TY - JOUR A1 - Krankenhagen, Rainer A1 - Zirker, Stefan A1 - Joniertz, Florian T1 - Determination of thermal parameters of concrete by active thermographic measurements JF - Journal of Nondestructive Evaluation 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 - Scheid, Marc A1 - Klippel, Alexander A1 - Tschirschwitz, Rico A1 - Schröder, Volkmar A1 - Zirker, Stefan A1 - Kusche, Christian ED - Makhviladze, G. ED - Molkov, V. ED - Bradley, D. ED - Sunderland, P. ED - Tamanini, F. T1 - New ignition source 'exploding wire' for the determination of explosion characteristics of combustible dusts in the 20-L sphere T2 - ISFEH7 - 7th International seminar on fire & explosion hazards (Proceedings) N2 - According to international standards several safety characteristics of dusts are determined in the 20-L sphere (also known as SIWEK-Chamber). Dust cloud ignition is carried out using pyrotechnical igniters. Due to various disadvantages of pyrotechnical igniters the need for alternative ignition sources arises again and again. An alternative ignition source could be the so-called 'exploding wire' or 'fuse wire'. The paper presents test results of a comparative study between both ignition sources for the determination of the safety characteristics Maximum Explosion Pressure and Maximum Rate of Explosion Pressure Rise of selected dusts in the 20-L sphere. In addition the propagation of flame and electrical arc was analysed by high speed camera recordings. Tests in a windowed autoclave were performed to get information on the influence of turbulence during ignition on the shape of the generated flame (electrical arc) and its propagation. Turbulence measurements with a LDA system in the windowed autoclave as well as in the 20-L sphere allowed investigation if the ignition sources led to an additional turbulence increase at the moment of ignition in comparison to tests without ignition. T2 - ISFEH7 - 7th International seminar on fire & explosion hazards CY - Providence, RI, USA DA - 05.05.2013 KW - Dust explosion testing KW - Exploding wire KW - Explosion characteristics KW - Ignition source KW - Sicherheitstechnische Kenngrößen Staub KW - Staubexplosionsschutz KW - Explodierender Draht KW - Alternative Zündquelle PY - 2013 SN - 978-981-07-5936-0 SN - 978-981-07-5940-7 DO - https://doi.org/10.3850/978-981-07-5936-0_13-04 SP - 810 EP - 819 PB - Research publishing AN - OPUS4-28553 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scheid, Marc A1 - Klippel, Alexander A1 - Tschirschwitz, Rico A1 - Schröder, Volkmar A1 - Zirker, Stefan A1 - Kusche, Christian T1 - New ignition source 'exploding wire' for the determination of explosion characteristics of combustible dusts in the 20-L-sphere T2 - GCPS 2013 - 9th Global congress on process safety (Proceedings) N2 - According to international Standards several safety characteristics of dusts are determined in the 20-L-sphere (also known as SIWEK-Chamber). Dust cloud ignition is carried out using pyrotechnical igniters. Due to various disadvantages of pyrotechnical igniters the need for alternative ignition sources arises again and again. An alternative ignition source could be the socalled “exploding wire” or “fuse wire". The paper presents test results of a comparative study between both ignition sources for the determination of the safety characteristics Maximum Explosion Pressure and Maximum Rate of Explosion Pressure Rise of selected dusts in the 20-Lsphere. In addition to that the flame/arc propagation of both ignition sources was analysed by high speed and IR camera recordings. Tests in a windowed autoclave were performed to get information on the influence of turbulence generated due to dispersion of the dust on the shape of the generated flame and its propagation. Turbulence measurements in the windowed autoclave as well as in the 20-L-sphere with a LDA System allowed investigation if the igniter led to turbulence increase at the moment of ignition in comparison to tests without ignition. T2 - GCPS 2013 - 9th Global congress on process safety CY - San Antonio, TX, USA DA - 28.04.2013 KW - Sicherheitstechnische Kenngrößen Staub KW - Staubexplosionsschutz KW - Explodierender Draht KW - Alternative Zündquelle PY - 2013 SN - 978-0-8169-1075-5 SP - 1 EP - 10 AN - OPUS4-28552 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -