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The thermodynamic stability of etringite
Magrla, Radek ; Durica,, Tibor (referee) ; Bílek,, Vlastimil (referee) ; Brauner,, Josef (referee) ; Fridrichová, Marcela (advisor)
The theoretical part of this doctoral thesis summarizes the current knowledge of portland cement and its manufacturing technology, information of FBC ash, Aft phases, AFm phases and the current knowledge of thermodynamic stability of ettringite. The practical part of the doctoral thesis focuses on manufacturing of ettringite based on yeelimite clinker, studying the influence of environment on thermodynamic stability of ettringite and manufacturing of ettringite by direct addition of calcium hydroxide and aluminum sulfate.
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The influence of barium and its compounds on the formation and properties of Portland clinker
Zezulová, Anežka ; Rovnaníková, Pavla (referee) ; Palou, Martin (referee) ; Ptáček, Petr (advisor)
The work deals with the study of barium cement. Barium cements are used to prepare concrete that protects against ionizing radiation. Barium can be also present in a conventional Portland cement clinker as an impurity from alternative fuels or raw materials, which are increasingly used for clinker production, and thus change the structure and properties of the product. Various methods of preparation of this cement were studied in this work. Barium cements were prepared from raw meals of different composition, but always with the same procedure and burning temperature. Using suitable analytical methods, the work describes the influence of individual admixtures of raw meal on the phase composition of the resulting clinker. Furthermore, the work deals with monitoring the form and location of barium in the prepared clinker. Several experiments are focused on the study of hydration of prepared barium clinkers, the phase transformation is monitored by XRD and supplemented by analyses of hydration products. In this way, it was possible to obtain the data needed to describe the preparation, burning, and hydration of barium cements with different compositions. The work also deals in detail with the real use of barium cements. The ability of pastes and mortars from prepared barium cements to shield various types of ionizing radiation was tested and described experimentally. The results are presented in comparison with reference samples, which were prepared from commonly used Portland cement.
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Hybrid binders containing Portland clinker
Kratochvilová, Lucie ; Hrubý, Petr (referee) ; Opravil, Tomáš (advisor)
This bachelor thesis is focused on the use of cement kiln dust in combination with portland clinker. Cement kiln dust is a fine bulk material which is not good to mix further with cement, due to its unsuitable chemical composition. The aim of the bachelor thesis is to verify the possibilities of using this secondary material as a potential component of hybrid binders. For experimental part were taken several cement kiln dusts from different sources. The evaluation of the prepared binders was similar to Portland cement, the tests were performed according to ČSN EN 196.
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Possibilities of using recycled brick in binders systems with p-clinker content
Tušla, Václav ; Ptáček, Petr (referee) ; Opravil, Tomáš (advisor)
This diploma thesis deals with the preparation binder systems based on Portland clinker and recycled brick. Recycled brick is considered a waste material from construction or production of brick products. This thesis uses finely grounded brick recycled and brick dust, which is produced during final processing of burnt bricks. By incorporating brick dust in alternative system based on Portland clinker could bring ecological and economic benefits. This diploma thesis deals with option using brick dust as pozzolan admixture to Portland clinker, with the aim to prepare and test Portland cement, which is defined in v ČSN EN 197-1. This thesis also deals with possibility preparation of alternative binders based on p-clinker, but those not defined by ČSN EN 197-1. Specifically these are ternary binders with fluid bed ash and binders based on hybrid cements containing sodium sulfate.
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Milling activators use in the Portland clinker production practice
Spurný, Marek ; Kejík, Pavel (referee) ; Svěrák, Tomáš (advisor)
This work deals kinetics of grinding Portland cement clinker which is influenced by addition of grinding inlays surfactants. In an experiment, attritor-type stirred mill was used and surface active grinding additives such as polyethylenglykol (PEG), triethylamin (TEA) and acetate of ammonium were utilized. Granulometric distribution graph obtained from laser diffraction analysis provides data for plotting development diagrams for milling process.
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Study of Phase Changes During Portland Clinker Firing
Pertlová, Alena ; Fridrichová, Marcela (referee) ; Gazdič, Dominik (advisor)
The presented bachelor thesis deals with monitoring of transformations during the burning of cement clinker. The theoretical part is devoted to the theories regarding the burning of Portland clinker and to the description of clinkers properties in general. The focus is put on the modern low-energy clinkers as well. Moreover, the thesis deals with several methods for determining the phase composition of cement clinker including HT-XRD analysis, which allows to monitor the behaviour of individual phases at high temperatures besides the determination of the phase composition. In the experimental part, there is introduced the project proposal of the model raw mixture used to produce ordinary Portland clinker and raw mixture of low-energy ternesite clinker. Furthermore, the thesis shows HT-XRD analysis done in the high temperature chamber, followed by the evaluation of results and their comparison with the theoretical background.
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Milling activators use in the very fine powder material practice.
Spurný, Marek ; Kejík, Pavel (referee) ; Svěrák, Tomáš (advisor)
This work deals kinetics of grinding Portland cement clinker which is influenced by addition of grinding inlays surfactants. In an experiment, attritor-type stirred mill was used and surface active grinding additives such as polyethylenglykol (PEG), triethylamin (TEA) and acetate of ammonium were utilized. Granulometric distribution graph obtained from laser diffraction analysis provides data for plotting development diagrams for milling process.
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Specification of the phase composition of Portland clinker
Vávrová, Alžběta ; Dlabajová, Lucie (referee) ; Másilko, Jiří (advisor)
This bachelor thesis deals with the determination of the phase composition of portland clinker and its optimization. The X-ray fluorescence spectroscopy, X-ray diffraction analysis and optical microscopy were used to solve this task. In the experimental section, X-ray fluorescence spectrometry results were used to calculate the potential phase composition of the clinker using the Bogue method. Then the X-ray diffraction analysis followed, it was used not only to determine the phase composition but also to determine amorphous content in the clinker. The microscope integration method was used to study the samples using optical microscopy. The obtained results were compared with each other and the main deficiencies of the individual methods were identified.
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The Role of Ferrous Sulphate as a Setting Regulator and a Portland Clinker Reduction Agent
Mončeková, Miroslava ; Rovnaníková, Pavla (referee) ; Drábik, Milan (referee) ; Havlica, Jaromír (advisor)
In 2003, the European Community Obligation (directive 2003/5C/EC) regulates a maximal value of soluble hexavalent chromium to 0.0002 % (per weight of dry cement). This limitation leads to modifications of the regular Portland cement by using of suitable reduction agents. Therefore, the possibilities of chromium reduction become a very actual topic. The primary goal of this work is a basic research of the ferrous sulphate influence on hexavalent chromium reduction and also its influence on Portland clinker hydration process. The reduction ability was determined by UV/VIS method. The mechanism and ferrous sulphate influence on Portland clinker hydration process was observed by isothermal calorimetry and mechanical strength tests. XRD method, SEM-EDS analysis and Raman microscopy were used for identification of formed hydration products. Study of hydration mechanism occurring in this system was focused on the divergence observations from the regular Portland cement hydration. Pore solution analysis provided significant information about chromium behavior during the hydration process (substitution and releasing). Chromium incorporation into structure of hydration products during the reduction process was also studied in the pure tricalciumaluminate system with targeted Cr6+ content. This work suggests the possible substitution of the trivalent and hexavalent chromium into structure of monosulphate (AFm) phase.
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