TY - JOUR A1 - Markwart, J. C. A1 - Battig, Alexander A1 - Velencoso, M. M. A1 - Pollok, D. A1 - Schartel, Bernhard A1 - Wurm, F. R. T1 - Aromatic vs. Aliphatic Hyperbranched Polyphosphoesters as Flame Retardants in Epoxy Resins N2 - The current trend for future flame retardants (FRs) goes to novel efficient halogen-free materials, due to the ban of several halogenated FRs. Among the most promising alternatives are phosphorus-based FRs, and of those, polymeric materials with complex shape have been recently reported. Herein, we present novel halogen-free aromatic and aliphatic hyperbranched polyphosphoesters (hbPPEs), which were synthesized by olefin Metathesis polymerization and investigated them as a FR in epoxy resins. We compare their efficiency (aliphatic vs. aromatic) and further assess the differences between the monomeric compounds and the hbPPEs. The decomposition and vaporizing behavior of a compound is an important factor in its flame-retardant behavior, but also the interaction with the pyrolyzing matrix has a significant influence on the performance. Therefore, the challenge in designing a FR is to optimize the chemical structure and its decomposition pathway to the matrix, with regards to time and temperature. This behavior becomes obvious in this study, and explains the superior gas phase activity of the aliphatic FRs. KW - Phosphorus KW - Metathesis KW - Dendritic KW - Cone calorimeter KW - Fire test PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-494535 DO - https://doi.org/10.3390/molecules24213901 SN - 1420-3049 VL - 24 IS - 21 SP - 3901 PB - MDPI AN - OPUS4-49453 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rabe, Sebastian A1 - Klack, Patrick A1 - Bahr, Horst A1 - Schartel, Bernhard T1 - Assessing the fire behavior of woods modified by N-methylol crosslinking, thermal treatment, and acetylation N2 - Wood products are often treated by different techniques to improve their longevity when used as building materials. Most of the time, the goal is to increase their resistance to weathering effects, deformations in material dimensions or biotic decomposition. These wood treatment techniques have a significant impact on pyrolysis and burning behavior. The general effects of three different common wood treatments on flame retardancy were investigated by comparing treated woods with their untreated counterparts and with other kinds of wood. While the acetylation of beech leads to a slightly increased fire hazard, the thermal treatment of wood and crosslinking of cellulose microfibrils dimethyloldihydroxy-ethyleneurea show a limited flame retarding effect. Switching to woods with a higher lignin content, and thus higher char yield, however, results in a more pronounced improvement in flame retardancy performance. This article delivers a comprehensive and balanced assessment of the general impact of different wood modifications on the fire behavior. Further, it is a valuable benchmark for assessing the flame retardancy effect of other wood modifications. KW - Acetylation KW - Cone claorimeter KW - DMDHEU KW - Heat of combustion KW - Thermal treatment KW - Wood modification PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-507397 DO - https://doi.org/10.1002/fam.2809 SN - 1099-1018 SN - 0308-0501 VL - 44 IS - 4 SP - 530 EP - 539 PB - Wiley Online Libary AN - OPUS4-50739 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Teng, Jun A1 - Tang, De-Hui A1 - Zhang, Xiao A1 - Hu, Wei-Hua A1 - Said, Samir A1 - Rohrmann, Rolf G. T1 - Automated modal analysis for tracking structural change during construction and operation phases N2 - The automated modal analysis (AMA) technique has attracted significant interest over the last few years, because it can track variations in modal parameters and has the potential to detect structural changes. In this paper, an improved density-based spatial clustering of applications with noise (DBSCAN) is introduced to clean the abnormal poles in a stabilization diagram. Moreover, the optimal system model order is also discussed to obtain more stable poles. A numerical Simulation and a full-scale experiment of an arch bridge are carried out to validate the effectiveness of the proposed algorithm. Subsequently, the continuous dynamic monitoring system of the bridge and the proposed algorithm are implemented to track the structural changes during the construction phase. Finally, the artificial neural network (ANN) is used to remove the temperature effect on modal frequencies so that a health index can be constructed under operational conditions. KW - Automated Modal Analysis for Tracking Structural Change during Construction and Operation Phases PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-475116 UR - https://www.mdpi.com/1424-8220/19/4/927/pdf DO - https://doi.org/10.3390/s19040927 SN - 1424-8220 VL - 19 IS - 4 SP - 927, 1 EP - 23 PB - MDPI AG CY - Basel, Switzerland AN - OPUS4-47511 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tambara, R. F. A1 - Durlo Tambara, Luis Urbano A1 - Venquiaruto, S. D. A1 - Pereira da Costa, F. B. T1 - Evaluation of the mechanical performance and capillary absorption of concretes with incorporation of crystallizing admixtures and subjected to damage at early ages T1 - Avaliação do desempenho mecânico e absorção capilar de concretos com incorporação de aditivos cristalizante submetidos a danos nas primeiras idades N2 - This study assessed the self-healing phenomenon in the mechanical properties and capillary absorption of structural concretes. Two crystalline powder additives were evaluated, dosed according to the manufacturers’ recommendations. Crystalline additives increase the density of the C-S-H gel and form insoluble crystals, effectively blocking fissures. Three concrete mixes were produced: a reference mix, additive-X with 0.8%, and additive-Y with 2.0%, relative to the mass of cement. 75% of the rupture load was applied at 3- and 14-days to induce microfissures for comparison with the reference mix. Subsequently, self-healing was assessed at 28- and 76-days. The property of axial compressive strength was determined at 28-days, revealing that crystalline additives contributed to an average increase of 12% in this property. While the age of loading did not significantly impact axial compressive strength, there were significant variations among the types of additives studied, as indicated by ANOVA. Water absorption properties through capillarity were evaluated at 28- and 76-days, showing an average reduction of 42% in water absorption due to the use of crystalline additives. In conclusion, the inclusion of crystalline additives positively contributed to the self-healing of the studied concretes, suggesting a partial recovery of microfissures. N2 - Esta pesquisa avaliou o fenômeno de autocicatrização nas propriedades mecânicas e absorção capilar de concretos estruturais. Foram avaliados dois aditivos cristalizantes em pó, dosados de acordo com o teor recomendado pelos fabricantes. Aditivos cristalizantes aumentam a densidade do gel C-S-H e formam cristais insolúveis, bloqueando fissuras. Três traços de concreto foram produzidos: referência, aditivo-X com 0,8% e aditivo-Y com 2,0% em relação a massa do cimento. Aplicou-se 75% da carga de ruptura aos 3- e 14-dias para gerar microfissuras e comparar com a referência. Posteriormente, a autocicatrização foi avaliada aos 28- e 76-dias. A propriedade de resistência à compressão axial foi determinada aos 28-dias, revelando que os aditivos cristalizantes contribuíram para um aumento médio de 12% desta propriedade. A idade do carregamento dos concretos não apresentou um impacto significativo na resistência à compressão axial, mas apontou resultados significativos entre os tipos de aditivos estudados, conforme ANOVA. As propriedades de absorção de água por capilaridade foram avaliadas aos 28- e 76-dias, indicando uma redução de absorção de água média de 42% devido ao uso dos aditivos cristalizantes. Em conclusão, a incorporação dos aditivos cristalizantes contribuiu de maneira positiva para a autocicatrização dos concretos estudados, indicando uma recuperação parcial das microfissuras. KW - Self-healing KW - Crystalline admixture KW - Concrete KW - Cracks PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599140 DO - https://doi.org/10.1590/1517-7076-RMAT-2023-0355 SN - 1517-7076 VL - 29 IS - 1 SP - 1 EP - 20 CY - Rio de Janeiro AN - OPUS4-59914 LA - por AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Coelho Lima, Isabela A1 - Robens-Radermacher, Annika A1 - Titscher, Thomas A1 - Kadoke, Daniel A1 - Koutsourelakis, P.-S. A1 - Unger, Jörg F. T1 - Bayesian inference for random field parameters with a goal-oriented quality control of the PGD forwardmodel's accuracy N2 - Numerical models built as virtual-twins of a real structure (digital-twins) are considered the future ofmonitoring systems. Their setup requires the estimation of unknown parameters, which are not directly measurable. Stochastic model identification is then essential, which can be computationally costly and even unfeasible when it comes to real applications. Efficient surrogate models, such as reduced-order method, can be used to overcome this limitation and provide real time model identification. Since their numerical accuracy influences the identification process, the optimal surrogate not only has to be computationally efficient, but also accurate with respect to the identified parameters. This work aims at automatically controlling the Proper Generalized Decomposition (PGD) surrogate’s numerical accuracy for parameter identification. For this purpose, a sequence of Bayesian model identification problems, in which the surrogate’s accuracy is iteratively increased, is solved with a variational Bayesian inference procedure. The effect of the numerical accuracy on the resulting posteriors probability density functions is analyzed through two metrics, the Bayes Factor (BF) and a criterion based on the Kullback-Leibler (KL) divergence. The approach is demonstrated by a simple test example and by two structural problems. The latter aims to identify spatially distributed damage, modeled with a PGD surrogate extended for log-normal random fields, in two different structures: a truss with synthetic data and a small, reinforced bridge with real measurement data. For all examples, the evolution of the KL-based and BF criteria for increased accuracy is shown and their convergence indicates when model refinement no longer affects the identification results. KW - Variational inference KW - Proper generalized decomposition KW - Goal-oriented KW - Digital twin KW - Random field PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-555755 DO - https://doi.org/10.1007/s00466-022-02214-6 SN - 1432-0924 SP - 1 EP - 22 PB - Springer CY - Berlin AN - OPUS4-55575 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Titscher, Thomas A1 - van Dijk, T. A1 - Kadoke, Daniel A1 - Robens-Radermacher, Annika A1 - Herrmann, Ralf A1 - Unger, Jörg F. T1 - Bayesian model calibration and damage detection for a digital twin of a bridge demonstrator N2 - Using digital twins for decision making is a very promising concept which combines simulation models with corresponding experimental sensor data in order to support maintenance decisions or to investigate the reliability. The quality of the prognosis strongly depends on both the data quality and the quality of the digital twin. The latter comprises both the modeling assumptions as well as the correct parameters of these models. This article discusses the challenges when applying this concept to realmeasurement data for a demonstrator bridge in the lab, including the data management, the iterative development of the simulation model as well as the identification/updating procedure using Bayesian inference with a potentially large number of parameters. The investigated scenarios include both the iterative identification of the structural model parameters as well as scenarios related to a damage identification. In addition, the article aims at providing all models and data in a reproducibleway such that other researcher can use this setup to validate their methodologies. KW - Damage detection KW - Finite element analysis KW - Load identification KW - Model updating KW - Estimation KW - System identification KW - Variational Bayesian statistics PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-574496 DO - https://doi.org/10.1002/eng2.12669 SN - 2577-8196 SP - 1 EP - 27 PB - Wiley CY - Hoboken, NJ AN - OPUS4-57449 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tabaka, Weronika A1 - Timme, Sebastian A1 - Lauterbach, Tobias A1 - Medina, L. A1 - Berglund, L. A. A1 - Carosio, F. A1 - Duquesne, S. A1 - Schartel, Bernhard T1 - Bench-scale fire stability testing - Assessment of protective systems on carbon fibre reinforced polymer composites N2 - Fire resistance testing of components made of carbon fibre reinforced polymers (CFRP) usually demands intermediate-scale or full-scale testing. A bench-scale test is presented as a practicable and efficient method to assess how different fire protective systems improve the structural integrity of CFRPs during fire. The direct flame of a fully developed fire was applied to one side of the CFRP specimen, which was simultaneously loaded with compressive force. Three different approaches (film, non-woven, and coatings) were applied: paper with a thickness in the range of μm consisting of cellulose nanofibre (CNF)/clay nanocomposite, nonwoven mats with thickness in the range of cm and intumescent coatings with a thickness in the range of mm. The uncoated specimen failed after just 17 s. Protection by these systems provides fire stability, as they multiply the time to failure by as much as up to 43 times. The reduced heating rates of the protected specimens demonstrate the reduced heat penetration, indicating the coatings’ excellent heat shielding properties. Bench-scale fire stability testing is shown to be suitable tool to identify, compare and assess different approaches to fire protection. KW - Fire stability KW - Bench-scale fire resistance KW - Carbon fibre reinforced polymer KW - Protective coatings PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-532401 DO - https://doi.org/10.1016/j.polymertesting.2021.107340 SN - 0142-9418 SN - 1873-2348 VL - 102 SP - 7340 PB - Elsevier CY - Amsterdam AN - OPUS4-53240 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stohl, Leonie A1 - Manninger, Tanja A1 - von Werder, Julia A1 - Dehn, F. A1 - Gorbushina, Anna A1 - Meng, Birgit T1 - Bioreceptivity of concrete - A review N2 - Materials that support natural biodiversity on their surfaces can compensate for human activities that have a negative impact on nature and thus contribute to a carbon-neutral and nature-positive world. Specifically designing bioreceptive materials which favor the growth of biofilms on their surface is an approach complementing conventional, macroscopic green façades. But what exactly characterizes a bioreceptive substrate and how do biofilm and substrate interact? How and why does a spontaneous colonization and the formation of biofilms take place? What are biofilms and how can they be established in a laboratory setting? How can this existing knowledge be transferred to the artificial stone concrete so that this material can be tuned to increase (or decrease) its bioreceptivity? This review paper aims at summarizing the existing state of knowledge on bioreceptive concrete and pointing out inconsistencies and contradictions which can only be removed by more interdisciplinary research in the field. KW - Bioreceptivity KW - Biofilm KW - Green facades KW - Developing building materials KW - Surface interactions KW - Concrete PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-581685 DO - https://doi.org/10.1016/j.jobe.2023.107201 SN - 2352-7102 VL - 76 SP - 1 EP - 17 PB - Elsevier AN - OPUS4-58168 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Günther, Martin A1 - Levchik, S. V. A1 - Schartel, Bernhard T1 - Bubbles and collapses: Fire phenomena of flame-retarded flexible polyurethane foams N2 - Flexible polyurethane foams (FPUF) are easy to ignite and exhibit rapid flame spread. In this paper, the fire phenomena of two standard foam formulations containing tris (1,3-dichloro-2-propyl) phosphate (FR-2) and a halogen-freepoly (ethyl ethylene phosphate) (PNX), respectively, as flame retardants are compared. A multimethodological approach is proposed which combines standard fire tests as well as new investigatory approaches. The thermophysical properties of the foams were determined by thermogravimetric analysis (TG), reaction to small flames was studied by means of the limiting oxygen index (LOI) and UL 94 HBF test, and the burning behavior was investigated with the cone calorimeter. Further, temperature development in burning cone calorimeter samples was monitored using thermocouples, and rheological measurements were performed on pyrolyzed material, delivering insight into the dripping behavior of the foams. This paper gives comprehensive insight into the fire phenomena of flame-retarded FPUFs that are driven by the two-step decomposition behavior of the foams. LOI and UL 94 HBF tests showed a reduced flammability and reduced tendency to drip for the flame-retarded foams. TG and cone calorimeter measurements revealed that the two-step decomposition behavior causes two stages during combustion, namely structural collapse and pool fire. The flame-retardant mode of action was identified to take place primarily during the foam collapse and be based mainly on flame inhibition. However, some condensed-phase action was been measured, leading to significantly increased melt viscosity and improved dripping behavior for foams containing PNX. KW - Burning behavior KW - Flame retardant KW - Flexible PU foam PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-512145 DO - https://doi.org/10.1002/pat.4939 SN - 1042-7147 SN - 1099-1581 VL - 31 IS - 10 SP - 2185 EP - 2198 PB - Wiley Online Libary AN - OPUS4-51214 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schönsee, Eric A1 - Hüsken, Götz A1 - Jeyifous, Olubunmi Anthony A1 - Mezhov, Alexander A1 - Strangfeld, Christoph T1 - Calculating rheological properties of fresh mortar for additive manufacturing based on experimental, multi-sensor data N2 - Additive manufacturing of concrete structures is a novel and emerging technology. Freecontouring in civil engineering, which allows for entirely new designs, is a significant advantage. Inthe future, lower construction costs are expected with increased construction speeds and decreasingrequired materials and workers. However, architects and civil engineers rely on a certain quality ofexecution to fulfil construction standards. Although several techniques and approaches demonstratethe advantages, quality control during printing is highly challenging and rarely applied. Due to thecontinuous mixing process commonly used in 3D concrete printing, it is impossible to exclude varia-tions in the dry mixture or water content, and a test sample cannot be taken as a representative samplefor the whole structure. Although mortar properties vary only locally, a defect in one layer duringprinting could affect the entire integrity of the whole structure . Therefore, real-time process monitor-ing is required to record and document the printing process.At the Bundesanstalt für Materialforschung und -prüfung (BAM) a new test rig for the additive man-ufacturing of concrete is built. The primary purpose is measuring and monitoring the properties of amortar during the printing process.The following study investigates an approach for calculating yield stress and plastic viscosity based onexperimentally recorded pressure data. The calculations assume that fresh mortar behaves as a Bing-ham fluid and that the Buckingham-Reiner-equation is applicable. A test setup consisting of rigid pipeswith integrated pressure sensors at different positions is utilized.Monitoring the printing process with different sensors is crucial for the quality control of an ongoingprocess. T2 - Non-Traditional Cement and Concrete 2023 Conference CY - Brno, Czech Republic DA - 25.06.2023 KW - 3DCP KW - Monitoring KW - Additive manufacturing KW - Rheology KW - Bingham fluid KW - Concrete printing PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-598179 DO - https://doi.org/10.4028/p-EV4gPv SN - 1662-0356 VL - 145 SP - 131 EP - 139 PB - Trans Tech Publications CY - Baech AN - OPUS4-59817 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gluth, Gregor A1 - Ke, X. A1 - Vollpracht, A. A1 - Weiler, L. A1 - Bernal, S. A. A1 - Cyr, M. A1 - Dombrowski-Daube, K. A1 - Geddes, D. A. A1 - Grengg, C. A1 - Le Galliard, C. A1 - Nedeljkovic, M. A1 - Provis, J. L. A1 - Valentini, L. A1 - Walkley, B. T1 - Carbonation rate of alkali-activated concretes and high-volume SCM concretes: a literature data analysis by RILEM TC 281-CCC N2 - The current understanding of the carbonation and the prediction of the carbonation rate of alkali-activated concretes is complicated inter alia by the wide range of binder chemistries used and testing conditions adopted. To overcome some of the limitations of individual studies and to identify general correlations between mix design parameters and carbonation resistance, the RILEM TC 281-CCC ‘Carbonation of Concrete with Supplementary Cementitious Materials’ Working Group 6 compiled and analysed carbonation data for alkali-activated concretes and mortars from the literature. For comparison purposes, data for blended Portland cement-based concretes with a high percentage of SCMs (≥ 66% of the binder) were also included in the database. The analysis indicates that water/CaO ratio and water/binder ratio exert an influence on the carbonation resistance of alkali-activated concretes; however, these parameters are not good indicators of the carbonation resistance when considered individually. A better indicator of the carbonation resistance of alkali-activated concretes under conditions approximating natural carbonation appears to be their water/(CaO + MgOeq + Na2Oeq + K2Oeq) ratio, where the subscript ‘eq’ indicates an equivalent amount based on molar masses. Nevertheless, this ratio can serve as approximate indicator at best, as other parameters also affect the carbonation resistance of alkali-activated concretes. In addition, the analysis of the database points to peculiarities of accelerated tests using elevated CO2 concentrations for low-Ca alkali-activated concretes, indicating that even at the relatively modest concentration of 1% CO2, accelerated testing may lead to inaccurate predictions of the carbonation resistance under natural exposure conditions. KW - Alkali-activated materials KW - Durability KW - Carbonation KW - Accelerated testing PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-560037 DO - https://doi.org/10.1617/s11527-022-02041-4 VL - 55 IS - 8 SP - 1 EP - 15 PB - Springer Nature AN - OPUS4-56003 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lu, Z. A1 - Haist, M. A1 - Ivanov, D. A1 - Jakob, C. A1 - Jansen, D. A1 - Leinitz, Sarah A1 - Link, J. A1 - Mechtcherine, V. A1 - Neubauer, J. A1 - Plank, J. A1 - Schmidt, Wolfram A1 - Schilde, C. A1 - Schröfl, C. A1 - Sowoidnich, T. A1 - Stephan, D. T1 - Characterization data of reference cement CEM I 42.5 R used for Priority Program DFG SPP 2005 “Opus Fluidum Futurum - Rheology of reactive, multiscale, multiphase construction materials” N2 - A thorough characterization of starting materials is the precondition for further research, especially for cement, which contains various phases and presents quite a complex material for fundamental scientific investigation. In the paper at hand, the characterization data of the reference cement CEM I 42.5 R used within the priority program 2005 of the German Research Foundation (DFG SPP 2005) are presented from the aspects of chemical and mineralogical compositions as well as physical and chemical properties. The data were collected based on tests conducted by nine research groups involved in this cooperative program. For all data received, the mean values and the corresponding errors were calculated. The results shall be used for the ongoing research within the priority program. KW - Portland cement KW - Characterization KW - DFG SPP 2005 PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-500849 DO - https://doi.org/10.1016/j.dib.2019.104699 SN - 2352-3409 VL - 27 SP - 104699 PB - Elsevier Inc. AN - OPUS4-50084 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lu, Z. C. A1 - Haist, M. A1 - Ivanov, D. A1 - Jakob, C. A1 - Jansen, D. A1 - Schmid, M. A1 - Kißling, P. A. A1 - Leinitz, Sarah A1 - Link, J. A1 - Mechtcherine, V. A1 - Neubauer, J. A1 - Plank, J. A1 - Schmidt, Wolfram A1 - Schilde, C. A1 - Schröfl, C. A1 - Sowoidnich, T. A1 - Stephan, D. T1 - Characterization data of reference cement CEM III/A 42.5N used for priority program DFG SPP 2005 "Opus Fluidum Futurum - Rheology of reactive, multiscale, multiphase construction materials" N2 - Two types of cements were selected as the reference cement in the priority program 2005 of the German Research Foundation (DFG SPP 2005). A thorough characterization of CEM I 42.5 R has been made in a recent publication. In this paper, the characterization data of the other reference cement CEM III/A 42.5 N are presented from the aspects of chemical and mineralogical compositions as well as physical and chemical properties. The characterization data of the slag, which is the second main constituent of this specific cement besides the clinker, are presented independently. For all data received, the mean values and the corresponding errors were calculated. The data shall be used for the ongoing research within the priority program. Also, researchers from outside this priority program can benefit from these data if the same materials are used. KW - Cement KW - Slag KW - Characterization KW - DFG SPP 2005 PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-568980 DO - https://doi.org/10.1016/j.dib.2020.105524 SN - 2352-3409 VL - 30 SP - 1 EP - 14 PB - Elsevier CY - Amsterdam AN - OPUS4-56898 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pott, U. A1 - Crasselt, Claudia A1 - Fobbe, N. A1 - Haist, M. A1 - Heinemann, M. A1 - Hellmann, S. A1 - Ivanov, D. A1 - Jakob, C. A1 - Jansen, D. A1 - Lei, L. A1 - Li, R. A1 - Link, J. A1 - Lowke, D. A1 - Mechtcherine, V. A1 - Neubauer, J. A1 - Nicia, D. A1 - Plank, J. A1 - Reißig, S. A1 - Schäfer, T. A1 - Schilde, C. A1 - Schmidt, Wolfram A1 - Schröfl, C. A1 - Sowoidnich, T. A1 - Strybny, B. A1 - Ukrainczyk, N. A1 - Wolf, J. A1 - Xiao, P. A1 - Stephan, D. T1 - Characterization data of reference materials used for phase II of the priority program DFG SPP 2005 “Opus Fluidum Futurum –Rheology of reactive, multiscale, multiphase construction materials” N2 - A thorough characterization of base materials is the prereq- uisite for further research. In this paper, the characterization data of the reference materials (CEM I 42.5 R, limestone pow- der, calcined clay and a mixture of these three components) used in the second funding phase of the priority program 2005 of the German Research Foundation (DFG SPP 2005) are presented under the aspects of chemical and min- eralogical composition as well as physical and chemical properties. The data were collected based on tests performed by up to eleven research groups involved in this cooperative program. KW - Portland cement KW - Limestone powder KW - Calcined clay KW - Sustainable cement KW - DFG SPP 2005 PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-569913 DO - https://doi.org/10.1016/j.dib.2023.108902 VL - 47 SP - 1 EP - 19 PB - Elsevier AN - OPUS4-56991 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gluth, Gregor A1 - Mundra, Shishir A1 - Henning, Ricky T1 - Chloride binding by layered double hydroxides (LDH/AFm phases) and alkali-activated slag pastes: an experimental study by RILEM TC 283-CAM 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. Chloride binding isotherms of individual hydrate phases would be required to model chloride ingress but are only scarcely available and partly conflicting. The present study by RILEM TC 283-CAM ‘Chloride transport in alkali-activated materials’ significantly extends the available database and resolves some of the apparent contradictions by determining the chloride binding isotherms of layered double hydroxides (LDH), including 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 results of the present study show that the chloride binding isotherms of LDH/AFm phases depend strongly on the liquid/solid ratio during the experiments. This is attributed to kinetic restrictions, which are, however, currently poorly understood. Chloride binding by AAS pastes is only moderately influenced by the employed activator. A steep increase of the chloride binding by AAS occurs 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. KW - Chloride binding KW - Sorption isotherm KW - Layered double hydroxide KW - AFm phase KW - Alkali-activated materials PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599370 DO - https://doi.org/10.1617/s11527-024-02311-3 SN - 1359-5997 SN - 1871-6873 VL - 57 IS - 4 SP - 1 EP - 17 PB - Springer Nature AN - OPUS4-59937 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Manes, M. A1 - Sauca, A. A1 - El Houssami, M. A1 - Andersson, P. A1 - McIntyre, C. A1 - Campbell, R. A1 - Rush, D. A1 - Hofmann-Böllinghaus, Anja A1 - Wagner, P. A1 - Leene, M. A1 - Oberhagemann, D. A1 - Jomaas, G. A1 - Grone, F. A1 - Guillaume, E. T1 - Closing Data Gaps and Paving the Way for Pan-European Fire Safety Efforts: Part II—Terminology of Fire Statistical Variables N2 - A well-defined terminology of fire-related variables is important for correct analyses and supporting knowledge-based decisions regarding the evaluation of building fires at the European level. After developing an overview of current practices for fire statistics in Part I, the terminology used and the data collected by the EU Member States and eight other countries regarding fire incidents, property damage and human losses were mapped to increase awareness of their practice and support a comprehensive assessment of several fire statistical datasets. A questionnaire was distributed to relevant authorities responsible for the collection, elaboration/analysis, and fire statistical data publications to define and select the essential variables for an appropriate fire assessment and fire incident description. Based on the results of the questionnaire able to identify the essential fire statistical variables and a detailed analysis of current definitions adopted in the fire statistics of the EU Member States and other countries, a common terminology is proposed to collect the necessary data in the EU Member States and obtain meaningful datasets based on standardised terms and definitions. The results will generate essential outputs to move towards harmonised fire statistics at the EU level and contribute to an appropriate analysis able to improve fire prevention and fire mitigation in building fires. KW - Fire statistics PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-575725 DO - https://doi.org/10.1007/s10694-023-01408-5 SN - 1572-8099 SP - 1 EP - 32 PB - Springer CY - Heidelberg AN - OPUS4-57572 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Manes, M. A1 - El Houssami, M. A1 - Campbell, R. A1 - Sauca, A. A1 - Rush, D. A1 - Hofmann-Böllinghaus, Anja A1 - Andersson, P. A1 - Wagner, P. A1 - Veeneklaas, J. A1 - van Hees, P. A1 - Guillaume, E. T1 - Closing Data Gaps and Paving the Way for Pan-European Fire Safety Efforts: Part I—Overview of Current Practices for Fire Statistics N2 - The analysis of the current state of fire statistics and data collection in Europe and other countries is needed to increase awareness of how fire incidents affect buildings and to support pan-European fire prevention and fire mitigation measures. The terminology and data collected regarding fire incidents in buildings in the EU Member States were mapped to obtain meaningful datasets to determine common terminology, collection methodology, and data interpretation system. An extensive literature review showed that fire data collection systems have been instrumental in informing firefighting strategies, evidence-based planning, prevention, and educational programmes. Differences and similarities between fire data collection systems were also investigated. The amount and quality of the information in fire statistical recording systems appear to be influenced by the complexity and structure with which the data are collected. The analysis also examined the existing fire statistics in the EU Member States and a few other countries. Finally, a detailed investigation of the number of fires, fire deaths, and injuries from 2009 to 2018 in several countries was examined based on data from a report by CTIF. The trends showed differences attributable to the existing fire statistical practices in terms of terminology and data collection, and interpretation. Part II proposes a common terminology for selected fire statistical variables. The results provide relevant information regarding fire safety at the European level and should be used to guide the development of more uniform fire statistics across Europe. KW - Fire statistics KW - European project PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-575711 DO - https://doi.org/10.1007/s10694-023-01415-6 SN - 1572-8099 SP - 1 EP - 44 PB - Springer CY - Heidelberg AN - OPUS4-57571 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zirnstein, Benjamin A1 - Schulze, Dietmar A1 - Schartel, Bernhard T1 - Combination of phosphorous flame retardants and aluminum trihydrate in multicomponent EPDM composites N2 - Ethylene propylene diene monomer (EPDM) Rubbers with the flame retardants tris(2-ethylhexyl)phosphate, ammonium polyphosphate, polyaniline, and aluminum trihydroxide were prepared and analyzed in this study. The homogenous dispersion of the fillers in the rubber matrix was confirmed by scanning electron microscope. To investigate the interplay of the different flame retardants, the flame retardants were varied systematically. The comprehensive study sought combinations of flame retardants that allow high loadings of flame retardants without deterioration of the physical and mechanical properties of the EPDM rubber. The eight EPDM rubbers were investigated via thermogravimetric analysis and pyrolysis gas chromatography coupled with a mass spectrometer (Py GC/MS) to investigate the potential synergistic effects. In the Py-GC/MS experiments, 27 pyrolysis products were identified. Furthermore, UL 94, limiting oxygen index, FMVSS 302, glow wire tests, and cone calorimeter tests were carried out. In the cone calorimeter test the EPDM rubbers R-1AP and R-1/2P achieved an increase in residue at flameout of 76% and a reduction in total heat evolved of about 35%. Furthermore, the compounds R-1AP and R-1/2P achieved a reduction in MARHE to about 150 kW m−1, a reduction of over 50% compared to the unprotected rubber R. KW - EPDM KW - Rubber KW - Aluminum hydroxide (ATH) KW - Phosphorous flame retardant PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-502859 DO - https://doi.org/10.1002/pen.25280 SN - 1548-2634 VL - 60 IS - 2 SP - 267 EP - 280 PB - Wiley AN - OPUS4-50285 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Geburtig, Anja A1 - Wachtendorf, Volker A1 - Falkenhagen, Jana T1 - Combined impact of UV radiation and nitric acid on high‐density polyethylene containers as a laboratory test N2 - In a laboratory test, transparent high‐density polyethylene (HDPE) jerrycans have been exposed to both UV radiation and 55 wt‐% nitric acid solution at (41 ± 2)°C, for up to 20 days. For comparison, UV radiant exposure (21 days) and nitric acid exposure (up to 6 weeks) were performed separately, at nearly equal temperatures. The damages are compared with FTIR spectroscopy in ATR and HT‐gel permeation chromatography(GPC) on a molecular level and with hydraulic internal pressure testing as a component test. For the used jerrycans, relevant oxidation can only be found after the combined exposure. This is caused by the decomposition of nitric acid into nitrous gases by UV radiation, which is also observed at lower concentrations (28 wt‐%). After 6 days of laboratory exposure, this is rated as critical, which corresponds to about 1/10 year in Central Europe, according to the UV radiant exposure. The gradual increase in oxidative damage shows the reproducibility of the test. KW - Molecular mass distribution KW - High-density polyethylene KW - Nitric acid KW - UV radiation PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-550141 DO - https://doi.org/10.1002/pts.2673 SN - 0894-3214 SP - 1 EP - 7 PB - John Wiley & Sons Ltd AN - OPUS4-55014 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Priebe, Nsesheye Susan A1 - Gluth, Gregor A1 - Sturm, Patrick A1 - Vogler, Nico A1 - Kühne, Hans-Carsten T1 - Comparison of calcined illitic clays (brick clays) and low-grade kaolinitic clays as supplementary cementitious materials N2 - The use of calcined clays as supplementary cementitious materials (SCMs) has been identified as a viable option to decrease the CO2 emissions related to cement production. However, while extensive data is available about kaolinitic clays in this context, other clays such as illitic clays appear to be under-studied. Therefore, in the present study, two illitic clays were compared to two low-grade kaolinitic clays in terms of transformations in the calcination temperature range 650–900 °C, and performance of the calcined clays in blended cement pastes as measured by strength evolution, heat release, hydrated phase formation and portlandite consumption. The illitic clays required a higher calcination temperature for complete dehydroxylation of their illite than what is necessary for dehydroxylation of kaolinite. These higher calcination temperatures also led to particle sintering, significantly decreasing the specific surface area of the illitic clays, particularly for the clay with the higher Fe2O3 content. Nevertheless, while the kaolinitic clays generally exhibited the best performance as SCM, the illitic clay with lower Fe2O3 content performed similar to the kaolinitic clays when calcined at optimum temperature and applied at a moderate substitution rate. These findings demonstrate that several different clays have the potential to be used as SCM and indicate possible routes to identify suitable deposits for this purpose. KW - Blended cement KW - Calcined clay KW - Brick clay KW - Illite KW - Kaolinite PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-488195 DO - https://doi.org/10.1617/s11527-019-1393-2 SN - 1359-5997 SN - 1871-6873 N1 - Geburtsname von Priebe, Nsesheye Susan: Msinjili, N. S. - Birth name of Priebe, Nsesheye Susan: Msinjili, N. S. VL - 52 IS - 5 SP - Article Number 94 PB - Springer Nature AN - OPUS4-48819 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Herzel, Hannes A1 - Stemann, J. A1 - Simon, Sebastian A1 - Adam, Christian T1 - Comparison of thermochemical treatment of sewage sludge ash with sodium sulphate in laboratory-scale and pilot-scale experiments N2 - There is an ongoing debate on European scale concerning the criticality of phosphorus. In Switzerland and Germany, phosphorus recovery from phosphorus-rich waste streams will become obligatory. Sewage sludge ash is rich in phosphorus and may become an important secondary feedstock. Thermochemical treatment of sewage sludge ash with sodium sulphate under reducing conditions was shown to remove heavy metals from the solid product and produce the fully plant available crystalline phase CaNaPO4. Pilot-scale experiments in a rotary kiln were carried out at temperatures between 750 and 1000 °C and were compared to laboratory-scale experiments with crucibles. Process upscaling was successfully demonstrated but a series of differences were noticed: In comparison to laboratory-scale, solubility of phosphorus in samples from pilot-scale experiments was lower at all chosen treatment temperatures because of shorter retention time and incomplete decomposition of sodium sulphate. X-ray diffraction analysis revealed remaining phase fractions of whitlockite (Ca3-x(Mg,Fe)x(PO4)2) and sodium sulphate from the starting materials in products and thus indicated incomplete reaction. In contrast to the results of laboratory-scale experiments, the crystalline phase CaNaPO4 was clearly absent in the products from the rotary kiln but instead a Mg-bearing phase (Ca,Mg)NaPO4 was formed. Laboratory-scale experiments confirmed (Ca,Mg)NaPO4 is an intermediate phase between whitlockite and CaNaPO4. However, both crystalline phases are characterized by high plant availability. It was shown that heavy metal removal increased at higher temperatures whereas solubility and thus plant availability of phosphorus already reached its maxima at temperatures of 950 °C in pilot-scale and 875 °C in laboratory-scale experiments. KW - Crystalline phase identification KW - Heavy metal removal KW - Phosphorus availability KW - Process upscaling KW - Recovery KW - Rhenanite PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-524084 DO - https://doi.org/10.1007/s13762-021-03252-y VL - 19 IS - 3 SP - 1997 EP - 2006 PB - Springer AN - OPUS4-52408 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Amano, K. O. A. A1 - Hahn, S.-K. A1 - Butt, N. A1 - Vorwerk, P. A1 - Gimadieva, E. A1 - Tschirschwitz, Rico A1 - Rappsilber, Tim A1 - Krause, U. T1 - Composition and Explosibility of Gas Emissions from Lithium-Ion Batteries Undergoing Thermal Runaway N2 - Lithium-based batteries have the potential to undergo thermal runaway (TR), during which mixtures of gases are released. The purpose of this study was to assess the explosibility of the gaseous emission from LIBs of an NMC-based cathode during thermal runaway. In the current project, a series of pouch lithium-based battery cells was exposed to abuse conditions (thermal) to study the total amount of gases released and the composition of the gas mixture. First, the battery cells were placed in a closed vessel, and the pressure and temperature rise inside the vessel were measured. In a second step, the composition of gases was analysed using a Fourier transform Infrared (FTIR) spectrometer. We found that the amount of released gases was up to 102 ± 4 L, with a clear dependence on the battery capacity. This study showed that the concentration of gaseous emissions such as carbon monoxide (CO), methane (CH4), ethylene (C2H4), ethane (C2H6), and hydrogen cyanide (HCN) increased with higher cell capacity. Of the five studied flammable gases, the maximum concentrations of carbon monoxide (16.85 vol%), methane (7.6 vol%), and ethylene (7.86 vol%) were identified to be within their explosible range. Applying Le Chatelier’s law, a calculated lower explosion limit (LEL) of 7% in volume fraction was obtained for the gas mixture. The upper explosion limit (UEL) of the gas mixture was also found to be 31% in volume. A filter comprising pyrobubbles was used for the removal of the studied gas components released during the thermal abuse. The investigation revealed that the pyrobubbles filter was highly effect in the removal of HCN (up to 94% removal) and CO2 (up to 100% removal). Herein, we report the dependency of the method of thermal runaway trigger on the measured maximum temperature. KW - Lithium-ion battery KW - Thermal runaway KW - Smoke gas emission KW - Gas explosion KW - Explosion limit PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-576477 DO - https://doi.org/10.3390/batteries9060300 VL - 9 IS - 6 SP - 1 EP - 19 PB - MDPI CY - Basel, Switzerland AN - OPUS4-57647 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schepers, Winfried A1 - Kulke, D. T1 - Cone penetration tests and dynamic soil properties N2 - ISO 14837-32:2015 and DIN EN 1998-1/NA:2021 as well as prEN 1997-2:2022 allow for us-ing correlations between the results of in-situ soil penetration tests and shear wave velocity (or shear modulus) to determine soil properties to be used in dynamic analyses. While the ISO and prEN standards even provide some recommendations on specific correlations to be used, the DIN standard does not. Due to the statistical nature of such correlations their general applica-bility has to be verified. We collected data sets from test sites from Germany as well as New Zealand at which cone penetration tests (CPT) as well as seismic site investigation methods were conducted. These sites comprise sandy soils as well as clayey soils, mixed soils as well as glacial soils. We compare the results of several correlations between CPT results and shear wave velocity. The accuracy of such correlations is assessed with respect to the accuracy of seismic in-situ tests. It turns out that for clean sands such correlations between CPT and Vs have a similar order of variability as seismic in-situ tests conducted at the same site. The higher the fines portion of the soil, the higher the variability of the statistical correlations, and conse-quently the less the general applicability. For glacial soils and other special soil types usage of statistical correlations to determine dynamic soil properties is not recommended. T2 - XII International Conference on Structural Dynamics CY - Delft, Netherlands DA - 02.07.2023 KW - Wave propagation KW - Soil properties KW - Dynamic excitation PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604887 DO - https://doi.org/10.1088/1742-6596/2647/25/252005 VL - 2647 SP - 1 EP - 11 PB - IOP Publishing CY - Bristol AN - OPUS4-60488 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wallau, Wilma A1 - Pirskawetz, Stephan A1 - Voland, K. A1 - Meng, Birgit T1 - Continuous expansion measurement in accelerated concrete prism testing for verifying ASR-expansion models N2 - The susceptibility of concrete structures due to alkali–silica reaction (ASR) can be assessed by means of ASR concrete prism testing at 60 °C, according to RILEM AAR 4.1. There, expansion of concrete prisms indicates alkali-reactivity of the examined concrete mix. This work applies in situ expansion measurement to accelerated concrete prism testing. Automated measuring facilitates both storage without the usually necessary interruptions for manual measurement and acquisition of quasi-continuousexpansion data. A comparative experimental programme showed that conventional testing resulted in stronger expansion and leaching of alkalis than automated testing. Experimental simulation of interruptions, typically associated with manual measurements in conventional testing, could prove the influence of these cooling–heating cycles. Two phenomenological approaches, frequently used for describing reaction kinetics of ASR by linking it to expansion results from ASR-testing, were validated with continuous expansion data of three types of aggregate. Experimental expansion depicted s-shaped curves similar to them of the modelling approaches. However, strong swelling recorded in the beginning of the test was not covered by the model curves. Auxiliary measurement of acoustic emissions and ultrasonic velocity helped characterising mechanisms such as hydration and cracking, which also influence prism expansion. The proposed modification of the measurement procedure provides an extended basis to analyse expansion mechanisms. Regarding data for validation of ASR-expansion models, continuous expansion results are preferable to conventional test results. KW - Alkali–silica reaction KW - Accelerated concrete prism test KW - Automated expansion measurement KW - ASR modelling PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-455959 DO - https://doi.org/10.1617/s11527-018-1205-0 SN - 1359-5997 SN - 1871-6873 VL - 51 IS - 3 SP - 51 EP - 79 PB - Springer AN - OPUS4-45595 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bender, R. A1 - Féron, D. A1 - Mills, D. A1 - Ritter, S. A1 - Bäßler, Ralph A1 - Bettge, Dirk A1 - de Graeve, I. A1 - Dugstad, A. A1 - Grassini, S. A1 - Hack, T. A1 - Halama, M. A1 - Han, E.-H. A1 - Harder, T. A1 - Hinds, G. A1 - Kittel, J. A1 - Krieg, R. A1 - Leygraf, C. A1 - Martinelli, L. A1 - Mol, A. A1 - Neff, D. A1 - Nilsson, J.-O. A1 - Odnevall, I. A1 - Paterson, S. A1 - Paul, S. A1 - Prošek, T. A1 - Raupach, M. A1 - Revilla, R. I. A1 - Ropital, F. A1 - Schweigart, H. A1 - Szala, E. A1 - Terryn, H. A1 - Tidblad, J. A1 - Virtanen, S. A1 - Volovitch, P. A1 - Watkinson, D. A1 - Wilms, M. A1 - Winning, G. A1 - Zheludkevich, M. T1 - Corrosion challenges towards a sustainable society N2 - A global transition towards more sustainable, affordable and reliable energy systems is being stimulated by the Paris Agreement and the United Nation's 2030 Agenda for Sustainable Development. This poses a challenge for the corrosion industry, as building climate‐resilient energy systems and infrastructures brings with it a long‐term direction, so as a result the long‐term behaviour of structural materials (mainly metals and alloys) becomes a major prospect. With this in mind “Corrosion Challenges Towards a Sustainable Society” presents a series of cases showing the importance of corrosion protection of metals and alloys in the development of energy production to further understand the science of corrosion, and bring the need for research and the consequences of corrosion into public and political focus. This includes emphasis on the limitation of greenhouse gas emissions, on the lifetime of infrastructures, implants, cultural heritage artefacts, and a variety of other topics. KW - Corrosion KW - Corrosion costs KW - Corrosion protection KW - Preventive strategies PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-554801 DO - https://doi.org/10.1002/maco.202213140 SN - 1521-4176 VL - 73 IS - 11 SP - 1730 EP - 1751 PB - Wiley-VCH CY - Weinheim AN - OPUS4-55480 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ebell, Gino A1 - Mayer, T. F. A1 - Harnisch, J. A1 - Dauberschmidt, Ch. T1 - Corrosion monitoring of reinforced concrete structures:The DGZfP specification B12 Collaboration N2 - Corrosion monitoring of reinforced or prestressed concrete structures has becomeincreasingly important in recent years. Areas of application include componentsthat are no longer accessible after completion or where potential fieldmeasurements cannot be carried out due to existing coatings. Corrosion monitoringcan also be used to monitor the progress of corrosion in corroding systems, e.g. to prove the success of repair measures according to repair principle 8 in accordancewith EN 1504‐9 or repair method 8.3 in accordance with the DIBt repair guideline.It also could be used to prove the functionality of cathodic corrosion protectionsystems in accordance with ISO 12696. Despite the increasing importance ofcorrosion monitoring, no guidelines orrecommendations existed until 2018. Thisgap was closed by the English version of specification B12,“Corrosion Monitoringof Reinforced and Prestressed Concrete Structures,”of the German Society for Non‐Destructive Testing, which was published in 2021. This article introducesspecification B12 by explaining the basicmeasurement principles and illustratingthe potential of corrosion monitoring in new and existing buildings. KW - Corrosion KW - Monitoring PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-580982 DO - https://doi.org/10.1002/maco.202313934 SN - 0947-5117 SP - 1 EP - 9 PB - Wiley VHC-Verlag AN - OPUS4-58098 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Aristia, Gabriela A1 - Le, Quynh Hoa A1 - Bäßler, Ralph T1 - Corrosion of Carbon Steel in Artificial Geothermal Brine: Influence of Carbon Dioxide at 70 °C and 150 °C N2 - This study focuses on the corrosion mechanism of carbon steel exposed to an artificial geothermal brine influenced by carbon dioxide (CO2) gas. The tested brine simulates a geothermal source in Sibayak, Indonesia, containing 1500 mg/L of Cl-, 20 mg/L of SO4 2-, and 15 mg/L of HCO3-with pH 4. To reveal the temperature effect on the corrosion behavior of carbon steel, exposure and electrochemical tests were carried out at 70 °C and 150 °C. Surface analysis of corroded specimens showed localized corrosion at both temperatures, despite the formation of corrosion products on the surface. After 7 days at 150 °C, SEM images showed the formation of an adherent, dense, and crystalline FeCO3 layer. Whereas at 70 °C, the corrosion products consisted of chukanovite (Fe2(OH)2CO3) and siderite (FeCO3), which are less dense and less protective than that at 150 °C. Control experiments under Ar-environment were used to investigate the corrosive effect of CO2. Free corrosion potential (Ecorr) and electrochemical impedance spectroscopy (EIS) confirm that at both temperatures, the corrosive effect of CO2 was more significant compared to that measured in the Ar-containing solution. In terms of temperature effect, carbon steel remained active at 70 °C, while at 150 °C, it became passive due to the FeCO3 formation. These results suggest that carbon steel is more susceptible to corrosion at the near ground surface of a geothermal well, whereas at a deeper well with a higher temperature, there is a possible risk of scaling (FeCO3 layer). A longer exposure test at 150 °C with a stagnant solution for 28 days, however, showed the unstable FeCO3 layer and therefore a deeper localized corrosion compared to that of seven-day exposed specimens. KW - Carbon steel KW - CO2 KW - Corrosion KW - Electrochemical impedance spectroscopy KW - Geothermal PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-498168 DO - https://doi.org/10.3390/ma12223801 SN - 1996-1944 VL - 12 IS - 22 SP - 3801-1 EP - 20 PB - MDPI CY - Basel AN - OPUS4-49816 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heyn, A. A1 - Müller, Thoralf A1 - Balzer, M. A1 - Fenker, M. A1 - Kappl, H. T1 - Corrosion protection mechanisms of TiMgN hard coatings on steel N2 - Hard coated steel components are used in a wide application range, mostly for protective, wear resistant and decorative purposes. Despite of these coatings being regarded as relatively dense, there is always a high risk of localized corrosion when a coated low alloyed steel component encounters a surrounding high humidity atmosphere or even an aqueous medium. An approach to enhance the corrosion properties is the addition of magnesium to physical vapor deposited hard coatings, like TiN. It has been found that there is a remarkable increase in corrosion resistance in dependence of magnesium content of the TiMgN coating and its surface properties. In this work the authors will explain the underlying corrosion protection mechanisms by means of electrochemical and analytical studies. The positive impact of magnesium in the coating relates on its preferred dissolution vs. steel. This causes the potential to shift to more negative direction with respect to the steel substrate and additionally leads to a temporarily passivation of the steel due to alkalization of the surrounding electrolyte by formation of magnesium hydroxide. T2 - 20. Werkstofftechnisches Kolloquium CY - Chemnitz, Germany DA - 14.03.2018 KW - Corrosion KW - Titanium nitride KW - PVD hard coating KW - magnesium PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-457117 DO - https://doi.org/10.1088/1757-899X/373/1/012009 SN - 1757-8981 VL - 373 IS - 1 SP - 012009, 1 EP - 10 PB - IOP Publishing Ltd AN - OPUS4-45711 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Le, Quynh Hoa A1 - Bäßler, Ralph A1 - Bettge, Dirk A1 - Buggisch, E. A1 - Schiller, Bernadette Nicole A1 - Beck, M. T1 - Corrosion Study on Wellbore Materials for the CO2 Injection Process N2 - For reliability and safety issues of injection wells, corrosion resistance of materials used needs to be determined. Herein, representative low-cost materials, including carbon steel X70/1.8977 and low alloyed steel 1.7225, were embedded in mortar to mimic the realistic casing-mortar interface. Two types of cement were investigated: (1) Dyckerhoff Variodur commercial Portland cement, representing a highly acidic resistant cement and (2) Wollastonite, which can react with CO2 and become stable under a CO2 stream due to the carbonation process. Exposure tests were performed under 10 MPa and at 333 K in artificial aquifer fluid for up to 20 weeks, revealing crevice corrosion and uniform corrosion instead of expected pitting corrosion. To clarify the role of cement, simulated pore water was made by dispersing cement powder in aquifer fluid and used as a solution to expose steels. Surface analysis, accompanied by element mapping on exposed specimens and their crosssections, was carried out to trace the chloride intrusion and corrosion process that followed. KW - Carbon capture storage KW - CCS KW - Carbon dioxide KW - Corrosion KW - Carbon steel KW - Aquifer fluid KW - Cement KW - Casing KW - Pitting PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-519774 DO - https://doi.org/10.3390/pr9010115 SN - 2227-9717 VL - 9 IS - 1 SP - 115 PB - MDPI CY - Basel AN - OPUS4-51977 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Makris, Ruben A1 - Hille, Falk A1 - Thiele, Marc A1 - Kirschberger, D. A1 - Sowietzki, D. T1 - Crack luminescence as an innovative method for detection of fatigue damage N2 - In structural parts under vibrational loading fatigue cracks can initiate and grow, which can lead to structural failure. Conventional non-destructive testing methods for crack detection provide just a snapshot of fatigue crack evolution, whereas crack luminescence coating realizes clear visibility of the entire crack formation. Fatigue causing cyclic tensile tests and examinations on special test bodies allowing control of the crack opening width demonstrate a high sensitivity of the coating. KW - Fatigue damage KW - Crack KW - Luminescence KW - Detection PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-446693 DO - https://doi.org/10.5194/jsss-7-259-2018 SN - 2194-8771 SN - 2194-878X VL - 7 SP - 259 EP - 266 PB - Copernicus Publications CY - Göttingen, Germany AN - OPUS4-44669 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Thuy, Maximilian A1 - Niebergall, Ute A1 - Oehler, H. A1 - Alig, I. A1 - Böhning, Martin T1 - Damaging effect of admixtures used in crop protection products on high density polyethylene packaging material N2 - The phenomenon of environmental stress cracking is still a major issue in materials engineering as well as from a scientific perspective. Especially in the case of packaging materials made of high-density polyethylene, assessing the potential of premature damage due to environmental stress cracking is complex because of the large number of components in possible liquid filling goods. As a first guideline, the well-known effect of detergents and dispersants is usually considered, but the interplay with other components, such as organic solvents is often unknown. Particularly challenging in this respect are crop protection products, consisting of several different admixtures in addition to the biologically active ingredients. This study is based on two model liquids representing these admixtures that were established for testing in this context. The model liquids as well as their constituting components were used as liquid media in the Full Notch Creep Test to characterize the environmental stress cracking behavior of a typical high-density polyethylene. Complementary to the time-to failure of a notched specimen obtained from these tests, the crack opening was monitored optically, and the fracture surface was analyzed post-failure by laser scanning microscopy as well as scanning electron microscopy. Based on the results, the effect of various surfactants as well as the influence of organic solvents on environmental stress cracking are discussed. KW - Environmental stress cracking KW - High-density polyethylene KW - Crop protection products KW - Full notch creep test KW - Fracture surface analysis KW - Crack opening displacement PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-554631 DO - https://doi.org/10.1016/j.polymertesting.2022.107672 SN - 0142-9418 VL - 114 SP - 1 EP - 16 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-55463 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Völker, Christoph A1 - Kruschwitz, Sabine A1 - Ebell, Gino T1 - Datengesteuerte Multisensor-Fusion zur Korrosionsprüfung von Stahlbetonbauteilen N2 - Potentialfeldmessung (PM) ist die beliebteste Methode der Zerstörungsfreien Prüfung (ZfP) zur Lokalisierung von aktiver Betonstahlkorrosion. PM wird durch Parameter wie z. B. Feuchtigkeits- und Chloridgradienten im Bauteil beeinflusst, so dass die Sensitivität gegenüber der räumlich sehr begrenzten, aber gefährlichen Lochkorrosion gering ist. Wir zeigen in dieser Studie, wie zusätzliche Messinformationen mit Multisensor-Datenfusion genutzt werden können, um die Detektionsleistung zu verbessern und die Auswertung zu automatisieren. Die Fusion basiert auf überwachtem maschinellen Lernen (ÜML). ÜML sind Methoden, die Zusammenhänge in (Sensor-) Daten anhand vorgegebener Kennzeichnungen (Label) erkennen. Wir verwenden ÜML um „defekt“ und „intakt“ gelabelte Bereiche in einem Multisensordatensatz zu unterscheiden. Unser Datensatz besteht aus 18 Messkampagnen und enthält jeweils PM-, Bodenradar-, Mikrowellen-Feuchte- und Wenner-Widerstandsdaten. Exakte Label für veränderliche Umweltbedingungen wurden in einer Versuchsanordnung bestimmt, bei der eine Stahlbetonplatte im Labor kontrolliert und beschleunigt verwittert. Der Verwitterungsfortschritt wurde kontinuierlich überwacht und die Korrosion gezielt erzeugt. Die Detektionsergebnisse werden quantifiziert und statistisch ausgewertet. Die Datenfusion zeigt gegenüber dem besten Einzelverfahren (PM) eine deutliche Verbesserung. Wir beschreiben die Herausforderungen datengesteuerter Ansätze in der zerstörungsfreien Prüfung und zeigen mögliche Lösungsansätze. T2 - DGZfP Jahrestagung 2018 CY - Leipzig, Germany DA - 07.05.2018 KW - Maschinelles Lernen KW - Datenfusion KW - ZfP KW - Beton KW - Korrosion PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-444852 UR - http://www.ndt.net/?id=23106 SN - 1435-4934 VL - 23 IS - 9 SP - 1 EP - 9 PB - NDT.net CY - Kirchwald AN - OPUS4-44485 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kapoor, M. A1 - Overgaard Christensen, Ch. A1 - Wittrup Schmidt, J. A1 - Dalsgaard Sørensen, J. A1 - Thöns, Sebastian T1 - Decision analytic approach for the reclassification of concrete bridges by using elastic limit information from proof loading N2 - Reclassification of bridges, i.e., a change in load rating, using reliability-based methods and a direct update with proof load information has been presented by many authors. However, bridge reclassification has hardly been studied from a decision analytic perspective, i.e., with quantification of the risks and benefits of different classification choices, and the expected benefit gain from proof loading. We derive, explain and exemplify a decision analytic approach for bridge reclassification along with models for (1) elastic and ultimate capacity and their adaptation with proof load information, (2) proof load information with classification outcomes accounting for target reliabilities and, (3) utilities including socio-economic benefits from reclassification. The approach and models are exemplified with a case study based on reclassification of bridges with a low existing classification. Decision rules, for practical use by a highway authority to find the optimal classification, are identified and documented based on: (1) the measurement of the capacity at elastic limit by proof loading, (2) the bridge reclassification benefits, and, (3) the required annual reliability level. From a Value of Information analysis, it is concluded that the proof load information is highly valuable for reclassification in cases of high socio-economic benefits and high reliability requirements. KW - Proof loading KW - Structural reliability KW - Value of information KW - Decision analysis PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-596845 DO - https://doi.org/10.1016/j.ress.2022.109049 SN - 0951-8320/ VL - 232 SP - 1 EP - 16 PB - Elsevier Ltd. AN - OPUS4-59684 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tan, Yi A1 - Wachtendorf, Volker A1 - Kukofka, Tobias A1 - Klack, Patrick A1 - Ruder, J. A1 - Lin, Xuebao A1 - Schartel, Bernhard T1 - Degradation of flame retardance: A comparison of ethylene‐vinyl acetate and low‐density polyethylene cables with two different metal hydroxides N2 - The durability of flame retardancy is a challenge for cables over long lifetimes. The degradation of flame retardance is investigated in two kinds of exposures, artificial weathering and humidity. In this basic study, typical mineral flame retardants in two polymers frequently used in cable jackets are investigated to get the fundamental picture. Aluminum hydroxide (ATH) and magnesium hydroxide (MDH) are compared in ethylene‐vinyl acetate (EVA), and further in EVA and linear low‐density polyethylene (LLDPE) cables containing the same ATH. The changes in chemical structure at the surface are studied through attenuated total reflectance Fourier transform infrared spectroscopy (ATR‐FTIR), the formation of cracks, and changes in color are investigated. The cone calorimeter and a bench scale fire testing cable module are utilized to evaluate the fire behavior of the cables. Although the flame retardancy deteriorated slightly, it survived harsh exposure conditions for 2000 h. Compared to EVA/MDH and LLDPE/ATH, the fire behavior of EVA/ATH is the least sensitive. Taken together, all of the results converge to estimate that there will be no problem with flame retardancy performance, for materials subjected to natural exposure for several years; the durability of fire retardancy is questionable for longer periods, and thus requires further investigation. KW - Durability KW - Flame retardant KW - Aluminum hydroxide (ATH) KW - Magnesium hydroxide KW - Ethylene-vinyl acetate KW - Cables KW - Weathering PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-519573 DO - https://doi.org/10.1002/app.50149 VL - 138 IS - 14 SP - 50149 PB - Wiley AN - OPUS4-51957 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogler, Nico A1 - Drabetzki, Philipp A1 - Lindemann, Mathias A1 - Kühne, Hans-Carsten T1 - Description of the concrete carbonation process with adjusted depth resolved thermogravimetric analysis N2 - The thermal gravimetric analysis (TG) is a common method for the examination of the carbonation progress of cement-based materials. Unfortunately, the thermal properties of some components complicate the evaluation of TG results. Various hydrate phases, like ettringite (AFt), C-S-H and AFm decompose almost simultaneously in the temperature range up to 200 °C. Additionally, physical bound water is released in the same temperature range. In the temperature range between 450 °C and 600 °C the decomposition of calcium hydroxide and amorphous or weakly bound carbonates takes place simultaneously. Carbonates, like calcite, from limestone powder or other additives may be already contained in the noncarbonated sample material. For this research an attempt was made to minimise the influence of these effects. Therefore, differential curves from DTG-results of non-carbonated areas and areas with various states of carbonation of the same sample material were calculated and evaluated. Concretes based on three different types of cement were produced and stored under accelerated carbonation conditions (1 % CO2 in air). The required sample material was obtained by cutting slices from various depth of previously CO2-treated specimen and subsequent grinding. During the sample preparation, a special attention was paid that no additional carbonation processes took place. As reference method for the determination of the carbonation depth the sprayed application of phenolphthalein solution was carried out. Microscopic analysis where examined to confirm the assumptions made previously. Furthermore, the observed effect of encapsulation of calcium hydroxide by carbonates caused by the accelerated carbonation conditions was examined more closely. KW - Microscopy KW - Accelerated carbonation KW - Carbonation behaviour KW - Concrete KW - Thermal Analysis PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530571 DO - https://doi.org/10.1007/s10973-021-10966-1 VL - 147 IS - 11 SP - 1 EP - 14 PB - Springer AN - OPUS4-53057 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mendler, A. A1 - Döhler, M. A1 - Hille, Falk T1 - Detecting changes in boundary conditions based on sensitivity-based statistical tests N2 - Structural health monitoring is a promising technology to automatically detect structural changes based on permanently installed sensors. Vibration-based methods that evaluate the global system response to ambient excitation are suited to diagnose changes in boundary conditions, i.e., changes in member prestress or imposed displacements. In this paper, these changes are evaluated based on sensitivity-based statistical tests, which are capable of detecting and localizing parametric structural changes. The main contribution is the analytical calculation of sensitivity vectors for changes in boundary conditions (i.e., changes in prestress or support conditions) based on stress stiffening, and the combination with a numerically efficient algorithm, i.e., Nelson’s method. One of the main advantages of the employed damage diagnosis algorithm is that, although it uses physical models for damage detection, it considers the uncertainty in the data-driven features, which enables a reliabilitybased approach to determine the probability of detection. Moreover, the algorithm can be trained and the probability of detecting future damages can be predicted based on data and a model from the undamaged structure, in an unsupervised learning mode, making it particularly relevant for unique structures, where no data from the damaged state is available. For proof of concept, a numerical case study is presented. The study assesses the loss of prestress in a two-span reinforced concrete beam and showcases suitable validation approaches for the sensitivity calculation. T2 - International Symposium on Non-Destructive Testing in Civil Engineering (NDT-CE 2022) CY - Zurich, Switzerland DA - 16.08.2022 KW - Nelson’s method KW - Global ambient vibrations KW - Asymptotic local approach KW - Sensitivity vectors KW - Probability of detection KW - Stress stiffening PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-566632 DO - https://doi.org/10.58286/27311 SN - 1435-4934 VL - 27 IS - 9 SP - 1 EP - 13 PB - NDT.net CY - Kirchwald AN - OPUS4-56663 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Oesch, Tyler A1 - Weise, Frank A1 - Bruno, Giovanni T1 - Detection and Quantification of Cracking in Concrete Aggregate through Virtual Data Fusion of X-ray Computed Tomography Images N2 - In this work, which is part of a larger research program, a framework called “virtual data fusion“ was developed to provide an automated and consistent crack detection method that allows for the cross-comparison of results from large quantities of X-ray Computed Tomography (CT) data. A partial implementation of this method in a custom program was developed for use in research focused on crack quantification in Alkali-Silica Reaction (ASR)-sensitive concrete aggregates. During the CT image processing, a series of image analyses tailored for detecting specific, individual crack-like characteristics were completed. The results of these analyses were then “fused” in order to identify crack-like objects within the images with much higher accuracy than that yielded by any individual image analysis procedure. The results of this strategy demonstrated the success of the program in effectively identifying crack-like structures and quantifying characteristics, such as surface area and volume. The results demonstrated that the source of aggregate has a very significant impact on the amount of internal cracking, even when the mineralogical characteristics remain very similar. River gravels, for instance, were found to contain significantly higher levels of internal cracking than quarried stone aggregates of the same mineralogical type. KW - X-ray Computed Tomography (CT) KW - Alkali-Silica Reaction (ASR) KW - Crack Detection KW - Damage Quantification KW - ASR-Sensitive Aggregate PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-512170 DO - https://doi.org/10.3390/ma13183921 VL - 13 IS - 18 SP - Paper 3921 PB - MDPI CY - Basel, Switzerland AN - OPUS4-51217 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pirskawetz, Stephan A1 - Schmidt, S. T1 - Detection of wire breaks in prestressed concrete bridges by Acoustic Emission analysis N2 - problem. One reason is the sensitivity to stress corrosion cracking of the prestressing steel. Failure of prestressing wires can result in collapse of the entire structure without premature indication by transverse bending cracks or considerable deformation. The response of a structure to significant number of prestressing wire breaks was studied on a bridge in Brandenburg, Germany. Two thirds of the prestressing wires in concentrated tendons of two girders were cut before the bridge was demolished. Acoustic Emission Analysis was used to detect the wire breaks. Thus, the number of wire breaks was correlated with results of other measurement techniques, in particular strain measurements on the girders. In preparation of the measurements, the acoustic properties of the bridge were determined and the suitability of Schmidt hammer impacts as an acoustic reference source was validated. KW - Real scale test KW - Acoustic emission monitoring KW - Structural health monitoring (SHM) KW - Prestressed concrete bridge KW - Stress corrosion cracking KW - Wire break KW - Destructive testing KW - Nondestructive testing PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-573927 DO - https://doi.org/10.1016/j.dibe.2023.100151 SN - 2666-1659 VL - 14 SP - 1 EP - 10 PB - Elsevier Ltd AN - OPUS4-57392 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grengg, C. A1 - Gluth, Gregor A1 - Mittermayr, F. A1 - Ukrainczyk, N. A1 - Bertmer, M. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Leis, A. A1 - Dietzel, M. T1 - Deterioration mechanism of alkali-activated materials in sulfuric acid and the influence of Cu: A micro-to-nano structural, elemental and stable isotopic multi-proxy study N2 - In this study, a multi-proxy approach combining 29Si, 27Al and 1H MAS-NMR, FEG-EPMA, XANES at the Cu K-edge and XRD analytics with hydrochemical tools such as ICP-OES analyses, oxygen-isotope signatures, and thermodynamic modelling was applied to K-silicate-activated metakaolin specimens - with and without CuSO4·5H2O addition - exposed to sulfuric acid at pH = 2 for 35 days. The results revealed a multistage deterioration mechanism governed by (i) acid diffusion, (ii) leaching of K-A-S-H, (iii) microstructural damage related to precipitation of expansive (K,Ca,Al)-sulfate-hydrate phases (iv) complete dissolution of the K-A-S-H framework, (v) and formation of silica gel in the outermost corroded regions. Copper ions were mainly located in layered spertiniite-chrysocolla-like phases in the as-cured materials. The results demonstrate an overall negative effect of Cu addition on chemical material durability, implying that the reported higher durability of Cu-doped AAM in biocorrosion environments can be best explained by bacteriostatic effects. KW - Alkali-activated materials KW - Acid resistance KW - Microbially induced corrosion KW - MIC PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-520567 DO - https://doi.org/10.1016/j.cemconres.2021.106373 SN - 0008-8846 VL - 142 SP - 1 EP - 15 PB - Elsevier CY - Oxford AN - OPUS4-52056 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Long, Lijia A1 - Döhler, M. A1 - Thöns, Sebastian T1 - Determination of structural and damage detection system influencing parameters on the value of information N2 - A method to determine the influencing parameters of a structural and damage detection system is proposed based on the value of Information analysis. The value of information analysis utilizes the Bayesian pre-posterior decision theory to quantify the value of damage detection system for the structural integrity management during service life. First, the influencing parameters of the structural system, such as deterioration type and rate are introduced for the performance of the prior probabilistic system model. Then the influencing parameters on the damage detection system performance, including number of sensors, sensor locations, measurement noise, and the Type-I error are investigated. The preposterior probabilistic model is computed utilizing the Bayes’ theorem to update the prior system model with the damage indication information. Finally, the value of damage detection system is quantified as the difference between the maximum utility obtained in pre-posterior and prior analysis based on the decision tree analysis, comprising structural probabilistic models, consequences, as well as benefit and costs analysis associated with and without monitoring. With the developed approach, a case study on a statically determinate Pratt truss bridge girder is carried out to validate the method. The analysis shows that the deterioration rate is the most sensitive parameter on the effect of relative value of information over the whole service life. Furthermore, it shows that more sensors do not necessarily lead to a higher relative value of information; only specific sensor locations near the highest utilized components lead to a high relative value of information; measurement noise and the Type-I error should be controlled and be as small as possible. An optimal sensor employment with highest relative value of information is found. Moreover, it is found that the proposed method can be a powerful tool to develop optimal service life maintenance strategies—before implementation—for similar bridges and to optimize the damage detection system settings and sensor configuration for minimum expected Costs and risks. KW - Damage detection systems KW - Value of information KW - Deteriorating structures KW - Probability of damage indication KW - Decision theory PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-508083 DO - https://doi.org/10.1177/1475921719900918 SN - 1475-9217 SN - 1741-3168 VL - 21 IS - 1 SP - 19 EP - 36 PB - Sage Publications CY - Thousand Oaks, Calif. AN - OPUS4-50808 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Valet, Svenja A1 - Burkert, Andreas A1 - Ebell, Gino A1 - Babutzka, Martin T1 - Determination of the corrosion product layer resistance on zinc and electrolytically galvanized steel samples by using gel electrolytes N2 - Although zinc and zinc coatings have been widely used for corrosion protection for decades new zinc coatings are constantly being developed. Characterizing the corrosion protectiveness of these new coatings, however, should not be underestimated. While exposure tests are time intensive, cyclic tests can only be used for a very limited field of application. Thus, electrochemical measurements provide both an efficient and an effective alternative. Conventional aqueous bulk electrolytes influence the surface layers of a tested zinc coating and are therefore not reliable. Gel electrolytes, however, have evolved over the last few years, are minimally invasive and provide reliable results. This work describes experiments with gel electrolytes made of agar. Unlike previous work, it proposes a composition of gel electrolyte for minimally invasive description of the protective power of naturally formed oxide layers on zinc and zinc coatings. Therefore, as a first part, the gel electrolyte made of agar is verified as a method for zinc and zinc-coated samples. Afterwards, this paper introduces the corrosion product layer resistance RL as a promising parameter to evaluate the protective power of zinc coatings. Results are verified with EIS and FTIR measurements. An example on a representative zinc coating demonstrates the practical application. KW - Gel electrolytes KW - Agar KW - Zinc coatings KW - Atmospheric exposure KW - Corrosion PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-526053 DO - https://doi.org/10.1016/j.electacta.2021.138191 SN - 0013-4686 VL - 385 SP - 138191 PB - Elsevier Ltd. AN - OPUS4-52605 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kazlagic, Anera A1 - Russo, Francesco A1 - Vogl, Jochen A1 - Sturm, Patrick A1 - Stephan, D. A1 - Gluth, Gregor ED - Resch-Genger, Ute ED - Koch, Matthias ED - Meermann, Björn ED - Weller, Michael G. T1 - Development of a sample preparation procedure for Sr isotope analysis of Portland cements N2 - The 87Sr/86Sr isotope ratio can, in principle, be used for provenancing of cement. However, while commercial cements consist of multiple components, no detailed investigation into their individual 87Sr/86Sr isotope ratios or their influence on the integral 87Sr/86Sr isotope ratio of the resulting cement was conducted previously. Therefore, the present study aimed at determining and comparing the conventional 87Sr/86Sr isotope ratios of a diverse set of Portland cements and their corresponding Portland clinkers, the major component of these cements. Two approaches to remove the additives from the cements, i.e. to measure the conventional 87Sr/86Sr isotopic fingerprint of the clinker only, were tested, namely, treatment with a potassium hydroxide/sucrose solution and sieving on a 11-µm sieve. Dissolution in concentrated hydrochloric acid/nitric acid and in diluted nitric acid was employed to determine the 87Sr/86Sr isotope ratios of the cements and the individual clinkers. The aim was to find the most appropriate sample preparation procedure for cement provenancing, and the selection was realised by comparing the 87Sr/86Sr isotope ratios of differently treated cements with those of the corresponding clinkers. None of the methods to separate the clinkers from the cements proved to be satisfactory. However, it was found that the 87Sr/86Sr isotope ratios of clinker and cement generally corresponded, meaning that the latter can be used as a proxy for the clinker 87Sr/86Sr isotope ratio. Finally, the concentrated hydrochloric acid/nitric acid dissolution method was found to be the most suitable sample preparation method for the cements; it is thus recommended for 87Sr/86Sr isotope analyses for cement provenancing. KW - Cement KW - Provenancing KW - Sr isotopes KW - Portland clinker KW - Dissolution PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-542239 DO - https://doi.org/10.1007/s00216-021-03821-7 SN - 1618-2642 SN - 1618-2650 VL - 414 IS - 15 (Topical collection: Analytical methods and applications in the materials and life sciences) SP - 4379 EP - 4389 PB - Springer CY - Berlin AN - OPUS4-54223 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz T1 - Different types of continuous track irregularities as sources of train-induced ground vibration and the importance of the random variation of the track support N2 - Irregularities of the track are a main cause of train-induced ground vibration, and track maintenance is of great importance. Although geometric irregularities at the wheel-rail contact are widely used, other types of irregularities, such as stiffness irregularities, irregularities from different track positions and irregularities in the wave propagation, were analysed in the present study. The track behaviour was investigated by a multi-beam-on-soil model. This track model is coupled with a vehicle model to calculate the vehicle–track interaction. The track model was also used for the track filtering, which transfers a track support error to the equivalent rail irregularity or, conversely, the sharp axle pulse on the rail to a smoother pulse on the soil. In the case in which this filtering varies randomly along the track, the pulses of the moving static load induce a certain ground Vibration component (“the scatter of axle pulses”). This effect was calculated by the superposition of axle pulses in the frequency domain and by a stochastic simulation. Simultaneous vehicle, track and soil measurements at a certain site were used to evaluate the different excitation and ground Vibration components. The agreement between calculations and axle-box and soil measurements is good. The ground vibrations calculated from rail irregularities and corresponding dynamic loads, however, clearly underestimate the measured ground vibration amplitudes. Only the static load that is moving over a varying track support stiffness can produce the important mid-frequency ground Vibration component by the scatter of axle pulses. KW - Train-induced ground vibration KW - Geometric vehicle and track irregularities KW - Stiffness variation KW - Multi-beam track model KW - Track filtering KW - Dynamic axle loads KW - Static axle loads KW - layered soil PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543846 DO - https://doi.org/10.3390/app12031463 SN - 2076-3417 VL - 12 IS - 3 SP - 1 EP - 22 PB - MDPI CY - Basel AN - OPUS4-54384 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wallau, Wilma A1 - Recknagel, Christoph T1 - Durability Assessment of Structural Sealant Glazing Systems applying a Performance Test Method N2 - During the service life of a Structural Sealant Glazing (SSG) facade, its silicone bond is exposed to climatic, chemical, and mechanical loads. While current durability assessment methods schedule separate test programmes for accelerated weathering and fatigue, the presented test applies mechanical loading and weather cycling simultaneously to simulate 50 years of use. Specifically designed medium-scale system specimens resemble a common SSG-bond. Displacement-controlled sinusoidal load cycles in two load directions subject these specimens to tensile, compression and shear loads. Weathering comprises temperature and humidity cycles, UV-radiation, and application of water and detergent. During testing, the forces transmitted by the system specimens are continuously measured for performance assessment. The resulting system response reveals mechanical performance characteristics like elastic moduli and dissipated energies which decrease during exposure, indicating stress relaxation and degradation. Two common structural sealants were tested. After testing, sections of the system specimens were subjected to tensile and shear tests for mechanical characterisation. Strengths and moduli are notably reduced by combined loading compared to those of reference and weathered specimens. Hardness and visual inspections of the bond correlate with the performance and bond characteristics. The approach introduced in this article provides a basis for life cycle assessment of SSG-systems. KW - Structural sealant glazing KW - Cyclic weathering KW - Mechanical loading KW - Artificial ageing KW - Durability assessment PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-519172 DO - https://doi.org/10.1080/00218464.2020.1840985 VL - 98 IS - 5 SP - 464 EP - 487 PB - Taylor & Francis Group AN - OPUS4-51917 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Häßler, Dustin A1 - Mund, Maximilian A1 - Daus, Lars-Hendrik A1 - Hothan, Sascha A1 - Schaumann, Peter A1 - Schartel, Bernhard T1 - Durability of intumescent coatings and recommendations for test concepts for a working life of more than 10 years N2 - It is an essential requirement for all building products to ensure durability of their fire safety. Throughout the working life of products, intumescent coatings are aged by certain climatic factors. To predict a lifetime of several years, generally the behaviour of the intumescent coating is extrapolated based on accelerated artificial ageing. The established German and European procedures to assess the durability assume a working life of at least 10 years. For a longer period, additional evidence is required; yet the procedure and the specifications to justify this are not described. In addition to addressing this formal lack, from a scientific point of view it is necessary to investigate the degradation of intumescent coatings in detail and to propose a reliable test concept to assess durability for more than 10 years. This paper summarises the existing knowledge about the ageing of intumescent coatings. The results of various demanding weathering approaches are presented for two intumescent coatings tested in a joint research project. Moreover, formulations with a reduced amount of functionally relevant components were analysed to gain insight into the associated effects. Derived from these research results and knowledge, recommendations are proposed to assess the durability of intumescent coatings for more than 10 years based on a combination of verifications. KW - Ageing KW - Fire protection KW - Intumescent coating KW - Steel construction KW - Working life PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603852 DO - https://doi.org/10.1016/j.firesaf.2024.104173 SN - 0379-7112 VL - 146 SP - 1 EP - 10 PB - Elsevier B.V. AN - OPUS4-60385 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz A1 - Song, Jiaojiao T1 - Dynamic damage detection of slab tracks – finite element models on Winkler soil and finite-element boundary-element models on continuous soil N2 - The train passages over intact or damaged slab tracks on different soils have been calculated by two methods. The finite element method (FEM) uses a Winkler soil under the track model by adding a thin “soil layer”. The combined finite element boundary element method has a continuous soil model which is included by the boundary element method. The basic results are the distributions of the track (rail, track plate, and base layer) displacements along the track for a single axle laod. These solutions are superposed to a complete train load and transformed to time histories. The influence of track and soil parameters has been analysed. The main interest is the influence of the track damage. A gap between track plate and base layer of different lengths has been studied for changes in amplitudes and widths of deflection. A best fit to measured track displacements has been found so that the track damage can be identified and quantified. The FEM model with Winkler soil cannot be fitted to the amplitude and width with the same soil parameters. Therefore, the FEBEM model is preferable for these railway track problems. KW - Track damage quantification KW - Finite element method KW - Combined finite-element boundary-element method PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-562207 DO - https://doi.org/10.3390/civileng3040055 SN - 2673-4109 VL - 3 IS - 4 SP - 979 EP - 997 PB - MDPI CY - Basel AN - OPUS4-56220 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kratzig, A. A1 - Le, Quynh Hoa A1 - Bettge, Dirk A1 - Menneken, M. A1 - Bäßler, Ralph T1 - Early Stage of Corrosion Formation on Pipeline Steel X70 Under Oxyfuel Atmosphere at Low Temperature N2 - The early stage of corrosion formation on X70 pipeline steel under oxyfuel atmosphere was investigated by applying a simulated gas mixture (CO2 containing 6700 ppmv O2, 100 ppmv NO2, 70 ppmv SO2 and 50 ppmv H2O) for 15 h at 278 K and ambient pressure. Short-term tests (6 h) revealed that the corrosion starts as local spots related to grinding marks progressing by time and moisture until a closed layer was formed. Acid droplets (pH 1.5), generated in the gas atmosphere, containing a mixture of H2SO4 and HNO3, were identified as corrosion starters. After 15 h of exposure, corrosion products were mainly X-ray amorphous and only partially crystalline. In-situ energy-dispersive X-ray diffraction (EDXRD) results showed that the crystalline fractions consist primarily of water-bearing iron sulfates. Applying Raman spectroscopy, water-bearing iron nitrates were detected as subordinated phases. Supplementary long-term tests exhibited a significant increase in the crystalline fraction and formation of additional water-bearing iron sulfates. All phases of the corrosion layer were intergrown in a nanocrystalline network. In addition, numerous globular structures have been detected above the corrosion layer, which were identified as hydrated iron sulphate and hematite. As a type of corrosion, shallow pit formation was identified, and the corrosion rate was about 0.1 mma−1. In addition to in-situ EDXRD, SEM/EDS, TEM, Raman spectroscopy and interferometry were used to chemically and microstructurally analyze the corrosion products. KW - Corrosion KW - CCUS KW - In-situ ED-XRD KW - CO2 pipeline transport KW - Oxyfuel KW - Carbon steel KW - Impurities PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506303 DO - https://doi.org/10.3390/pr8040421 SN - 2227-9717 VL - 8 IS - 4 SP - 421-1 EP - 421-19 PB - MDPI CY - Basel AN - OPUS4-50630 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ji, Y. A1 - Becker, S. A1 - Lu, Z. A1 - Mezhov, Alexander A1 - von Klitzing, R. A1 - Schmidt, Wolfram A1 - Stephan, D. T1 - Effect of resting time on rheological properties of glass bead suspensions - Depletion and bridging force among particles N2 - The effect of resting time on the rheological properties of cement suspensions is generally explained by early formed structure and overconsumption of polycarboxylate superplasticizers (PCEs). In this paper, we propose that the influence of resting time on the rheological properties is closely related to size variation of non-absorbed PCE. To identify this, glass bead suspensions were prepared with various amounts of PCE and ionic solution, and their rheological properties were evaluated at various times. We found that the yield stress increases with time at higher PCE concentrations and higher ionic strength solutions. Adsorbed PCE during resting tends to bridge the particles rather than disperse them. In addition, it was found that hydrodynamic radius of PCE increased with resting time, and depletion forces resulting from non-absorbed PCE size changes correlate well with the increased yield stress. KW - Depletion force KW - Ionic stregth KW - PCE KW - Rheology KW - Resting time PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-587193 DO - https://doi.org/10.1111/jace.19469 SN - 0002-7820 SN - 1551-2916 VL - 107 IS - 1 SP - 624 EP - 639 PB - Wiley-Blackwell CY - Oxford AN - OPUS4-58719 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lenz, J. U. A1 - Pospiech, D. A1 - Komber, H. A1 - Korwitz, A. A1 - Kobsch, O. A1 - Paven, M. A1 - Albach, R. W. A1 - Günther, Martin A1 - Schartel, Bernhard T1 - Effective halogen-free flame-retardant additives for crosslinked rigid polyisocyanurate foams: Comparison of chemical structures N2 - The impact of phosphorus-containing flame retardants (FR) on rigid polyisocyanurate (PIR) foams is studied by systematic variation of the chemical structure of the FR, including non-NCO-reactive and NCO-reactive dibenzo[d,f][1,3,2]dioxaphosphepine 6-oxide (BPPO)- and 9,10 dihydro-9-oxa-10 phosphaphenanthrene-10-oxide (DOPO)-containing compounds, among them a number of compounds not reported so far. These PIR foams are compared with PIR foams without FR and with standard FRs with respect to foam properties, thermal decomposition, and fire behavior. Although BPPO and DOPO differ by just one oxygen atom, the impact on the FR properties is very significant: when the FR is a filler or a dangling (dead) end in the PIR polymer network, DOPO is more effective than BPPO. When the FR is a subunit of a diol and it is fully incorporated in the PIR network, BPPO delivers superior results. KW - Flame retardant; KW - Dibenzo[d,f][1,3,2]dioxaphosphepine 6-oxide; BPPO KW - 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; DOPO KW - Polyisocyanurate; PIR KW - Rigid foam KW - Cone calorimeter KW - Pudovik reaction PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-567712 DO - https://doi.org/10.3390/ma16010172 SN - 1996-1944 VL - 16 IS - 1 SP - 1 EP - 22 PB - MDPI CY - Basel AN - OPUS4-56771 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Strobl, Dominic A1 - Unger, Jörg F. A1 - Ghnatios, C. A1 - Klawoon, Alexander A1 - Pittner, Andreas A1 - Rethmeier, Michael A1 - Robens-Radermacher, Annika T1 - Efficient bead-on-plate weld model for parameter estimation towards effective wire arc additive manufacturing simulation N2 - Despite the advances in hardware and software techniques, standard numerical methods fail in providing real-time simulations, especially for complex processes such as additive manufacturing applications. A real-time simulation enables process control through the combination of process monitoring and automated feedback, which increases the flexibility and quality of a process. Typically, before producing a whole additive manufacturing structure, a simplified experiment in the form of a beadon-plate experiment is performed to get a first insight into the process and to set parameters suitably. In this work, a reduced order model for the transient thermal problem of the bead-on-plate weld simulation is developed, allowing an efficient model calibration and control of the process. The proposed approach applies the proper generalized decomposition (PGD) method, a popular model order reduction technique, to decrease the computational effort of each model evaluation required multiple times in parameter estimation, control, and optimization. The welding torch is modeled by a moving heat source, which leads to difficulties separating space and time, a key ingredient in PGD simulations. A novel approach for separating space and time is applied and extended to 3D problems allowing the derivation of an efficient separated representation of the temperature. The results are verified against a standard finite element model showing excellent agreement. The reduced order model is also leveraged in a Bayesian model parameter estimation setup, speeding up calibrations and ultimately leading to an optimized real-time simulation approach for welding experiment using synthetic as well as real measurement data. KW - Proper generalized decomposition KW - Model order reduction KW - Hardly separable problem KW - Additive manufacturing KW - Model calibration KW - Wire arc additive manufacturing PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-596502 DO - https://doi.org/10.1007/s40194-024-01700-0 SN - 0043-2288 SP - 1 EP - 18 PB - Springer AN - OPUS4-59650 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -