TY - JOUR A1 - Kaplan, F. A1 - Steinbock, O. A1 - Saloga, K. A1 - Ebell, Gino A1 - Schmidt, S. T1 - Überwachung der Brücke am Altstädter Bahnhof T1 - Monitoring of the bridge at the Altstadter Bahnhof in Brandenburg a. d. Havel N2 - Die B 1-Brücke am Altstädter Bahnhof war der wichtigste Verkehrsknotenpunkt in Brandenburg an der Havel. Im Dezember 2019 wurden die überführte Bundesstraße und die Straßenbahnlinie für den Verkehr gesperrt. Grund für die Sperrung war eine einsetzende Rissbildung in den Längsträgerstegen in Verbindung mit Hohlstellen, die letztlich auf gerissene Spanndrähte zurückgeführt werden. Um eine Sperrung der hoch frequentierten unterführten Verkehrswege zu verhindern, wurde ein umfangreiches Überwachungskonzept erforderlich. Wesentlicher Bestandteil dieses Konzepts war ein auf der Schallemissionsanalyse basierendes Monitoringsystem, mit dessen Hilfe Spanndrahtbrüche aufgezeichnet und lokalisiert werden konnten. Auf Grundlage der so gewonnenen Ergebnisse konnten Schwerpunkte für die Bauwerksprüfung abgeleitet werden. In diesem Bericht werden die gewonnenen Erkenntnisse zum messtechnisch erfassten Schadensfortschritt und den damit verbundenen visuell festgestellten Schäden beschrieben. Dabei werden die Besonderheit des verbauten konzentrierten Spannglieds (Spannblockverfahren nach TGL 173-33) und des Spannstahls in Bezug auf die Schadensbilder dargestellt. Die gewonnenen Erkenntnisse sollten bei der Beurteilung anderer Bauwerke mit vergleichbarer Bauart berücksichtigt werden. KW - Korrosion KW - Spannstahl KW - Spannungsrisskorrosion PY - 2022 DO - https://doi.org/10.1002/bate.202200008 SN - 0932-8351 VL - 99 IS - 3 SP - 222 EP - 230 PB - Ernst & Sohn AN - OPUS4-54485 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fulawka, K. A1 - Kwietniak, A. A1 - Lay, Vera A1 - Jaskiewicz-Proc, I. T1 - Importance of seismic wave frequency in FEM-based dynamic stress and displacement calculations of the earth slope N2 - Reliable assessment of earthen dams’ stability and tailing storage facilities widely used in the mining industry is challenging, particularly under seismic load conditions. In this paper, we propose to take into account the effect of the dominant frequency of seismic load on the stability assessment of tailing/earthen dams. The calculations are performed by finite element modelling (FEM) with the Mohr–Coulomb failure criteria. To separate the frequency content from other dynamic parameters describing the seismic wave, synthetic waveforms with identical amplitude and attenuation characteristics, but differing spectral characteristics have been used. The analysis has been performed for three different slope angles and two scenarios of seismic wave propagation. Consequently, the changes of total displacement and shear stresses depending on the frequencies have been determined and clearly show that lower frequencies cause higher stress levels and displacement. Finally, the response surface methodology has been applied to determine how different parameters affect the slope stability under dynamic load conditions. Overall, this study is a first step to improve the existing methods to assess slope stability when considering seismic load. KW - Slope stability KW - Numerical analysis KW - Seismic load KW - Frequency analysis PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-544047 DO - https://doi.org/10.2478/sgem-2022-0002 SN - 2083-831X VL - 44 IS - 1 SP - 82 EP - 96 PB - De Gruyter CY - Berlin AN - OPUS4-54404 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph T1 - Evaluation of Corrosion Resistance of Metallic Materials in Geothermal Applications N2 - Evaluation of corrosion resistance of metallic materials is essential to assure safe and reliable operation of geothermal sites. One need to be aware that corrosion is not a material's but a system property, determined by medium, material and construction aspects. Various corrosion types have to be evaluated. Conditions in laboratory shall reflect on-site reality. Depending on brine composition and temperature suitability of metallic materials can be ranked. Most important outcome of the research is that highly saline geothermal brines require high alloyed materials, for safe long-term operation. T2 - Geothermal Essentials - Moving Geothermal Forward in Canada: Scaling and Corrosion (Surface Facilities) CY - Online Webinar DA - 16.03.2022 KW - Corrosion KW - Geothermal KW - Steel PY - 2022 AN - OPUS4-54482 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aristia, Gabriela A1 - Le, Quynh Hoa A1 - Bäßler, Ralph T1 - Integrated Coating System for Corrosion Protection of Carbon Steel in Artificial Geothermal Brine N2 - Corrosive geothermal brines are a major challenge to geothermal power-plants. For cost reasons, plant designers prefer to use carbon and low alloyed steels, which are susceptible to uniform and localized corrosion when exposed to geothermal brines having acidic and saline properties. To solve such problem, coatings or inhibitors would be a protective solution as an alternative to the use of high alloyed materials. This study investigated a coating system consisting of polyaniline/silicon dioxide based on resources locally available in Indonesia. Protection against corrosion of carbon steel was shown by long-term (28 day) exposure and electrochemical tests of coated carbon steels, performed in an artificial acidic and saline geothermal brine, comparable to the conditions encountered at a site in Indonesia. Therefore, an integrated coating system is proposed for corrosion protection, combining the electrochemical functionality of polyaniline and the physical advantages of silica. T2 - AMPP International Corrosion Conference CY - Online meeting DA - 06.03.2022 KW - Geothermal KW - Corrosion KW - Coating KW - Polyaniline KW - Silicon dioxide PY - 2022 SP - 1 EP - 11 CY - Houston TX (USA) AN - OPUS4-54451 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph A1 - Aristia, G. A1 - Le, Quynh Hoa T1 - Integrated Coating System for Corrosion Protection of Carbon Steel in Artificial Geothermal Brine N2 - Corrosive geothermal brines are a major challenge to geothermal power-plants. For cost reasons, plant designers prefer to use carbon and low alloyed steels, which are susceptible to uniform and localized corrosion when exposed to geothermal brines having acidic and saline properties. To solve such problem, coatings or inhibitors would be a protective solution as an alternative to the use of high alloyed materials. This study investigated a coating system consisting of polyaniline/silicon dioxide based on resources locally available in Indonesia. Protection against corrosion of carbon steel was shown by long-term (28 day) exposure and electrochemical tests of coated carbon steels, performed in an artificial acidic and saline geothermal brine, comparable to the conditions encountered at a site in Indonesia. Therefore, an integrated coating system is proposed for corrosion protection, combining the electrochemical functionality of polyaniline and the physical advantages of silica. T2 - AMPP International Corrosion Conference 2022 CY - San Antonio, TX, USA DA - 08.03.2022 KW - Geothermal KW - Corrosion KW - Coating KW - Polyaniline KW - Silicon dioxide PY - 2022 AN - OPUS4-54452 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino T1 - Corrosion of Steel in Concrete and Corrosion Behavior of Stainless Steel N2 - In order to obtain a statement on the corrosion resistance of stainless steel against pitting corrosion, a well-tested measuring arrangement is required. For this purpose, the so-called ECISS test can be used to determine the critical chloride content. This makes it possible to assess the corrosion resistance of various stainless steels that have different chromium contents. T2 - ISO-TC17-SC16-WG13 Expertensitzung CY - Online meeting DA - 11.01.2022 KW - Corrosion KW - Lochkorrosion KW - Chloride induced corrosion KW - Concrete KW - Stainless steel PY - 2022 AN - OPUS4-54239 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Neumann, Patrick P. A1 - Hüllmann, Dino A1 - Winkler, Nicolas P. A1 - Kohlhoff, Harald A1 - Bartholmai, Matthias A1 - Hirschberger, Paul A1 - Bennetts, V. H. A1 - Lilienthal, A. J. T1 - Aerial Robot Olfaction - An Overview of Research @BAM N2 - This presentation gives an introduction to the gas-sensitive aerial robots developed at BAM, including various application examples in the field of mobile robot olfaction: gas source localization, gas distribution mapping, and trial following. T2 - The 6th Meeting of the Investigation Committee on Measurement of Odors and Applications of Their Psychological/Physiological Effects CY - Online meeting DA - 21.01.2022 KW - Mobile Robot Olfaction KW - Gas Tomography KW - Tunable Diode Laser Absorption Spectroscopy (TDLAS) KW - Gas Source Localization KW - Gas Distribution Mapping KW - Trial Following PY - 2022 AN - OPUS4-54241 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Die Berechnung der Einfügedämmung bei Schienenfahrwegen – die Impedanzmethode mit einem Freiheitsgrad N2 - Mit dieser Methode kann man die Einfügedämmung eines Schienenstützpunkts/einer Schwelle korrekt berechnen. Sie gilt in ihrer ursprünglichen Form für eine Unterschottermatte in einem Tunnel T2 - Norm-Arbeitsausschuss Schwingungsminderung in der Umgebung von Verkehrswegen CY - Online meeting DA - 20.1.2022 KW - Impedanzmethode KW - Elastische Elemente KW - Schienenfahrweg PY - 2022 AN - OPUS4-54243 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Babutzka, Martin A1 - Lehmann, Jens A1 - Burkert, Andreas T1 - Update nach 10 Jahren Bewitterung - Langzeitkorrosionsverhalten nichtrostender Stähle in maritimer Atmosphäre N2 - Durch Fortführung der Untersuchungen aus einem Forschungsvorhaben wurden neun verschiedene Stahllegierungen unter maritimen Umgebungsbedingungen über zehn Jahre ausgelagert und deren Korrosionsverhalten untereinander verglichen und bewertet. Anhand der Ergebnisse der Auslagerungsprüfungen konnten Rückschlüsse auf die Einflüsse der Legierungszusammensetzung, der Oberfächenausführung und der Auslagerungszeit unter maritimen Auslagerungsbedingungen gewonnen werden. Die Proben der drei untersuchten Duplexwerkstoffe zeigten über den Auslagerungszeitraum von zehn Jahren sowohl mit als auch ohne Spaltgeometrie die beste Korrosionsbeständigkeit. Ebenso konnte der molybdänlegierte Ferrit 1.4521 eine vergleichbar gute Korrosonsbeständigkeit erzielen, wie die klassischen austenitischen Werkstoffe 1.4301 und 1.4404. T2 - Korrosionsschutz in der maritimen Technik 2022 CY - Online meeting DA - 27.01.2022 KW - Auslagerungsversuche KW - Korrosionsschutz KW - Korrosion KW - Nichtrostende Stähle PY - 2022 AN - OPUS4-54276 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krankenhagen, Rainer A1 - Zirker, Stefan A1 - Joniertz, Florian T1 - Determination of thermal parameters of concrete by active thermographic measurements N2 - The knowledge of the thermal parameters of a particular concrete is essential for thermal design of a building, but also could help to identify and assess the state of a concrete structure. Active thermography has the potential to be applied onsite and to provide a fast investigation of thermal properties. In this work, three different concrete samples were investigated by active thermography in reflection and in transmission setup. It was found that this method yields the same results without direct contact as the Transient Plane Source (TPS) method as an established inspection tool. KW - Concrete KW - Effusivity KW - Thermal diffusivity KW - Photothermal KW - Thermography KW - Hot disc method KW - Parker method KW - Onsite inspection PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543781 DO - https://doi.org/10.1007/s10921-022-00861-6 SN - 0195-9298 SN - 1573-4862 VL - 41 IS - 1 SP - 1 EP - 20 PB - Springer AN - OPUS4-54378 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin T1 - Monitoring von Strukturverhalten mittels integrierter verteilter faseroptischer Sensorik - Verteilte akustische Sensorik (DAS) N2 - Die verteilte faseroptische akustische Sensorik (DAS) wird vorgestellt, hinsichtlich ihrer Leistungsfähigkeit beschrieben und verschiedenste Anwendungsfelder, z.B. für das Zustandsmonitoring oder für seismische Messungen, beispielhaft gezeigt. Zudem werden mögliche Anwendungsfelder von DAS für den Kontext Kerntechnische Entsorgung (KTE) und Rückbau aufgezeigt. T2 - Online-Workshop „Dauerhafte Verschlussbauwerke für Endlager“ CY - Online meeting DA - 14.02.2022 KW - Verteilte faseroptische Sensorik KW - Verteilte akustische Sensorik KW - DAS KW - KTE KW - Monitoring Endlager PY - 2022 AN - OPUS4-54348 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abbas, Z. A1 - Gabel, D. A1 - Krietsch, Arne A1 - Krause, U. T1 - Quasi-static dispersion of dusts for the determination of lower explosion limits of hybrid mixtures N2 - Knowledge of explosion limiting concentration of explosible materials is necessary forthe design of explosion protection measures. Currently employed methods of testing MEC of a dust cloud or LEL of a hybrid mixture are based on arbitrary assumptionsand possess technical limitations that often lead to values of MEC/LEL, which are unrealistically low or poorly reproducible. This contribution presents an improved method for experimental determination of MEC of a combustible dust cloud or LEL of a flammable gas or hybrid mixture. The new setup operates under laminar conditions and allows a uniform suspension of dust particles in an open top acrylic glass tube. Dust concentration is measured with the help of infrared sensors installed a few centimeters above and below the ignition source. In order to evaluate the dependence of MEC on flow front velocity, MEC of lycopodium was determined at four flow velocities. The results show that the flow field intensity does not significantly influence the MEC of lycopodium for the flow ranges tested in this work. Moreover, LEL of hybrid mixtures of lycopodium and methane was also tested at flow velocities of 4.7 cm/s, 5.8 cm/s, 7 cm/s and 11 cm/s and compared with the values obtained from other sources. The results suggest that the requirement of high energy pyrotechnical igniter may be relinquished, provided that a truly homogeneous suspension of dust particles could be achieved. Moreover, the effect of relative amount of dust and gas, on the course of ignition and flame propagation in hybrid mixtures at their LEL, was studied by the help of high speed videos. For hybrid mixtures of carbonaceous dusts (like lycopodium) at their LEL, ignition occurs in the gas phase, however, flame propagation is only possible through a two-way interaction of dust and gas during the course of combustion. KW - Dust explosions KW - Gas explosions KW - Lower explosion limit KW - Hybrid mixtures PY - 2022 DO - https://doi.org/10.1016/j.jlp.2021.104640 SN - 0950-4230 VL - 74 SP - 1 EP - 18 PB - Elsevier Ltd. AN - OPUS4-54077 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kasch, Thomas A1 - Thomas, Brock A1 - Hesse, Olaf T1 - Assessment Criteria to Evaluate Test Results on Compatibility of Nonmetallic Materials for Oxygen Service Based on BAM’s Safety Philosophy N2 - The general requirement, that nonmetallic materials for oxygen service must be tested and found suitable for their intended use in plants and components is the current state of technical safety. However, numerous requests of manufacturers, sales offices, and users show, that there is still a strong need for information on how these materials are tested and evaluated. Based on more than 60 years of expertise, this paper provides background information on BAM’s test approach. It explains why BAM applies additional assessment criteria on nonmetallic materials for certain use conditions. Hence, the test schedule as well as the final evaluation shall reflect the practical application in a more customer-related way in combination with a higher safety level. That is the demand of BAM’s safety philosophy. T2 - 15th international symposium on flammability and sensitivity of materials in oxygen-enriched atmospheres CY - Online meeting DA - 03.05.2022 KW - Oxygen compatibility KW - Background information on test approaches KW - Evaluation of test results KW - Assessment criteria KW - BAM’s safety philosophy PY - 2022 AN - OPUS4-54887 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Elastische Elemente in der Emission, Transmission und Immission von Bahnerschütterungen N2 - Dieser Vortrag präsentiert einige Prinzipien und einige Beispiele zur Minderung von Eisenbahnerschütterungen. Die Prinzipien unterscheiden sich für die Minderungsmaßnahmen im Gleis, im Boden und bei Gebäuden. Kraftübertragungsfunktionen isolierter und nicht isolierter Gleissysteme, reflektierte und durchgelassene Wellenamplituden bei gefüllten Bodenschlitzen und die Übertragung der Freifeldschwingungen ins Gebäude werden analysiert. Bei den einfachen Gleismodellen muss der richtige Anteil der unabgefederte Fahrzeugmasse zum eindimensionalen Gleismodell hinzugefügt werden. Der Minderungseffekt eines gefüllten Bodenschlitzes ist von der Steifigkeit und nicht von der Impedanz des Schichtmaterials bestimmt. Bei einer elastischen Gebäudelagerung muss die Minderungswirkung mit der richtigen Boden- (Fundament-) Steifigkeit berechnet werden, und das abgeminderte Gebäudeverhalten hängt wesentlich von der effektiven Gebäudemasse ab, die mit zunehmender Frequenz deutlich kleiner als die starre Gebäudemasse ist. T2 - Norm-Arbeitsausschuss Schwingungsminderung in der Umgebung von Verkehrswegen CY - Bludenz, Austria DA - 17.5.2022 KW - Erschütterungsminderung KW - Bahngleis KW - Bodenschlitz KW - Gebäudelagerung KW - Elastische Elemente PY - 2022 AN - OPUS4-54916 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liao, Chun-Man A1 - Bernauer, F. A1 - Hadziioannou, C. A1 - Fontoura Barroso, Daniel T1 - Passive and active bridge monitoring N2 - This research is to perform passive and active measurements on a large-scale prestressed concrete bridge model under the outdoor condition. Multi sensors were applied to this test structure – BLEIB, which is located at the BAM test site. The experimental evaluation of ultrasonic wave propagation and seismic noise recordings were considered for revealing the bridge damage condition, as a basic for developing a reliable bridge monitoring system. T2 - DGZfP-Jahrestagung 2022 CY - Kassel, Germany DA - 23.05.2022 KW - Bridge monitoring PY - 2022 AN - OPUS4-54918 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Boschmann Käthler, C. A1 - Ebell, Gino A1 - Keßler, S. A1 - Schiegg, Y, A1 - Dauberschmidt, C. A1 - Angst, U. M. T1 - A comparison of methods to assess the resistance of reinforcing steel against chloride‐induced corrosion in concrete - Particular consideration of 12% chromium steel N2 - The critical chloride content C(crit) is an indicator for the corrosion resistance of reinforcing steels in concrete. In this article, several experimental methods for determining the critical chloride content C(crit) of mild and an alloyed (12% Cr) steel in cementitious materials are compared. The methods used include accelerated polarization tests and tests using more natural (unpolarized) conditions in which chloride ingress occurs by diffusion and capillary uptake. The advantages and disadvantages of the methods are discussed, in particular, with the objective of reaching a compromise between applicability to practice and feasibility in laboratory testing. KW - Chloride‐induced corrosion KW - Critical chloride content KW - Reinforced concrete KW - Testing methods PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-529751 DO - https://doi.org/10.1002/maco.202112826 SN - 0947-5117 N1 - This article has been published in 2021 as an "Early View" version with the DOI 10.1002/maco.202112609. VL - 73 IS - 3 SP - 306 EP - 325 PB - Wiley-VCH CY - Weinheim AN - OPUS4-52975 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Viefhues, Eva A1 - Döhler, M. A1 - Hille, Falk A1 - Mevel, L. T1 - Statistical subspace-based damage detection with estimated reference N2 - The statistical subspace-based damage detection technique has shown promising theoretical and practical results for vibration-based structural health monitoring. It evaluates a subspacebased residual function with efficient hypothesis testing tools, and has the ability of detecting small changes in chosen system parameters. In the residual function, a Hankel matrix of Output covariances estimated from test data is confronted to its left null space associated to a reference model. The hypothesis test takes into account the covariance of the residual for decision making. Ideally, the reference model is assumed to be perfectly known without any uncertainty, which is not a realistic assumption. In practice, the left null space is usually estimated from a reference data set to avoid model errors in the residual computation. Then, the associated uncertainties may be non-negligible, in particular when the available reference data is of limited length. In this paper, it is investigated how the statistical distribution of the residual is affected when the reference null space is estimated. The asymptotic residual distribution is derived, where its refined covariance term considers also the uncertainty related to the reference null space estimate. The associated damage detection test closes a theoretical gap for real-world applications and leads to increased robustness of the method in practice. The importance of including the estimation uncertainty of the reference null space is shown in a numerical study and on experimental data of a progressively damaged steel frame. KW - Damage detection KW - Uncertainty quantification KW - Statistical tests KW - Ambient excitation KW - Vibration measurement PY - 2022 DO - https://doi.org/10.1016/j.ymssp.2021.108241 SN - 0888-3270 VL - 164 SP - 108241 PB - Elsevier Ltd. AN - OPUS4-52998 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Herrmann, Ralf T1 - Digitalisierung sichert die Bauwerke von gestern und das Wissen von morgen N2 - Die moderne Gesellschaft in Deutschland und Europa profitiert von der hervorragenden baulichen Infrastruktur, die für uns viele Aspekte aus den Bereichen Mobilität, Energieversorgung, Transport, Umweltschutz, (Nah-)Erholung und Gefahrenabwehr zur Alltäglichkeit werden lassen und uns ein hohes Gefühl der technischen Sicherheit vermitteln. Viele der Annehmlichkeiten, wie beispielweise ein Hochgeschwindigkeitseisenbahnverkehrsnetz, zuverlässige Stromversorgung im europäischen Verbundsystem und ein immenser Personen-, Güter- und Warenverkehr auf der Straße, zu Wasser und in der Luft ist ohne eine leistungsfähige, resiliente und zuverlässige bauliche Infrastruktur undenkbar. KW - Bauwerksmonitoring KW - Bauwerksdiagnostik KW - Digitalisierung PY - 2022 DO - https://doi.org/10.1002/bate.202270303 SN - 1437-0999 SN - 0932-8351 VL - 99 IS - 3 SP - 161 EP - 162 PB - Ernst & Sohn GmbH CY - Berlin AN - OPUS4-54557 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krentel, Daniel T1 - Wehrmedizinisches Sonderforschungsvorhaben 29K4 "Primäres Explosionstrauma": „Entwicklung und Validierung eines Körpermodells und eines Stoßwellengenerators zur Simulation der intrakorporalen Stoßwellenausbreitung nach Explosionen“ N2 - Im Rahmen dieses Vortrags wurden aktuelle Arbeiten im Rahmen der Forschungszusammenarbeit mit dem Bundeswehrkrankenhaus Berlin zum primären Explosionstrauma vorgestellt. T2 - 8. KSK Symposium Rüstung 2022 CY - Altensteig/Wart, Germany DA - 13.09.2022 KW - Blast KW - Primäres Explosionstrauma KW - Einsatzkräfte KW - Polizei KW - Körpermodell PY - 2022 AN - OPUS4-55841 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lengas, Nikolaos A1 - Müller, Karsten A1 - Schlick-Hasper, Eva A1 - Neitsch, Marcel A1 - Johann, Sergej A1 - Zehn, M. W. T1 - Bewertung von Fallfundamenten in der mechanischen Sicherheitsprüfung von Gefahrgutverpackungen N2 - Bericht über die Vorgehensweise der systematischen Untersuchungen zur Entwicklung angepasster Kriterien für die Bewertung von Aufprallfundamenten in der mechanischen Sicherheitsprüfung von Gefahrgutverpackungen T2 - AK Prüfstellen CY - Berlin, Germany DA - 21.09.2022 KW - Fallprüfung KW - Aufprallfundament KW - Gefahrgutverpackung KW - Fallfundament KW - Mechanische Sicherheitsprüfung PY - 2022 AN - OPUS4-55842 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lengas, Nikolaos A1 - Müller, Karsten A1 - Schlick-Hasper, Eva A1 - Neitsch, Marcel A1 - Johann, Sergej A1 - Zehn, M. W. T1 - Bewertung von Fallfundamenten in der mechanischen Sicherheitsprüfung von Gefahrgutverpackungen N2 - Bericht über die Vorgehensweise der systematischen Untersuchungen zur Entwicklung angepasster Kriterien für die Bewertung von Aufprallfundamenten in der mechanischen Sicherheitsprüfung von Gefahrgutverpackungen T2 - ERFA Verpackungen CY - Berlin, Germany DA - 22.09.2022 KW - Fallprüfung KW - Aufprallfundament KW - Gefahrgutverpackung KW - Fallfundament KW - Mchanische Sicherheitsprüfung PY - 2022 AN - OPUS4-55843 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lengas, Nikolaos A1 - Johann, Sergej A1 - Kadoke, Daniel A1 - Müller, Karsten A1 - Schlick-Hasper, Eva A1 - Neitsch, Marcel A1 - Zehn, M. W. T1 - Damage assessment of complete, filled fibreboard boxes in regulative vertical impact tests by dropping N2 - Due to the high damping mechanical properties of fibreboard materials, corrugated fibreboard boxes are widely used as transport packages of dangerous goods. Since there is a hazard of vertical impact within the distribution system, drop tests are performed as design type tests to assess the package’s ability to withstand damage. However, there is little information in this context regarding the mechanical response of a filled fibreboard box. This work aims to propose a concept utilizing experimental drop test results by means of finite-element (FE) analyses in order to predict the damage resistance of complete, filled corrugated fibreboard boxes which are ready for transportation. T2 - 38th Danubia Adria Symposium on Advances in Experimental Mechanics CY - Poros Island, Greece DA - 20.09.2022 KW - Drop test KW - Dangerous goods packagings KW - Corrugated fibreboard box KW - Finite-element-analysis KW - Explicit transient simulation KW - Crash simulation PY - 2022 AN - OPUS4-55845 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wu, Dejian A1 - Schmidt, Martin A1 - Krietsch, Arne A1 - Krause, U. T1 - Effect of oxygen concentration, inert gas and CH4/H2 addition on the minimum ignition energy of coal dusts N2 - MIKE III apparatus tests were conducted to investigate the minimum ignition energy (MIE) of coal dusts in air and O2/CO2 atmospheres with and without small amount of CH4/H2. The O2 mole fraction (XO2) in the gas mixtures varied from 21% to 50% with the CH4/H2 mole fraction from 0 to 2%. Experimental result showed that MIE of coal dusts significantly decreases even by three orders of magnitude in mJ with increasing XO2 and the addition of CH4/H2. Compared with CH4, H2 had a relatively strong promotion effect on the spark ignition of coal dusts. The inhibiting effect of CO2 was found to be much stronger than N2, but this inhibiting effect of CO2 could be eliminated by 9% increment of XO2. The effect on MIE of coal dusts thus followed by the order: 9% increment of XO2 > CO2 replacing N2 > 2% CH4 or H2 addition. Moreover, two empirical models were used to estimate the MIE of hybrid dust-gas mixture (HMIE), and the results showed that calculated data can well reflect the promoting effect of elevated XO2 and flammable gas addition, and the inhibiting effect of inert gas KW - Ignition energy KW - Hybrid mixture KW - Oxygen rich KW - Inerting effect KW - Empirical model PY - 2022 DO - https://doi.org/10.1016/j.jlp.2022.104772 SN - 0950-4230 VL - 77 SP - 1 EP - 10 PB - Elsevier Ltd. AN - OPUS4-55888 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wu, Dejian A1 - Zhu, Z. A1 - Bao, Z. T1 - Optimization of the content distribution of expanded natural graphite in a multilayer metal hydride bed for thermochemical heat storage N2 - The poor thermal conductivity of MH beds limits hydrogen absorption in metal hydride (MH) reactors for thermochemical heat storage. The compaction of MH powder with expanded natural graphite (ENG) is an efficient and cost-effective approach for the heat transfer enhancement of MH beds. However, the addition of ENG reduces the hydrogen storage density of the compacted composites. How to optimize the allocation of a limited amount of ENG in the MH bed has not been studied. In this study, a multilayer MH bed configuration with an ENG grade content was adopted to improve the heat transfer performance of an MH reactor for thermochemical heat storage. The effect of the ENG content gradient on the performance of the MH reactor was investigated using a mathematical model of the MH reactor. Furthermore, an optimization method based on the entransy dissipation extremum principle (EDEP) was proposed to optimize the ENG distribution in magnesium hydride (MgH2)-ENG compacts. The results showed that a larger ENG content gradient resulted in faster hydrogen absorption and better heat-discharge performance. Compared with a configuration with a uniform ENG content, the optimized configuration based on the EDEP exhibited a shorter reaction time, more uniform bed temperature distribution, and 15.33% higher gravimetric exergy-output rate. In addition, the number of optimization iterations had little effect on the optimal results, which could be obtained by implementing only one optimization iteration. The optimization results showed that more ENG should be allocated to the internal layer of the MgH2-ENG compact. The compacts were divided into three layers, and the ENG content of each layer was calculated according to the optimized configuration based on the EDEP. The optimization method proposed in this study can be applied to optimize KW - Metal hydride reactor KW - Expanded natural graphite KW - Multilayer bed KW - Entransy dissipation exremum principle KW - Thermochemical heat storage PY - 2022 DO - https://doi.org/10.1016/j.applthermaleng.2022.119115 SN - 1359-4311 VL - 216 SP - 1 EP - 10 PB - Elsevier Ltd. AN - OPUS4-55890 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klimek, André A1 - Stelzner, Ludwig A1 - Hothan, Sascha A1 - Rogge, Andreas T1 - Fire induced concrete spalling in combination with size effects N2 - The size effect has its origin in fracture mechanics and describes the formation as well as propagation of cracks in brittle and solid materials in dependence of the specimen size. However, the size effect in concrete spalling describes the damage behaviour on a macroscopic scale for different sized specimens in case of fire. Concrete spalling is a very complex and yet not fully understood phenomenon. To reduce the effort of fire tests to analyse the spalling behaviour of concrete mixtures, this study investigates the susceptibility to spalling for six different concrete mixtures and three specimen sizes. The sizes were divided in full scale slabs (1.8 m x 1.2 m x 0.3 m), intermediate scale cuboids (0.6 m x 0.6 m x 0.3 m) and small scale cylinders (Ø0.15 m x 0.3 m). For this purpose, a novel test set-up was built to test six intermediate scale or twelve small scale specimens simultaneously to ensure a similar heating regime for every specimen. All specimens were fire exposed on one side and remained unrestrained. A size effect occurred for four of the six concrete mixtures. Compared to the full scale specimens the spalling was reduced significantly for all smaller specimen sizes. Additionally, spalling did not occur for the small scale specimens. The results show that the specimen size is an essential parameter to investigate the susceptibility to spalling of a concrete mixture. For future investigations the testing conditions must be adjusted for the intermediate scale specimens to recreate the conditions of the slabs. KW - Concrete KW - Spalling KW - Size effect KW - Fire test PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559231 DO - https://doi.org/10.1617/s11527-022-02051-2 VL - 55 IS - 8 SP - 1 EP - 14 PB - Springer AN - OPUS4-55923 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Michalchuk, Adam T1 - The Mechanochemical Excitation of Crystalline LiN3 N2 - Mechanochemical reactions are driven by the direct absorption of mechanical energy by a solid (often crystalline) material. Understanding how this energy is absorbed and ultimately causes a chemical transformation is essential for understanding the elementary stages of mechanochemical transformations. Using as a model system the energetic material LiN3 we here consider how vibrational energy flows through the crystal structure. By considering the compression response of the crystalline material we identify the partitioning of energy into an initial vibrational excitation. Subsequent energy flow is based on concepts of phonon–phonon scattering, which we calculate within a quasi-equilibrium model facilitated by phonon scattering data obtained from Density Functional Theory (DFT). Using this model we demonstrate how the moments (picoseconds) immediately following mechanical impact lead to significant thermal excitation of crystalline LiN3, sufficient to drive marked changes in its electronic structure and hence chemical reactivity. This work paves the way towards an ab initio approach to studying elementary processes in mechanochemical reactions involving crystalline solids. KW - Energetic materials KW - Ab initio simulation KW - DFT KW - Mechanochemistry PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559310 DO - https://doi.org/10.1039/d2fd00112h SP - 1 EP - 20 PB - Royal Society of Chemistry AN - OPUS4-55931 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Henning, Ricky A1 - Sturm, Patrick A1 - Geddes, D.A. A1 - Keßler, S. A1 - Walkley, B. A1 - Gluth, Gregor T1 - The influence of curing temperature on the strength and phase assemblage of hybrid cements based on GGBFS/FA blends N2 - Hybrid cements are composites made of Portland cement or Portland clinker and one or more supplementary cementitious materials like slag, fly ash or metakaolin, activated with an alkali salt. To date, their hydration mechanism and the phase formation at various temperatures is insufficiently understood, partly due to the large variability of the raw materials used. In the present study, three hybrid cements based on ground granulated blast furnace slag, fly ash, Portland clinker and sodium sulfate, and an alkali-activated slag/fly ash blend were cured at 10 and 21.5°C, and subsequently analyzed by XRD, 27Al MAS NMR, and TGA. The compressive strength of the hybrid cements was higher by up to 27% after 91-day curing at 10°C, compared to curing at 21.5°C. The experimental results as well as thermodynamic modeling indicate that the differences in compressive strength were related to a different phase assemblage, mainly differing amounts of strätlingite and C-N-A-S-H, and the associated differences of the volume of hydration products. While the strätlingite was amorphous to X-rays, it could be identified by 27Al MAS NMR spectroscopy, TGA and thermodynamic modeling. The microstructural properties of the hybrid cements and the alkali-activated slag/fly ash blend as well as the compatibility between thermodynamic modeling results and experimental data as a function of curing temperature and time are discussed. KW - Hybrid cements KW - Strätlingite KW - Thermodynamic modelling KW - Hydration PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-557767 DO - https://doi.org/10.3389/fmats.2022.982568 SN - 2296-8016 VL - 9 SP - 1 EP - 16 PB - Frontiers AN - OPUS4-55776 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino T1 - Prestressed Concrete Structures with Concentrated Tendons - Structural Damage due to Hydrogen-Induced Stress Corrosion Cracking N2 - In the course of the deconstruction of the "Bridge of the 20th anniversary of the GDR" at the Altstädter Bahnhof in Brandenburg a. d. Havel, new information on the initiation of hydrogen-induced stress cracks was obtained. BAM was commissioned by the Brandenburg State Road Administration to participate in a corresponding joint project which is financed by the Federal Ministry for Digital and Transport. The added value of the new information gained in this project goes beyond the specific structure. It describes unexpected new damage patterns that can be transferred to other structures with concentrated tendons (tendon block method and Baur-Leonhardt method) and were previously unknown in this form. These should be made known to other developers to enable them to initiate any necessary actions. T2 - Eurocorr 2022 CY - Berlin, Gemany DA - 29.08.2022 KW - Korrosion KW - Corrosion KW - Hydrogen KW - Stress Cracking PY - 2022 AN - OPUS4-55613 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fürst, Richard A1 - Häßler, Dustin A1 - Hothan, Sascha T1 - Brandversuch eines Stahlzuggliedes mit reaktivem Brandschutzsystem N2 - Das Poster stellt den im Rahmen des Workshops "Feuerwiderstand von Stahlzuggliedern mit reaktiver Brandschutzbeschichtung" durchgeführten Brandversuch vor. T2 - Workshop - Feuerwiderstand von Stahlzuggliedern mit reaktiver Brandschutzbeschichtung CY - Berlin, Germany DA - 06.09.2022 KW - Brandschutz KW - Brandversuch KW - Feuerwiderstand KW - Reaktives Brandschutzsystem PY - 2022 AN - OPUS4-55699 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fürst, Richard A1 - Häßler, Dustin A1 - Hothan, Sascha T1 - Research Project FIRESTEMIC - Results and Recommendations N2 - The presentation summarizes the results of the research project. T2 - Workshop 2022 - Feuerwiderstand von Stahlzuggliedern mit reaktiver Brandschutzbeschichtung CY - Berlin, Germany DA - 06.09.2022 KW - Fire tests KW - Intumescent coating KW - Steel KW - Tension member PY - 2022 AN - OPUS4-55700 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Häßler, Dustin A1 - Hothan, Sascha A1 - Fürst, Richard T1 - Neue Prüfnorm für reaktive Brandschutzsysteme auf Stahlzuggliedern N2 - Der Vortrag stellt den Entwurf der neuentwickelten Prüfnorm vor. T2 - Workshop 2022 - Feuerwiderstand von Stahlzuggliedern mit reaktiver Brandschutzbeschichtung CY - Berlin, Germany DA - 06.09.2022 KW - Feuerwiderstand KW - Brandschutz KW - Stahlzugglieder KW - Reaktives Brandschutzsystem KW - Prüfnorm PY - 2022 AN - OPUS4-55701 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liao, Chun-Man A1 - Petryna, Y. T1 - Damage Assessment of Civil Structures Using Wave Propagation Analysis and Transmissibility Functions N2 - A common damage detection method in civil engineering is to monitor dynamic characteristics such as natural frequencies and modal shapes, which are directly related to the structural stiffness. However, the discrepancy in measured natural frequencies may result from environmental changes, the soil-structure interaction or effects caused by earthquakes. This makes it difficult to decide whether the local change in structural properties is caused by damage or other factors. To address this challenge and thus improve the current damage detection method, the wave propagation analysis method and the transmissibility relationship were considered. In our study, the wave propagation field in structures was reconstructed by applying the Normalized-Input-Output-Minimization (NIOM) method to vibration recordings. Wave velocities and transmissibility functions were considered as reference values for the damage indicators. This paper demonstrates the evaluation of local property changes in two examples of large-scale structures: a 14-story RC building and a 64 m long pedestrian bridge. The proposed damage indicators show a clear correspondence to structural changes. T2 - EVACES2021 9th International Conference on Experimental Vibration Analysis for Civil Engineering Structures CY - Online meeting DA - 14.09.2021 KW - Damage detection KW - Damage indices KW - Normalized-Input-Output-Minimization KW - Transmissibility function KW - Wave propagation PY - 2022 SN - 978-3-030-93235-0 SN - 978-3-030-93236-7 DO - https://doi.org/10.1007/978-3-030-93236-7_2 SP - 3 EP - 13 PB - Springer CY - Cham AN - OPUS4-55565 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jauregui-Correa, J. C. A1 - Otremba, Frank A1 - Hurtado-Hurtado, G. A1 - Romero-Navarrete, J. A. T1 - Experimental test rig for simulating dynamic loads on subway systems N2 - Degradation in substructures, Mexico’s City Subway. Improve predictions using vibration Measurements. Ability to test operating conditions at Laboratory. Improve previous laboratory rig. Control operating conditions. Produce enough data for evaluating actual conditions. T2 - Fifth International Conference on Railway Technology CY - Montpellier, France DA - 22.08.2022 KW - Test rig KW - Simulating KW - Dynamic loads KW - Subway PY - 2022 AN - OPUS4-55568 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Thoralf A1 - Wagner, Adrian A1 - Burkert, Andreas T1 - Field exposure studies of austenitic and duplex stainless steels in tunnel atmospheres N2 - Due to the high corrosivity that are present in road tunnel structures, cleaning and maintenance work on stainless steel components in the tunnels is carried out at regular intervals in the tunnels, which means that parts of the lanes or the whole tunnel have to be temporarily closed. To reduce these traffic disruptions and maintenance costs, it is important to reduce the work that is needed for cleaning and maintenance of stainless steel components in road tunnels. One possibility is the identification and utilization of better suited alternatives to the commonly used austenitic stainless steels AISI 316L and AISI 316Ti. Thus, a field exposure study was carried out in different road tunnels throughout Germany to qualify different duplex and lean duplex stainless steels for tunnel constructions. The proposed scientific poster gives an overview of results after the first three years of exposure in three different road tunnels. Samples of different stainless steels were placed in different areas of the tunnel – at lane height and at the ceiling. Some samples were exposed under sheltered conditions. Pit depths were evaluated on the free surface and in crevice areas after each year of exposure. The investigations show that duplex stainless steels have a comparable or even better corrosion resistance than austenitic steels in tunnel atmospheres. T2 - EUROCORR 2022 CY - Berlin, Germany DA - 28.08.2022 KW - Corrosion KW - Atmosphere KW - Tunnel KW - Stainless Steel PY - 2022 AN - OPUS4-55595 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pirskawetz, Stephan A1 - Steinbock, O. A1 - Hille, Falk A1 - Schmidt, S. A1 - Hofmann, Detlef T1 - Erfahrungen aus dem Rückbau der Brücke am Altstädter Bahnhof in der Stadt Brandenburg - Teil 2: Schadensmonitoring bei zerstörenden Versuchen N2 - Im Dezember 2019 wurden bei einer turnusmäßigen Inspektion der B 1-Brücke am Altstädter Bahnhof in Brandenburg an der Havel massive und schnell voranschreitende Schäden festgestellt. Als Ursache für die Risse entlang der Längsträger wurde das Versagen eines signifikanten Anteils der Spanndrähte der konzentrierten Spannglieder vermutet. Die Brücke wurde umgehend für den Verkehr gesperrt und im Mai 2021 gesprengt. Im Vorfeld der Sprengung wurden durch das Bundesministerium für Digitales und Verkehr (BMDV) weiterführende Untersuchungen zum Schadensbild veranlasst, welche vom Landesbetrieb Straßenwesen Brandenburg koordiniert und in den Bauablauf integriert wurden. Das von der Hochschule für Technik und Wirtschaft (HTW) Dresden erstellte Versuchskonzept ist Bestandteil des vorangestellten ersten Teils des Beitrags [1]. Hier im zweiten Teil werden ausgewählte Ergebnisse der umfangreichen versuchsbegleitenden Mess- und Monitoringmaßnahmen beschrieben, welche in Kooperation der HTW Dresden, der Bilfinger Noell GmbH sowie der Bundesanstalt für Materialforschung und -prüfung (BAM) durchgeführt wurden. N2 - A routine inspection of the B1 bridge at the Altstädter Bahnhof in Brandenburg an der Havel in December 2019 revealed massive and rapidly progressing damage. The cause of the cracks along the longitudinal girders was suspected to be the failure of a significant portion of the prestressing wires of the concentrated tendons. The bridge was immediately closed to traffic and demolished in May 2021. Prior to the demolition, the Federal Ministry for Digital and Transport (BMDV) initiated further investigations into the damage pattern, which were coordinated and integrated into the deconstruction process by the Landesbetrieb Straßenwesen Brandenburg. The test concept was developed by the Hochschule für Technik und Wirtschaft Dresden (HTW) and is described in the previous article (Part 1). The article at present (Part 2) describes selected results of the extensive measurement and monitoring measures accompanying the tests. The Tests were carried out in cooperation with the HTW Dresden, Bilfinger Noell GmbH and the Bundesanstalt für Materialforschung und -prüfung (BAM). KW - Spannbetonbrücke KW - Spannstahlbruch KW - Schallemission KW - Fotogrammetrie KW - Faseroptik KW - Stochastische Subspacebasierte Schadensdetektion PY - 2022 DO - https://doi.org/10.1002/best.202200052 SN - 1437-1006 VL - 117 IS - 8 SP - 581 EP - 589 PB - Ernst & Sohn CY - Berlin AN - OPUS4-55513 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Moye, Janis A1 - Sturm, Patrick A1 - Kühne, H.-C. A1 - Keßler, S. A1 - Pistol, K. T1 - Entwicklung und Charakterisierung von alkalisch aktivierten Mörteln für die Betoninstandsetzung - Robustheits- und Dauerhaftigkeitsbetrachtungen N2 - Für die flächige Instandsetzung von Stahlbetonkonstruktionen kommen nahezu ausschließlich zementgebundene Systeme mit hohem Zementgehalt zum Einsatz (1). Bereits 2008 war die Zementproduktion für 5% des weltweiten, anthropogenen CO2-Ausstoßes verantwortlich (2). Um die prozessbedingten CO2-Emissionen zu senken, wird der Zement bereits durch gewisse Mengen an Sekundärrohstoffen wie Flugasche, Silicastaub oder Hüttensandmehl (Hochofenschlacke) substituiert. Das Potenzial für weitere Modifikationen ist inzwischen begrenzt (3). Zudem ist eine hohe Lebensdauer der Konstruktionen in vielen Anwendungsbereichen nur bedingt realisierbar. Spätestens mit Erreichen der geplanten Nutzungsdauer müssen Stahlbetonkonstruktionen mit zementgebundenen Systemen instandgesetzt werden, was im ökonomischen und ökologischen Sinne keine nachhaltige Lösung darstellt. Die Verwendung neuer Baustoffe wie alkalisch aktivierte Mörtel hält sich bisher in Grenzen (4), sodass die Akzeptanz durch praxisnahe Forschung adressiert werden muss. Vorangegangene Forschungsergebnisse zeigen, dass alkalisch aktivierte Bindemittel vielversprechende technische Eigenschaften besitzen. So zeigen sich im Vergleich zu herkömmlichem Portlandzement ein ausgesprochen wirkungsvoller Verbund zu Stahl und Zementmörtel (5), (6), eine hohe chemische Beständigkeit sowie ein Erfolg versprechendes Abwitterungsverhalten bei Frost-Tau-Wechseln (7). Mit diesen Eigenschaften können alkalisch aktivierte Mörtel einen erheblichen Beitrag zur dauerhaften Betoninstandsetzung leisten und somit durch die verringerten CO2-Emmissionen dem Prinzip des nachhaltigen Bauens gerecht werden. Wichtig für die Produktion im größeren Maßstab ist die Verfügbarkeit der möglichen Reststoffe, um eine CO2-positivere Bilanz abzubilden. Im Zuge des Forschungsvorhabens sollen Rezepturen für Instandsetzungsprodukte entworfen werden, die auf alkalisch aktivierte industrielle Reststoffe zurückgreifen und die Anforderungen an konventionelle Instandsetzungsprodukte erfüllen. Hierzu wurden potenzielle Ausgangs-stoffe mit Natriumcarbonat aktiviert und die Verarbeitbarkeit der Leime sowie die Druckfestigkeiten nach sieben Tagen verglichen. Hüttensandmehl reagiert ausreichend mit diesem Aktivator, was sich mit Ergebnissen von (8) und (9) deckt. Es werden 〖CO〗_3^(2-)-Ionen in das System eingebaut, was zu einer anfänglichen Erstarrung des Gefüges durch die Bildung von Carbonaten (Calcit und Hydrotalcit) führt. Nach einer längeren dormanten Phase bilden sich zusätzlich Hydratphasen, die die Festigkeit weiter erhöhen. Weiterhin ist die chemische Zusammensetzung der Schlacken für die Erhärtung und die späteren Eigenschaften von großer Bedeutung (10), (11), was mit einer Parameterstudie im laufenden Jahr an natriumcarbonataktivierten Schlacken näher betrachtet werden soll. Erkenntnisse aus vergleichenden Versuchen durch (12) bestätigen die Einflussnahme der chemischen Zusammensetzung. Die übrigen Reststoffe konnten mit anderen Aktivatoren (z. B. Natriumsilicat und -hydroxid) zu einer Reaktion angeregt werden. Im Hinblick auf die Akzeptanz der alkalisch aktivierten Bindemittel stellen diese Aktivatoren jedoch bei der Herstellung höhere technische Anforderungen an das Personal und die verwendeten Geräte im Vergleich zur konventionellen Beton- und Mörteltechnik. Die Aktivierung mittels Alkalicarbonaten ermöglicht die Herstellung von Beton bzw. Mörtel nach dem üblichen „just add water“-Prinzip (13). Aktuell wird unter Einbindung einer studentischen Abschlussarbeit eine Rezeptur mit Hüttensandmehl hinsichtlich der Frisch- und Festeigenschaften charakterisiert und einer Referenzmischung – basierend auf Portlandzement – gegenübergestellt. Hieraus resultierende Ergebnisse sollen neben den Erkenntnissen aus den Vorversuchen zur Konferenz vorgestellt und ein Ausblick auf die weitere Forschungsarbeit gegeben werden. T2 - Nachwuchswissenschaftler*innenkonferenz 2022 CY - Brandenburg an der Havel, Germany DA - 11.05.2022 KW - Alternative Bindemittel KW - Alkalische Aktivierung KW - Instandsetzung KW - Realkalisierung PY - 2022 AN - OPUS4-55517 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rübner, Katrin A1 - Schumann, G. A1 - Hahn, A. A1 - Vöge, M. A1 - Bruch, I. A1 - Schnell, A. T1 - HYTEGRA - Hydrothermalgranulate - Rohstoffliches Recycling von Mauerwerkbruch N2 - Ziel des Projekts HYTEGRA ist die Herstellung leichter Gesteinskörnungen durch hydrothermale Behandlung quarz- und kalkreicher Reststoffe. Als Ausgangsstoffe dienen heterogener Mauerwerkbruch aus Bau- und Abbruchabfällen als SiO2-Träger und Papierasche aus dem Altpapierrecycling als CaO-Träger. Für beide Reststoffe besteht derzeit ein Verwertungsdefizit. Das Verfahren beruht auf der Idee des rohstofflichen Recyclings, d. h. die chemisch-mineralogischen Stoffeigenschaften werden für die hydrothermale Stoffumwandlung genutzt. Bei der Härtung der Hydrothermalgranulate bilden sich Calciumsilicathydrat-Phasen (CSH) aus der Reaktion zwischen Quarzpartikeln und Kalk im Autoklav bei 200 °C und 16 bar Sattdampf. T2 - Innovationstag Mittelstand des BMWK am 22. Juni 2022 CY - Berlin, Germany DA - 23.06.2022 KW - Mauerwerkbruch KW - Papierasche KW - Rohstoffliches Recycling KW - Leichte Gesteinskörnung KW - Bodenfilter PY - 2022 AN - OPUS4-55552 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino T1 - Potential Mapping - What could we measure and what should we able to detect – guideline B03 of DGZfP N2 - “Electrochemical potential mapping according to guideline B3 of DGZfP (German Society for Non-Destructive Testing) is a recognized technique for the localization of corroding reinforcing steels. Areas of corroding reinforcement steel can be located in a non-destructive manner by means of this procedure. Half‐cell potential measurements are used in order to detect chloride‐induced corrosion. However, it is not recommended in order to assess the risk of carbonation‐induced corrosion. For this purpose, determining the carbonation depth and the concrete cover appears more appropriate. The content of this specification exclusively refers to the application of mobile, local variable reference electrodes, which are only placed on the concrete surface while measuring. The technique distinguishes itself thereby from the range of corrosion monitoring systems with stationary installed reference electrodes and sensor systems, respectively, whereby it is possible to continuously track measurements within the area of the installed electrodes. However, these methods are not dealt with in this specification.” T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Korrosion KW - Potentialfeldmessung KW - Corrosion KW - Half-cell potential KW - Potential mapping PY - 2022 AN - OPUS4-55524 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Feistkorn, S. A1 - Algernon, D. A1 - Arndt, R. A1 - Ebell, Gino A1 - Friese, M. A1 - Grosse, C. U. A1 - Holstein, R. A1 - Niederleithiger, Ernst A1 - Schickert, M. A1 - Schulze, S. A1 - Taffe, A. A1 - Walther, A. A1 - Wolf, J. A1 - Zoega, A. A1 - Zwanzig, M. T1 - Introduction to DIN 4871: Qualification of NDT Personnel in Civil Engineering (NDT‐CE) N2 - Recently, non-destructive testing in civil engineering (NDT-CE), in particular of concrete components, has successfully mastered the leap from research to practice. Several methods have been established for field inspections to determine the concrete cover of reinforcement or to estimate the compressive strength as well as other parameters related to the concrete material. In addition, the application of non-destructive testing is indispensable, if information about the inner structure - such as the location of rebars and tendon ducts or the damage-related condition assessment to detect grouting defects, honeycombs, delamination, or corrosion - is required. Besides the selection of a suitable NDT method and an appropriate inspection system, the reliability of the results depends largely on the person who applies the non-destructive inspection technique and evaluates the inspection results. To ensure a high quality of non-destructive concrete evaluation as well as to keep the uncertainty caused by the inspection personnel to a minimum, structured, consistent, and regulated theoretical as well as practical training of inspection personnel is essential. To close this gap, the subcommittee of education and training (UA-A) within the committee for NDT-CE of the German Society for Non-Destructive Testing (DGZfP) has been reactivated in 2018 to establish uniform training standards for non-destructive concrete inspections in the long term. The subcommittee consists of scientists, practitioners, authorities, and clients. So far, the national standard DIN 4871 “Non-destructive testing - Qualification of NDT personnel in Civil Engineering (NDT-CE)” was developed. This standard considers the civil-industry-specifics, for example, that standards for NDT of concrete, as well as related product standards with a few exceptions, still do not exist at the moment. Within this presentation, the concept, the connection to ISO 9712 and other standards as well as an overview of the recently developed German standard DIN 4871 will be presented. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Non-destrucive testing KW - Civil engineering PY - 2022 AN - OPUS4-55526 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schwarz, W. A1 - Wilsch, Gerd A1 - Katsumi, N. A1 - Ebell, Gino A1 - Völker, Tobias T1 - Ion distribution in concrete overlay, mapped by laser induced breakdown spectroscopy (LIBS), modified by an embedded zinc anode N2 - Galvanic corrosion protection by embedded zinc anodes is an accepted technique for the corrosion protection of reinforcing steel in concrete. Galvanic currents flow between the zinc anode and the steel reinforcement due to the potential difference that is in the range of a few hundred mV. The ion distribution was studied on two steel reinforced concrete specimens admixed with 3 wt.% chloride/wt. cement and galvanically protected by a surface applied EZ-anode. On both specimens, a zinc anode was embedded and glued to the concrete surface by a geo-polymer-based chloride-free binder. At one specimen, the EZ-anode was operated for 2,5 years, the EZ-anode at the other specimen was not electrically connected to the reinforcement, this specimen serves as a reference. Both specimens have been stored under identical conditions. The ion distribution between the anode (EZ-anode) and cathode (steel reinforcement) was studied by laser-induced breakdown spectroscopy (LIBS) after 7 months, 12 months, and 2,5 years. Results of the LIBS studies on the specimen with activated EZ-anode after 7 months, 12 months, and 2,5 years and of the reference specimen after 2,5 years are reported. Results show that diffusion of ions contributes to the changes in the ion distribution but migration, especially of chlorides towards the EZ-anode is significant despite the weak electric field – several hundred millivolts - generated by the galvanic current. Results show that chloride ions accumulate near the zinc-anode as in water-insoluble zinc-hydroxy chlorides - Simonkolleit. T2 - ICCRRR 2022 CY - Capetown, South Africa DA - 03.10.2022 KW - Korrosion KW - Corrosion KW - LIBS KW - Zinc PY - 2022 AN - OPUS4-55948 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Romero Navarrete, J. A. A1 - Otremba, Frank A1 - Lozano Guzmán, A. A. T1 - Liquid cargo effect on load transfer under orthogonal accelerations N2 - A methodology is proposed for the experimental analysis of the liquid cargo effect under combined orthogonal accelerations. To simultaneously subject the vehicle-cargo system to longitudinal and lateral accelerations, the vehicle is set obliquely on a tilt table. The experimental outputs suggest that there is a significant effect of the liquid cargo on the lateral load transfer ratio (LTR), on the order of 20%, which is attributable to the resulting shifting of the liquid cargo’s centre of gravity. That is, the peak LTR values due exclusively to sloshing were not significant, in such a way that the liquid cargo would only pose a safety risk under a steady acceleration input. Also, the inverse of the product of the magnitude of the acceleration times the free surface length, correlates with the liquid cargo effect. That is, the magnitude of the input acceleration is not fully determinant for greater load transfers. KW - Sloshing KW - Liquid cargo KW - Cargo shifting KW - Lateral load transfer KW - Braking in a turn manoeuvre KW - Experimental methods KW - Transport safety PY - 2022 DO - https://doi.org/10.1504/ijhvs.2022.127011 SN - 1744-232X VL - 29 IS - 3 SP - 213 EP - 226 PB - Inderscience Enterprises CY - Geneva AN - OPUS4-56016 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klimek, André A1 - Stelzner, Ludwig A1 - Hothan, Sascha A1 - Zehfuß, J. T1 - Screening-tests on the susceptibility to spalling of two ordinary concretes N2 - Investigating the spalling behaviour of a concrete mixture using large scale members is complex and expensive. Thus, the susceptibility of concrete to spalling is investigated by means of fire tests on small scale specimens. However, the reduction of the fire exposed surface increases the influence of boundary effects. Macrocracking and the water loss via the lateral surfaces reduce the impact of the thermomechanical and thermohydraulic damage mechanisms and therefore, lower the risk of spalling. Thus, the influence of different restraints on the spalling behaviour of intermediate scaled specimens (Ø=0.47 m; h=0.29 m) was investigated for two ordinary concrete mixtures. Both mixtures had the same composition except the type of aggregate. One mixture contained only quartzitic aggregates, whereas the other mixture was made with basalt grit as coarse aggregates. Applied steel rings restrained the thermal expansion of the specimen and prevented the loss of water, whereas applied steel sheet primarily reduced the loss of water during the fire test. Additionally, the fire exposed surface of one specimen of each mixture was pre-dried under controlled climate conditions and fire tested with applied steel rings. The results show a higher spalling volume for the ring restrained specimens compared to the other covering types. Further, the pre-dried boundary zone leads to delayed and decreased occurrence of spalling compared to the non-dried specimens for the concrete with quartzitic aggregates and to a prevention of spalling for the mixture with basalt aggregates. Additionally, the results show that the influence of the thermomechanical behaviour of the coarse aggregates increases with increasing restraint. The restrained conditions of the specimens with applied steel ring are comparable to the conditions in the centre of a large scale member. This test series is a further step for possible concept of steel ring restraint concrete specimens as “screening-tests” in upcoming projects. T2 - IWCS 2022 CY - Berlin, Germany DA - 12.10.2022 KW - Spalling KW - Fire test KW - Concrete KW - Restraint PY - 2022 SP - 15 EP - 24 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-56020 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klimek, André A1 - Stelzner, Ludwig T1 - Screening-tests on the susceptibility to spalling of two ordinary concretes N2 - Investigating the spalling behaviour of a concrete mixture using large scale members is complex and expensive. Thus, the susceptibility of concrete to spalling is investigated by means of fire tests on small scale specimens. However, the reduction of the fire exposed surface increases the influence of boundary effects. Macrocracking and the water loss via the lateral surfaces reduce the impact of the thermomechanical and thermohydraulic damage mechanisms and therefore, lower the risk of spalling. Thus, the influence of different restraints on the spalling behaviour of intermediate scaled specimens (Ø0.47 m; h=0.29 m) was investigated for two ordinary concrete mixtures. Both mixtures had the same composition except the type of aggregate. One mixture contained only quartzitic aggregates, whereas the other mixture was made with basalt grit as coarse aggregates. Applied steel rings restrained the thermal expansion of the specimen and prevented the loss of water, whereas applied steel sheet primarily reduced the loss of water during the fire test. Additionally, the fire exposed surface of one specimen of each mixture was pre-dried under controlled climate conditions and fire tested with applied steel rings. The results show a higher spalling volume for the ring restrained specimens compared to the other covering types. Further, the pre-dried boundary zone leads to delayed and decreased occurrence of spalling compared to the non-dried specimens for the concrete with quartzitic aggregates and to a prevention of spalling for the mixture with basalt aggregates. Additionally, the results show that the influence of the thermomechanical behaviour of the coarse aggregates increases with increasing restraint. The restrained conditions of the specimens with applied steel ring are comparable to the conditions in the centre of a large scale member. This test series is a further step for possible concept of steel ring restraint concrete specimens as “screening-tests” in upcoming projects. T2 - 7th International Workshop on Concrete Spalling due to Fire Exposure CY - Berlin, Germany DA - 12.10.2022 KW - Spalling KW - Fire test KW - Concrete KW - Restraint PY - 2022 AN - OPUS4-56023 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 - RPRT A1 - Patzelt, Anne-Katrin A1 - Krentel, Daniel A1 - Wiesner, Anja T1 - InnoBOSK - Ergebnisse der Bedarfserhebung N2 - Im Projekt InnoBOSK wurden insgesamt vier wissenschaftlich basierte Bedarfserhebungsworkshops durchgeführt. Die Workshops hatten jeweils thematische Schwerpunkte und wurden mit Vertretern unterschiedlicher BOS (Behörden und Organisationen mit Sicherheitsaufgaben) durchgeführt. In der vorliegenden Arbeit werden die erhobenen Bedarfe ausgewertet. KW - BOS KW - InnoBOSK KW - Bedarfserhebung KW - Forschungsbedarf PY - 2022 SP - 1 EP - 23 AN - OPUS4-55831 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Epple, Niklas A1 - Fontoura Barroso, Daniel A1 - Niederleithinger, Ernst A1 - Hindersmann, I. A1 - Sodeikat, C. A1 - Groschup, R. T1 - Monitoring of a German Road Bridge Using Embedded Ultrasonic Transducers and Coda Waves N2 - The ‘G¨anstorbr¨ucke’ bridge between the cities of Ulm and Neu-Ulm is one of the best-monitored bridges all over Germany. In addition to an already active bride monitoring system, we have equipped the bridge with 30 ultrasonic transducers to explore the monitoring possibilities at an in-service large-scale reinforced concrete structure with continuous active ultrasonic measurements. The monitoring system is based on the detection of small changes in the entire signal, especially the multiply scattered parts of the recording, the so-called coda. Applying Coda Wave Interferometry (CWI), subtle changes in the signal can be detected and related to changing velocities in the area between source and receiver. A comparison of the results from coda wave interferometry with the strain measurements of the permanent monitoring system shows a correlation between strain measurements and CWI results. We discuss the challenges of changing environmental conditions, pose for interpretation of the results, and highlight the advantages of embedded versus externally attached ultrasonic transducers in permanent bridge monitoring, especially when coda wave interferometry is applied. T2 - EWSHM 2022 CY - Palermo, Italy DA - 04.07.2022 KW - Bridge monitoring KW - Ultrasound KW - Embedded sensors KW - Coda wave interferometry PY - 2022 AN - OPUS4-55383 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Epple, Niklas A1 - Fontoura Barroso, Daniel A1 - Niederleithinger, Ernst A1 - Hindersmann, I. A1 - Sodeikat, C. A1 - Groschup, R. ED - Rizzo, P. ED - Milazzo, A. T1 - From the Lab to the Structure: Monitoring of a German Road Bridge Using Embedded Ultrasonic Transducers and Coda Waves N2 - The ‘Gänstorbrücke’ bridge between the cities of Ulm and Neu-Ulm is one of the best-monitored bridges all over Germany. In addition to an already active bride monitoring system, we have equipped the bridge with 30 ultrasonic transducers to explore the monitoring possibilities at an in-service large-scale reinforced concrete structure with continuous active ultrasonic measurements. The monitoring system is based on the detection of small changes in the entire signal, especially the multiply scattered parts of the recording, the so-called coda. Applying Coda Wave Interferometry (CWI), subtle changes in the signal can be detected and related to changing velocities in the area between source and receiver. A comparison of the results from coda wave interferometry with the strain measurements of the permanent monitoring system shows a correlation between strain measurements and CWI results. We discuss the challenges of changing environmental conditions, pose for interpretation of the results, and highlight the advantages of embedded versus externally attached ultrasonic transducers in permanent bridge monitoring, especially when coda wave interferometry is applied. KW - Bridge monitoring KW - Ultrasound KW - Embedded sensors KW - Coda wave interferometry PY - 2022 SN - 978-3-031-07258-1 DO - https://doi.org/10.1007/978-3-031-07258-1_83 VL - 254 SP - 824 EP - 832 PB - Springer Cham CY - Cham AN - OPUS4-55385 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mundra, S. A1 - Furcas, F. E. A1 - Huthwelker, T. A1 - Simon, Sebastian A1 - Borca, C. N. A1 - Provis, J. L. A1 - Gluth, Gregor T1 - Kinetics of Sulfide Oxidation in alkaline solutions studied by X-ray absorption near-edge structure spectroscopy N2 - The oxidation of sulfur in aqueous solutions is an important process in several geochemical and industrial contexts. In concrete technology, it is particularly relevant for the protection of steel reinforcement in slag cement-based concretes, as the presence of sulfides affects the passivation of the steel and corrosion initiation in the presence of chlorides. However, the knowledge about the kinetics of sulfide oxidation in alkaline solutions, such as concrete pore solutions, is incomplete. To address this issue, we prepared solutions with 0.80 M NaOH, and nominally 10, 100 and 350 mM HS−, respectively, and followed the evolution of the sulfur species during bubbling with oxygen-containing gas (concentration 100% or 22%) using X-ray absorption near-edge structure (XANES) spectroscopy at the sulfur K-edge. Polysulfide, thiosulfate, sulfite and sulfate were identified and quantified via linear combination fitting of the spectra, using previously measured standards. A preliminary analysis of the results shows that the initial rate constant of sulfide oxidation depends strongly on the HS− concentration, while it less strongly depending on the oxygen concentration, in line with previous results for lower pH values. Approaches to fit the data to obtain the rate constants of all relevant reactions will be discussed. T2 - 41st Cement & Concrete Science Conference CY - Leeds, Great Britain DA - 12.09.2022 KW - XANES KW - Sulfide oxidation KW - Kinetics PY - 2022 SP - 1 EP - 3 PB - Institute of Materials, Minerals & Mining (IOM3) AN - OPUS4-55650 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph A1 - Stoljarova, A. A1 - Regenspurg, S. T1 - Influence of brine components on materials performance in geothermal applications N2 - Significant Cu-deposition and ‑precipitation only occurred in combination with carbon steel. High-alloyed materials prevent the disturbing Cu-agglomeration. Pb-deposition and ‑precipitation only occurred in combination with carbon steel. No negative Pb-effect could be observed in combination with high-alloyed steels. High alloyed corrosion resistant alloys are suitable and shall be chosen for future design of the piping system, either in massive or in cladded form, if formation of crevices with non-metallic materials can be excluded! T2 - EUROCORR 2022 CY - Berlin, Germany DA - 28.08.2022 KW - Corrosion KW - Geothermal KW - Copper PY - 2022 AN - OPUS4-55624 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liao, Chun-Man A1 - Hicke, Konstantin A1 - Bernauer, F. A1 - Igel, H. A1 - Hadziioannou, C. A1 - Niederleithinger, Ernst ED - Isecke, B. ED - Krieger, J. T1 - Multi-Sensor measurements on a large-scale bridge model N2 - This contribution introduces an investigation of a large-scale prestressed concrete bridge model (“BLEIB” structure at the BAM-TTS open air test site) by means of on-site cooperative measurements. This bridge has an external post-tensioning system and has been instrumented with the ultrasonic transducers, temperature sensors and optical fibers for Distributed Acoustic Sensing (DAS). Our experiment was designed to test the suitability of the novel 6C sensors developed within the framework of the GIOTTO project – the IMU50. The IMU50 sensor enables vibration measurements in translation along three axes and rotation around three axes. The geophone sensors were considered for complementary measurements of vertical velocity response. In the experiment, several perturbations were achieved by controlling the external influence factors such as loading and prestressing changes. The aim of the integrated measurement strategy was to fully observe the results of the condition change and to verify the effectiveness of multiple sensors for bridge monitoring. T2 - 5. Brückenkolloquium CY - Ostfildern, Germany DA - 06.09.2022 KW - Concrete KW - Bridge KW - Monitoring KW - Rotation KW - Distributed acoustic sensing PY - 2022 SN - 978-3-8169-3549-0 SP - 223 EP - 230 PB - Expert Verlag CY - Tübingen AN - OPUS4-55625 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -