TY - JOUR A1 - Bock, Hans Michael A1 - Korzen, Manfred T1 - Brandschutztechnische Ertüchtigung von Stahlverbundhohlprofilstützen - Bericht über die "Proving Trials" an einem europäischen Prüfverfahren JF - Beiträge zum Forschungs-Kolloquium des Deutschen Ausschusses für Stahlbeton T2 - Beiträge zum 33. Forschungskolloquium CY - Berlin, BAM, Deutschland DA - 1996-10-10 PY - 1996 VL - 33 SP - 62 EP - 71 PB - Dt. Ausschuss für Stahlbeton im DIN CY - Berlin AN - OPUS4-12023 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Correia, A.M. A1 - Rodrigues, J.P.C. A1 - Korzen, Manfred T1 - Experimental research on the load-bearing capacity of partially encased steel columns under fire conditons JF - Journal of structural fire engineering N2 - The composite steel and concrete columns are known to have enhanced fire behaviour when compared with bare steel columns. However there are still aspects that must be clarified, as the influence of the building surrounding structure on the fire resistance of the columns. In this paper, the results of fire resistance tests on partially encased steel columns carried out with two different experimental systems are compared. In one of the experimental systems, the building surrounding structure is materialised by a steel restraining frame, and in the other is performed by the so-called substructuring method. Due to the concept of hybrid substructuring, the entire building is decomposed in two parts: one is represented by the building element under test, whereas the remaining building is simulated numerically in a computer. The main conclusion drawn from this work was that the surrounding structure has a major influence in the development of axial forces in the test columns. Moreover, it was observed that the higher the non-dimensional axial restraint ratio the lower the critical time of the columns. KW - Fire resistance KW - Thermal restraint KW - Composite steel-concrete columns KW - Substructuring method KW - Restraining frame PY - 2012 DO - https://doi.org/10.1260/2040-2317.3.1.81 SN - 2040-2317 VL - 3 IS - 1 SP - 81 EP - 94 PB - Multi-Science Publ. Co. CY - Brentwood AN - OPUS4-25632 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Daus, Lars-Hendrik A1 - Schartel, Bernhard A1 - Wachtendorf, Volker A1 - Mangelsdorf, R. A1 - Korzen, Manfred T1 - A chain is no stronger than its weakest link: Weathering resistance of water-based intumescent coatings for steel applications JF - Journal of Fire Sciences N2 - A systematic approach was used to investigate the weathering-induced degradation of a common water–based intumescent coating. In this study, the coatings are intended for humid indoor applications on steel substrates. The coating contains ammonium polyphosphate, pentaerythritol, melamine, and polyvinyl acetate. By replacing each ingredient with a less water-soluble substance, the most vulnerable substances, polyvinyl acetate and pentaerythritol, were identified. Furthermore, the weathering resistance of the system was improved by exchanging the ingredients. The coatings were stressed by artificial weathering tests and evaluated by fire tests. Thermogravimetry and Fourier-transform infrared spectroscopy were used to study the thermal decomposition. This study lays the foundation for the development of a new generation of water-based intumescent coatings. KW - Intumescence KW - Fire resistance KW - Fire protective coatings KW - Weathering KW - Thermogravimetric analyses PY - 2021 DO - https://doi.org/10.1177/0734904120961064 SN - 0734-9041 SN - 1530-8049 VL - 39 IS - 1 SP - 72 EP - 102 PB - SAGE AN - OPUS4-52015 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Huismann, Sven A1 - Korzen, Manfred A1 - Rogge, Andreas T1 - Entwicklung und Validierung eines allgemeinen Rechenverfahrens für Stahlbetonstützen aus hochfestem Beton unter Brandbeanspruchung JF - Beton- und Stahlbetonbau N2 - Ausgehend von einer kritischen Analyse der Materialkennwerte für normalfesten (NFB) und hochfesten Beton (HFB) im Eurocode 2 wurden in grundlegenden Untersuchungen an der BAM exemplarisch für einen HFB die thermomechanischen Materialkennwerte bestimmt, um auf der Basis eines geeigneten Materialmodells das Verhalten von Stahlbetonstützen aus HFB unter Brandbeanspruchung zu simulieren. Die Validierung des Modells erfolgte mittels großmaßstäblicher Brandversuche an belasteten Stahlbetonstützen aus dem gleichen HFB wie in den Materialuntersuchungen. Es konnte gezeigt werden, dass die Festigkeit als charakteristischer Parameter des Materialmodells zwingend auf der Basis instationärer Versuche – und nicht aus stationären Versuchen wie bei NFB üblich – bestimmt werden muss. Mit den in vorgeschlagenen Materialbeziehungen für HFB wird das Tragverhalten der untersuchten Stützen dagegen deutlich überschätzt, was sich in den numerischen Simulationen insbesondere durch zu geringe Verformungen äußert.------------------------------------------------------------------------------------------------------ Development and Validation of an Advanced Calculation Model for High Strength Concrete Columns Subjected to Fire Loading Following a critical analysis of the material parameters of normal strength (NSC) and high strength concrete (HSC) presented in Eurocode 2 the thermo-mechanical material parameters of one representative HSC were identified. Using these parameters and based on an appropriate material model the behavior of HSC columns was simulated. The validation of the model was realized through real scale fire resistance tests on loaded columns of the same type of HSC as in the material identification tests. It was found that the strength as a characteristic parameter of the material model has to be identified on the basis of transient creep tests and not of stationary tests, respectively as realized usually for NSC. It could be shown that the structural behavior of the tested columns is overestimated if the numerical simulations are based on the material properties of HSC as proposed in. This feature is expressed especially through insufficient displacements. KW - Brandschutz KW - Verformungsverhalten KW - Hochleistungsbeton KW - Nichtlineare Berechnungsverfahren KW - Modellierung KW - EC KW - Eurocode KW - Normen KW - Berechnungs- und Bemessungsverfahren KW - Normen/Vorschriften/Richtlinien KW - Brandschutz KW - Versuche KW - Eurocode KW - Hochfester Beton KW - Feuerwiderstandsdauer KW - Finite-Elemente-Methode PY - 2012 DO - https://doi.org/10.1002/best.201200010 SN - 0005-9900 SN - 1437-1006 VL - 107 IS - 6 SP - 372 EP - 378 PB - Ernst CY - Berlin AN - OPUS4-26100 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hörold, Andreas A1 - Schartel, Bernhard A1 - Trappe, Volker A1 - Gettwert, V. A1 - Korzen, Manfred T1 - Protecting the structural integrity of composites in fire: Intumescent coatings in the intermediate scale JF - Journal of reinforced plastics and composites N2 - The fire behaviour of light-weight material used in structural applications is regarded as the main challenge to be solved for mass transportation. The task is to perform realistic experiments, including a mechanical test scenario under fully developed fires, to improve the material's reliability in structural applications. Our approach utilises an intermediate-scale test set-up (specimen size 500 × 500 mm) to apply realistic compressive loads and fully developed fires directly to one side of a carbon-fibre-reinforced sandwich composite. Three different intumescent coatings were applied to sandwich structures and compared to a bench-scale study. The results emphasise intumescent coatings as a promising method to sustain fire resistance, multiplying the time to failure. Nevertheless, the realistic intermediate-scale test using severe direct flame application underlines the extremely short failure times when the actual composite components are tested without any additional insulation. KW - Carbon-fibre-reinforced KW - Fire stability KW - High-temperature properties KW - Mechanical testing KW - Fully developed fire KW - Post-crash scenario PY - 2015 DO - https://doi.org/10.1177/0731684415609791 SN - 0731-6844 SN - 1530-7964 VL - 34 IS - 24 SP - 2029 EP - 2044 PB - Technomic Publ. Co. CY - Westport, Conn. AN - OPUS4-35120 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hörold, Andreas A1 - Schartel, Bernhard A1 - Trappe, Volker A1 - Korzen, Manfred A1 - Bünker, J. T1 - Fire stability of glass-fibre sandwich panels: The influence of core materials and flame retardants JF - Composite Structures N2 - Fire resistance has become a key property for structural lightweight sandwich components in aviation, shipping, railway vehicles, and construction. The development of future composite materials and components demands adequate test procedures for simultaneous application of compression and fully developed fire. Therefore an intermediate-scale approach (specimen size = 500 mm x 500 mm) is applied with compressive loads (up to 1 MN) and direct application of a burner to one side of the specimens, as established in aviation for severe burn-through tests. The influence of different core structures (polyvinylchloride foam, polyisocyanorate foam reinforced by stitched glass bridges, and balsa wood) was investigated for glass-fibre-reinforced sandwich specimens with and without flame retardants applied on the fabrics, in the matrix, and on surface for each specimen at the same time. Times to failure were increased up to a factor of 4. The intumescent coating prolongs the time to failure significantly. What is more, using the intrinsic potential of the front skin together with the core to protect a load bearing back skin in sandwich panels, the design of the core – here using the wood core – is the most promising approach. KW - Fire resistance KW - Fire stability KW - Glass-fibre-reinforced plastics KW - Composite KW - Core materials PY - 2017 DO - https://doi.org/10.1016/j.compstruct.2016.11.027 SN - 0263-8223 SN - 1879-1085 VL - 160 SP - 1310 EP - 1318 PB - Elsevier AN - OPUS4-38622 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hörold, Andreas A1 - Schartel, Bernhard A1 - Trappe, Volker A1 - Korzen, Manfred A1 - Naumann, Maurice T1 - Structural integrity of sandwich structures in fire: an intermediate-scale approach JF - Composite interfaces N2 - A test set-up in intermediate scale was conceived to investigate the structural integrity of materials under fire. The task was to develop a realistic test scenario targeting component-like behaviour. Carbon-fibre-reinforced sandwich specimens (500 X 500 X 20 mm) were used to examine failure mechanisms, times to failure and critical failure loads under compression. Fire tests were performed with fully developed fire applied to one side of the specimen by an oil burner. In a first test series, the applied load was varied, but the fully developed fire remained unchanged. In general, times to failure were short. Decreased load levels resulted in prolonged times to failure and led to a different failure mechanism. Results obtained in the test series were compared with a bench-scale study (150 X 150 X 20 mm) investigating identical material. The comparison clearly revealed the influence of size on the time to failure and the load-bearing capacity. KW - Fire testing KW - Structural integrity KW - Carbon-fibre-reinforced plastics KW - Fully developed fire KW - Composites PY - 2013 DO - https://doi.org/10.1080/15685543.2013.816620 SN - 0927-6440 SN - 1568-5543 VL - 20 IS - 9 (Special Issue: ECCM15: Part 3) SP - 741 EP - 759 PB - VSP CY - Zeist AN - OPUS4-29647 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kamlah, M. A1 - Korzen, Manfred A1 - Tsakmakis, Ch. T1 - Uniaxial ratchetting in rate-independent plasticity laws JF - Acta mechanica PY - 1997 SN - 0001-5970 SN - 1619-6937 VL - 120 SP - 173 EP - 198 PB - Springer CY - Wien AN - OPUS4-12020 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Korzen, Manfred T1 - Experimentally observed phenomena vis-à-vis current constitutive theories JF - Res mechanica PY - 1987 SN - 0143-0084 VL - 22 SP - 171 EP - 184 PB - Applied Science Publ. Ltd. CY - Barking, Ess. AN - OPUS4-12083 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Korzen, Manfred A1 - Haupt, P. T1 - Über eine Materialgleichung vom viskoelastisch-plastischen Typ JF - Zeitschrift für angewandte Mathematik und Mechanik = Journal of applied mathematics and mechanics PY - 1988 SN - 0044-2267 SN - 0946-8463 VL - 68 IS - 4 SP - T 203 EP - T 204 PB - Wiley-VCH CY - Potsdam AN - OPUS4-12081 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -