TY - GEN A1 - Krakow, Lutz A1 - Hünger, Klaus-Jürgen A1 - Brigzinsky, Maria T1 - Projekt ALEKOM – Aschegebundenes Ton-/Lehmfeinkornsystem T2 - Ceramic forum international : cfi, Berichte der Deutschen Keramischen Gesellschaft Y1 - 2010 SN - 0173-9913 VL - 87 SP - D8 EP - D10 ER - TY - CHAP A1 - Brigzinsky, Maria A1 - Hünger, Klaus-Jürgen T1 - Durable Extruded and Self-Hardening Loam Bricks Based on Fly Ash from Lignite T2 - Proceedings, 23rd Czech Concrete Day 2016 N2 - The basis of the primary energy supply in the Czech Republic is mainly lignite combustion. Power plants are for example Chvaletice, Melnik, Pocerady, Porici, Prunerov, Ledvice, Tusimice, Tisova and Hodonin [1,2]. Accordingly, there is a large amount of fly ash with its latent hydraulic and puzzolanic properties, depending on the composition. In terms of sustainability, such industrial residues offer huge potential for conversation of resources and often connected with it, a CO2-reduction. Especially lime-rich fly ashes offer a variety of possibilities in the high quality production of self-hardening loam-bricks, having an improved durability. Different clays/loams were mixed with fly ashes (10 to 30 wt-%) and homogenized by addition of water. Out of these mixtures, samples were moulded in different dimensions by using an extruding press. After curing under different humidity conditions at room temperature, the samples were tested for their strength and their durability. The investigations showed, that the choice of the starting materials has significant impact to the workability and the development of the strength. Furthermore, there is an optimal amount for the ash in the recipes to prevent a rapid destruction by capillary water absorption. The modified clay bricks could make a decisive contribution to the improvement of weather resistance e.g. in tropical areas with sudden rain showers. KW - Waste materials KW - Fly ash KW - CO2-reduction KW - Resource conservation KW - Durability Y1 - 2016 UR - https://www-docs.b-tu.de/fg-baustoffe/public/P37-Brigzinsky.pdf SN - 978-80-906097-6-1 ER - TY - CHAP A1 - Hünger, Klaus-Jürgen A1 - Brigzinsky, Maria T1 - An alternative alumino-silicate binder based on the "just add water method" T2 - ICCM, 10th ACI/RILEM International Conference on Cementitious Materials and Alternative Binders for Sustainable Concrete, 2017, Montreal, Kanada N2 - Alumino silicate compounds are important for alternative binders for concretes because of the reduction of CO2 and resource conservation. Such multi-phase systems consist of a solid component, such as e.g. slag, ash, calcined clays and others, and a liquid component, in generally highly concentrated alkaline solutions (water glass or NaOH/KOH). Because of safety and other reasons, such systems exclude large-scale practical applications. The newly developed alternative binder consists of a highly soluble silicate waste material, which is not common in geopolymere production, and a powdered Al-provider. It is called alumino silicate network (ASN) binder. Both components can be mixed dry in different ratios. Only after addition of water, a polymerization process is induced and the formation of amorphous phases, and sometimes zeolites can be observed. Mortar bars were produced and tested for different properties. The best results regarding to workability, strength development and sustainability were obtained with a molar Si/Al ratio of 2:1 in combination with fine-grained rock filler components. Investigations on the hardening process showed, that the mechanical properties varied over a wide range. Strength reserves, a ratio between compressive and tensile strength of approx. 3 and so far good resistance against acid solutions allow the use as a binder in high performance mortar and concrete structures. KW - alternative binders KW - geopolymere KW - alumino silicate structures KW - Si/Al ratio KW - industrial residues Y1 - 2017 UR - https://www-docs.b-tu.de/fg-baustoffe/public/Supp_320_24.pdf PB - RILEM ER - TY - CHAP A1 - Hünger, Klaus-Jürgen A1 - Kositz, Mario A1 - Brigzinsky, Maria A1 - Ajami, Fouad T1 - A fast testing method to characterize ashes and ash mixtures using the ultrasonic technique T2 - Recent Advances in Concrete Technology and Sustainability Issues Proceedings Fourteenth International Conference Beijing, China October-November 2018 N2 - Fly ash is a typical mortar constituent in Germany, other European countries and worldwide. If cement alone is used as a binder, then the mortar is too expensive and cannot provide all properties. That`s why many companies have special recipes with fly ash, especially hard coal fly ash components, in the mortar. The aim of this project is to substitute such fly ashes by lignite coal fly ashes, which are cheaper, available at every times or have better properties. However this means, that the calcium free or calcium poor ash should be substituted by calcium rich ashes, which are not certificated because of fluctuations. To compensate the fluctuations in the ash compositions, several ashes are mixed. The European standard EN 450, which contains requirements, for example for the chemical composition of ashes, has to be taken into account. Fly ash mortar compound prisms have been produced and the different mechanical and deformation values were determined in comparison to a reference material. The basis for all experiments was the recipe of the company for a special mortar. An ash compound could be developed with the same workability by considering the economic reasons of the company. An important result too is that the fluctuations of the fly ash batches can be controlled by special developed chemical (color test) and physical (Ultrasonic velocity) test methods. Y1 - 2018 UR - https://www-docs.b-tu.de/fg-baustoffe/public/A%20fast%20test%20method%20for%20ashes-huenger.pdf ER - TY - CHAP A1 - Hünger, Klaus-Jürgen A1 - Brigzinsky, Maria ED - Ludwig, Horst-Michael ED - Fischer, Hans-Bertram T1 - Zur Entwicklung eines alumosilicatischen Binders auf der Basis industrieller Reststoffe für den Bereich hochaggressiver Beanspruchungen T2 - Tagungsbericht, 20. Internationale Baustofftagung IBAUSIL, 12. - 14. September 2018, Weimar, Teil 1 N2 - Im Rahmen eines AiF-geförderten Forschungsprojektes wurde ein alumosilicatisches Bindersystem entwickelt, welches nur durch die Zugabe von Wasser zu einem Feststoff mit definierten Eigenschaften erhärtet. Ein wesentlicher Grundgedanke bei der Auswahl der Ausgangsstoffe war, industrielle Reststoffe zu verwenden, die verfügbar sind und beispielweise nicht über einen aufwändigen C alcinierprozess hergestellt werden müssen. Diese sollten andererseits aber eine sehr gute Löslichkeit besitzen, damit sich das hoch alkalische Milieu sofort nach Wasserzugabe einstellt und der alumosilicatische Strukturbildungsprozess unmittelbar in Gang gesetzt wird. Unterschiedliche silicatische und aluminatische Ausgangsmaterialien wurden getestet. Es wurde ein Stoffsystem unter Verwendung eines silicatischen Reststoffes aus der Glasproduktion in Kombination mit einer Natriumaluminatkomponente aus der Waschmittelproduktion entwickelt, welches die gestellten Anforderungen gut erfüllt. Dieses Stoffsystem dient gleichzeitig als Modell, an dem der Strukturbildungsprozess, der zur Bildung eines alumosilicatischen Netzwerkes (ASN) führt, z.B. mittels NMR-Untersuchungen untersucht werden kann. Im Unterschied zu den „klassischen“ Geopolymermaterialien Metakaolin, Hüttensand bzw. Flugaschen, ist das für den Strukturbildungsprozess entscheidende Verhältnis zwischen Si und Al in einem breiten Spektrum frei einstellbar und damit auch die mit dem Binder erzielbaren Eigenschaften variierbar. An Mörtel- und Betonprismen wurden zerstörungsfrei und zerstörend Festigkeiten und Formänderungen untersucht und Dauerhaftigkeitskennwerte bestimmt. Hohe mechanische Festigkeiten bis 60 N/mm2 Druckfestigkeit, aber insbesondere der sehr gute Widerstand gegen Säureangriffe machen Mörtel und Betone unter Verwendung des ASN-Binders interessant für Anwendungen im Bereich der Einwirkungen von aggressiven chemischen Reagenzien. Entsprechende Untersuchungen zum Säureangriff wurden durchgeführt und die Veränderungen mikroskopisch und mittels Eigenfrenquenzanalyse (Grindosonic) verfolgt. Y1 - 2018 SN - 978-3-00-059950-7 SP - 371 EP - 382 PB - F.A. Finger-Inst. für Baustoffkunde, Bauhaus-Univ. Weimar CY - Weimar ER - TY - CHAP A1 - Brigzinsky, Maria A1 - Hünger, Klaus-Jürgen T1 - Extruded lime-rich fly ash-clay mictures for the use in "cold ceramics" bricks T2 - 2nd International Conference on Advances in Cement and Concrete Technology in Africa N2 - There is a huge potential for the resource conservation and for reduction of CO2 emissions by using industrial by-products, as well as natural slags or ashes in a precise and high-class manner. Apart from mineral coal fly ash, which is used and certificated as an additive for concrete, especially lime- rich fly ashes with their latent hydraulic and puzzolanic properties offer a variety of possibilities in the high quality production of small-sized components like bricks. Fine-grain-mixtures from different clays and fly ashes were homogenized and plasticized by the addition of water in an Eirich-mixer. The added amount of ash was varied from 10 to 30 wt%. Out of these mixtures, test items with a sufficient strength for transport were moulded in an extrusion process. The test samples were stored under various humidity conditions (RH= 33, 65 and 88 %) at 20 °C and, subsequently after different times of self-hardening (28, 70 and 105 days), tested on their strength and durability. Compressive strength up to 15 MPa was achieved. In order to reach that result, at least 20 wt% of the clay should be substituted by ash to get an increase in strength compared to the pure clay samples. Further examinations have shown that it is possible to prevent the destruction by capillary water absorption of pure clay/loam specimens by an optimal use of ash in the recipes. Overall, it can be stated that due to the self-hardening potential of these mixtures there is no need for an energy-intensive and highly CO2 emitting combustion process, if the clay is substituted in fine grain mixtures by high lime component fly ashes. KW - Waste materials KW - Fly ash KW - Self-hardening bricks KW - CO2-reduction KW - Resource conservation KW - Enhancing durability Y1 - 2016 SN - 978-3-9817502-3-2 SP - 545 EP - 552 PB - BAM Bundesanstalt für Materialforschung und –prüfung CY - Berlin ER - TY - CHAP A1 - Hünger, Klaus-Jürgen A1 - Krakow, Lutz A1 - Brigzinsky, Maria T1 - Asche Ton Komposite - Baukeramik ohne Trocknen und Brennen T2 - Tagungsbericht, IBAUSIL, 18. Internationale Baustofftagung, 12. - 15. September 2012, Weimar Bauhaus-Universität, Teil 2 Y1 - 2013 SN - 978-3-00-034075-8 PB - F.-A.-Finger-Inst. CY - Weimar ER - TY - CHAP A1 - Hünger, Klaus-Jürgen A1 - Gerasch, Robert A1 - Sander, Ingolf A1 - Brigzinsky, Maria T1 - On the Reactivity of calcined clays from lower Lusatia for the production of durable Concrete Structures T2 - Calcined Clays for Sustainable Concrete, Proceedings of the 2nd International Conference on Calcined Clays for Sustainable Concrete N2 - Metakaolin used as a SCM in concrete is obviously a very good tool to improve the resistance against acid and alkali attack too. Even if, finally, the mechanisms are not fully understood until now, lower mass loss (acid attack) or lower expansions (ASR) are showing their efficiency. Metakaolin, burnt by using relatively pure natural kaolin clays, contains Al2O3 and SiO2 only with a ratio of approx. one. The question is: Are there any other clays maybe also in mixtures which are suitable for use as an admixture for concrete or even as a binder? This research work has a strong regional reference. Three clays from Lower Lusatia were selected. The clays and a wide range of mixtures too were burnt at different temperatures (between 600 to 700 °C) to find out the “best” results for such materials. The mixing process has also the background to eliminate fluctuations in the compositions of the clays. A continuous working rotary kiln with a continuous supply of clay materials was used for the production of calcined clay samples. Using this equipment, the rate of heating and the duration of stay of the material under almost practical conditions can be varied. Mineralogical compositions, measured before and after heating, confirm the formation of amorphous phases already under relatively low temperature conditions in dependence on the clay mineral species and the mixing relations. Reactivity (activity index and solubility in alkaline solutions) of each sample were determined and mortar bars were produced. In dependence on their reactivity parameters the so produced calcined clay samples influence mechanical and durability properties of concrete structures. The aim of this research project is to produce concrete bars with such calcined clay as a SCM and store them under extreme conditions in some of the Lusatian lakes. KW - Clay mixtures Solubility KW - Meta clays KW - Activity index KW - Solubility KW - Pozzolani behavior KW - Dynamic modulus of elasticity Y1 - 2017 SN - 978-94-024-1206-2 SN - 978-94-024-1207-9 SP - 205 EP - 211 PB - Springer CY - Dordrecht ER -