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Odloučení dopravního vzduchu surovinové moučky / Severance of raw material flour transportation airBrzobohatý, Lukáš January 2013 (has links)
The dissertation is focused on the applied technical and economic analysis of the influence separation of transport air from raw meal on the economy clinker/cement production, in specific cement production. The analysis is performed on the basis of a detailed understanding and analysis of the function of each component of the technology of cement production, which are affected by separation of transport air from raw meal, mainly the dosing and preheat system of the raw meal. The results of the analysis show a significant effect (impact) separation of transport air on the production costs.
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Využití odpadního tepla spalin pro výrobu elektrické energie / Utilization of waste heat from combustion gases for power productionRejnuš, Vojtěch January 2015 (has links)
Methods of utilization waste heat are increasingly on the rise and can be applied in many technologies. One of the technologies is the manufacture of cement, which is focused issue of work. Within the solution, and for understanding the problem is outlined cement production process and the analysis of the waste heat from the process, on this basis are selected a suitable method using waste heat with a closer focus on ORC units. After following evaluation and selection of the most suitable unit is made design, calculation and construction of heat exchangers. The result is the evaluation of the entire proposal.
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Studium vlivu přísad a příměsí na vlastnosti vysokohodnotných betonů / The Study of Aditives and Admixture Influence on High-Performance Concrete PropertiesŠiler, Pavel January 2009 (has links)
The aim of this work was to develop the method for the determination of the superperplasticizers (SP) content in the water solution. The method developed was then applied to study the SP adsorption on the individual components used for high-performance concrete and the influence of the temperature and pH values over this adsorption. Furthermore the influence of the water to binder ratio, SP, finely grounded granulated blast furnace slag, fly ash, silica fume, finely ground silica sand and bauxite on the hydration process was studied by means of isoperibolic, isothermal and solution calorimetry. The compressive and flexural strength of most samples used in calorimetric experiments was also determined.
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Reologie v technologii anorganických materiálů / Rheology of Inorganic Materials in TechnologyWirthová, Michaela January 2013 (has links)
Disertační práce se zabývá studiem reologického chování materiálů na bázi cementu. Úvodní část obsahuje teoretické poznatky týkající se reologie a zkoumaných materiálů (cement, samozhutnitelný beton, superplastifikátory). Poté následuje detailní popis reologických vlastností čerstvých cementových materiálů. Kromě toho je dále uvedena hydratace cementu, kalorimetrie, Vicatův test, rentgenová difrakční analýza a elektronová mikroskopie. Experimentální část práce je rozdělena do dvou částí. První část se zabývá základní charakterizací, reologickým měřením a studiem statické meze toku směsí samozhutnitelných betonů a jejich matric. Druhá část se týká cementových past, které byly podrobeny testování pomocí reometru, Vicatova přístroje, isoperibolického a modulárního kalorimetru, rentgenového difraktometru a elektronového mikroskopu.
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Rehydratace alkalicky aktivované strusky po vysokoteplotním namáhání / Rehydration of alkali-activated slag after high temperature loadingFialová, Barbora January 2016 (has links)
Ground granulated blast furnace slag is a by-product of the steel industry and is often used in combination with ordinary Portland cement as a binder in concrete. When concrete is exposed to high temperatures, physical and chemical transformations lead to significant loss of mechanical properties. This study aims to investigate the effect of high temperatures and rehydration on the mechanical properties, microstructure and phase composition of alkali activated slag. The results of the research could make an important contribution to decisions made concerning the reconstruction of structures affected by fire. In suitable cases it would be possible to regenerate parts of a structure instead of totally rebuilding it.
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Vliv částečné náhrady portlandského cementu diatomitovou zeminou na vybrané parametry cementových malt / Effect of partial replacement of Portland cement by diatomaceous earth on selected parameters of cement mortarRousková, Jana January 2016 (has links)
The subject of this thesis is selected parameters cement mortars with partial replacement of Portland cement diatomaceous earth. This work provides information on the basic properties of diatomaceous earth and its deposits with a focus on deposit in Borovany. From the properties is very important pozzolanic activity due to the high content of amorphous silica of this soil. The main use of diatomaceous earth is in the area filtration and is used widely as a nutritional supplement. In the building industry, diatomite can be applied as an admixture to mortar and concrete, where it can, with its abilities, improve some physical mechanical properties. In the experimental part was diatomaceous earth, in its raw and calcined form, tested as admixture for cement pastes and mortars. The main criterion for evaluating these composites was bulk density, flexural and compressive strength. It was also investigated mineralogical composition, microstructure, freeze–thaw resistance and sulfate resistance.
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THE INFLUENCE OF PORE SYSTEM CHARACTERISTICS ON ABSORPTION AND FREEZE-THAW RESISTANCE OF CARBONATED, LOW-LIME CALCIUM SILICATE CEMENT (CSC) BASED MATERIALSHyunGu Jeong (8816915) 08 May 2020 (has links)
This dissertation presents the study of freeze-thaw resistance of carbonated, low-lime calcium silicate cement based paste, mortar, and concrete and the pore system of these materials characterized by MIP, SEM, and image J analysis.
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Stabilität der belasteten dorsalen Verbundinstrumentierung im humanen osteoporotischen thorakolumbalen ModellGerhardt, Julia 28 March 2017 (has links)
In dieser Arbeit wird das Revisionsverhalten kanülierter, fenestrierter Pedikelschrauben
evaluiert. Dies erfolgt zum einen anhand von Messungen des Drehmoments bei dem Entfernen von Pedikelschrauben aus osteoporotischen Wirbelkörpern eines Kadermodells.
Hierbei werden Werte nicht zementierter und zementierter, kanülierter Pedikelschrauben erhoben, verglichen und ausgewertet.
Während der Schraubenexplantation werden etwaig auftretende Rotationsbewegungen des Zements im Wirbelkörper radiografisch detektiert.
Darüber hinaus wird das Revisionsverhalten kanülierter, fenestrierter Pedikelschrauben nach Zementaugmentation in vivo anhand monozentrisch, retrospektiv erhobener Patientenbeispiele aus dem klinischen Alltag beurteilt.
Im Rahmen der Drehmomentmessungen bei Entfernung der kanülierten, fenestrierten Pedikelschrauben nach vorangeganger Zementierung konnte keine Destruktion des Wirbelkörpers beobachtet werden. Auch in den untersuchten Fallbeispielen des klinischen Alltags konnten die zementaugmentierten Pedikelschrauben komplikationslos entfernt werden.
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Hybrid Fabrics as Cement Matrix ReinforcementPeled, Alva, Cohen, Zvi, Janetzko, Steffen, Gries, Thomas January 2011 (has links)
Hybrid systems with two or more fiber materials were used to combine the benefits of each fiber into a single composite product. Strength and toughness optimization of hybrid thin sheet composites has been studied extensively using combination of different fiber types with low and high modulus of elasticity. Hybrid reinforcement is more significant when the reinforcing structure is in fabric geometry. Fabric structure provides full control on the exact location of each yarn and its orientation in the composite during production, thus maximizes the reinforcing efficiency. A high-strength, high-modulus fiber primarily tends to increase the composite strength with nominal improvements in toughness. A low-modulus fiber expected to mainly improve toughness and ductility. Combination of two or more types of fiber can produce a composite that is both strong and tough as compared to a mono fiber composite. The purpose of the current work was to study hybrid warp knitted fabrics as reinforcement for cementbased composite, having AR (Alkali Resistance) glass and Polypropylene (PP) as the reinforcing yarns. The examined ratios between the two different yarns were 0:100, 25:75, 50:50, 75:25, 100:0 (glass: PP, by percentage). It was found that in the hybrid system, the fracture mechanism is a superposition of the mono systems, and the tensile behavior is a combination between the two materials.
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Cement Penetrability Characteristics in Textile Cement SystemsPeled, Alva 03 June 2009 (has links)
Cement penetrability is a key factor in multifilament cement composites. However, the modes of action and the concepts vary because of brittle and ductile fibers. In the case of brittle fibers such as glass, high penetrability of cement products in between the bundle filaments can lead to brittle composite behavior, and therefore addition in ductility is required. In order to have efficient bundle action and high bonding, fillers can be introduced in between the glass filaments, keeping the telescopic mode of failure but at the same time improving the bond and stress transfer within the filaments of the bundle, even at late ages, resulting in a ductile and high strength composite. On the other hand, ductile fibers such as polypropylene (PP), which also developing low bonding with the cement matrix, result in ductile cement composite but with relatively low strength. Therefore, in this case good penetrability of the cement in between the filaments of the bundle is essential in order to maximize the reinforcing efficiency of the bundle by improving bond. The penetrability of the matrix into a fabric structure and especially in between the bundle filaments made up the fabric is a result of fiber- matrix compatibility, which depends on: level of opening and spaces between the filaments, bundle surface properties including wetting and chemical affinity to the cement matrix, matrix viscosity, processing of the composite, and the nature of the fabric junctions and the resulting tightening effects of the bundle, i.e., influenced by the fabric structure itself.
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