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Development of Composite Mortar and Cement Mixtures
Hlavinková, Eva ; Gemrich, Jan (referee) ; Fridrichová, Marcela (advisor)
This diploma thesis deals with the design of composition and the study of properties of the ternary binding system based on purposeful ettringite formation, which was subsequently used for the preparation of self-leveling floor materials, specifically self-levelling underlay and thin-layer floor screed. In the designed compositions of the mixtures is then focused attention on optimizing the dosage of two kinds of plasticizer agents, followed by assessing their impact on the technological properties of these materials.
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Utilization of liquefied soils in the form of backfilling self-compacting grouts
Chlachula, Jakub ; Krejčí, Pavel (referee) ; Drochytka, Rostislav (advisor)
The bachelor thesis focuses on the research of liquefied soils based on backfilling self compacting grouts. These grouts could be used as bedding for utility lines with lower cost and without unnecessary waste. The prerequisite is that the soil will be stabilized by a suitable stabilizing admixture, which should increase the strength of the composite. It will be necessary to liquefy this composite by using water and suitable liquefaction or plasticizers. As part of this thesis, currently known and used stabilizing admixture and plasticizers are also evaluated, same as the geological situation in the Czech Republic.
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The possibilities regulation of production hydration heat of concrete with plasticizer
Hermann, Radek ; Halas, Vladimír (referee) ; Sedlmajer, Martin (advisor)
This thesis studies the problematics of water reducing and high range water reducing admixtures and their influence on the process of hydration of cement pastes. The process of hydration is examined in this thesis both in terms of hydration heat and hydration temperature rise. Attention is also paid to the influence of plasticizers in combination with retarding admixture regarding rheological properties of modified fresh cement pastes and their mechanical properties after 3 and 7 days from mixing.
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Mixing cement for special purposes
Hrdina, Matěj ; Kulísek, Karel (referee) ; Fridrichová, Marcela (advisor)
Thesis deals with the technology of production of portland cement its raw material composition, mineralogical composition, theory of clinker minerals during firing and possible mixing with other materials suitable character. It provides an overview of specialty cements. It was prepare a proposal cement mixtures normatively called "Masonry cement." Cement was examined on required properties depending on the amount and the type of chemical additives.
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Action of organic additives in various alkali-activated binders
Markusík, David ; Kalina, Lukáš (referee) ; Bílek, Vlastimil (advisor)
This thesis explores the influence of admixtures (lignosulfonate plasticizer, hexylene glycol) on the rheology of AAM. With the characterized precursors, the rheology of AAM without admixtures is examined based on the chosen activator. Then the influence of the additives was measured. Rheological measurements were complemented by the determination of LS admixture adsorption on chosen precursors in solutions of NaOH, NaVS, and Na2CO3, and the determination of zeta potential of chosen plastified AAP. For comparison, measurements of cement pastes with the same admixtures were made in parallel to the AAM. the ability of plasticizer to improve the workability of slag and fly ash-based AAM when activated by NaOH was observed. No plastifying effect was found in MK-based pastes in none of the studied environments. The rheological measurements are in accord with most of the measured adsorptions and determined zeta potentials. In the case of hexylene glycol, the rheology of pastes is primarily influenced by the combination of precursors and admixtures. With hexylene glycol admixture the NaVS activator is inapplicable because silicates and hexylene glycol interact and worsen the rheological properties of the AAP.
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The development of self-compacting concrete with fast runs of strength and elasticity modulus
Skřivánek, Michal ; Hela,, Vlastimil (referee) ; Hela, Rudolf (advisor)
My bachelor thesis is about a development of self-compacting concrete. The main advantage of this method is a shorter duration of producing strength concrete and also modulus of elasticity. My analysis consists of describing self-compacting concrete properties, methods for speeding up the process of building strength concrete from less effective heating to using advanced concrete admixtures. Further, an important chapter about influence of concrete mixture composition on modulus of elasticity measurements and in-depth analysis of the SCC mixture composition. Theoretical part is ended by a summary of SCC properties in a fresh or hardened state – all experiment specifics are included. In order to deliver a shorter duration of producing strength concrete and modulus of elasticity in early stages of curing, every SCC mixture mentioned in practical part have been carefully created based on achieved theoretical knowledge with a goal to minimize the impact on rheology of concrete mixture.
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Technology design watertight concrete
Skřivánek, Michal ; Hubertová,, Michala (referee) ; Hela, Rudolf (advisor)
My work describes technology design of pervious concrete. The theoretical part contains a research about this kind of concrete usually from foreign authors. In general, I focused on the composition of the PC, aggregate grading curve, behaviour of concrete in fresh state, storing and compaction of concrete. A critical part is the aggregate grading curve – it plays the main role in the final level of water permeability. Further, we will go through the real world scenarios where we can use this type of concrete and also through the associated drawbacks. A substantial part of this work is about development of water-permeability test. The practical part shows variety of recipes with a list of measured and observed characteristics (compressive strength, frost resistence and water-permeability). The conclusion includes evaluation of the results and suggestions for future development in this area.
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Development a new technology of liquefaction and soil stabilization
Chlachula, Jakub ; Krejčí, Pavel (referee) ; Drochytka, Rostislav (advisor)
Nowadays, efforts are being made to reduce the environmental impact on the planet even at soils management. Excavated soils are treated as waste and often end up in landfill or depot landfills. It is an effort to exploit these soils. By adding suitable stabilizing additives, features such as yield fluidity, moisture or compressive strength can be adjusted. This composite can be further liquefactioned by using water and suitable liquefiers or plasticizers. Such iquefactioned soils are a suitable self-compacting grouts dressing for excavation for the laying of utility grids, where it is necessary to fill the hole again. The advantage are low economic demands and the absence of excess waste. In the course of this thesis the situation of soil usability in the Czech Republic will be evaluated and possible technologies of soil adjusters will be described. Further, the known types of stabilizing additives and their influence on soil stabilization will be evaluated and verified. Then, different types of liquefying additives will be evaluated and verified. The aim of the thesis is to develop a new technology of liquefaction and soil stabilization.
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