW - Putz KW - Erdbau KW - Kalzinierter Ton PY - 2023 UR - https://www.uni-weimar.de/de/bauingenieurwesen/institute/fib/ibausil/ VL - 2023 SP - 1 EP - 6 PB - Sonderausgabe des Online-Journals ce/papers von Wiley AN - OPUS4-58316 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - von Werder, Julia A1 - Simon, Sebastian A1 - Meng, Birgit T1 - Internal sulfate resistance of concrete N2 - If the amount of sulfate within the mix design for concrete is not balanced, ettringite formation which first controls solidification continues while the concrete is hardening. Ettringite forms by reaction of sulfate contained in the cement or in some admixture with calcium aluminate (C3A) as cement component. The “late primary ettringite formation” promotes an increase in volume within the hardened concrete leading to cracks. To analyze the effect of substituting part of ordinary Portland cement (OPC) by a treated brown coal fly ash mortar bars were tested according to ASTM C452. This test method was originally developed to extrapolate from the internal to external sulfate attack and is based on the idea that by testing a concrete mixture containing sulfate the process of deterioration is accelerated because it does not have to diffuse into the concrete before reaction first. In addition to the samples prescribed in ASTM C452 further samples in the size of the German SVA procedure were tested also designed for accessing the external sulfate resistance. The results show that while the replacement of 25 % of cement by brown coal fly ash leads to length changes around the limit defined by ASTM, the substitution of 50 % cement exceeded the limit by a multiple. The progress of expansion is the very similar for the two geometries tested. In-situ XRD measurements confirmed that while for pastes made of OPC the formation of ettringite is completed after 20 hours, this is not true for the mixtures containing the brown coal fly ash. In a different study the effect of hydrothermal treatment on the phase composition of ultra-high-performance concrete was analyzed. The results show that the sulfate and aluminate resulting from the decomposition of ettringite are bound into new phases. If this binding is permanent this might allow the larger use of sulfate bearing raw materials. T2 - EuroCoalAsh 2021 Conference CY - Online meeting DA - 02.11.2021 KW - Brown coal fly ash KW - Ettringite KW - Internal sulfate resistance KW - Test methods KW - In-situ XRD KW - Hydrothermal treatment PY - 2021 SP - 131 EP - 137 CY - Thessaloniki AN - OPUS4-54133 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mundra, Shishir A1 - Hüsken, Götz A1 - Kühne, Hans-Carsten ED - Sena-Cruz, J. ED - Correia, L. ED - Azenha, M. T1 - Electrochemical realkalisation of carbonated "Dalle de Verre" windows N2 - Concrete-glass windows or commonly referred to as “Dalle de Verre” windows are prevalent in historical monuments across Europe. “Dalle de Verre” windows were made by placing cut stained glasses, of various shapes and sizes, into a steel reinforced concrete frame. In addition to the steel reinforcement, a few steel wires run across the concrete elements to hold the glass windows into place. Much of these structures have been damaged due to carbonation of the thin concrete covers and consequent corrosion of the steel reinforcement; and exhibit several cracks due to the expansive nature of corrosion products formed at the steel–concrete interface. This study focussed on understanding the efficacy of electrochemical realkalisation in reinstating the passive state of the steel reinforcement embedded in such concrete glass windows. Simulant “Dalle de Verre” windows (representative of windows at Kaiser-Wilhelm Gedächtniskirche) were produced using different cements with a water/cement ratio of 0.6 and carbonated under accelerated conditions. Post carbonation, the concrete glass windows were electrochemically realkalised using a sacrificial anode. The influence of highly alkaline conditions due to electrochemical realkalisation on the glass-concrete interface has also been investigated. This study shows that the passive state of the steel reinforcement in “Dalle de Verre” windows, particularly at the Kaiser-Wilhelm Gedächtniskirche (memorial church) in Berlin, can be reinstated using the electrochemical realkalisation method. T2 - 3rd RILEM Spring Convention and Conference (RSCC 2020) CY - Online meeting DA - 10.03.2020 KW - Electrochemical realkalisation KW - Carbonation KW - Concrete-glass windows KW - Passivation KW - Dalle-de-verre PY - 2021 SN - 978-3-030-76465-4 DO - https://doi.org/10.1007/978-3-030-76465-4_15 SN - 2211-0844 VL - RILEM bookseries 34 SP - 163 EP - 171 PB - Springer CY - Cham AN - OPUS4-54299 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weise, Frank T1 - Begutachtung Berliner Tuffsteinfassaden - Turmruine der Kaiser-Wilhelm-Gedächtniskirche und Charlottenburger Tor N2 - Am Ende des 19. und zu Beginn des 20. Jahrhunderts wurden auch in Berlin vermehrt Fassadenverblendung aus Eifeler Tuffsteinen errichtet. Die Eifeler Tuffsteine zeichnen sich aufgrund ihrer hohen Porosität einerseits durch eine gute Verarbeitbarkeit aus. Andererseits sind sie nur schwach gebunden und besitzen deshalb eine geringe Verwitterungsbeständigkeit. T2 - Workshop zur Kulturguterhaltung CY - Berlin, Germany DA - 17.11.2021 KW - Fassade KW - Tuffstein KW - Schalenbildung PY - 2021 AN - OPUS4-54633 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strangfeld, Christoph T1 - In situ Prozessüberwachung und Qualitätskontrolle bei der additiven Fertigung von Betonbauteilen N2 - In der additiven Fertigung von Beton wird kontinuierlich Material gemischt und verarbeitet. Dies erfordert eine kontinuierliche in situ Prozessüberwachung und Qualitätskontrolle. An der BAM wurde ein 3D-Betondrucker aufgebaut, der eine umfängliche Prozessüberwachung ermöglicht. Druck-, Temperatur- und Feuchtesensoren in der Pumpe und im Fördersystem erlauben ein kontinuierliches Monitoring des Frischbetons, während ein Laserlinienscanner am Druckkopf unmittelbar die gedruckte Ist-Kontur verfolgt. Die so gewonnenen Daten können Grundlage für die Erarbeitung von Normen für die additive Fertigung von Betonbauteilen sein und somit deren Standsicherheit gewährleisten. T2 - 63. For‍schungs‍kol‍lo‍qui‍um des Deutschen Ausschuss für Stahlbeton CY - Berlin, Germany DA - 16.10.2024 KW - Additive Fertigung KW - Beton KW - Frischbetoncharakterisierung KW - Extrusionsdruck PY - 2024 AN - OPUS4-61390 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jeyifous, Olubunmi Anthony A1 - Schönsee, Eric A1 - Strangfeld, Christoph A1 - Hüsken, Götz T1 - Correlation of continuously measured in-line process parameters and extruded geometry in 3D concrete printing experiments N2 - Additive manufacturing of concrete structures is a novel and emerging tech-nology. Free contouring in civil engineering, which allows for entirely new designs, is a significant advantage. Although several techniques and ap-proaches demonstrate these advantages, quality control during printing is highly challenging and rarely applied. Due to the continuous mixing process used in 3D concrete printing, it is impossible to exclude variations in the dry mixture or water content, and a single test sample is insufficient to represent the whole structure. A defect in one layer during printing can affect the in-tegrity of the entire structure. Therefore, continuous and real-time process monitoring is required to record and document the printing process. At the Bundesanstalt für Materialforschung und -prüfung (BAM), a test rig for 3D concrete printing was developed to monitor the properties during the printing process. This study investigates the relationship between geometric accuracy and process parameters (pressure, pump torque, print speed, layer height, water content) in extrusion-based 3D concrete printing. Using a high-precision laser scanner, the geometric measurements of printed concrete ele-ments are evaluated in real-time. The concrete elements are printed under controlled conditions with varied process parameters. Preliminary findings indicate a significant correlation between process variables and geometric ac-curacy. T2 - Fourth RILEM International Conference on Concrete and Digital Fabrication CY - Munich, Germany DA - 04.09.2024 KW - 3D concrete printing KW - Geometric accuracy KW - Process monitoring KW - Quality control PY - 2024 DO - https://doi.org/10.1007/978-3-031-70031-6_15 SP - 127 EP - 133 AN - OPUS4-61534 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hüsken, Götz T1 - Wiederholbarkeit additiv gedruckter Betonbauteile N2 - Die additive Fertigung von Betonbauteilen, auch bekannt als 3D-Betondruck, ist eine Technologie, die im letzten Jahrzehnt aufgrund ihrer finanziellen und ökologischen Vorteile als nachhaltige Fertigungstechnologie viel Aufmerksamkeit erhalten hat. Obwohl die Vorteile der additiven Fertigung bereits durch zahlreiche Forschungs- und Demonstrationsprojekte gezeigt wurden, ist die Qualitätskontrolle während des Druckens äußerst anspruchsvoll und wird auch aufgrund fehlender harmonisierter Normen kaum angewendet. Aufgrund des kontinuierlichen Mischprozesses beim 3D-Betondruck ist es unmöglich Schwankungen des Trockenmörtels oder des Wassergehalts auszuschließen. Daher ist eine einzelne Stichprobe nicht mehr repräsentativ für das gesamte Bauteil und ein während des Druckens in einer Schicht auftretender Fehler kann die Integrität der gesamten Struktur beeinträchtigen. In diesem Beitrag werden die Ergebnisse eines als Fachwerkstruktur konzipierten Bogens, der unter vergleichbaren Randbedingungen mehrmals mit einem 3D-Betonextrusionsdrucker gedruckt wurde, vorgestellt. Jeder Bogen wurde auf seine mechanische Festigkeit und sein Tragverhalten geprüft. Die Ergebnisse der mechanischen Prüfungen der gedruckten Bögen werden mit Materialdaten aus klassischen Materialprüfungen verglichen und hinsichtlich ihrer statistischen Signifikanz diskutiert. T2 - 11. Jahrestagung des DAfStb mit 63. Forschungskolloquium der BAM Green Intelligent Building CY - Berlin, Germany DA - 16.10.2024 KW - Additiv gedruckte Betonbauteile KW - Wiederholbarkeit KW - Monitoring KW - 3D-Betondruck PY - 2024 AN - OPUS4-61569 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jeyifous, Olubunmi Anthony T1 - Correlation of continuously measured in-line process parameters and extruded geometry in 3D concrete printing experiments N2 - Additive manufacturing of concrete structures is a novel and emerging tech-nology. Free contouring in civil engineering, which allows for entirely new designs, is a significant advantage. Although several techniques and ap-proaches demonstrate these advantages, quality control during printing is highly challenging and rarely applied. Due to the continuous mixing process used in 3D concrete printing, it is impossible to exclude variations in the dry mixture or water content, and a single test sample is insufficient to represent the whole structure. A defect in one layer during printing can affect the in-tegrity of the entire structure. Therefore, continuous and real-time process monitoring is required to record and document the printing process. At the Bundesanstalt für Materialforschung und -prüfung (BAM), a test rig for 3D concrete printing was developed to monitor the properties during the printing process. This study investigates the relationship between geometric accuracy and process parameters. T2 - Fourth RILEM International Conference on Concrete and Digital Fabrication CY - Munich, Germany DA - 04.09.2024 KW - 3D concrete printing KW - Geometric accuracy KW - Process monitoring KW - Quality control PY - 2024 AN - OPUS4-61535 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hering, Marcus A1 - Fiedler, Georg T1 - Investigation of multiple impact-damaged reinforced concrete structures as a reference for liquid penetration behavior and tomographic studies N2 - The structural integrity of outer reinforced concrete (RC) containments of nuclear power plants provides an essential shield against external hazards. If this containment is damaged by an impact event, such as an aircraft crash, the question arises to which degree the reinforced concrete containment still has its protective capability. This concerns both purely structural protection and protection against liquids penetrating the interior of the containment. Due to the dimensions of the containment structures, it is difficult to perform real scale impact experiments, so in the past decades plate geometries at medium scale have been used for investigations. Detailed investigations on the structural behaviour of RC members or RC plates subjected to impact loading have already been presented in Just et al., Hering, Hering et al., Bracklow et al., Hille et al. and Nerger et al. The following investigations deal with the single and multiple impact event (first hard impact and/or subsequent soft impact) on a RC specimen, which provides the basis for further investigations. A description of the test setup and the test procedure as well as a presentation of the test results from the impact tests are provided. Furthermore, the experimental program is presented, which the damaged RC specimens are to undergo to deal with the question of how much the impact-damaged RC structure has become permeable to liquid media, such as water and kerosene, depending on the intensity of the impact. The aim of these following investigations is to develop a test setup that can be applied to investigate the liquid penetration behaviour (LPB) of small, medium, and large-scale RC members. In addition to the liquid penetration experiments, the damaged specimens are to be examined by planar tomography to obtain the damage inside the specimen. The combination of damaging event, fluid penetration behaviour and tomography should enable a comprehensive understanding of the damage to the RC specimen. T2 - Conference: 27th International Conference on Structural Mechanics in Reactor Technology (SMiRT) CY - Yokohama, Japan DA - 04.03.2024 KW - Drop Tower KW - Hard Impact KW - Multiple Impact KW - Soft Impact PY - 2024 AN - OPUS4-61991 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin T1 - Measuring Dynamic Behavior and Damage Evolution of a Reinforced Concrete Wall Subjected to Explosive Blasts using Embedded Distributed Fiber Optic Sensors N2 - Results from highly dynamic and static strain measurements, respectively, using embedded distributed fiber optic sensors in a steel-reinforced concrete wall under explosive blast-loading are presented, detailing the structure’s dynamic behavior and the evolutions of cracks. T2 - 28th International Conference on Optical Fiber Sensors (OFS-28) CY - Hamamatsu, Japan DA - 20.11.2023 KW - Distributed acoustic sensing KW - DAS KW - Structural response KW - Blast experiment KW - Embedded fiber optic sensor PY - 2023 AN - OPUS4-59094 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hering, Marcus A1 - Fiedler, Georg A1 - Schubert, T. A1 - Hille, Falk A1 - Hüsken, Götz A1 - Beckmann, B. A1 - Grunwald, Marcel A1 - Redmer, Bernhard A1 - Rogge, Andreas T1 - Investigation of multiple impact-damaged reinforced concrete structures as a reference for liquid penetration behavior and tomographic studies N2 - The structural integrity of outer reinforced concrete (RC) containments of nuclear power plants provides an essential shield against external hazards. If this containment is damaged by an impact event, such as an aircraft crash, the question arises to which degree the reinforced concrete containment still has its protective capability. This concerns both purely structural protection and protection against liquids penetrating the interior of the containment. Due to the dimensions of the containment structures, it is difficult to perform real scale impact experiments, so in the past decades plate geometries at medium scale have been used for investigations. Detailed investigations on the structural behaviour of RC members or RC plates subjected to impact loading have already been presented in Just et al., Hering, Hering et al., Bracklow et al., Hille et al. and Nerger et al. The following investigations deal with the single and multiple impact event (first hard impact and/or subsequent soft impact) on a RC specimen, which provides the basis for further investigations. A description of the test setup and the test procedure as well as a presentation of the test results from the impact tests are provided. Furthermore, the experimental program is presented, which the damaged RC specimens are to undergo to deal with the question of how much the impact-damaged RC structure has become permeable to liquid media, such as water and kerosene, depending on the intensity of the impact. The aim of these following investigations is to develop a test setup that can be applied to investigate the liquid penetration behaviour (LPB) of small, medium, and large-scale RC members. In addition to the liquid penetration experiments, the damaged specimens are to be examined by planar tomography to obtain the damage inside the specimen. The combination of damaging event, fluid penetration behaviour and tomography should enable a comprehensive understanding of the damage to the RC specimen. T2 - Conference: 27th International Conference on Structural Mechanics in Reactor Technology (SMiRT) CY - Yokohama, Japan DA - 04.03.2024 KW - Drop tower KW - Hard impact KW - Soft impact KW - Multiple impact PY - 2024 SP - 1 EP - 10 PB - IASMiRT CY - Yokohama, Japan AN - OPUS4-59723 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hüsken, Götz A1 - Shamsuddoha, Md A1 - Pirskawetz, Stephan A1 - Hofmann, Detlef A1 - Baeßler, Matthias A1 - Kühne, Hans-Carsten T1 - Potential of a Repair System for Grouted Connections in Offshore Structures: Development and Experimental Verification N2 - Grouted connections are intensively used in offshore rigs, platforms as well as jacket and monopile offshore wind turbine structures. Being located in remote offshore conditions, these connections can experience considerable adverse loading during their lifetimes. Degradation was reported inside similar connections, which were installed in the last three decades. Grouting in the offshore sites may often be proven difficult, which eventually leads to reduced load-bearing capacity of connections in the long run. Thus, repair and rehabilitation of such connections should be planned ahead to minimize operational delays and costs. In this study, scaled grouted connections were manufactured using a novel mould, whose integrity were monitored using digital image correlation (DIC). The connections were loaded under static load to visualize the main failure pattern using distributed fibre optic sensors and acoustic emission (AE) analysis. Grouted connections were then repaired using a cementitious injectable grout. The effectiveness of the grout injection was monitored using dye penetration technique. Finally, specimens are reloaded to identify the potential of such repair for grouted connections. KW - Offshore KW - Grouted connection KW - Fibre optic sensors KW - Acoustic emission analysis KW - Cracks KW - Repair KW - Rehabilitation KW - Static loading PY - 2021 DO - https://doi.org/10.1016/j.marstruc.2021.102934 VL - 77 SP - 102934 PB - Elsevier Ltd. AN - OPUS4-52059 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kühne, Hans-Carsten T1 - Handlungshilfe zur Betoninstandsetzung N2 - Die TR Instandhaltung des Deutschen Instituts für Bautechnik wird als maßgebliches Bezugswerk der Betoninstandsetzung ür die Fachöffentlichkeit hinsichtlich ihrer Inhalte und Zielrichtung vorgestellt KW - Beton KW - Instandsetzung KW - Technische Regel KW - Planung KW - Ausführung KW - DIBt PY - 2021 UR - https://www.ingenieur.de/fachmedien/bauingenieur/ PB - VDI Fachmedien GmbH & Co. KG Unternehmen für Fachinformationen CY - Düsseldorf AN - OPUS4-52117 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Rübner, Katrin A1 - Seher, Julia A1 - Müller, Constanze A1 - Müller, Anette A1 - Liebezeit, Steffen A1 - Schnell, Alexander A1 - Martin, Falk ED - Schermer, Detleff ED - Brehm, Eric T1 - REALight - Leichtgranulate und REA-Gips aus feinkörnigen sulfatbelasteten Bau- und Abbruchabfällen und industriellen Nebenprodukten N2 - Die Zielstellung des Forschungsprojekts REALight ist die Entwicklung eines Verfahrens zur Herstellung von Leichtgranulaten auf der Grundlage der Ergebnisse des BMBF-Projekts „Aufbaukörnungen“ unter Erweiterung der Technologie, um Gips zurückzugewinnen und weitere mineralische Einsatzstoffe zu nutzen. In einem thermischen Verfahren werden mineralische Bau- und Abbruchabfälle über ein rohstoffliches Recycling, d. h. einen thermisch-chemischen Stoffumwandlungsprozess, zu leichten Gesteinskörnungen verarbeitet. Dabei werden im Bauschutt vorhandene Sulfate zersetzt. In einer anschließenden Rauchgaswäsche werden die Sulfate abgetrennt. Sie können als Ersatz für REA-Gips verwendet werden. Dies ist Voraussetzung für die Übertragung der Produkt- und Verfahrensidee in die Praxis und für den Nachweis der Sulfatabtrennung und -rückgewinnung aus gipshaltigem Inputmaterial. Es werden Untersuchungen zur Verbreiterung der Rohstoffbasis durch Einkopplung spezifischer mineralischer Stoffströme durchgeführt, die im Ergebnis zu einer Reduktion des Blähmittelbedarfs und einer Absenkung der Brenntemperatur führen sollen. Die Herstellung ausreichender Mengen Leichtgranulate für eine umfassende Charakterisierung nach Norm und die Praxiserprobung in bekannten Anwendungen und neuen Einsatzfeldern ist ein weiteres Projektziel. KW - Bau- und Abbruchabfälle KW - Bauschutt KW - Leichtgranulat KW - Leichte Gesteinskörnung KW - Gipsrückgewinnung PY - 2024 UR - https://www.ernst-und-sohn.de/mauerwerk-kalender-2024-schwerpunkte-klimagerechtes-und-nachhaltiges-bauen-befestigungen-bauen-im?tab=inhalt#rs SN - 978-3-433-03408-8 SP - 515 EP - 518 PB - Ernst & Sohn CY - Berlin AN - OPUS4-60356 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seher, Julia T1 - Lightweight aggregates made from construction and demolition waste - Application in lightweight concrete and mortars N2 - Heterogeneous construction and demolition waste can be used as raw material to produce lightweight aggregates (LWA) similar to expanded clays. In the joint research project “REALight”, LWA were produced from masonry rubble in a thermal expanding process using a pilot production plant with a rotary kiln. Our research focuses on the characterisation of the novel LWA and their use in different hydraulically bound applications. Infra-lightweight concrete (ILC) was produced with the novel LWA, which accounts for two thirds of total aggregate volume, and Celitement, which is a hydraulic binder with a low carbon footprint. Its dry bulk density is ≤ 800 kg/m³. Strength and durability properties are comparable to ILC data from the literature. Lime-based repair mortars (LRM) containing LWA are beneficial for sandstone conservation due to their similar properties regarding porosity, water absorption and strength. A two-layer repair mortar system, which consists of a filling mortar to fill large voids and a covering mortar to modulate the surface texture to the historic sandstone, was developed. In our contribution, we present results of the LWA characterisation according to the European standard EN 13055:2016. Requirements and challenges of the use of the novel LWA in ILC and LRM are discussed. T2 - V. International Conference Progress of Recycling in the Built Environment (V. PRE) CY - Weimar, Germany DA - 10.10.2023 KW - CDW recycling KW - Lightweight aggregates KW - Masonry rubble KW - Lightweight concrete KW - Repair mortar PY - 2023 AN - OPUS4-58540 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seher, Julia T1 - Anwendung der Leichtgranulate in Mörtel und Beton N2 - Im Verbundforschungsprojekt REALight wurden Leichtgranulate aus gemischtem Mauerwerkbruch in einem thermischen Blähverfahren im Pilotmaßstab hergestellt. Im Teilprojekt der BAM stand die Charakterisierung dieser Leichtgranulate und ihre Anwendung in gebundenen Systemen im Vordergrund. Im Rahmen des Abschlussvortrags wurden Ergebnisse zur Entwicklung von Steinergänzungsmörteln sowie Infraleichtbeton vorgestellt. T2 - Kolloquium "Nachhaltig effizient - Ressourcen des zukünftigen Bauens" CY - Berlin, Germany DA - 18.01.2024 KW - Leichtgranulat KW - Mauerwerkbruch KW - Steinergänzungsmörtel KW - Denkmalpflege KW - Infraleichtbeton KW - Leichtbeton PY - 2024 AN - OPUS4-59398 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Constanze A1 - Seher, Julia A1 - Martin, Falk A1 - Schnell, Alexander A1 - Rübner, Katrin T1 - Leichtgranulate aus gemischtem Mauerwerkbruch für die Anwendung in Infraleichtbeton T1 - Lightweight granular materials made from mixed masonry rubble for use in infra-lightweight concrete N2 - Infraleichtbeton zeichnet sich durch eine äußerst geringe Trockenrohdichte von maximal 800 kg/m³ aus, bei gleichzeitig ausreichender Festigkeit. Daraus resultieren geringe Wärme- und Schallleitfähigkeiten. Dies ermöglicht den Einsatz als Sichtbeton in Wandelementen ohne die Notwendigkeit einer zusätzlichen Dämmschicht. Vielversprechend erscheint der Einsatz von Leichtgranulaten in Infraleichtbeton, um seinen ökologischen Fußabdruck zu reduzieren und somit ein energieeffizientes und zugleich nachhaltiges Bauen zu ermöglichen. Die Leichtgranulate werden in einem thermo-chemischen Prozess aus gemischtem Mauerwerkbruch hergestellt. Ihre Verwendung bietet neben der Alternative zu herkömmlichen leichten Gesteinskörnungen auch die Möglichkeit, Abfallprodukte sinnvoll zu nutzen. In diesem Artikel werden die Leichtgranulate vorgestellt, ihre Anwendung in Infraleichtbeton geprüft und mit konventionellem Blähton verglichen. N2 - Infra-lightweight concrete exhibits an extremely low dry bulk density of up to 800 kg/m³ while also providing sufficient strength, resulting in low thermal and acoustic conductivity. This allows it to be used as exposed concrete in wall panels without requiring an additional insulating layer. Using lightweight granular materials in infra-lightweight concrete appears to be promising for reducing its environmental footprint and thus enabling energy-efficient and sustainable construction. Lightweight granules are produced from mixed masonry rubble in a thermo-chemical process. In addition to being an alternative to conventional lightweight aggregates, their use also provides the opportunity to put waste products to good use. This article reports on lightweight granules, their use in infra-lightweight concrete, and related tests in comparison to conventional expanded clay. KW - Infraleichtbeton KW - Leichtgranulat KW - Mauerwerkbruch KW - Recycling KW - Leichte Gesteinskörnungen PY - 2024 VL - 90 IS - 7 SP - 52 EP - 59 PB - Bauverlag CY - Gütersloh AN - OPUS4-60557 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hering, Marcus A1 - Agasty, Amit A1 - Costard, René A1 - Hüsken, Götz A1 - Chruscicki, Sebastian A1 - Hicke, Konstantin T1 - Explosion effects on reinforced concrete structures – A preliminary study of scaling laws N2 - Blast tests are required to investigate accidental or intentional blast events and to assess the level of protection for people and facilities in critical infrastructures. Conducting large-scale field tests for complex scenarios is very resource intensive. Reliable small-scale experiments are a promising alternative. However, the scaling laws for the design of reinforced concrete structures under blast loads are not sufficiently established. In our research work, a consortium made up of three BAM departments, focuses on reinforced concrete structures that are suitable for the standardization of scaled blast tests. As part of the feasibility study, blast tests were carried out on test specimens of different sizes on the BAM Test Site for Technical Safety (TTS). Various reinforced concrete plates were tested and subjected to different blast loads. The blast tests included various measurement techniques to quantify the blast load and the behavior of the reinforced concrete plate. The blast load was measured with flush-mounted piezoelectric pressure gauges, while accelerometers and embedded fiber optic sensor cables were used to characterize the dynamic behavior of the plate under blast loading. In addition, damage characteristics were also determined using distributed fiber optic sensing. The application of these measurement techniques as well as the use of different numerical software tools offer the possibility to verify or adapt the scaling laws. T2 - 19th International Symposium on Interaction of the Effects of Munitions with Structures (19th ISIEMS) CY - Bonn, Germany DA - 09.12.2024 KW - Scaling KW - Blast KW - Fiber optic sensing PY - 2024 SP - 1 EP - 9 AN - OPUS4-62258 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agasty, Amit T1 - Replica scaling of RC slabs under blast loading: a preliminary assessment N2 - Blast testing is undoubtedly the most straightforward and direct method of evaluating the blast resistance of a structure. For the calibration and validation of numerical models as well, blast tests must be carried out. However, true-scale prototype testing under different blast loading scenarios is not always feasible. Reliable small-scale experiments are a promising alternative. Application of dimensional analysis and similarity principals can be found in different engineering fields. For applications to the phenomenon of shock wave propagation, Hopkinson-Cranz or cube-root scaling is a well-established concept. When it comes to the scaling the structural response, research has predominantly focused on structures made of metallic materials. Scaled investigations with concrete or reinforced concrete (RC) structures remain limited, specifically under blast loading. In a preliminary study, we tested RC slabs at two different scales under near-field blast loading. Replica scaling, which is geometrical scaling while using the same materials at different scales, was implemented in the construction of the test specimens. The assessment of scaling and the discrepancy in its application was investigated by characterizing the blast loads, dynamic response, and damage. The experiments were supplemented by numerical simulations of these scenarios. The quantification of scenario-and-response-specific discrepancy can be used to modify the scaling laws, so that a blast assessment can be performed based on resource efficient small-scale tests. T2 - 25th International Physical Security Forum CY - Schwarzenburg, Switzerland DA - 11.05.2025 KW - Blast KW - RC slabs KW - Scaling PY - 2025 AN - OPUS4-63184 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agasty, Amit A1 - Hering, Marcus T1 - Experimental and Numerical Analysis of Reinforced Concrete Structures Under Blast Loading: Scopes and Challenges N2 - Protection against terrorist or accidental scenarios in industrial settings requires suitable designs of structures to resist blast loads. Field testing as well as finite element simulations are among the techniques available to engineers in the understanding of the structural behavior against blast loading. As blast testing of complex scenarios can be very resource intensive, tests are generally performed for simplified scenarios. Numerical tools can be used to model these scenarios in order to get a better insight into blast loading, structural response and the resulting damage to the structure. In the next steps, the simplified scenario is successively modified in numerical simulations to incorporate complexities that cannot be covered in blast testing experiments. One of the conditions for this approach to work is that the original simplified numerical simulation is valid. The scopes and challenges encountered in such a validation are the focus of this presentation. A relatively ‘simple’ field test of a horizontal reinforced concrete (RC) slab subjected to blast loading is taken as an example for validation of the performance of numerical tools. The blast test incorporated various measurement techniques to quantify the blast load as well as the behavior of the RC slab. Blast load was measured using flush-mounted piezoelectric pressure gauges, whereas acceleration sensors and fiber-optic sensor cables were used to characterize the dynamic behavior of the slab under blast loading. Additionally, damage characteristics were ascertained also using fiber-optic sensing. The application of such measurement techniques, along with different numerical software available for the analysis of the scenario in question, demonstrate the scope of our contribution. T2 - 24th International Physical Security Forum Brussels CY - Brussels, Belgium DA - 15.04.2024 KW - Blast KW - Reinforced Concrete Structures KW - Numerical simulations PY - 2024 AN - OPUS4-60880 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hering, Marcus T1 - Explosion effects on reinforced concrete structures: A preliminary study of scaling laws N2 - Blast tests are required to investigate accidental or intentional blast events and to assess the level of protection for people and facilities in critical infrastructures. Conducting large-scale field tests for complex scenarios is very resource intensive. Reliable small-scale experiments are a promising alternative. However, the scaling laws for the design of reinforced concrete structures under blast loads are not sufficiently established. In our research work, a consortium made up of three BAM departments, focuses on reinforced concrete structures that are suitable for the standardization of scaled blast tests. As part of the feasibility study, blast tests were carried out on test specimens of different sizes on the BAM Test Site for Technical Safety (TTS). Various reinforced concrete plates were tested and subjected to different blast loads. The blast tests included various measurement techniques to quantify the blast load and the behavior of the reinforced concrete plate. The blast load was measured with flush-mounted piezoelectric pressure gauges, while accelerometers and embedded fiber optic sensor cables were used to characterize the dynamic behavior of the plate under blast loading. In addition, damage characteristics were also determined using distributed fiber optic sensing. The application of these measurement techniques as well as the use of different numerical software tools offer the possibility to verify or adapt the scaling laws. T2 - 19th International Symposium on Interaction of the Effects of Munitions with Structures (19th ISIEMS) CY - Bonn, Germany DA - 09.12.2024 KW - Blast KW - Fiber optic sensing KW - Scaling PY - 2024 AN - OPUS4-62260 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Costard, René T1 - Auswirkungsbetrachtungen auf Strukturen T1 - Scaling of Blast Effects on Reinforced Concrete Structures N2 - Protection against terroristic or accidental scenarios in industrial settings requires suitable designs of structures to resist blast loads. Field testing as well as finite element simulations are among the techniques available to engineers in the understanding of the structural behavior against blast loading. As blast testing of complex scenarios can be very resource intensive, tests are generally performed for simplified scenarios. Numerical tools can be used to model these scenarios to get better insight into blast loading, structural response, and the resulting damage to the structure. During the next steps, the simplified scenario is successively modified in numerical simulations to incorporate complexities that cannot be covered in blast testing experiments. One of the conditions for this approach to work is that the original simplified numerical simulation is valid. The scopes and challenges encountered in such a validation are the focus of this presentation/article. A relatively ‘simple’ field test of a horizontal reinforced concrete (RC) slab subjected to blast loading is taken as an example for validation of the performance of numerical tools. The blast test incorporated various measurement techniques to quantify the blast load as well as the behavior of the RC slab. Blast load was measured using flush mounted piezoelectric pressure gauges, whereas acceleration sensors and fiber-optic sensor cables were used to characterize the dynamic behavior of the slab under blast loading. Additionally, damage characteristics were ascertained also using fiber optic sensing. The application of such measurement techniques, along with different numerical software available for the analysis of the scenario in question, demonstrate the scope of our contribution. When it comes to the challenges, it begins with proper instrumentation of the test specimen followed by the data processing. For numerical modelling, geometric conditions with appropriate boundary constraints, physical conditions such as the configuration of the rebars, as well as material parameters add to this challenge. The issues of choosing appropriate material models and comparison of results with multiple software tools will be discussed. This discussion forms the basis for a coherent approach to technical-safety assessment of blast effects on structures in its broader sense. T2 - Beiratssitzung Infrastruktur CY - Berlin, Germany DA - 11.04.2024 KW - Blast KW - Scaling KW - Fiber optic sensing KW - CFD KW - FEM PY - 2024 AN - OPUS4-59849 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Costard, René T1 - Explosionsauswirkungen auf Strukturen Versuche und Simulationen N2 - Vorstellung der Versuche von Explosionsversuchen auf dem TTS. Diese werden ergänzt durch die Ergebnisse durchgeführter Simulationen und zeigen die Wirkung von zivilen Explosivstoffen auf Gebäudestrukturen und die aufgetretenen Schädigungen. T2 - 46. Informationstagung Sprengtechnik CY - Siegen, Germany DA - 25.04.2025 KW - Explosivstoff KW - Skalierung KW - Strukturauswirkung KW - Numerische Simulation PY - 2025 AN - OPUS4-62998 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agasty, Amit T1 - Structural behavior and damage assessment of a reinforced concrete wall by various NDT methods and embedded sensors under blast-loading N2 - A safety or security related assessment of explosions, accidental and intentional scenarios alike, often necessitate performance of replication-tests. Such test results are necessary to clarify the causes within the scope of forensic investigations. To gain important insights into the behavior of structures and materials under such loading, field tests may also be performed in accordance with different test standards. To determine the resistance of building-structures after explosions, estimation of the residual load-bearing capacity in addition to the assessment of dynamic structural response and damage to the building components is important. In most cases an evaluation of structural integrity is based only on the visual damage, resulting in an overestimation of the residual capacity. The Bundesanstalt für Materialforschung und -prüfung (BAM) operates the Test site for Technical Safety (TTS) on an area measuring about 12 km2 in the Federal State of Brandenburg for execution of true-to-scale explosion tests. At the TTS, building component testing was performed to assess the suitability of different non-destructive testing methods to characterize the dynamic structural response and damage resulting from the detonation of high explosives. Different blast-loading scenarios were realized by varying the net explosive mass and the standoff distance with all scenarios representing a near-field detonation. The test object was a reinforced concrete wall 2 m high, 2.5 m wide and 20 cm thick, fixed at both vertical edges. The dynamic loading of the wall was characterized with 8 piezoelectric pressure sensors flush-mounted on the front surface, thus measuring the reflected pressures from the shock wave. The tests were conducted with the aim of characterizing the global behavior of the wall under dynamic shock loading and the resulting local damage pattern, respectively. High speed digital image correlation was implemented in combination with multiple acceleration sensors to observe the rear surface of the wall to chart the dynamic deflection during the loading and to determine the residual deformation after the loading had ceased. In addition, one test specimen was instrumented with fiber optic sensor cables, both fixed to the rebars and embedded in the concrete-matrix, respectively. Firstly, these sensors were interrogated during the blast test by a distributed acoustic sensing (DAS) device using a particularly high sampling rate to measure the shock-induced vibrations in the structure with high temporal resolution. This delivers information on dynamics of compression and tension cycles from within the structure. Secondly, the local damage-pattern emerging during the series of blasts was determined via distributed fiber optic strain sensing (DSS) by interrogating the embedded fiber optic sensors with a high spatial resolution DSS device after each blast. This enabled the characterization of non-visual damage to the structure, in particular with regard to the formation of localized cracks in the concrete matrix. The DSS was further complimented by a structure-scanner based on ultrasonic measurements. Our contribution describes this new test approach in detail. Results of the three datasets, namely dynamic shock loading, global behavior of the test object and the local damage pattern will be presented. The suitability of the implemented measurement methods will be discussed in combination with the challenges in their application for technical safety evaluation of building components under explosive loading. T2 - 26th International Symposium on Military Aspects of Blast and Shock (MABS26) CY - Wollongong, Australia DA - 03.12.2023 KW - Blast tests KW - Reflected pressure KW - Embedded sensors KW - Distributed fiber optic sensors KW - Acceleration sensors KW - Digital image correlation KW - Ultrasonic structure-scanner PY - 2023 AN - OPUS4-58927 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Costard, Rene A1 - Hering, Marcus T1 - Explosionsauswirkungen auf Strukturen N2 - Wir berichten über die Entwicklungen des AP2 im Hinblick auf Explosionsauswirkungen auf Strukturen und den Weg zur systematischen messtechnischen Erfassung zur ganzheitlichen Bewertung der Bauwerksicherheit unter Detonationsbelastung. Zusätzlich werden die Vorführungen zu Kontaktdetonationen während der 16. Informationsveanstaltung Sprengstoffe und Pyrotechnik vorgeführt. T2 - 16. Informationsveranstaltung Sprengstoffe und Pyrotechnik CY - Berlin, Germany DA - 20.05.2025 KW - Explosion KW - Kontaktdetonation KW - Blast PY - 2025 AN - OPUS4-63192 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rogge, Andreas T1 - Large scale impact tests with reinforced concrete plates for impact safety N2 - As part of a nuclear safety research project, large-scale impact tests were conducted on reinforced concrete slabs to investigate the structural integrity of containment structures under aircraft crash scenarios. The aim was to experimentally validate numerical models for both hard and soft impact conditions. Using a drop tower, concrete slabs were subjected to controlled impacts with a 404 kg impactor dropped from a height of 9.5 meters. The tests included force measurements, photogrammetric evaluations, and 3D scans to analyze deformations and damage. A total of six impact experiments were performed (2x hard impact, 2x combined hard/soft impact). The results provide a robust basis for advancing safety assessments of nuclear facilities. T2 - SMiRT28 - 28th International Conference on Structural Mechanics In Reactor Technology CY - Toronto, Canada DA - 10.08.2025 KW - Experimental mechanics KW - Aircraft crash scenario KW - Coupled impact loading PY - 2025 AN - OPUS4-64126 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schultz, C. A1 - Cunningham, Patrick A1 - Fan, J. A1 - Miller, S.A. T1 - Balancing the Mechanical Performance and Environmental Sustainability of Fiber-Reinforced Concrete N2 - Fiber-reinforced concrete (FRC) can have improved durability and tensile properties, potentially enabling the more efficient use of concrete and lowering greenhouse gas (GHG) emissions. Yet, systematic quantifications of the environmental impacts of FRC, particularly when paired with changes to mechanical properties and the implications for material longevity, are limited. Herein, an assessment following the life-cycle assessment methodology for four common FRCs was performed, namely, those reinforced with polyvinyl alcohol (PVA), steel (ST), polypropylene (PP), and polyethylene terephthalate (PET). The analysis was bound to a cradle-to-gate scope, and solely virgin fiber material production was considered for the environmental impacts. Coupled changes in compressive and tensile strength, environmental impacts, and the role of material longevity and cost relative to unreinforced concrete were examined. Findings from this work show that, similar to unreinforced concrete, cement remains a key source of GHG emissions in FRC production. However, in FRCs fibers can drive additional emissions by up to 55%. Notably, PVA and ST led to the highest impacts and costs, which were minimal for inclusions of PP and PET. Yet ST contributed to the greatest benefits in flexural and compressive strengths. When the effects of longevity were integrated, FRC with PP reinforcement could offer desired emissions reductions with minimal increase in use period and cost, but the other fiber reinforcements considered may need to offer longer service life extension to reduce emissions compared with conventional concrete. These results indicate that FRC can enhance mechanical performance, but fiber type selections should be informed by the design life to achieve actual GHG emissions reductions. KW - Fiber-reinforced concrete KW - Greenhouse gas emissions KW - Concrete KW - Cement KW - Durability PY - 2025 DO - https://doi.org/10.1061/JMCEE7.MTENG-19454 SN - 0899-1561 VL - 37 IS - 7 SP - 04025178-1 EP - 04025178-11 PB - American Society of Civil Engineers (ASCE) CY - Reston, VA AN - OPUS4-62987 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lay, Vera A1 - Baensch, Franziska A1 - Skłodowska, Anna A1 - Fritsch, Tobias A1 - Stamm, Michael A1 - Prabhakara, Prathik A1 - Johann, Sergej A1 - Sturm, Patrick A1 - Kühne, Hans-Carsten A1 - Niederleithinger, Ernst T1 - Multi–sensory Monitoring and Non–destructive Testing of New Materials for Concrete Engineered Barrier Systems N2 - The crucial part of nuclear waste storage is the construction of sealing structures made of reliable, safe and well–understood materials. We present an extended analysis of long-term multi–sensory monitoring and non–destructive testing (NDT) inspection of two laboratory specimens aiming at potential materials for sealing structures for nuclear waste repositories. Specimens with a volume of 340 litres made from newly developed alkali–activated materials (AAM) and established salt concrete (SC) were analysed using embedded acoustic emission and wireless radio-frequency identification (RFID) sensors, ultrasonic echo imaging, active thermography, and X–ray computed tomography. The monitoring analysis showed lower heat of reaction and 50% less acoustic emission events in AAM compared to SC. However, due to the surface effects of the AAM material, the number of acoustic emission events increased significantly after approximately two months of monitoring. Subsequently performed NDT inspections reliably located embedded sensors and confirmed the absence of major cracks or impurities. The presented laboratory results show the feasibility and potential of comprehensive NDT monitoring and inspection to characterise cementitious and alternative materials as well as the need for multi–parameter long–term monitoring. Thus, our study demonstrates that tailored NDT investigations will help to develop safe sealing structures for nuclear waste repositories. KW - Radioactive waste KW - Barrier KW - Concrete KW - AAM KW - Non-destructive testing PY - 2024 DO - https://doi.org/10.3151/jact.22.516 SN - 1347-3913 VL - 22 IS - 9 SP - 516 EP - 529 PB - Japan Concrete Institute AN - OPUS4-61461 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lay, Vera A1 - Mielentz, Frank A1 - Prabhakara, Prathik A1 - Baensch, Franziska A1 - Johann, Sergej A1 - Hofmann, Detlef A1 - Sturm, Patrick A1 - Stamm, Michael A1 - Niederleithinger, Ernst T1 - Multi-sensory monitoring and ultrasound for quality assurance at underground sealing structures N2 - Within the safety concepts of underground disposal sites of nuclear waste, engineered barriers play an important role. As these sealing structures have high demands concerning integrity, we aim at advancing the available construction materials, monitoring, and inspection techniques within the project SealWasteSafe. A specifically developed alkali-activated material is compared to classical salt concrete. A comprehensive multi-sensory monitoring scheme is used at 150-340 l specimens to monitor setting and hardening of both materials. All sensors are demonstrated to resist the highly alkaline environments. Besides cabled and wireless temperature and humidity of the materials, strain variations using fibre optic sensors and acoustic emissions are recorded over periods of at least 28 days, partly for more than eight months. After hardening of the specimens, further nondestructive evaluations using ultrasonic echo and thermographic measurements are conducted. Preliminary results proof the suitability of the tested sensors and clearly highlight differences between the tested materials. Particularly, the newly developed alkali-activated material shows lower acoustic emission activity indicating less cracking activity. Additionally, unique ultrasonic methods will enable better images of potential internal objects and cracks at in-situ sealing structures. A largescale ultrasonic system is optimised to reliably detect objects at a depth exceeding 9 m while still obtaining a good resolution. Modelling studies show the potential of further increasing the distance between individual transducer arrays. Additionally, a new ultrasonic borehole probe using phased arrays allowing for beam focussing is constructed and tested. Laboratory measurements at a halfcylindrical concrete specimen coincide well with the previous modelling. In total, the presented safe materials, detailed monitoring approaches and ultrasonic quality assurance methods will help to obtain safe sealing structures within salt as a host rock. The concepts can partly be transferred to sealing structures in alternative host rocks and will also be valuable for non-nuclear waste repositories. T2 - NDE NucCon CY - Espoo, Finland DA - 25.01.2023 KW - SealWasteSafe KW - Engineered barriers KW - Monitoring KW - Embedded sensors KW - Ultrasonic imaging PY - 2023 SP - 2 EP - 10 AN - OPUS4-56928 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -