TY - CONF A1 - Müller, P. A1 - Miccoli, Lorenzo A1 - Fontana, Patrick A1 - Ziegert, Ch. T1 - Partial safety factors for earth block masonry N2 - In the beginning of the 1980s earth building has undergone a renaissance, which nowadays leads to an increasing use of load-bearing earth constructions and in particular, earth block masonry. At present, there are no common structural standards according to the semi-probabilistic design concept, which is the state-of-the-art in European standards. A solid database is needed for the determination of the partial safety factor on the resistance side. Therefore, compressive strength tests were carried out with two types of earth blocks and two types of prefabricated earth mortar. The evaluation showed that the variation of the compressive strength was remarkably less than expected, which seems to indicate high quality standards of the components earth block and mortar with regard to industrial production. On the basis of these results and together with the reliability method, a partial safety factor for earth block masonry subjected to compression was determined. The main aim of the research was the development of a first valid database for material parameters of earth block masonry with particular regard to statistical characteristics. The results showed that a common calculation method for earth block masonry based on partial safety factors following the valid masonry construction standard is feasible. T2 - Terra Lyon 2016 - XIIth World Congress on Earthen Architecture CY - Lyon, France DA - 11.07.2016 KW - Safety factors KW - Earth block masonry KW - Compressive strength PY - 2016 SN - 979-10-96446-12-4 SP - 1 EP - 8 PB - Editions CRAterre CY - Villefontaine AN - OPUS4-45151 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Miccoli, Lorenzo A1 - Silva, R. A. A1 - Garofano, A. A1 - Oliveira, D. V. ED - Papadrakakis, M. ED - Fragiadakis, M. T1 - In-Plane behaviour of earthen materials: A numerical comparison between adobe masonry, rammed earth and cob N2 - The paper presents a comparison between different numerical modelling approaches aiming to simulate the in-plain behaviour of three types of earthen materials, namely adobe masonry, rammed earth and cob. For this purpose, uniaxial and diagonal compression tests were carried out, which allowed determining important mechanical parameters, such as compressive strength, Young’s modulus, Poisson’s ratio, shear strength and shear modulus. Furthermore, the tests allowed assessing the level of non-linear behaviour of the respective stress–strain relationships as well as the failure modes. The experimental results were then used for the calibration of numerical models (based on the finite element method) for simulating the non-linear behaviour of the earth materials under in-plane shear loading. Both macro- and micro-modelling approaches were considered for this purpose. The procedures adopted for model calibration established the reliability of various modelling strategies for the different loading conditions. The simplified Approach based on macromodelling shows a satisfactory accuracy and low computational costs. The results reproducing the uniaxial compression are in good correspondence with the post-elastic behaviour observed in the experimental campaign. The micro-modelling approach adopted to reproduce the shear behaviour, even with higher computational cost, represents a suitable tool to predict the adobe masonry and rammed earth collapse mechanisms. T2 - 6th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2017) CY - Rhodes, Greece DA - 15.06.2017 KW - Earthen materials KW - Compression behaviour KW - Shear behaviour KW - Digital image corelation KW - Finite element method PY - 2017 SN - 978-618-82844-1-8 VL - 1 SP - 2478 EP - 2504 AN - OPUS4-42579 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ferraioli, M. A1 - Miccoli, Lorenzo A1 - Abruzzese, D. ED - Mazzolani, F. M. ED - Lamas, A. ED - Calado, L. ED - Proenca, J. M. ED - Faggiano, B. T1 - Seismic risk assessment of the Santa Maria a Vico bell tower. Ambient vibration measurements and numerical model tuning N2 - The paper investigates the dynamic characterisation along with the numerical model tuning and the seismic risk assessment of a monumental masonry tower in Italy namely the Santa Maria a Vico bell tower. Full-scale ambient vibration tests were performed under the impact of environmental loads. The technique of modal extraction in the frequency domain was applied. In-situ investigation survey was used in calibrating the refined 3D finite element model. The FEM tuning was carried out by varying the mechanical parameters and accounting for the restraint offered by the neighbouring buildings and the role of soil–structure interaction. The paper shows that the modal identification is a reliable technique that can be used in-situ for assessing the dynamic behaviour of monumental buildings. The tuned FEM model of the tower was usefully employed to determine the theoretical fundamental frequencies, which accurately fit the experiment data. Finally, the seismic performance of the bell tower was assessed using a non-linear static procedure based on the multi-modal pushover analysis and the capacity spectrum method. The results confirm that seismic events of moderate intensity can produce heavy damage to the masonry tower presented in this study. T2 - 3rd International Conference on Protection of Historical Constructions (PROHITECH 2017) CY - Lisbon, Portugal DA - 12.07.2017 KW - Masonry tower KW - Ambient vibration tests KW - Dynamic characterisation KW - Seismic assessment PY - 2017 SN - 978-989-8481-58-0 SP - 159 EP - 160 PB - IST-Press AN - OPUS4-41279 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Miccoli, Lorenzo A1 - Müller, U. A1 - Fontana, Patrick ED - Mazzolani, F. M. ED - Lamas, A. ED - Calado, L. ED - Proenca, J. M. ED - Faggiano, B. T1 - Strengthening of rammed earth structural elements. Mechanical behaviour under shear and cyclic loading N2 - An experimental investigation was carried out to study the in-plane shear behaviour of rammed earth structural elements strengthened with polyester fabric strips. The original idea for the retrofitting with polyester fabric strips was to introduce a vertical element for walls in order to take up horizontal loads resulting in a shear response of the building element. It has to be considered that vertical slits into the walls for fixing the strips are points of weakness and have to be mitigated by the adhesive. In this case a base coat mortar was employed. Strengthened elements were tested to exploit the strength potential of earthen materials and to solve its lack of tensile strength, significantly improving not only strength but also ductility. As part of the study results of a testing campaign of unstrengthened structural elements were considered. Strengthened elements were tested in diagonal compression/shear and cyclic shear-compression. A unique reinforcement orientation was used. The results of these tests are presented in this paper and include the load-displacement behaviours, crack patterns, failure modes. The results showed that the reinforcement was the most effective under cyclic shear-compression tests, with increase in load and displacement capacity observed. Under diagonal compression the reinforcement did not likely contribute significantly to the shear resistance, due to a lack of embedment length of the strips. T2 - 3rd International Conference on Protection of Historical Constructions (PROHITECH 2017) CY - Lisbon, Portugal DA - 12.07.2017 KW - Rammed earth KW - Diagonal compression tests KW - Shear-compression tests KW - Strengthening KW - Polyester fabric strips PY - 2017 SN - 978-989-8481-58-0 SP - 157 EP - 158 PB - IST-Press AN - OPUS4-41263 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Miccoli, Lorenzo A1 - Fontana, Patrick A1 - Kreft, O. A1 - Pietruszka, B. A1 - Lukaszewska, A. A1 - Klinge, A. ED - De Schutter, G. ED - De Belie, N. ED - Janssens, A. ED - Van Den Bossche, N. T1 - Design of UHPC-AAC light-weight composite facade elements for refurbishment N2 - The aim of this study was to develop a lightweight composite façade element for refurbishment of existing façades. It was crucial to minimize the thermal bridges and to undercut the thermal requirement of the system existing façade new element. The awareness of the environmental impact of the building sector is increasing. In this context, ultra-high performance concrete (UHPC) materials are shown to be promising alternatives with advantages such as lower embodied energy and reduced environmental impact. Predictions suggest that UHPC composite elements for building envelopes could have other benefits such as an increased service life, optimized use of building area due to thinner elements and minimized maintenance due to the absence of reinforcement or use of non-corrosive reinforcing materials such as carbon fibers. In this framework, composite elements have been developed combining an autoclaved aerated concrete insulation layer with an external UHPC supporting layer. The results show that the lightweight composite element has a good performance in term of thermal transmittance and minimization of thermal bridges. T2 - XIV DBMC - 14th International Conference on Durability of Building Materials and Components CY - Gent, Belgium DA - 29.05.2017 KW - Composite panels KW - Ultra-high performance concrete KW - Autoclaved aerated concrete KW - Hygrothermal behaviour KW - Production technology PY - 2017 SN - 978-2-35158-159-9 VL - PRO 107 SP - 1 EP - 10 PB - RILEM Publications S.A.R.L. AN - OPUS4-40498 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, U. A1 - Miccoli, Lorenzo A1 - Fontana, Patrick T1 - A lime-based grouting material for the repair of earthen structures N2 - The repair of earthen structures is not an easy task. Earth as a construction material has comparatively weak mechanical properties. It is also susceptible towards liquid water, were it can lose cohesion very quickly if certain moisture contents are exceeded. Repair concepts of structures built with such materials are therefore challenging. Historical earthen structures often exhibit damages in form of extensive cracking, which may have been caused by static or dynamic loads. Frequently these cracks are insufficiently or inappropriately repaired because of lack of knowledge and / or technology. In particular, the behaviour of crack repair by grouting poses a challenge in earthen materials and demands specific requirements for the grouting mortar, such as low water content, good water retention, low shrinkage. Grouting materials require additional specifications such as compatible strengths and Young’s modulus as well as good adhesion to the earthen substrates. In addition, grouts have to be sufficiently flowable to fill small cracks and voids without segregation or bleeding. Therefore, the rheological behaviour has to be well understood and controlled to gain the desired effects. The repair of cracks in earthen buildings is traditionally done by stuffing manually mortar into the gap. Naturally, this method is only usable for cracks with large widths. Another disadvantage is that cracks going through thicker walls cannot be completely reached by the tools used for stuffing the mortar into the crack. Lime based grouts for earthen materials were usually used for re-attachment of plasters but less for structural reasons. Due to the nature of earthen materials grouts based on formulated or hydraulic lime (according to the definition in EN 459-1) have to meet considerable demands on a variety of properties, which are related to compatibility, durability and in particular to the ability of being injected. The goal of this study was to create a grout, which can be used to re-establish structural continuity in cracked earthen masonry or other massive earth walls (rammed earth and cob) with the focus on grouting cracks. The grout material was based on hydrated lime (calcium hydroxide) with additions of pozzolana and lime stone filler. T2 - Lehm 2016 - 7th International Conference on Building with Earth CY - Weimar, Germany DA - 12.11.2016 KW - Building Materials KW - Grout mortar KW - Hydraulic lime KW - Earth construction KW - Repair KW - Historical buildings PY - 2016 SP - 1 EP - 8 PB - Eigenverlag Dachverband Lehm e. V. CY - Weimar AN - OPUS4-38825 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, U. A1 - Miccoli, Lorenzo A1 - Fontana, Patrick T1 - Ein Kalkeinpressmörtel für die Instandsetzung von Lehmbauten N2 - Die Instandsetzung von Lehmbauwerken ist keine einfache Aufgabe. Der Baustoff Lehm hat vergleichsweise schwache mechanische Eigenschaften. Er ist außerdem anfällig gegenüber eindringendem Wasser, wobei er sehr schnell seinen Zusammenhalt verlieren kann, wenn gewisse Feuchtegehalte überschritten werden. Instandsetzungskonzepte für Bauwerke aus solchen Materialien stellen deshalb eine Herausforderung dar. Historische Lehmbauwerke zeigen oft Schäden in Form von starker Rissbildung, die durch statische oder dynamische Lasten hervorgerufen sein kann. Häufig werden solche Risse wegen mangelnder Fachkenntnis und / oder fehlender Techniken nur ungenügend instandgesetzt. Die Rissinstandsetzung mit Einpressmörteln birgt insbesondere für Lehmbaustoffe eine Herausforderung und erfordert spezifische Anforderungen an den Einpressmörtel, wie z. B. niedriger Wassergehalt, gutes Wasserrückhaltevermögen, niedriges Schwindmaß, an das instandzusetzende Material angepasste Festigkeit und E-Modul sowie eine gute Haftung am Lehmuntergrund. Zusätzlich müssen Einpressmörtel eine ausreichende Fließfähigkeit aufweisen, um kleine Risse und Hohlräume ohne Entmischung zu füllen. Deshalb muss das rheologische Verhalten des Einpressmörtels gut untersucht und kontrolliert werden, um die gewünschte Wirkung zu erzielen. Die Rissinstandsetzung bei Lehmbauwerken erfolgt traditionell durch manuelles Stopfen mit einem Mörtel. Natürlich können auf diese Weise nur Risse mit einer großen Breite verfüllt werden. Ein weiterer Nachteil ist, dass Risse, die durch dickere Wände verlaufen, nicht vollständig mit den für das Stopfen verwendeten Werkzeugen erreicht werden können. Kalkgebundene Einpressmörtel für Lehmbaustoffe werden gewöhnlich für die Wiederbefestigung von Putzen und weniger aus statisch-konstruktiven Gründen eingesetzt Aufgrund der Eigenschaften von Lehm, müssen Einpressmörtel auf Basis von hydraulischem Kalk nach EN 459-1 wesentliche Anforderungen an eine Reihe von Eigenschaften erfüllen, die sich auf die Verträglichkeit, die Dauerhaftigkeit und insbesondere die Injektionsfähigkeit beziehen. Das Ziel der vorgestellten Untersuchungen war einen Einpressmörtel zu herzustellen, mit dem die strukturelle Kontinuität in Lehmmauerwerk oder anderen massiven Lehmwänden (Stampf- und Wellerlehm) durch Rissverpressung wiederhergestellt werden kann. Das Material bestand aus Kalkhydrat mit Zusätzen von Puzzolanen und Kalksteinfüller. T2 - Lehm 2016 - 7. Internationale Fachtagung für Lehmbau CY - Weimar, Germany DA - 12.11.2016 KW - Baustoffe KW - Einpressmörtel KW - Kalkhydrat KW - Lehmbau KW - Instandsetzung KW - Historische Bauwerke PY - 2016 SP - 1 EP - 10 PB - Eigenverlag Dachverband Lehm e. V. CY - Weimar AN - OPUS4-38824 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Miccoli, Lorenzo A1 - Fontana, Patrick A1 - Müller, U. ED - Van Balen, K. ED - Verstrynge, E. T1 - In-plane shear behaviour of earthen materials panels strengthened with polyester fabric strips N2 - An experimental investigation was carried out to study the in-plane shear behaviour of earthen material Panels strengthened with polyester fabric strips. Strengthened panels were developed to exploit the strength potential of earthen materials and to solve its lack of tensile strength, significantly improving not only strength but also ductility. Three earthen materials were considered: cob, earth block masonry (EBM) and rammed earth (RE). As first approach the strengthening configuration, based on different adhesive materials, was tested only for cob panels. As part of the study the results of a big testing campaign of unstrengthened Panels were considered. Seven strengthened panels were tested in diagonal compression/shear.A unique reinforcement orientation was used. The results of these tests are presented in this paper, and include the load-displacement behaviours, crack patterns, failure modes. The results showed that the reinforcement was the most effective in EBM panels, with increase in strength and ductility observed. In RE and cob panels the reinforcement did not likely contribute significantly to the shear resistance, due to a lack of embedment length of the strips. Instead, in EBM it was likely that the vertical reinforcement acted in tension to restrain shear induced dilation and to restrain sliding. T2 - 10th International Conference on Structural Analysis of Historical Constructions (SAHC 2016) CY - Leuven, Belgium DA - 13.09.2016 KW - Earthen materials KW - Strengthening KW - Diagonal compression test KW - Shear strength PY - 2016 SN - 978-1-138-02951-4 SP - 1099 EP - 1105 PB - Taylor & Francis Group CY - London AN - OPUS4-38993 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, U. A1 - Miccoli, Lorenzo A1 - Fontana, Patrick T1 - Ein Kalkeinpressmörtel für die Instandsetzung von Lehmbauten T1 - A lime-based grouting material for the repair of earthen structures N2 - Die Instandsetzung von Lehmbauwerken ist keine einfache Aufgabe. Der Baustoff Lehm hat vergleichsweise schwache mechanische Eigenschaften. Er ist außerdem anfällig gegenüber eindringendem Wasser, wobei er sehr schnell seinen Zusammenhalt verlieren kann, wenn gewisse Feuchtegehalte überschritten werden. Instandsetzungskonzepte für Bauwerke aus solchen Materialien stellen deshalb eine Herausforderung dar. Historische Lehmbauwerke zeigen oft Schäden in Form von starker Rissbildung, die durch statische oder dynamische Lasten hervorgerufen sein kann. Häufig werden solche Risse wegen mangelnder Fachkenntnis und / oder fehlender Techniken nur ungenügend instandgesetzt. Die Rissinstandsetzung mit Einpressmörteln birgt insbesondere für Lehmbaustoffe eine Herausforderung und erfordert spezifische Anforderungen an den Einpressmörtel, wie z. B. niedriger Wassergehalt, gutes Wasserrückhaltevermögen, niedriges Schwindmaß, an das instandzusetzende Material angepasste Festigkeit und E-Modul sowie eine gute Haftung am Lehmuntergrund. Zusätzlich müssen Einpressmörtel eine ausreichende Fließfähigkeit aufweisen, um kleine Risse und Hohlräume ohne Entmischung zu füllen. Deshalb muss das rheologische Verhalten des Einpressmörtels gut untersucht und kontrolliert werden, um die gewünschte Wirkung zu erzielen. Die Rissinstandsetzung bei Lehmbauwerken erfolgt traditionell durch manuelles Stopfen mit einem Mörtel. Natürlich können auf diese Weise nur Risse mit einer großen Breite verfüllt werden. Ein weiterer Nachteil ist, dass Risse, die durch dickere Wände verlaufen, nicht vollständig mit den für das Stopfen verwendeten Werkzeugen erreicht werden können. Kalkgebundene Einpressmörtel für Lehmbaustoffe werden gewöhnlich für die Wiederbefestigung von Putzen und weniger aus statisch-konstruktiven Gründen eingesetzt. Aufgrund der Eigenschaften von Lehm, müssen Einpressmörtel auf Basis von hydraulischem Kalk nach EN 459-1 [4] wesentliche Anforderungen an eine Reihe von Eigenschaften erfüllen, die sich auf die Verträglichkeit, die Dauerhaftigkeit und insbesondere die Injektionsfähigkeit beziehen. Das Ziel der vorgestellten Untersuchungen war einen Einpressmörtel zu herzustellen, mit dem die strukturelle Kontinuität in Lehmmauerwerk oder anderen massiven Lehmwänden (Stampf- und Wellerlehm) durch Rissverpressung wiederhergestellt werden kann. Das Material bestand aus Kalkhydrat mit Zusätzen von Puzzolanen und Kalksteinfüller. N2 - The repair of earthen structures is not an easy task. Earth as a construction material has comparatively weak mechanical properties. It is also susceptible towards liquid water, were it can lose cohesion very quickly if certain moisture contents are exceeded. Repair concepts of structures built with such materials are therefore challenging. Historical earthen structures often exhibit damages in form of extensive cracking, which may have been caused by static or dynamic loads. Frequently these cracks are insufficiently or inappropriately repaired because of lack of knowledge and / or technology. In particular, the behaviour of crack repair by grouting poses a challenge in earthen materials and demands specific requirements for the grouting mortar, such as low water content, good water retention, low shrinkage. Grouting materials require additional specifications such as compatible strengths and Young’s modulus as well as good adhesion to the earthen substrates. In addition, grouts have to be sufficiently flowable to fill small cracks and voids without segregation or bleeding. Therefore, the rheological behaviour has to be well understood and controlled to gain the desired effects. The repair of cracks in earthen buildings is traditionally done by stuffing manually mortar into the gap. Naturally, this method is only usable for cracks with large widths. Another disadvantage is that cracks going through thicker walls cannot be completely reached by the tools used for stuffing the mortar into the crack. Lime based grouts for earthen materials were usually used for re-attachment of plasters but less for structural reasons. Due to the nature of earthen materials grouts based on formulated or hydraulic lime (according to the definition in EN 459-1 [4]) have to meet considerable demands on a variety of properties, which are related to compatibility, durability and in particular to the ability of being injected. The goal of this study was to create a grout, which can be used to re-establish structural continuity in cracked earthen masonry or other massive earth walls (rammed earth and cob) with the focus on grouting cracks. The grout material was based on hydrated lime (calcium hydroxide) with additions of pozzolana and lime stone filler. T2 - Lehm 2016 - 7. Internationale Fachtagung für Lehmbau - 7th International Conference on Building with Earth CY - Weimar, Germany DA - 12.11.2016 KW - Baustoffe KW - Einpressmörtel KW - Kalkhydrat KW - Lehmbau KW - Instandsetzung KW - Historische Bauwerke KW - Building materials KW - Grout mortar KW - Hydraulic lime KW - Earth construction KW - Repair KW - Historical buildings PY - 2016 SP - 1 EP - 10 PB - Eigenverlag Dachverband Lehm e. V. CY - Weimar AN - OPUS4-38992 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Miccoli, Lorenzo A1 - Oliveira, D. V. A1 - Silva, R. A. A1 - Drougkas, A. A1 - Fontana, Patrick T1 - Numerische Modellierung von Stampflehm unter verschiedenen Lasteinflüssen N2 - Der Beitrag präsentiert einen Vergleich zwischen verschiedenen numerischen Modellierungsansätzen die dazu dienen sollen, das flächige Verhalten von Stampflehmwänden, genauer unter axialer, diagonaler und zyklischer Scherkraftbelastung zu simulieren. Im ersten Teil der Studie werden die mechanischen Eigenschaften der Wandscheiben, die unter einachsiger und diagonaler Druckbelastung getestet wurde und der Wände, die in flächigen, zyklischen Scherkraftbelastung getestet wurden, dargestellt. Die Ergebnisse werden verwendet, um die Finite Elemente Simulation anzuwenden und zu bewerten. Die numerische Modellierung der getesteten Stampflehmproben wird dann im zweiten Teil diskutiert. Ein nichtlineares Materialgesetz basierend auf dem Gesamtdehnungsrissmodell (total strain rotating crack model – TSRCM) wurde, wie durch die Software DIANA® verwendet, angesetzt. Ziel dieser hier präsentierten numerischen Analyse ist es, das Verhalten von Stampflehm unter verschiedenen Lasteinflüssen zu simulieren. Für die Wandscheiben wurden Versuche unter linearer Last, sowohl in Makro- als auch Mikromodellansätze für die Simulation der experimentellen Versuche gewählt. Für die Wände, welche zyklischer Belastung ausgesetzt waren, wurden nur die Mikromodellansätze für die Simulation der experimentellen Versuche gewählt. Das betreffende FEM Modell wurde mit den experimentellen Ergebnissen kalibriert. Die Stampflehmlagen wurden mit durchgehenden Elementen, die Kontaktflächen zwischen den Lagen mit Oberflächenelementen repräsentiert. Dieser Ansatz erlaubte die Bewertung des Einflusses der auftretenden Schwächung in den Oberflächen zwischen den Lagen auf das Scherverhalten des Stampflehms. Ziel der numerischen Simulation von zyklischen Versuchen war es, die Eignung allgemeiner Analysemethoden (z. B. für Mauerwerk) für die Analyse von Stampflehm einzuführen und anzuwenden. Stampflehm zeigt brüchige Eigenschaften vergleichbar zu Mauerwerksbaustoffen und wird in geometrischen Formen, wie Wänden, genutzt, die im Mauerwerk üblich sind. T2 - Lehm 2016 - 7. Internationale Fachtagung für Lehmbau CY - Weimar, Germany DA - 12.11.2016 KW - Baustoffe KW - FEM-Analyse KW - Stampflehm KW - Druck- und Schubprüfung KW - Zyklische Belastung KW - Versagensart KW - Rissmuster PY - 2016 SP - 1 EP - 9 PB - Eigenverlag Dachverband Lehm e. V. CY - Weimar AN - OPUS4-38821 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -