TY - CONF A1 - Richter, Matthias A1 - Horn, Wolfgang A1 - Jann, Oliver A1 - Juritsch, Elevtheria A1 - Klinge, A. A1 - Roswag, E. A1 - Fontana, Patrick A1 - Miccoli, Lorenzo T1 - Indoor air emission tests of natural materials N2 - Emissions of building materials might have negative impact on human health and well-being. In the EU-funded research project H-House more than 30 natural materials (earthen dry boards and plasters, bio-based insulation materials made of wood, flax, reed, straw, etc.) used for renovation and refurbishment were tested regarding emissions of VOC, formaldehyde and radon. Different to ordinary emission tests on single materials this study focuses on the emissions from complete wall assemblies. Therefore, specially designed test chambers were used allowing the compounds to release only from the surface of the material facing indoors. The testing parameters were chosen in order to simulate model room conditions. The emission results were finally evaluated using the AgBB evaluation scheme, a procedure currently applied for the approval of flooring materials in Germany. T2 - 1st ICBBM - International conference on bio-based building materials CY - Clermont-Ferrand, France DA - 22.06.2015 KW - Emission testing KW - Natural materials KW - VOC KW - Formaldehyde KW - Radon PY - 2015 SN - 978-2-35158-154-4 SP - 641 EP - 643 AN - OPUS4-33609 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pirskawetz, Stephan A1 - Weise, Frank A1 - Fontana, Patrick ED - van Breugel, K. ED - Ye, G. ED - Sun, W. ED - Miao, C. T1 - Analysis of early-age cracking of cementitious materials by combination of various non destructive testing methods N2 - High performance concrete shows high proneness to autogenous shrinkage and micro cracking due to the low water-binder-ratio and high content of microsilica. An internal restraint of the shrinkage caused by aggregate and reinforcement presence, or the external restraint due to adjacent structural members, causes high tensile stress development in the concrete matrix. The commonly used existing measurement methods enable characterization of the degree of damage only at discrete points in time. The ongoing research work presented in this paper looks into combining the acoustic emission and ultrasonic measurements with the existing experimental techniques (such as shrinkage, tensile strength development, etc.) to potentially better illustrate crack formation in cementitious matrix. T2 - 2nd International conference on microstructural-related durability of cementitious composites CY - Amsterdam, The Netherlands DA - 11.04.2012 KW - Self-desiccation shrinkage KW - Nondestructive testing KW - Acoustic emission KW - Microcracking PY - 2012 SN - 978-2-35158-129-2 IS - 83 SP - 1 EP - 10 AN - OPUS4-25769 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mishurova, Tatiana A1 - Rachmatulin, Natalia A1 - Fontana, Patrick A1 - Oesch, Tyler A1 - Bruno, Giovanni A1 - Radi, E. A1 - Sevostianov, I. T1 - Evaluation of the probability density of inhomogeneous fiber orientations by computed tomography and its application to the calculation of the effective properties of a fiber-reinforced composite N2 - This paper focuses on the experimental evaluation of one of the key microstructural Parameters of a short-fiber reinforced composite – the orientation distribution of fibers. It is shown that computed tomography (CT) produces results suitable for reconstruction of the orientation distribution function. This function is used for calculation of the effective elastic properties of polymer-fiber reinforced concrete. Explicit formulas are derived for overall elastic moduli accounting for orientation distribution in the frameworks of the noninteraction approximation, the Mori–Tanaka–Benveniste scheme, and the Maxwell scheme. The approach illustrated can be applied to any kind of composite material. KW - Computed tomography KW - Orientation distribution KW - Effective properties KW - Fiber-reinforced composite PY - 2018 DO - https://doi.org/10.1016/j.ijengsci.2017.10.002 SN - 0020-7225 SN - 1879-2197 VL - 122 SP - 14 EP - 29 PB - Elsevier AN - OPUS4-42814 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mishurova, Tatiana A1 - Léonard, Fabien A1 - Oesch, Tyler A1 - Meinel, Dietmar A1 - Bruno, Giovanni A1 - Rachmatulin, Natalia A1 - Fontana, Patrick A1 - Sevostianov, I. T1 - Evaluation of fiber orientation in a composite and its effect on material behavior N2 - The reinforcement of concrete with polymer fibers provides resistance to crack formation. The orientation distribution of these fibers has a significant influence on the mechanical behavior of the material. To optimize material performance, micromechanical models that are capable of making accurate predictions of the mechanical behavior of composite materials are needed. These models must be calibrated using experimental results from microstructural characterization. For the fiber orientation distribution analysis in the present study, computed tomography (CT) data were used to evaluate the properties of a fiber-reinforced cement mortar. The results have indicated that the fibers in this material have highly anisotropic orientation characteristics and that there is a clear tendency for the polymer fibers to agglomerate during mixing and casting. The incorporation of this experimental data into micromechanical models will increase the accuracy of those models for material simulation and optimization. T2 - 7th Conference on Industrial Computed Tomography (iCT 2017) CY - Leuven, Belgium DA - 07.02.2017 KW - Orientation distribution KW - Fiber-reinforced concrete KW - Computed tomography PY - 2017 UR - http://www.ndt.net/?id=20818 SN - 1435-4934 VL - 22 IS - 3 SP - 1 EP - 7 PB - NDT.net CY - Kirchwald AN - OPUS4-39338 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Paul, Astrid A1 - Fontana, Patrick A1 - Ziegert, Christof ED - Priebe, Nsesheye Susan ED - Schmidt, Wolfram T1 - Earthen panels - Quality control for an industrially prefabricated building component made of natural raw materials N2 - In the past few years, the share of earthen building materials used in constructions in Central Europe has increased. That is due to growing acknowledgement of its qualities regarding balancing of humidity, absorption of odours and acoustical insulation. To regulate these (mostly indoor) uses, the German Institute for Standardization (DIN) has published norms for adobe, earth mortar for masonry and earth plaster. In addition to these traditional building materials, earthen panels have been developed. As an ecological alternative to gypsum plaster boards, they combine climatic advantages of traditional materials with economic advantages of industrial processing, i.e. prefabrication and drywall techniques. Earthen panels are a composite layered material, comparable to Textile Reinforced Concrete (TRC). Most products contain an inner layer of reed tubes which improve the tensile strength and reduce the weight. Often, one or both surfaces are reinforced with a fibrous net to prevent cracks in the plastering that is usually applied on top. Additives range from straw to expanded clay. Special panels contain waxes that improve their heat storage capacity or water pipes to allow the usage as flat heating and cooling systems. T2 - 1st Symposium on Knowledge Exchange for Young Scientists (KEYS) CY - Dar es Salaam, Tanzania DA - 09.06.2015 KW - Earthen panel KW - Quality control KW - Industrial prefabrication KW - Building component KW - Natural raw material PY - 2015 SN - 978-3-9817149-3-7 N1 - Geburtsname von Priebe, Nsesheye Susan: Msinjili, N. S. - Birth name of Priebe, Nsesheye Susan: Msinjili, N. S. SP - 189 EP - 192 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-36857 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Meng, Birgit A1 - Fontana, Patrick A1 - Müller, U. A1 - Bürgisser, P. ED - Uzoegbo, H.C. ED - Schmidt, Wolfram T1 - Influence of natural pozzolans on the risk of alkali silica reaction N2 - Industrial byproducts and natural pozzolanas are increasingly being used as supplementary cementitious materials. In the group of natural pozzolanas volcanic ashes are the most prominent. Despite the fact that volcanic pozzolanas were used since Roman times, not much is known about their role in influencing the long term durability of concrete. The paper presents results of the volcanic pozzolana ‘Rhenish trass’, which is quarried in western Germany and its role during an alkali silica reaction (ASR). Field data and laboratory experiments indicate that trass releases alkalis into the pore solution but also changes cement paste chemistry and alkali binding behavior. There seems to be a sensitive balance between alkali release and increase of alkali binding capacity, both mechanisms crucial for the course of an ASR in concrete. T2 - ACCTA - International conference on advances in cement and concrete technology in Africa 2013 CY - Johannesburg, South Africa DA - 28.01.2013 KW - Alkali silica reaction KW - Natural pozzolans KW - Microscopy KW - Micro chemical analysis PY - 2013 SN - 978-3-9815360-3-4 SP - 801 EP - 808 AN - OPUS4-27765 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Miccoli, Lorenzo A1 - Perrone, C. A1 - Fontana, Patrick A1 - Müller, Urs A1 - Ziegert, C. T1 - Charakterisierung und Modellierung der mechanischen Eigenschaften von Lehmsteinmauerwerk / Mechanical characterization and modelling of earth block masonry N2 - Das Wissen über die Materialeigenschaften und die Versagensmechanismen bei Lehmbaustoffen ist begrenzt und lückenhaft. Im Rahmen des EU-Projekts NIKER (www.niker.eu) wurden deshalb die mechanischen Eigenschaften von Bauteilen aus Lehm unter statischer Druck- und Schubbeanspruchung bestimmt. Ziel der Untersuchungen war es, grundlegende Daten zum Verformungs- und Versagensverhalten von Lehmbauteilen zu erhalten und dieses mit einem numerischen Modell zu beschreiben. Die Versuchsergebnisse belegten das spröde Verhalten von Lehmsteinmauerwerk bei uniaxialer Druckbelastung und zeigten, dass das Versagen von Lehmsteinmauerwerk infolge Schubbelastung nach Erstrissbildung in Mörtelfugen und Lehmsteinen durch Gleiten der Lehmsteine entlang der Mörtelfugen erfolgt. Die numerische Makromodellierung erbrachte zwar befriedigende Resultate hinsichtlich des Spannungs-Dehnungs-Verhaltens, jedoch konnte bei der simulierten Rissbildung keine Übereinstimmung mit den in den Versuchen beobachteten Rissbildern erzielt werden. Bei Lehmsteinmauerwerk ist also eine wesentlich aufwendigere Mikromodellierung notwendig, um das Versagensverhalten korrekt beschreiben zu können.-------------------------------------------------------------------------------------------------------------- Knowledge of the material properties and failure mechanisms of earthen materials is limited and scattered. Within the framework of the NIKER project (www.niker.eu) funded by EC, the mechanical properties of earthen material elements were therefore determined under static compression and shear loads. The aim was to obtain fundamental data on deformation behaviour and failure mechanisms of earthen material structural elements and to describe them by means of a numerical model. The test results confirmed the brittle behaviour of earth block masonry under monoaxial compressive load and showed that the failure of earth block masonry under shear load occurs by sliding of the earth blocks along the mortar joints after initial cracking in mortar joints and earth block. Numerical macro modelling showed satisfying results with regard to stress-strain behaviour, but the simulated crack pattern was not consistent with experimental observations. In the case of earth block masonry, it is thus necessary to use micro modelling approaches in order to correctly predict the failure process at local level. KW - Lehmstein Mauerwerk KW - Druckversuche KW - Schubversuche KW - F.E.M. Modellierung PY - 2012 DO - https://doi.org/10.1002/dama.201200555 SN - 1432-3427 SN - 1437-1022 N1 - Sprachen: Deutsch/Englisch - Languages: German/English VL - 16 IS - 6 SP - 279 EP - 292 PB - Ernst CY - Berlin AN - OPUS4-27589 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -