TY - JOUR A1 - Zhang, K. A1 - Mezhov, Alexander A1 - Schmidt, Wolfram T1 - Effect of Polycarboxylate Superplasticizer in Ordinary Portland Cement and Sulfate Resistant Cement JF - Journal of Materials in Civil Engineering N2 - Polycarboxylate superplasticizers (PCE) are the most widely used admixtures in today’s cementitious construction materials. The molecular structure has a decisive influence on the effectiveness of PCE, which also can be tailored to serve in a different cementitious system. The current study investigates the influence of the backbone charge density of PCE on the rheology, hydration kinetics, and adsorption behavior of ordinary Portland cement (OPC) and sulfate-resistant cement (SRC). The results indicate that regardless of the PCE type, OPC requires a higher amount of PCE to be adsorbed to induce changing of rheological parameters and hydration kinetics. Regardless of the cement type, the PCE with a higher charge density exhibits higher adsorption behavior, corresponding to lower viscosity measurement. Compared to OPC, SRC is more sensitive to the introduction of both PCEs and has a lower saturation dosage, indicating that SRC generally provides better workability properties regardless of the PCE. KW - Polycarboxylate superplasticizers (PCE) KW - Sulfate resistant cement (SRC) KW - Rheological KW - Adsorption KW - Cement hydration PY - 2023 DO - https://doi.org/10.1061/JMCEE7.MTENG-15033 SN - 0899-1561 VL - 35 IS - 6 SP - 1 EP - 12 PB - ASCE Libary AN - OPUS4-58244 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zekhnini, Khalid A1 - Ebell, Gino T1 - Corrosion behavior of simulated monopile foundation by S355J2 steel in artificial seawater and sediment N2 - The development of offshore wind turbines (WTGs) presents many challenges in terms of safe operation over extended periods of time. One of these is the corrosive environment towards metallic materials, which can lead to a loss of material thickness and thus to a deterioration of mechanical performances, especially the strength of infrastructures. This can be counteracted by painting and cathodic protection (CP). Much research has already been done in this area about inhibiting the corrosion process. However, gaps exist regarding free corrosion. This plays a greater role especially for time intervals during the installation of the systems and their maintenance, during which often no CP can be operated. This is especially true for areas where painting surfaces is impossible e.g., sediment areas. This problem is exacerbated by the different corrosion rates caused by the different zones (water and sediment), with their different amounts of dissolved oxygen. This presentation deals with experiments in artificial seawater and sediment. Classical S355J2 steel samples in the form of coupons were fitted with welding wires that carried out the electrical contact to the outer side of the basin. Inside the basins, the specimens are stored in different zones like water and sediment which should simulate the foundation situation of monopiles. The mass loss was determined gravimetrically, elemental currents between specimens in water and sediment were measured and electrochemical investigations were carried out. The influences of the zones, based on different solved oxygen contents, and the rolling skin towards the corrosion behavior of the mild steel samples were determined in this work. Especially the influence of the sediment showed unexpected behavior, determined by electrochemical investigations. These results allow better conclusions to be drawn about the corrosion behavior of low alloy steels in offshore environments used in sediment and seawater, which cannot always be protected. T2 - Eurocorr 2023 CY - Brussels, Belgium DA - 28.08.2023 KW - Marine Corrosion KW - Offshore KW - Monopile KW - Sediment KW - Artificial seawater PY - 2023 AN - OPUS4-58175 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zekhnini, Khalid A1 - Ebell, Gino A1 - Burkert, Andreas T1 - Corrosion at metallic offshore constructions – Bundesanstalt für Materialforschung und -prüfung (BAM) N2 - In the maritime context of offshore operation, corrosion, in combination with the materials used, poses a particular challenge to ensure safe operation over long indefinite periods and to minimise susceptibility to failure. Until today, only a few corrosion protection systems have proven themselves for the interaction of efficiency, installation, and maintenance in the offshore sector. In addition, available corrosion test methods sometimes have major deficits about conclusions of the durability. Therefore, there is more research and development needed. The flagship project H2Mare of the Federal Ministry of Education and Research aims to enable the production of green hydrogen and PtX products at high seas. Research is being driven forward by the partners in four individual projects, where BAM is involved in two. In PtX-Wind, major kinds of corrosion attacks at offshore constructions are characterized and investigated, and suitable corrosion protection measures determined. In TransferWind, attention focusses on transferring scientific results into standardization. This poster at the H2Mare Conference 2023 presents an overview of the investigation methods and contribution of the department “Corrosion and Corrosion Protection”. T2 - H2Mare Conference 2023 CY - Frankfurt/Main, Germany DA - 12.06.2023 KW - Atmospheric Corrosion KW - Sea Water KW - Corrosion Testing KW - Offshore KW - Laboratory Container KW - Corrosion protecting system PY - 2023 AN - OPUS4-57838 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Xu, R. A1 - Hicke, Konstantin A1 - Chruscicki, Sebastian A1 - Marx, S. ED - Curbach, M. ED - Marx, S. ED - Scheerer, S. ED - Hampel, T. T1 - Akustisches SpRK-Monitoring mit SEA und verteilten faseroptischen Sensoren T2 - Schriftenreihe Konstruktiver Ingenieurbau Dresden N2 - Im vorliegenden Bericht wurde untersucht, Spanndrahtbrüche in einem Brückenträger sowohl mittels Schallemissionsanalyse (SEA) als auch mit (eingebetteter) verteilter faseroptischer akustischer Sensorik (DAS) zu erkennen. Die Ergebnisse zeigen, dass die Bruchsignale anhand beider Messverfahren detektiert werden können. Die jeweils detektierten Drahtbrüche werden miteinander verglichen. Durch eine Gegenüberstellung werden SEA und DAS detailliert dargestellt. T2 - 12. Symposium "Experimentelle Untersuchungen von Baukonstruktionen" (SEUB) CY - Dresden, Germany DA - 01.06.2023 KW - Verteilte faseroptische akustische Sensorik KW - DAS KW - Brückenmonitoring KW - Spanndrahtbruchdetektion KW - Schallemissionsanalyse KW - SEA PY - 2023 SN - 978-3-86780-740-1 SN - 1613-6934 VL - 67 SP - 136 EP - 147 PB - Technische Universität Dresden - Fakultät Bauingenieurwesen CY - Dresden AN - OPUS4-57581 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wu, Hongyi A1 - Christiani, Ricardo A1 - Hofmann-Böllinghaus, Anja T1 - Untersuchung von Brandausbreitungsmechanismen bei Waldbränden N2 - Das EU Projekt TREEADS „A Holistic Fire Management Ecosystem for Prevention, Detection and Restoration of Environmental Desasters” beschäftigt sich mit der Erforschung der drei Phasen „Prävention und Bereitschaft“, „Detektion und Reaktion“ und „Aufforsten und Anpassen“ der Waldbrandverhütung. Im Projekt gibt es acht ausgewiesene Pilotregionen, in denen Deutschland auch mit einer Pilotregion in Sachsen-Anhalt bzw. in Brandenburg vertreten ist. Unsere Arbeit auf Charakterisierung des Waldbodens und numerische Simulation wird vorgestellt. T2 - vfdb-Jahresfachtagung 2023 CY - Münster, Germany DA - 15.05.2023 KW - Waldbrand KW - Klimawandel KW - Charakterisierung des Waldbodens KW - Numerische Strömungsmechanik PY - 2023 AN - OPUS4-57621 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wu, Dejian A1 - Zhao, P. A1 - Spitzer, Stefan A1 - Krietsch, Arne A1 - Amyotte, P. A1 - Krause, U. T1 - A review on hybrid mixture explosions: Safety parameters, explosion regimes and criteria, flame characteristics JF - Journal of loss prevention in the process industries N2 - The hybrid mixture of combustible dusts and flammable gases/vapours widely exist in various industries, including mining, petrochemical, metallurgical, textile and pharmaceutical. It may pose a higher explosion risk than gas/vapor or dust/mist explosions since the hybrid explosions can still be initiated even though both the gas and the dust concentration are lower than their lower explosion limit (LEL) values. Understanding the explosion threat of hybrid mixtures not only contributes to the inherent safety and sustainability of industrial process design, but promotes the efficiency of loss prevention and mitigation. To date, however, there is no test standard with reliable explosion criteria available to determine the safety parameters of all types of hybrid mixture explosions, nor the flame propagation and quenching mechanism or theoretical explanation behind these parameters. This review presents a state-of-the-art overview of the comprehensive understanding of hybrid mixture explosions mainly in an experimental study level; thereby, the main limitations and challenges to be faced are explored. The discussed main contents include the experimental measurement for the safety parameters of hybrid mixtures (i.e., explosion sensitivity and severity parameters) via typical test apparatuses, explosion regime and criterion of hybrid mixtures, the detailed flame propagation/quenching characteristics behind the explosion severities/sensitivities of hybrid mixtures. This work aims to summarize the essential basics of experimental studies, and to provide the perspectives based on the current research gaps to understand the explosion hazards of hybrid mixtures in-depth. KW - Hybrid mixtures KW - Explosion protection KW - Safety characteristics PY - 2023 DO - https://doi.org/10.1016/j.jlp.2022.104969 SN - 0950-4230 VL - 82 SP - 1 EP - 54 PB - Elsevier CY - Amsterdam AN - OPUS4-56856 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Königsbauer, Korbinian A1 - Krebber, Katerina A1 - Schaller, M.B. A1 - Färber, J. A1 - Nöther, N. T1 - POF-based monitoring system using digital I-OFDR for strain detection in road construction N2 - We present a prototype of a distributed POF sensing system for strain detection in road construction and civil engineering ready to be used in practical applications. The system is based on a cost-efficient digital incoherent optical frequency domain reflectometry (I-OFDR). In this approach, the strain-induced changes in the Rayleigh backscattering profile along a perfluorinated polymer optical fiber (PF-POF) are determined by measuring the complex transfer function of the sensing fiber using a compact digital data acquisition unit. The digital unit replaces an oversized vector network analyzer (VNA) enabling suitability of the measurement system for out-door use and providing a significant reduction of the total system costs at the same time. The entire sensor con-cept includes the use of geosynthetics with integrated PF-POFs as two-dimensional sensor structures for geotech-nical applications. The robustness and the functionality of the distributed POF I-OFDR sensors were proven in the field. The field test involved embedding of two geomats, each with two polymer optical sensor loops, into the embankment of the federal road B 91 in a section near Leipzig. The measurements conducted after the sensor-based geomats had been installed confirmed both the potential of such smart geosynthetics and the functionali-ty of the digital I-OFDR prototype. T2 - POF2023 CY - Cork, Irland DA - 17.09.2023 KW - Digital I-OFDR KW - Distriubuted polymer optical fiber sensor KW - Smart geosynthetics KW - Strain detection KW - Structural health monitoring PY - 2023 AN - OPUS4-58423 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Winkler, Nicolas P. A1 - Johann, Sergej A1 - Kohlhoff, Harald A1 - Neumann, Patrick P. T1 - Revisiting Environmental Sensing Nodes: Lessons Learned and Way Forward T2 - SMSI 2023 Conference Sensor and Measurement Science International Proceedings N2 - Setting up sensors for the purpose of environmental monitoring should be a matter of days, but often drags over weeks or even months, preventing scientists from doing real research. Additionally, the newly developed hardware and software solutions are often reinventing existing wheels. In this short paper, we revisit the design of our environmental sensing node that has been monitoring industrial areas over a span of two years. We share our findings and lessons learned. Based on this, we outline how a new generation of sensing node(s) can look like. T2 - SMSI 2023 Conference Sensor and Measurement Science International CY - Nuremberg, Germany DA - 08.05.2023 KW - Sensing node KW - Sensor network KW - Environmental monitoring KW - Low-cost KW - LoRaWAN PY - 2023 SN - 978-3-9819376-8-8 DO - https://doi.org/10.5162/SMSI2023/C5.1 SP - 173 EP - 174 PB - AMA Service GmbH CY - Wunstorf AN - OPUS4-57454 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Winkler, Nicolas P. A1 - Johann, Sergej A1 - Kohlhoff, Harald A1 - Neumann, Patrick P. T1 - Revisiting Environmental Sensing Nodes: Lessons Learned and Way Forward N2 - Setting up sensors for the purpose of environmental monitoring should be a matter of days, but often drags over weeks or even months, preventing scientists from doing real research. Additionally, the newly developed hardware and software solutions are often reinventing existing wheels. In this short paper, we revisit the design of our environmental sensing node that has been monitoring industrial areas over a span of two years. We share our findings and lessons learned. Based on this, we outline how a new generation of sensing node(s) can look like. T2 - SMSI 2023 Conference Sensor and Measurement Science International CY - Nuremberg, Germany DA - 08.05.2023 KW - Sensing node KW - Sensor network KW - Environmental monitoring KW - Low-cost KW - LoRaWAN PY - 2023 AN - OPUS4-57455 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wilrich, Cordula A1 - Wilrich, T. T1 - Nachbarklage gegen einen Sauerstofftank JF - sicher ist sicher (sis) N2 - Technische Regeln im Arbeitsschutz – wie TRBS für die Betriebssicherheitsverordnung und TRGS für die Gefahrstoffverordnung – sind nicht zwingendes Recht, sondern konkretisierende Empfehlungen mit Vermutungswirkung. In Gerichtsurteilen werden sie eher selten herangezogen. Wie diese – und Branchenregelungen von Verbänden – von der Rechtsprechung diskutiert werden, zeigt ein Urteil des Verwaltungsgerichts Münster. KW - Arbeitsschutz KW - Gefahrstoffverordnung KW - Betriebssicherheitsverordnung KW - TRGS KW - TRBS KW - Sauerstofftank KW - Branchenregelung KW - Nachbarklage KW - Sicherheitsabstand PY - 2023 UR - https://sisdigital.de/ce/nachbarklage-gegen-einen-sauerstofftank/detail.html SN - 2199-7330 SN - 2199-7349 (eJournal) IS - 11 SP - 513 EP - 516 PB - Erich Schmidt Verlag (ESV) CY - Berlin AN - OPUS4-58773 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -