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Příprava historických pojiv s vysokou odolností proto okolním vlivům / Preparation of historical binders with high resistance to ambient influencesNehybka, Josef January 2019 (has links)
This master’s thesis is focused on preparation of the mortar mixtures inspired by roman cement with a great resistivity against the corrosion environment, especially a seawater. There were prepared samples of a roman cement containing of pure lime and various artificial pozzolans and natural tuff which were used as pozzolan admixtures. The task of this work is to explore possibility of using pure lime and for example pozzolan admixture which can resist against the corrosive environment like a roman cement. There were prepared a lot of various samples which were tested separately on their mechanical characteristics before and after their exposure of the influence of the corrosive environment. There were used X-ray diffraction analysis for the characterization of a phase composition of the raw materials and some selected samples.
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Calcination of Marls to Produce Roman CementHughes, David C., Jaglin, D., Kozlowski, R., Mayr, N., Mucha, D., Weber, J. January 2006 (has links)
no / Marls were identified from a range of European sources and assessed for their Cementation Index, as proposed by Eckel. Two were selected for calcination in a laboratory kiln; one from Folwark in Poland (CI 1.75) and one from Lillienfeld in Austria (CI 2.03). Analysis of historical documents, while not revealing precise kiln conditions, does suggest that they were such as not to yield complete decarbonation of the calcite. Consequently, a series of calcinations was undertaken in which the peak temperature control of the kiln was set in the range 730°C to 1100°C, with residence times in the range 150 to 1250 min. The airflow through the kiln was sufficient to maintain a minimum oxygen content of at least 12 %. The resulting clinker was ground to comply with the 19th century Austrian Norme. Pastes were produced at w/c = 0.65 and assessed for setting time and strength development (6 h to 1 year). Both parameters were highly dependent upon calcination conditions with both ¿low¿ and ¿high¿ calcinations producing slower setting and slower strength development than intermediate conditions. Two strength development profiles were identified; one being the expected continuous increase of strength, albeit with a declining rate of increase with time, while the other showed a three-step sequence of high initial strength, a dormant period which could last for many weeks and a final increase in strength to an age of one year. The cements were compared using X-ray diffraction (XRD). Considerable variation in the composition was noted and related to the calcination conditions. Of particular interest is the formation of both ¿'-belite and ß-belite under differing calcination conditions. Clinker particles were also compared using the SEM in back-scattered electron imaging mode and the development of morphology observed.
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Hydration processes in pastes of Roman and American Natural Cements.Vyskocilova, R., Schwarz, W., Muncha, D., Hughes, David C., Kozlowski, R., Weber, J. January 2007 (has links)
No / Hydration of five Roman and American natural cements was analyzed using X-ray diffraction, mercury intrusion porosimetry, and scanning electron microscopy of cement pastes. Two cements were prepared in the laboratory by burning marls from geological sources in Poland (Folwark) and Austria (Lilienfeld). The selection of raw materials and burning conditions were optimized so that the hydraulic nature and appearance of the final burnt materials matched as closely as possible historic Roman cements widely used in the 19th and the beginning of the 20th centuries in Europe to decorate buildings. Three other cements are produced commercially: quick setting Prompt cement from Vicat, France, and Rosendale cements from Edison Coatings Inc., USA. The hydration of the cements studied was shown to comprise two distinct stages. The immediate setting and early strength is due to the formation of calcium aluminum oxide carbonate (or sulfate) hydroxide hydrates. The development of long-term strength is brought about by the formation of calcium silicate hydrates. Similarities and differences between the individual cements are discussed.
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Low energy pre-blended mortars: Part 2-Production and characterisation of mortars using a novel lime drying techniqueHughes, David C., Illingworth, J.M., Starinieri, V. 30 December 2015 (has links)
No / The presence of free water in mortars destined for silo or bagged storage can lead to the degradation of the binder phase. Such water may be present as a result of using wet, as-delivered sand or as a consequence of prior processes such as de-activation of Roman cement. Thus, water must be removed from the system prior to storage. Part 1 of this paper describes the control of a technique by which quicklime is added to the wet system which principally dries it by both slaking the quicklime and evaporation as a consequence of the exothermic slaking reaction. Two examples of mortars are presented in which excess water is removed from the system by the inclusion of quicklime. In the first, the water is present in the as-delivered sand and the binder is a combination of the slaked lime and ggbs. In the second, the water remains after pre-hydration of a Roman cement which is a process to retard its rapid setting characteristics. It is shown that optimally dried mortars are not subject to degradation following storage of both mortar types. (C) 2015 Elsevier Ltd. All rights reserved.
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Řešení výtvarného díla v krajině - reliéf. (Prakticko-teoretická práce) / Design and emplacement of a sculpture in the landscapeŠINDELÁŘOVÁ, Barbara January 2010 (has links)
This thesis is focused to the ideal concept, design, implementation and em-placement of a sculpture in the respective area, designed in a deeper context of the work itself to its surroundings, its history and specific local character. To solve the emplacement of the sculpture, a scenic park surrounding the Castle at Štěkeň (South-West Bohemia) has been chosen. The design respects fully not only scenic dominants, but also neighboring architecture and vistas directly in the respective locality. A full appeal of the art work is enabled by applying convenient material re-specting its milieu and the sculpture theme itself as well. Also the onlooker´s position toward the sculpture proportions and its comprehensibility and readability has been taken in consideration. The theme and concept of the sculpture is closely connected to the Christian Or-der ?Congregatio Jesu? settled directly in the facilities of the Štěkeň Castle and related first of all to Mary Ward, its founder and to her first community of ?English Virgins? as well. A component part of this thesis is formed by a secondary pedagogic project ? a workhop meeting for children, convened in autumn 2010 directly to the Štěkeň Castle premises. It dealt with the human being´s relation to the landscape. This thesis focused to the relation between an art work and the surrounding sce-nery is concerned also to spiritual creativity from the point of view of actual cultural-social neediness respecting also the application and readability of Christian symbolism in respect to actual cultural experience.
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Možnosti využití odkalů po vypírce vápence / The possibilities of use of sludges from limestone washŠvec, Jiří January 2011 (has links)
In modern point of view of waste management is desirable to effectively process the grates possible amount of wastes. Sediments from cleaning of mined lime stones contains a lot of clay components, but there is also indispensable share of soft calcite. This composition makes these sediments a promising material for preparation of hydraulic binders. Production of common hydraulic binders, especially Portland cement, is very energy-intensive plus loads environment with considerable amount of combustion gases, therefore it is necessary to explore possibilities of alternative low - energy binders production and usage.
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Příprava a vlastnosti románského cementu / Preparation and Properties of Roman CementOpravil, Tomáš January 2009 (has links)
The Ph.D. thesis deals with the preparation of highly hydraulic binders based on roman cement. Roman cement (natural cement) is recently not available on the market due to uneconomic production of such a specific binder. On the other hand there is a big lack of information on this hydraulic binder. These results in failure in meeting the basic principle of modern approaches to restoration of historical buildings or monuments made of such kind of materials, which is such, that the materials used for restoration should be compatible with original material. Recognition of the processes of roman cement preparation based on progressive methods of study can provide substantial information for more efficient raw material selection or even for nontraditional utilization, for example for artworks. This work hence is aimed at studying and selection of traditional natural as well as nontraditional raw materials such as clay. This work also studies the preparation of highly hydraulic binders based on roman cement and the kinetics of burning and hydration processes
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