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Synthesis, properties and product of hydration of strontium aluminate cement
Kocián, Karel ; Bartoníčková, Eva (referee) ; Ptáček, Petr (advisor)
This diploma thesis deals with non-traditional binder, which is strontium aluminate, with his preparation and hydration. The behaviour of binary and ternary mixtures of strontium-calcium-barium aluminates was also studied. These aluminates were prepared by firing an equimolar mixture of aluminum oxide and the appropriate carbonate. Samples prepared this way, including their mixtures, were characterized by analytical methods such as X-ray diffraction analysis (XRD), thermal analysis with evolved gas analysis (TG-DTA and EGA), scanning electron microscopy (SEM), infrared spectroscopy (IR) and calorimetry, with the greatest importance for the study of the hydration process.
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The influence of hydration accelerators on cement doped with zinc
Beneš, Pavel ; Šilerová,, Iva (referee) ; Šiler, Pavel (advisor)
Zinc in cement has negative properties mainly due to a significant delay in hydration. This bachelor thesis deals with the study of hydration of cements containing zinc. The course of cement hydration was monitored by isoperibolic calorimetry. Zinc was doped to CEM I 42.5 R in the form of 1 weight percent zinc oxide. Calcium oxide, formic acid and calcium formate were used in various proportions as accelerators. The obtained results were compared with the measured strengths and finally the suitability of the given accelerators was discussed for use in construction application.
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Influence of zinc on mechanical properties of cement composites
Štarha, Tomáš ; Šilerová,, Iva (referee) ; Šiler, Pavel (advisor)
The theme of this bachelor thesis is to monitor the effect of zinc on mechanical properties of portland cement. Zinc was tested in the form of zinc oxide. Three acceleration additives were added, calcium oxide, formic acid and calcium formate in various proportions. Furthermore, the mechanical properties of all these mixtures were monitored by measuring flexural strength and compressive strength at 7 and 28 days after mixing and mixtures were analyzed by XRD and DTA. Also using isoperibolic calorimetry, the hydration of CEM 42.5 R cement zinc oxide was monitored.
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Preparation and Properties of Roman Cement
Opravil, Tomáš ; Palou, Martin (referee) ; Škvára, František (referee) ; Havlica, Jaromír (advisor)
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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Influence of hydration accelerators on zinc - doped cement mortars
Beneš, Pavel ; Šilerová, Iva (referee) ; Šiler, Pavel (advisor)
This work deals with monitoring the hydration of cement mortars and cement pastes made from CEM I 42.5 R cement doped with zinc oxide in an amount of 1 % wt. To eliminate the delay in the onset of hydration due to the presence of zinc oxide, the following accelerators were added to the cement mixtures in different proportions: calcium oxide, formic acids and calcium formate. Hydration was monitored using isoperibolic calorimetry. Furthermore, the mechanical properties of mixtures were investigated, namely the tensile strength after bending and the compressive strength after 7 days and after 28 days. The cement mortars were further subjected to additional analyses, such as porosimetry, DTA/TG and SEM.
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Influence of zinc on mechanical properties of cement composites
Štarha, Tomáš ; Šilerová,, Iva (referee) ; Šiler, Pavel (advisor)
The theme of this bachelor thesis is to monitor the effect of zinc on mechanical properties of portland cement. Zinc was tested in the form of zinc oxide. Three acceleration additives were added, calcium oxide, formic acid and calcium formate in various proportions. Furthermore, the mechanical properties of all these mixtures were monitored by measuring flexural strength and compressive strength at 7 and 28 days after mixing and mixtures were analyzed by XRD and DTA. Also using isoperibolic calorimetry, the hydration of CEM 42.5 R cement zinc oxide was monitored.
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The influence of hydration accelerators on cement doped with zinc
Beneš, Pavel ; Šilerová,, Iva (referee) ; Šiler, Pavel (advisor)
Zinc in cement has negative properties mainly due to a significant delay in hydration. This bachelor thesis deals with the study of hydration of cements containing zinc. The course of cement hydration was monitored by isoperibolic calorimetry. Zinc was doped to CEM I 42.5 R in the form of 1 weight percent zinc oxide. Calcium oxide, formic acid and calcium formate were used in various proportions as accelerators. The obtained results were compared with the measured strengths and finally the suitability of the given accelerators was discussed for use in construction application.
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Problematics of mountaineers' nutrition
Honzejková, Kateřina ; Vilikus, Zdeněk (advisor) ; Vágnerová, Tereza (referee)
Nutrition of both professional and occasional climbers in high altitude is often discussed topic in sports nutrition. Specially with latest studies showing connection between poor nutrition and high altitude sickness development. Dehydration in particular has a huge effect on the body at these altitudes and can be responsible for many of the symptoms previously attributed to hypoxia. The research was focused on the theoretical part, in which basic issue of nutrition and hydration are shown, as well as the acute issues that climbers may have experience on their journey to high altitude. The practical part was evaluated by a quantitative approach with the help of a questionnaire survey and its evaluation. The questionnaire was anonymous, nonstandardized with open and closed questions. A total of 68 respondents participated in the research. The results of the investigation are evaluated and discussed in the final parts of the thesis. The main objective of the thesis was focused on the dietary habits of respondents during their stay in high altitude, their awareness of the risks resulting from poor nutrition and dehydration and assess how much care respondents take about nutrition and hydration during their travels. Four hypotheses were set for the thesis. Key words: Nutrition; hydratation; acute...
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Computational Study of the Properties and Reactivity of Bioinroganic Transition Metal Complexes
Baxová, Katarína ; Burda, Jaroslav (advisor) ; Sochorová Vokáčová, Zuzana (referee)
This work is focused on the reactions of diaqua-tetrakis(μ-acetylato)dirhodium(II,II) with guanine, that shows anti-cancer activities. Guanine can bond to the complex either by oxygen O6 or by nitrogen N7. We studied three possible versions of the system - one that is protonated on guanine, one protonated on the paddle-wheel and a neutral one. For all 6 reactions transition structures were found. For reactants, tranzition states and products we computed the values of electron density in the critical points of bonds, partial atom charges and the interaction energies of the system, guanine and water on the b3lyp/aug-cc- pvdz level. Pseudobasis and pseudopotentials were employed in the case of rhodium atom. For all the reactions thermodynamical properties were computed. Powered by TCPDF (www.tcpdf.org)
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Preparation and Properties of Roman Cement
Opravil, Tomáš ; Palou, Martin (referee) ; Škvára, František (referee) ; Havlica, Jaromír (advisor)
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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