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Influence of the mineralogical composition of raw material on phases formed during the burning of hydraulic lime and natural cement
Kozlovcev, Petr ; Přikryl, Richard (advisor) ; Hladil, Jindřich (referee) ; Škvára, František (referee)
Natural hydraulic lime and natural cement have been used in the building industry for centuries. These inorganic hydraulic binders are called "traditional" or "alternative" because they can, in some cases, substitute modern Portland cement. The recent increased interest in these binders is due not only to their use in restoration practices, but also because their production and use is less energetically demanding than in modern cements. Historically, many types of hydraulic binders were produced in the regions of Bohemia and Moravia. However, much information has been lost about their manufacturing process, which raw materials were used, and we are uncertain of the exact character and properties of the burned material. To date, studies have only addressed the impact of the chemical composition of raw material on the parameters of the burned material - all this is well known for Portland cement, much less for other types of hydraulic binders. The aim of this dissertation was to study the various types of raw materials (limestone containing non- carbon admixtures) and to understand the characteristics of their respective hydraulic lime and natural cement. This was done by analyzing the impact of conditions (highest achieved burning temperature and time of burning) and the mineral and chemical...
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Properties of cementitious matrix in the environment of radioactive waste respositories
Podojil, Adam ; Jelínek, Emil (advisor) ; Kozlovcev, Petr (referee)
Cementitious materials will serve as a construction and filler material for the construction of a deep repository of radioactive waste. Therefore, three different materials represented by four samples were studied in the present work. This is CEM II AS 42,5R cement commercially available in Čížkovice, cement CEM III B / 32,5 SV with ash and aggregate used as filler concrete for storage chambers from radioactive waste repository Richard and cement CEM I 42, 5 with fine and coarseraggregate used for fixed radioactive waste (RAW) in Velké Zbytky in the area of ÚJV Řež,as Chemical (silicate analysis) and phase composition (XRD powder diffraction analysis) were determined in the studied materials. Further, the orientation strength of the monolithic samples and their mutual comparison (compression strength measurement) were determined. Percolation leaching experiments were carried out, three columns with CEMII, RICHARD and ÚJV samples were run. The conditions of the experiments were chosen to approach the conditions in the rock environment of a possible deep radioactive waste repository. Synthetic granite water (SGW) was used as the leaching solution. In all column experiments, attempts to observe changesin the concentrations of selectedindicators (Na+ , K+ , OH- ,Ca2+ ,pH, Conductivity, SiO2, Mg2+ and...
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Experimental study of Palaeozoic limestones of the Barrandian and their possible use for burning of hydraulic limes and natural cement
Kozlovcev, Petr
54 Summary In this experimental study, selected Devonian limestones of the Prague Basin (i.e. samples from the historic quarry of Branické skály) were examined to find their suitability for production of hydraulic limes or for natural cement. Four representative samples of the dvorecko-prokopské limestone were sampled in the form of blocks weighing approximately 10 kg each, from the layer of the quarry wall that had been chosen based on literature research. A detailed mineralogical-petrographic examination of samples was the first step, in an attempt to obtain their mineralogical composition, microstructure and texture. Samples were analysed by polarizing microscopy and cathodoluminescence of thin sections, and X-ray diffraction of insoluble residues determined by treatment with both the hydrochloric acid and the acetic acid solution. Mineralogical composition of the insoluble residuals was illite, kaolinite, quartz and Na-plagioclase (albite). Two samples contained among above mentioned mineral phases also chlorite. The utility of studied limestones for the production of hydraulic binders (hydraulic limes and natural cement) was derived from both the calculations based on obtained chemical analyses (included standard cement and lime indexes and modules) and the firing experiments. The firing experiments...
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Study of interaction between engineering barriers of deep repository of spent nuclear fuel and radioactive waste
Podojil, Adam ; Jelínek, Emil (advisor) ; Kozlovcev, Petr (referee)
The thesis describes the different types of radioactive wastes (RAW), it present classification used in Czech Republic (classification of RAW isn't unified but vary according to the needs of the region for which is created. Trend of recent years in RAW disposal aimed at building a deep repositories in suitable geological formations. So it is in Czech Republic where it is planned to build repository in granitic rocks similar to the Swedish model KBS-3V/KBS-3H. This model is based on multi-barrier system which serves to maintain radionuclides outside the environment for at least 100,000 years. The system consist of engineered barriers (waste form, storage overpack, bentonite and cement) and natural barriers (rock environment in the vicinity of deep depository (near field, far field)). Study of interactions of various barriers is an important factor in the development of appropriate forms of final storage. The interactions at interface bentonite-corrosion products of container and cement- bentonite are important in terms of functionality barriers over time. In the long run, there are many changes in the properties of the individual interacting barriers. At the interface bentonite-steel shell of the container when progressing corrosion occurs to the formation of secondary minerals (magnetite, siderite,...
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