TY - JOUR A1 - Fürst, Richard A1 - Fürst, E. A1 - Vlach, T. A1 - Repka, J. A1 - Pokorny, M. A1 - Mozer, V. T1 - Use of Cement Suspension as an Alternative Matrix Material for Textile-Reinforced Concrete N2 - Textile-reinforced concrete (TRC) is a material consisting of high-performance concrete (HPC) and tensile reinforcement comprised of carbon roving with epoxy resin matrix. However, the problem of low epoxy resin resistance at higher temperatures persists. In this work, an alternative to the epoxy resin matrix, a non-combustible cement suspension (cement milk) which has proven stability at elevated temperatures, was evaluated. In the first part of the work, microscopic research was carried out to determine the distribution of particle sizes in the cement suspension. Subsequently, five series of plate samples differing in the type of cement and the method of textile reinforcement saturation were designed and prepared. Mechanical experiments (four-point bending tests) were carried out to verify the properties of each sample type. It was found that the highest efficiency of carbon roving saturation was achieved by using finer ground cement (CEM 52.5) and the pressure saturation method. Moreover, this solution also exhibited the best results in the four-point bending test. Finally, the use of CEM 52.5 in the cement matrix appears to be a feasible variant for TRC constructions that could overcome problems with its low temperature resistance. KW - Textile-reinforced concrete KW - High-performance concrete KW - Carbon fibers KW - Cement matrix PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-527100 DO - https://doi.org/10.3390/ma14092127 SN - 1996-1944 VL - 14 IS - 9 SP - 2127 PB - MDPI CY - Basel AN - OPUS4-52710 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fürst, Richard A1 - Hejtmanek, P. A1 - Vlach, T. A1 - Repka, J. A1 - Mozer, V. A1 - Hajek, P. T1 - Experimental Evaluation of Carbon Reinforced TRC with Cement Suspension Matrix at Elevated Temperature N2 - Textile-reinforced concrete (TRC) is a new composite material comprising high-performance concrete and textile reinforcement from textile yarns with a matrix, usually consisting of epoxy resins (ER). The most significant advantage of ER is the homogenization of all filaments in the yarn and full utilization of its tensile potential. Nevertheless, ER matrix is a critical part of TRC design from the perspective of the fire resistance due to its relatively low resistance at temperatures of approximately 120 C. This work expands the previously performed mechanical tests at normal temperatures with cement suspension (CS) as a non-combustible material for the yarn matrix. Here, the mechanical properties of CS matrix at elevated temperatures were verified. It was found that the addition of polypropylene fibers into HPC negatively affected the mechanical results of CS matrix specimens. Simultaneously, thermal insulation effect of the covering layers with different thicknesses did not significantly influence the residual bending strength of specimens with CS matrix and achieved similar results as reference specimens. Furthermore, all specimens with ER matrix progressively collapsed. Finally, CS as a textile reinforcement of yarn matrix appears to be a suitable solution for increasing the temperature resistance of TRC structures and for substituting synthetic resins. KW - Cement matrix KW - Cement suspension KW - Carbon fibers KW - Textile reinforced concrete KW - High-performance concrete KW - Elevated temperature KW - Fire safety KW - Fire resistance PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-550766 DO - https://doi.org/10.3390/polym14112174 SN - 2073-4360 VL - 14 IS - 11 SP - 1 EP - 16 PB - MDPI CY - Basel, Switzerland AN - OPUS4-55076 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fürst, Richard A1 - Häßler, Dustin A1 - Hothan, Sascha T1 - Influence of the profile type and bar orientation on the performance of intumescent coatings applied to steel tension bars N2 - Intumescent coatings are commonly used in civil engineering to improve the fire resistance of steel constructions. Especially in the case of tension bars, where mostly circular or rectangular solid sections are used, intumescent coatings offer an efficient measure to improve the fire resistance taking advantage of profile-following application and low coating thickness requirements. Thus, the architectural appearance of slender profiles can be preserved. The paper describes real-scale mechanically loaded and unloaded fire tests of circular and rectangular solid steel tension bars with intumescent coating. The aim of these tests is to investigate the influence of the different profile types as well as different bar orientations on the performance of intumescent coatings. The results are used to specify a normative test and assessment procedure to be implemented in a new European standard for determining the contribution of intumescent coatings to the fire resistance of circular or rectangular bars used as tension members. KW - Fire test KW - Intumescent coating KW - Steel tension member KW - Fire resistance PY - 2022 DO - https://doi.org/10.1016/j.firesaf.2022.103678 SN - 0379-7112 VL - 134 SP - 1 EP - 14 PB - Elsevier CY - Amsterdam AN - OPUS4-56172 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fürst, Richard A1 - Mózer, V. A1 - Pokorný, M. A1 - Vlach, T. T1 - Nosné konstrukce z textilního betonu za zvýšené teploty T1 - Loadbearing structures made from textile reinforced concrete at elevated temperatures N2 - The work aims to assess the textile reinforced concrete at elevated temperatures and applications of additional fire protection as well. T2 - Fire Protection Conference CY - Ostrava, Czechia DA - 01.09.2021 KW - High Performance Concrete KW - Textile reinforcement KW - Fire test PY - 2021 SN - 978-80-7385-247-4 SP - 10 EP - 12 PB - Sdružení požárního a bezpečnostního inženýrství CY - Ostrava AN - OPUS4-53509 LA - ces AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fürst, Richard T1 - Nosné konstrukce z textilního betonu za zvýšené teploty T1 - Loadbearing structures made from textile reinforced concrete at elevated temperatures N2 - The work aims to assess the textile reinforced concrete at elevated temperatures and applications of additional fire protection as well. T2 - Fire Protection Conference CY - Ostrava, Czech Republic DA - 01.09.2021 KW - Fire test KW - High Performance Concrete KW - Textile reinforcement PY - 2021 AN - OPUS4-53510 LA - ces AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fürst, Richard A1 - Vlach, T. A1 - Pokorny, M. A1 - Mozer, V. T1 - Study of Behavior of Textile-Reinforced Concrete with Epoxy Resin Matrix in Fire N2 - Textile-reinforced concrete is currently most frequently used for non-load–bearing structures, but there is a vision for also using it in load–bearing construction elements. In recent years, this construction material has been subjected to detailed examination. Different combinations of materials for potential use in textile-reinforced concrete have been described. These differ in the type of concrete mix and the composition of the textile reinforcement. The aim of this work is to test the application of a specific textile-reinforced concrete, consisting of high-performance concrete, textile reinforcement from carbon fibers and its epoxy resin matrix, at an elevated temperature. The combination of these materials makes it possible to produce subtle load–bearing structures with excellent mechanical properties. The critical issue is the behavior of these structures when exposed to fire. A series of medium-scale fire condition experiments were carried out with a temperature load based on the ISO 834 curve, followed up by mechanical tests. The aim of these experiments was to describe critical areas of textile-reinforced concrete in fire and to propose possible solutions. In an indicative fire experiment, experimental samples displayed massive spall of concrete layers, and interaction between materials was lost due to the low temperature resistance of the epoxy resin. Concurrently, the optimal quantity of polypropylene fibers was experimentally determined. This paper presents an experimental demonstration of the problematic aspects of textile-reinforced concrete and subsequent recommendations for future work with practical application in the design of load–bearing structures. KW - Textile-reinforced concrete KW - High-performance concrete KW - Carbon fibers KW - Epoxy resin KW - Load–bearing structures KW - Fire resistance PY - 2021 DO - https://doi.org/10.1007/s10694-021-01116-y SN - 1572-8099 SN - 0015-2684 SP - 1 EP - 22 PB - Springer AN - OPUS4-52712 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 - Fürst, Richard A1 - Häßler, Dustin A1 - Hothan, Sascha T1 - European test standard for intumescent coatings applied to steel tension bars with solid section N2 - Description of the FIRESTEMIC project and the newly developed test standard for reactive fire protection systems on steel tension members. T2 - Symposium 2022 Heißbemessung - Structural Fire Engineering CY - Brunswick, Germany DA - 13.09.2022 KW - Fire tests KW - Tension member KW - Intumescent coating KW - Steel KW - Test standard PY - 2022 AN - OPUS4-55702 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fürst, Richard A1 - Häßler, Dustin A1 - Peter, A. A1 - Rohleder, R. A1 - Hothan, Sascha T1 - European test standard intumescent coatings applied to steel tension bars with solid section N2 - Intumescent coatings are used in civil engineering to improve the fire resistance of steel constructions. Due to the thin coating thickness and the profile-following application, the architectural appearance of the steel structure can be preserved. EN 13381-8 provides regulations to determine the contribution to the fire resistance of intumescent coatings applied to steel beams and columns. The scope of this standard excludes tension members and steel members with solid sections. For products that have already been successfully tested and assessed on beams and columns, EN 13381-10 offers the possibility based on unloaded fire tests to extend the scope of application of intumescent coatings to tension bars with solid sections. This approach contradicts the national safety level in Germany, where mechanically loaded testing is mandatory. Therefore, a new part of the test standard series EN 13381 is currently developed to enable the application of intumescent coatings on steel tension bars with solid section based on mechanically loaded fire tests. BAM has already carried out numerous fire tests on loaded steel tension members with intumescent coatings. Currently, in the BAM research project FIRESTEMIC, the influence of the steel bar orientation and the profile type on the thermal performance of intumescent coatings are investigated. Both questions concerning the thermal protection ability of intumescent coatings were analysed based on three different test sets, which were carried out in the tension furnace (Fig. 1a). The fire exposure corresponds to the standard temperature-time curve according to EN 1363-1. This paper summarises the main findings from the fire tests conducted in the FIRESTEMIC project. The results serve as an experimental background for the proposal of the new standard. Regarding the bar orientation, a new test setup was developed and proposed for the new standard. The two tested commercial water-based intumescent coatings with applied dry film thickness from 1.5 mm to 2.5 mm showed only a slight dependence on the bar orientation. In terms of the steel profile type, circular and rectangular solid sections with identical section factor and applied dry film thickness were tested. It was observed that the circular solid bars with diameter 30 mm heat up faster compared to the solid rectangular bars with dimension 30×30 mm (Fig. 1b). Also at larger steel bars, i.e. diameter 40 mm and dimension 40×40 mm, the same trend occurred. Thus, it is recommended for the new test standard to allow a transfer of the test results from circular to rectangular solid sections. In addition, the paper will describe and explain the test and assessment procedure proposed for the newly developed standard. T2 - 8th Symposium Structural Fire Engineering CY - Brunswick, Germany DA - 13.09.2022 KW - Fire test KW - Steel KW - Tension member KW - Intumescent coating KW - Test standard PY - 2022 SP - 1 EP - 14 PB - TU Braunschweig CY - Braunschweig AN - OPUS4-55703 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Hothan, Sascha A1 - Häßler, Dustin A1 - Fürst, Richard A1 - Peter, A. A1 - Wöhr, M. A1 - Rohleder, R. T1 - Entwicklung einer europäischen Prüfnorm zur Bestimmung des Feuerwiderstands von Stahlzuggliedern mit reaktiver Brandschutzbeschichtung anhand belasteter Brandprüfungen T1 - Development of a European test standard for the determination of the fire resistance of steel tension members with intumescent fire protection coating based on loaded fire tests N2 - Ziel des Forschungsvorhabens ist es, ein standardisiertes Prüf- und Bewertungsverfahren zur Bestimmung des Beitrags reaktiver Brandschutzsysteme (RBS) zum Feuerwiderstand von Stahlzuggliedern zu erarbeiten und dieses in ein Entwurfsdokument für eine europäische Prüfnorm zu überführen. Hierzu wurden einerseits bereits vorhandene Erfahrungen und Erkenntnisse genutzt und andererseits mittels Brandversuchen neue Prüfdaten zur Beantwortung bisher offengebliebener Aspekte zum Einfluss der Bauteilorientierung und Profilart erzeugt und ausgewertet. Dadurch wird die prüftechnische Grundlage für eine sichere, zulassungsbasierte Anwendung von reaktiven Brandschutzsystemen auf zugbeanspruchten Stahlbauteilen gelegt und ein einheitliches Sicherheitsniveau etabliert. Der im Rahmen des Forschungsprojektes entwickelte Normentwurf wurde mit den Fachexperten der zuständigen nationalen und europäischen Normungsgremien diskutiert und abgestimmt. Das erarbeitete Prüf- und Auswertungsverfahren basiert auf der Durchführung von Brandversuchen an mechanisch belasteten Stahlzuggliedern mit RBS. Ergänzend sind unbelastete Brandversuche zur Beurteilung des Einflusses der Bauteilorientierung sowie der Eignung bei Schwelbrandbeanspruchung möglich. Die im Projekt durchgeführten experimentellen Untersuchungen liefern die Grundlage für den im Normenentwurf vorgeschlagenen Prüfaufbau der mechanisch belasteten und unbelasteten Brandversuche. Ferner konnte durch die Untersuchungen gezeigt werden, dass sich unter bestimmten Voraussetzungen die Prüfergebnisse von Stahlzuggliedern mit Kreisvollprofil ohne zusätzliche Brandversuche auf entsprechende Zugglieder mit Rechteckvollprofil übertragen lassen. Darüber hinaus konnte belegt werden, dass die Leistungsfähigkeit eines RBS aufgrund unterschiedlicher Bauteilorientierungen abnehmen kann und daher zwingend beim Anwendungsbereich des RBS zu berücksichtigen ist. Hierzu wird ein Temperaturdifferenz-kriterium vorgeschlagen, bei dessen Einhaltung die Wirksamkeit des RBS bei von der horizontalen Referenzorientierung abweichenden Bauteilneigungen noch gleichwertig gegeben ist. Andernfalls bietet der Normenentwurf die Möglichkeit die reduzierte thermische Schutzwirkung des RBS im Assessment zu berücksichtigen. Die Ergebnisse aus dem Forschungsvorhaben wurden bereits auf einem wissenschaftlichen Symposium vorgestellt sowie in einer referierten Fachzeitschrift publiziert. Ferner wurden die Informationen zum Forschungsprojekt und dem Normenentwurf im Rahmen eines Anwenderworkshops interessierten Kreisen zugänglich gemacht. Der im Projekt ausgearbeitete Normenentwurf wird dem zuständigen europäischen Normungsgremien, CEN/TC 127/WG 1, zur Verfügung gestellt und dort zur Abstimmung gestellt. KW - Normung KW - Reaktives Brandschutzsystem KW - Stahl KW - Zugglied KW - Feuerwiderstand KW - Brandversuche PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-569363 SP - 1 EP - 57 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-56936 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -