TY - CONF A1 - Hofmann-Böllinghaus, Anja T1 - Wärmedämmverbundssysteme (WDVS) - Brandverhalten von WDVS N2 - Vortrag über Brandgefahren mit WDVS (Wäremdämmverbundsystemen) mit Polystyrolschaumdämmung, reale Brände, Brandversuche, Prüfmethoden T2 - Arbeitsgemeinschaft Schadenverhütung, Sitzung CY - Feuersozietät Berlin, Germany DA - 27.4.2016 KW - WDVS KW - Polystyrol KW - Brandverhalten KW - Sicherheit PY - 2016 AN - OPUS4-37009 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hofmann-Böllinghaus, Anja T1 - Fire safety of façades with polystyrene foam insulation N2 - Several fires involving ETIC (external thermal insulation composite) systems with polystyrene foam insulation in Germany led to an extensive discussion about fire safety of such systems. A collection initiated by the Frankfurt fire service of façade fires which include polystyrene insulation foam shows that especially fires which started in front of the buildings led to more severe fires of the façade than fires that started inside the buildings. In several fires the ignition source were burning waste containers. Three large scale tests which were initiated by German building ministries showed weaknesses of the existing systems when challenged by a bigger fire source in front of the façade. Since then measures have been introduced to enhance these systems and an additional test with a 200 kg wood crib in front of a large test rig has been used for approval of ETICS. However, the recently introduced German draft standard DIN E 4102-20 does not take these changes into account although real cases and the large scale tests showed that fire scenarios with a bigger ignition source as a waste container are not covered by the DIN E 4102-20. Numerical investigations show that regarding the heat flux to the area above the opening (e.g. a window) also only a fraction of real fires is covered. Additionally damaged systems have been investigated using the Single Burning Item (SBI) test with higher heat release rates of the burner. The damage significantly influenced the fire development of the specimen. Collapse of a damaged coating of an ETIC system occurred during the test and had a sudden fire growth as a result as the whole specimen was suddenly on fire. Several effects which could be seen in the intermediate scale tests correspond to observations which were made in the real cases. In Germany insulation of existing buildings is often enhanced with application of ETICS. In most cases the buildings are in use at the time when the construction takes place. At several stages of the construction process large amounts of unprotected polystyrene are stored in immediate proximity of the building and unprotected polystyrene can be in place on the façade for several weeks. As a consequence of the investigations challenges and possible measures to enhance fire safety of ETIC systems are discussed. T2 - Interflam Konferenz 2016 CY - Royal Holloway College, London, UK DA - 4.7.2016 KW - ETICS KW - Polystyrene KW - Insulation KW - Fire safety PY - 2016 AN - OPUS4-37011 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tschirschwitz, Rico T1 - Versagen von Gasbehältern für alternative Treibstoffe unter Berücksichtigung komplexer Brand- und Explosionsszenarien N2 - Die Zahl der zugelassenen Fahrzeuge auf deutschen Straßen, welche statt herkömmlichen Otto- und Dieselkraftstoffen alternative Treibstoffkonzepte (z.B. LPG, CNG, H2) für den Antrieb nutzen, ist in den vergangenen Jahren kontinuierlich gestiegen. Der dabei zunehmende Mix an Behältertypen und die große Anzahl an alternativen Treibstoffen macht in Unfallsituationen die Berücksichtigung zusätzlicher Risiken notwendig. Zum Beispiel kann es bei einem Unfall zum Austritt von gasförmigen Treibstoffen sowie infolge eines Brandes auch zu einem Behälterversagen kommen. Das Schadensausmaß in einem solchen Fall übersteigt dabei deutlich das zu erwartende Ausmaß infolge eines PKW-Brandes mit herkömmlichen Kraftstoffen. T2 - 14. Kolloquium zur chemischen und physikalischen Sicherheitstechnik (BAM-PTB-Kolloquium) CY - Berlin, Germany DA - 14.06.2016 KW - Explosion KW - alternative Treibstoffe KW - Behälterversagen KW - Composite PY - 2016 AN - OPUS4-37173 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geoerg, Paul T1 - Evacuation dynamics under consideration of vulnerable pedestrian groups N2 - The understanding of human behavior during evacuation processes is an important matter to improve the safety of infrastructures. In many countries, the implementation of performance based codes enables fire safety engineers to use computer based calculation tools to predict and evaluate pedestrian movement and human behavior in buildings. The models are based on experimentally obtained parameters and theoretical models. Pedestrian behavior can be influenced by the characteristics of the buildings (e.g. type of the building) as well as the characteristics of individuals and the pedestrian group. This paper shows that the approach of Required Safe Egress Time (RSET) / Available Safe Egress Time (ASET) is imprecise with regard on heterogeneous pedestrian groups, because this concept completely neglected the variability’s in individual pre-movement and movement abilities. T2 - Interflam CY - Royal Holloway College, London, UK DA - 04.07.2016 KW - Evacuation KW - Vulnerable groups KW - Simulation KW - Egress PY - 2016 AN - OPUS4-36822 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abdelkhalik, A. A1 - Askar, Enis A1 - Markus, D. A1 - Brandes, E. A1 - El-Sayed, I. A1 - Hassan, M. A1 - Nour, M. A1 - Stolz, T. T1 - Explosion regions of propane, isopropanol, acetone, and methyl acetate/inert gas/air mixtures N2 - The explosion regions for propane, isopropanol, acetone, and methyl acetate with air in the presence of nitrogen, argon, helium, and carbon dioxide were determined experimentally according to EN 14756/EN1839, method T. Except for propane, all the measurements were executed at 323 K and 1 bar. Propane experiments were carried out at 293 K and 1 bar. The results show that for the same type of inert gas, propane, isopropanol, and acetone have great closeness concerning the concentration of the inert gas at the apex of the explosion envelope in a ternary diagram with air as oxidizer. This leads to consistency in the limiting oxygen concentration (LOC) and minimum required amount of inert gas (MAI) values. Concerning methyl acetate, the apex was always reached at higher percentages of inert gases compared with the other fuels. This can be attributed to the presence of two oxygen atoms inside the chemical structure. Calculation of the explosion regions was carried out based on calculated adiabatic flame temperature (CAFT) method. The flame temperatures for the experimentally determined fuel/air/N2 mixtures were calculated. Then, these temperatures were used to predict the explosion limits of similar mixtures with other inert gases than nitrogen. The modeling results show reasonable agreement with the experimental results. KW - Flammability limits KW - Model of constant adiabatic flame temperatures (CAFT) KW - Inertisation KW - Explosion protection PY - 2016 DO - https://doi.org/10.1016/j.jlp.2016.04.001 SN - 0950-4230 VL - 2016/43 SP - 669 EP - 675 PB - Elsevier Ltd. CY - Oxford, UK AN - OPUS4-37996 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias A1 - Simon, Patrick ED - Cunha, Álvaro ED - Caetano, Elsa T1 - Review of Ballasted Track Destabilization on Shake Table Tests N2 - Shake table tests have been used for a long time to understand the densification and fluidization of granular materials. While purely vertical shaking is quite unlikely to be found in vibration analysis when it comes to granular materials as soils, it has been found that the vertical vibration of railway bridge support structures can affect the fabric of the ballasted track on top. Starting from the experience at French railway lines with destabilizing track conditions on short bridges in high speed lines in the 1990s, various shake table test configurations have been used to investigate the destabiliza-tion of ballast at high acceleration levels. This article describes the effects of the variously investigated dynamic excitations of railway bridges on the bal-lasted track itself. T2 - 11th International Conference on Experimental Vibration Analysis for Civil Engineering Structures (EVACES 2025) CY - Porto, Portugal DA - 02.07.2025 KW - Infrastructure KW - Ballasted track KW - Ballast KW - Railway bridge dynamics PY - 2025 SN - 978-3-031-96105-2 DO - https://doi.org/10.1007/978-3-031-96106-9_62 SP - 595 EP - 604 PB - Springer CY - Cham AN - OPUS4-64265 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Characteristic Frequencies of Train-Induced Bridge, Track, Ground and Building Vibrations – Excitation and Mitigation N2 - The characteristic frequencies of train-induced vibrations are discussed in theory and experiment following the propagation of vibrations from the source to the receiver: 1. Out-of-roundness frequencies of the wheels, 2. sleeper-passage frequency, 3. the vehicle-track eigenfrequency, 4. band frequency of the impulses of the passing static axle loads, 5. car-length frequency and multiples, 6. axle-distance frequencies with two characteristic zeros, 7. bridge eigenfrequencies, 8. the cut-on frequency due to the layering, and 9. the cut-off frequency due to the material damping of the soil, 10. the building-soil eigenfrequency, 11. as a rigid building or flexible wall/column mode, 12. floor eigenfrequencies, 13. acoustic room resonances, 14. the „resonance“ frequency or cut-off frequency of a base isolation. Coincidences of some of these characteristic frequencies or frequency ranges can be typically problematic and mitigation measures at the track or at the building can be necessary. The bridge response to the passing static loads is deter¬mined by the axle-sequence spectrum, the eigenfrequency (transfer function) of the bridge, and the modal force or mode shape spectrum. The ground vibration has typically high frequencies for a stiff soil and low frequencies for a soft soil. The high amplitudes between the zeros of the axle-sequence spectrum are often measured in the ground vibrations, and they can be mitigated by soft support elements or a higher bending stiffness of the track. T2 - EVACES 2025 CY - Porto, Portugal DA - 02.07.2025 KW - Train-induced vibration KW - Vehicle excitation KW - Track response KW - Bridge resonance KW - Ground vibration KW - Soil-building transfer KW - Floor resonance KW - Axle-sequence spectrum KW - Vehicle-track eigenfrequency KW - Axle impulses PY - 2025 SN - 978-3-031-96113-7 DO - https://doi.org/10.1007/978-3-031-96106-9_77 VL - 2025 SP - 1 EP - 8 PB - Springer CY - Cham, Schweiz AN - OPUS4-63655 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Simon, Patrick A1 - Baeßler, Matthias ED - Cunha, Álvaro ED - Caetano, Elsa T1 - On the reassessment of bridge superstructure vibrations for high-speed traffic N2 - The acceleration thresholds of bridge superstructures remain critical for designing and reassessing railway bridges on high-speed lines, with ballasted track systems historically limited to 3.5 m/s2 vertical accelerations due to destabilization risks. As part of the European InBridge4EU project, this study addresses methodological uncertainties in linking vertical bridge vibrations to lateral track creep—a key focus area for modernizing assessment protocols. A comparative analysis of two acceleration postprocessing methods (peak identification vs. fatigue-derived rainflow counting) as part of a recently proposed framework was conducted using an example bridge and train combination. Results demonstrate that rainflow counting yields more conservative creep estimates with the bulk of cumulative vibration-induced creep attributable to accelerations exceeding 3 m/s2. However, discretizing acceleration ranges into 1 m/s2 bins introduced significant errors compared to continuous cycle data, highlighting sensitivity to analysis parameters. These findings underscore the complexity of reconciling laboratory-derived harmonic vibration models with real-world bridge dynamics, where non-uniform acceleration patterns dominate. The research directly informs ongoing efforts to refine standardized criteria for ballasted track stability, particularly through the InBridge4EU project’s systematic re-evaluation of vibration limits and their engineering implications. By quantifying discrepancies between computational approaches, this work advances the development of robust protocols for predicting track degradation under high-speed operational loads. T2 - 11th International Conference on Experimental Vibration Analysis for Civil Enginering Structures (EVACES 2025) CY - Porto, Portugal DA - 02.07.2025 KW - Infrastructure KW - Railway bridges KW - Ballast destabilization KW - Acceleration limit KW - Ballasted track KW - Rainflow counting PY - 2025 SN - 978-3-031-96105-2 DO - https://doi.org/10.1007/978-3-031-96106-9_53 VL - 675 SP - 506 EP - 515 PB - Springer CY - Cham AN - OPUS4-64267 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liao, Chun-Man A1 - Bernauer, F. A1 - Niederleithinger, Ernst A1 - Igel, H. A1 - Hadziioannou, C. T1 - Assessment of prestress loss in a large-scale concrete bridge model under outdoor condition N2 - Environmental conditions affect the accuracy of field measurements used to monitor civil structures. Previous studies have shown that measured dynamic responses often lack the sensitivity needed for effective localized damage detection. To address this issue, our study focuses on distinguishing environmental effects from damage related effects in measured data to enhance vibration-based damage identification methods. Experimentally, the problem of prestress loss in a prestressed concrete bridge model was examined. By adjusting the pre-stressing force in a large-scale concrete bridge model, cracking phenomena were observed. To demonstrate field monitoring of a large-scale prestressed structure, noise recording was performed and the measurement data was analyzed with operational modal analysis. Additionally, ultrasonic testing, known for its high sensitivity in damage localization, was used to cross-check the structural damage. Seismic and coda wave interferometry were also employed to estimate wave velocities, providing insights into the level of prestress loss and temperature sensitivity. Ultimately, these measurable wave properties help to overcome the uncertainties associated with traditional vibration-based damage detection methods. T2 - EVACES 2025 CY - Porto, Portugal DA - 02.07.2025 KW - Prestress Loss KW - NDT KW - Ambient Vibration KW - Ultrasonic Testing KW - Coda Wave Interferometry KW - Seismic Interferometry PY - 2025 SN - 978-3-031-96105-2 DO - https://doi.org/10.1007/978-3-031-96106-9_20 VL - 675 SP - 181 EP - 189 PB - Springer Nature CY - Cham AN - OPUS4-64212 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baier, Johanna T1 - Down to Earth - Stampflehm N2 - Der Vortrag „Stampflehm“ gibt einen kurzen Überblick zur stofflichen Zusammensetzung von Stampflehm sowie zu verschiedenen Fertigungstechniken im Stampflehmbau. Es werden wichtige konstruktive Details erläutert und Hinweise bezüglich der Ausführung von Stampflehmwänden gegeben. Darüber hinaus wird das aktuell gültige Bemessungskonzept vorgestellt und dessen Schwachstellen aufgezeigt. Im Anschluss erfolgt eine Gegenüberstellung von Stampflehm mit verschiedenen Massivbauweisen hinsichtlich Tragfähigkeit, Schall- und Brandschutz sowie der Ökobilanz. Abschließend wird von aktuell laufenden Forschungsvorhaben im Bereich des Stampflehmbaus berichtet. T2 - Down to Earth - digitale Ringvorlesung CY - Online meeting DA - 10.12.2025 KW - Stampflehm PY - 2025 AN - OPUS4-65093 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schröpfer, Dirk T1 - Comparative residual stress analysis on a DED-Arc manufactured high-strength steel component using the contour method and XRD N2 - Lightweight construction is a vital approach for reducing CO₂ emissions. It contributes to the development of more energy-efficient structures and supports the overall goal of achieving carbon neutrality in the transition to sustainable manufacturing. Thus, a topology-optimized design often leads to complex geometries. Additive manufacturing (AM) processes such as direct energy deposition with arc (DED-Arc) offers a great design freedom due to the build-up of components in layers. Furthermore, they enable efficient production due to the high deposition rate, process reliability and good automation capability. Further efficiency can be achieved through weight optimization, enabled by high-strength steels. However, a major challenge is the process induced residual stresses (RS) in the component. High tensile residual stresses are detrimental as they increase the risk of cold cracking. Knowledge of residual stress distribution is crucial for predicting service life of the component and structural integrity assessment, especially for safety critical applications. Therefore, this study focuses on the use of Contour method (CM) to analyse the full field longitudinal residual stresses in an open hollow cuboid component (dimensions: 120 x 50 x 30 mm3) manufactured by DED-Arc (yield strength > 730 MPa). In the contour method, the component is cut along a desired plane of interest and the contour of deformed cut surface is measured. A finite element model is used to reconstruct the residual stresses field in the 2-dimensional plane of cut. In this paper a modified cutting strategy was employed, post cutting the deformed cut surfaces were measured utilizing two surface measurement techniques i.e., coordinate measuring machine (CMM) and a 3D Scanner. The accuracy of the contour method was validated against surface stresses measured using X-ray diffraction. Additionally, a comparison of neutron diffraction experiments was conducted. The residual stresses were further correlated with hardness measurements. The results from surface measurement techniques showed good agreement regarding the measured displacement contours and the contour method results revealed peak stresses in the DED-Arc walls, bending deformation in substrate induces tensile stresses at the bottom of the substrate plate and compressive stresses in the middle top region. The residual stresses obtained from diffraction and contour method showed a good agreement and correlated qualitatively with the hardness measurements. T2 - 78th IIW Annual Assembly and International Conference on Welding and Joining CY - Genoa, Italy DA - 22.06.2025 KW - Residual stress KW - Contour method KW - DED-Arc/M KW - High-strength steel KW - Filler metals KW - XRD KW - Neutron diffraction PY - 2025 AN - OPUS4-65215 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Winkler, Juliette A1 - Beck, M. A1 - Gluth, Gregor ED - Schneider, F. ED - Hehl, K. ED - Heyde, S. T1 - Kurz- und mittelfristige Verbundfestigkeit von alkaliaktivierten Mörteln auf Beton N2 - Ein zentrales Fundament moderner Gesellschaften ist eine intakte Abwasserinfrastruktur. Schäden infolge biogener Schwefelsäurekorrosion von konventionellen Betonen haben jedoch zu einem erheblichen Sanierungsbedarf geführt. Alkaliaktivierte Mörtel besitzen aufgrund eines hohen Säurewiderstands das Potential, einen Beitrag zur langfristigen Lösung dieses Problems zu leisten. Dazu müssen jedoch zunächst die Faktoren, die den Haftverbund zwischen diesen Mörteln und dem Betonsubstrat bestimmen, besser verstanden werden, um die Eigenschaften der Beschichtungssysteme gezielt anpassen und verbessern zu können. Die vorliegende Arbeit liefert hierzu einen Beitrag und zeigt dadurch Wege zu einer technisch machbaren und nachhaltigen Sanierung von Abwasserbauwerken auf. KW - Alkalisch aktivierte Bindemittel KW - Abwassersysteme KW - Reparatursysteme KW - Verbund KW - Dauerhaftigkeit PY - 2022 SN - 978-3-8440-8818-2 SP - 89 EP - 100 CY - Berlin AN - OPUS4-57701 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Anita T1 - Gefahrgutverpackungen - Gesetzliche Rahmenbedingungen und BAM Gefahrgutregeln N2 - Gefahrgut darf nur in speziell dafür zugelassenen Umschließungen (Verpackungen, IBC, Großverpackungen etc.) transportiert werden. Die BAM ist in Deutschland die zuständige Behörde für die Erteilung von Zulassungen, für die (Baumuster-)Prüfung von Gefahrgutverpackungen sowie die Anerkennung der Qualitätssicherungsprogramme, nach denen die Gefahrgutverpackungen zu fertigen sind. Hierfür erlässt die BAM sogenannte BAM-GGRs (Gefahrgutregeln). T2 - IK-Seminar Qualitätssicherung bei der Herstellung von Gefahrgutverpackungen aus Kunststoff CY - Bad Homburg, Germany DA - 15.10.2018 KW - Gefahrguttransport KW - Gefahrgutverpackungen KW - Regelsetzung KW - Transportrecht KW - Zuständige Behörde PY - 2018 AN - OPUS4-47123 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Anita T1 - Stapeldruck- und Stauchwiderstandsprüfung bei Kunststoffverpackungen N2 - Im Regelwerk für Gefahrgutverpackungen ist die statische Stapeldruckprüfung vorgesehen, in der Praxis wird der dynamische Stauchwiderstand angewendet. Wie kann man beides zueinander bringen ? - Ergebnisse einer Arbeitsgruppe und eine geplante BAM-Allgemeinverfügung. T2 - ERFA Verpackungen 2016 CY - Berlin, Germany DA - 20.09.2016 KW - Gefahrgutverpackungen KW - Prüfung KW - Stapeldruckprüfung PY - 2016 AN - OPUS4-38172 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mundra, Shishir A1 - Samson, G. A1 - Masi, G. A1 - Achenbach, R. A1 - Bastidas, D. M. A1 - Bernal, S. A. A1 - Bignozzi, M. C. A1 - Criado, M. A1 - Cyr, M. A1 - Gartner, N. A1 - von Greve-Dierfeld, S. A1 - Legat, A. A1 - Nikoonasab, Ali A1 - Provis, J. L. A1 - Raupach, M. A1 - Gluth, Gregor T1 - Stahlkorrosion in alkalisch aktivierten Bindemitteln und Betonen: Anwendung elektrochemischer Methoden N2 - Alkalisch aktivierte Bindemittel (AAB) und Betone können herkömmliche Zemente beziehungsweise Betone potentiell in vielen Anwendungen ersetzen und dadurch den CO2-Fußabdruck der Bauindustrie wesentlich verkleinern. Zur Untersuchung der Stahlkorrosion in bewehrten („armierten“) Betonbauteilen werden elektrochemische Methoden wie Messungen des Freien Korrosionspotentials, des Polarisationswiderstands oder von Stromdichte-Potential-Kurven eingesetzt. Diese Methoden und die etablierten Grenzwerte zur Detektion von Korrosion sind für die Anwendung bei herkömmlichen Zementen beziehungsweise Betonen entwickelt und erprobt worden. Neue Forschungsergebnisse demonstrieren, dass Unterschiede zwischen den Porenlösungszusammensetzungen von herkömmlichen Zementen und bestimmten AAB sowie anderen schlackehaltigen Zementen erhebliche Unterschiede bei den Ergebnissen der elektrochemischen Messungen bewirken und damit zur fehlerhaften Detektion von Stahlkorrosion führen können. Ursache hierfür sind vor allem reduzierte Schwefelspezies in den Porenlösungen von AAB und anderen schlackehaltigen Zementen. KW - Zement KW - Hüttensandmehl KW - Schlacke KW - Sulfid KW - Korrosion PY - 2023 UR - https://bit.ly/GIT-Gluth UR - https://analyticalscience.wiley.com/content/magazine-do/git-labor-fachzeitschrift-10-2023 SN - 0016-3538 VL - 67 IS - 10 SP - 28 EP - 31 PB - Wiley-VCH AN - OPUS4-58573 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gluth, Gregor T1 - Chloride binding by LDH/AFm phases and alkali-activated slag pastes N2 - Chloride binding by the hydrate phases of cementitious materials influences the rate of chloride ingress into these materials and, thus, the time at which chloride reaches the steel reinforcement in concrete structures. A particularly important role in this context is played by layered double hydroxides (LDHs), including AFm phases. Chloride binding isotherms of individual LDH/AFm phases would be required as input for computational models of chloride ingress, but such isotherms are only available for a few AFm phases, and in addition the available data are partly conflicting. The present study, conducted in the context of RILEM TC 283-CAM ‘Chloride transport in alkali-activated materials’, significantly extends the available database by determining the chloride binding isotherms of LDH/AFm phases (monosulfate, strätlingite, hydrotalcite, and meixnerite), and of alkali-activated slags (AAS) produced with four different activators (Na2SiO3, Na2O∙1.87SiO2, Na2CO3, and Na2SO4), in NaOH/NaCl solutions at various liquid/solid ratios. Selected solids after chloride binding were analysed by X-ray diffraction, and thermodynamic modelling was applied to simulate the phase changes occurring during chloride binding by the AFm phases. The chloride binding isotherms of LDH/AFm phases depended strongly on the liquid/solid ratio during the experiments, resolving apparent contradictions of the previously available data. The dependency on liquid/solid ratio must be attributed to kinetic restrictions, which are, however, currently poorly understood. Chloride binding by AAS pastes was generally higher than for Portland cement pastes and was only moderately influenced by the employed activator. A steep increase of the chloride binding by AAS occurred at free chloride concentrations above approx. 1.0 M, which is possibly related to chloride binding by the C-(N-)A-S-H gel in the AAS. T2 - RILEM Spring Convention 2024 & Conference on Advanced Construction Materials and Processes for a Carbon Neutral Society CY - Milan, Italy DA - 07.04.2024 KW - Chloride binding KW - Layered double hydroxides KW - AFm phases KW - Alkali-activated slags KW - Chloride sorption isotherms PY - 2024 AN - OPUS4-59855 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gluth, Gregor T1 - Thermo-mechanical and spalling behavior of normal weight and lightweight geopolymer concretes N2 - The mechanical and microstructural properties of two geopolymer concretes, produced with either quartz aggregate or expanded clay aggregate, were assessed before, during and after high-temperature exposure up to 750 °C in order to better understand the engineering properties of the material. SEM investigations were also undertaken to better understand the observed changes in the mechanical properties. It was found that dehydration of capillary water caused micro-cracking and strength losses at temperatures ≤ 300 °C. At higher temperatures (T ≥ 500 °C) sintering promoted strength increases, leading significant strength advantages over conventional concretes. Stress-mechanical strain curves, which are the basis of the fire design of concrete structures, were determined. In addition, the two geopolymer concretes where exposed to the ISO 834-1 standard fire curve in a small-scale spalling test set-up. Acoustic emission measurements during, and acoustic measurements and optical microscopy after heat exposure were employed to investigate crack formation during the tests. Both concretes did not spall, which is attributed to their comparatively high permeability and their low amount of chemically bound water. Significant crack formation was detected only around the temperature of the α–β quartz transition (573 °C) and on cooling. Because of aggregate deformations at the quartz transition temperature, deterioration after heating was more significant in the geopolymer concrete with quartz aggregates. Crack formation occurred also in the concrete with expanded clay aggregates, presumably caused by shrinkage of the geopolymer paste on cooling. T2 - Advances in Cement and Concrete Technology in Africa (ACCTA 2016) CY - Dar es Salaam, Tanzania DA - 27.01.2016 KW - Geopolymers KW - Concrete KW - Transient thermal creep KW - Spalling KW - Heat exposure PY - 2016 AN - OPUS4-36922 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gluth, Gregor T1 - Alkalisch aktivierte Bindemittel mit hohem Säurewiderstand für die Kanalsanierung N2 - Die biogene Schwefelsäurekorrosion (BSK) von Betonbauteilen in Abwassersystemen verursacht weltweit hohen Reparaturbedarf. Um zukünftigen Reparaturbedarf zu minimieren, werden für Neubau- und Sanierungsmaßnahmen z. T. Materialien mit besonders hohem Widerstand gegen BSK benötigt. Der vorliegende Beitrag beschreibt Forschungen zu alkalisch aktivierten Bindemitteln, die bei geeigneter Formulierung einen hohen Widerstand gegen BSK bzw. Säureangriff aufweisen. Zusätzlich werden jüngste Fortschritte bei der Bewertung von Methoden zur Prüfung des Widerstands gegen BSK dargestellt. T2 - 11. Jahrestagung des DAfStb mit 63. Forschungskolloquium der BAM Green Intelligent Building CY - Berlin, Germany DA - 16.10.2024 KW - Alkalisch aktivierte Bindemittel KW - Biogene Schwefelsäurekorrosion KW - Säurewiderstand PY - 2024 AN - OPUS4-61747 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - König, H. T1 - Practical tests with R290 used in reefer container refrigeration -leakage testing- N2 - The option of using flammable refrigerants in the reefer container has already been studied and reported by König (2013, 2014) in various publications. In the present paper, the results of experiments are presented, related to the investigation of the potential fire and explosions risks by R290 leaks in refrigerated containers. A safety concept for reefer containers operating with R290 as refrigerant has been tested and validated. In addition, there were extensive leakage simulations, the results have been evaluated for the comparison with the practical tests. Both experiments and the simulations were done at the Federal Institute for Materials Research and Testing (BAM). Further tests are carried out by the manufacturer with the support of the firefighting service and the Danish institute of Fire and Security Technology (DBI). The results from practical tests and the leakage simulations allow for first generalization and more precise studies with respect to potential risks of refrigerant leaks. Potentially explosive atmospheres situations can be evaluated much easier and appropriate measures can be derived. It turns out that dangerous situations for small, medium and rupture of pipe leaks are manageable. The results of the practical testing of leaking R290 inside and outside of a reefer container showed that the risk is being commonly overestimated. T2 - 12th IIR Gustav Lorentzen Conference on Natural Refrigerants CY - Glasgow, UK DA - 21.08.2016 KW - Reefer container KW - Safety concept KW - Leakage tests KW - Gas dispersion KW - Explosion tests PY - 2016 AN - OPUS4-38638 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gluth, Gregor T1 - Reinforcing steel in sulfide-containing concretes – corroding or not corroding? N2 - Blast furnace cements (CEM III) and alkali-activated slags are binders for concretes with several advantageous engineering properties, and their increased adoption in construction industry could contribute to reducing the CO2 emissions associated with cement production and use. However, the current knowledge about how these cements protect steel reinforcement in concretes against corrosion is very incomplete, which impedes their large-scale application. This knowledge gap is mainly due to the fact that these cements release sulfide and other reduced sulfur species into the concrete pore solution, the consequences of which for the state of the reinforcement and electrochemical measurements are not fully understood. The present contribution first describes peculiarities of electrochemical measurements of steel in sulfide-containing cementitious materials and related solutions as reported in the literature and a recent report by EFC Working Party 11. It is demonstrated that the high sulfide concentrations in these systems lead to low open circuit potentials and low polarisation resistances, which may be incorrectly interpreted as indicating active corrosion of the steel. Second, preliminary results of an ongoing project [funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – 458297195] related to the passivation and corrosion initiation of steel in sulfide-containing solutions and mortars are presented. Eight mortars based on one alkali-activated blast furnace slag (BFS), three alkali-activated BFS/fly ash blends, one sodium sulfate-activated CEM III/C (‘hybrid cement’), one CEM III/C, one CEM III/B, and one CEM I (ordinary Portland cement, OPC) were produced, and their pore solutions expressed and analysed after 7, 14, 28, and 56 days of curing. The pH values of the solutions differed systematically, with the highest pH values recorded for the CEM I and the alkali-activated BFS/fly ash blends with a high proportion of fly ash, and the lowest pH recorded for the CEM III/B. The redox potentials of the solutions were between −500 mV and −340 mV vs. Ag/AgCl for the alkali-activated binders, approx. +10 mV vs. Ag/AgCl for the CEM I, and in between for the CEM III/B and the CEM III/C. As expected, the electrical conductivity was highest for the alkali-activated binders. These results are explained by the chemical compositions of the pore solutions of the mortars. Finally, a test set-up to investigate the behaviour of steel in sulfide-containing solutions and the changes on subsequent oxygen and/or chloride addition is introduced. Preliminary electrochemical measurements of steel in sulfide-containing solutions are presented and discussed in the context of the above-mentioned data from the literature and the compositions of the pore solutions of the studied mortars. T2 - 7th Swiss Corrosion Science Day 2023 CY - Zurich, Switzerland DA - 24.04.2023 KW - Reinforcing steel KW - Sulfide KW - Concrete KW - Ground granulated blast furnace slag KW - Corrosion PY - 2023 AN - OPUS4-57386 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR ED - Rossignol, S. ED - Gluth, Gregor T1 - Special issue: Alkali-activated materials and geopolymers in ceramics and beyond N2 - Geopolymers and alkali-activated materials have emerged as a complement, and partly as an alternative, to traditional materials in various applications, such as traditional ceramics, energy saving, waste management, building construction, and filtration. These new materials can play an important role in mitigating climate change and promoting a circular economy, which is one of the reasons why they are being actively researched in many laboratories around the world. Open Ceramics, the official, peer-reviewed, Open Access journal of the European Ceramic Society, is dedicated to foster this research and is compiling a Special Issue with the title “Alkali-activated and geopolymer materials in ceramics and various applications”. The aim of this Special Issue is to promote new applications, the use of previously underused raw materials, and in particular a better understanding of the chemical and mechanical behavior of these materials. The scope of the Special Issue includes, but is not limited to, research on the following topics: - valorization of previously underused raw materials - a better understanding of established raw materials - detailed spectroscopic characterization of alkali-activated materials and geopolymers to elucidate their phase assemblage - the mechanism of formation of the phase(s) that comprise these binders - control of their mechanical properties - the effect of fillers/aggregates on their mechanical properties - their durability under various conditions and the underlying deterioration mechanisms - special applications and recycling-related considerations. KW - Alkali-activated materials KW - Geopolymers PY - 2021 UR - https://www.sciencedirect.com/journal/open-ceramics/special-issue/10789KQV7BR SN - 2666-5395 SP - 100013-1 EP - 100184-12 PB - Elsevier CY - Amsterdam AN - OPUS4-51984 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -