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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Možnosti využití popílků po SNCR pro výrobu portlandského cementu / Possibilities of utilization of fly ash from SNCR technology in the production of Portland cement

Kozlová, Romana January 2016 (has links)
The Master thesis deals with utilization possibilities of fly ash after selective non-catalytic reduction (SNCR) process for Portland cement preparation as a correction component to the raw material with regard to contaminated fly ash by ammonium sulphate or ammonium hydrogensulfate that is one of the products from SNCR process. Presented thesis was focused on behaviour of raw meal with ammonia hydrogensulfate contaminated fly ash after SNCR during burning of Portland clinker in simulated kiln conditions. The thesis deals with Portland clinker preparation from this kind of raw mix and it studies mainly clinker quality, clinker phases and structure. Quantitative phase composition of prepared samples of clinker was performed by optical microscopy measurements using point counting method and XRD analysis (Rietveld method). Hydration heat flow of prepared clinker was measured by Isothermal Calorimetry. TG-DTA analysis of prepared raw meal was studied due to better comparison of prepared samples and better understanding of processes during burning process.
22

Vliv technologie mletí na vlastnosti směsných cementů s pucolánovou složkou / Influence of grinding technology on the properties of blended cements with pozzolanic components.

Dočkal, Jakub January 2016 (has links)
The aim of this thesis was to summarize and assess the possibility of using recycled glass in the manufacture of blended portland cements. Work was focused on examining the possibilities to improve pozzolanic properties of recycled glass with new milling processes. The formation of agglomerates material during the course of grinding and their subsequent effect on the hydration process of binders has been also examining. Part of the thesis was also focused on grindability of materials and determination of using separate or inters grinding.
23

Studium vlastností ettringitu v dlouhodobém horizontu / Study of Properties of Ettringite in Long Term Horizon

Křižanová, Lucie January 2018 (has links)
This thesis is focused on monitoring attributes of ettringite in long term horizon, especially on his thermodynamic stability. Ettringit was prepared in two ways. Firstly, it is a method of hydration of yeelimite, secondly, ettringit is prepared by addition of aluminium sulphate and calcium hydroxide.
24

Studium trvanlivosti hmot na bázi účelového vzniku ettringitu / Study of durability of binders concept on purposeful creation of ettringite

Sokolt, Stanislav January 2013 (has links)
This master thesis is focused on the binary and ternary systems with connective purposeful ettringite formation for fast hardening adhesive for ceramic tiles. It deals with the durability of these materials after exposure to the corrosive environment. It examines the physical and mechanical properties and mineralogy changes after exposure to corrosive environments. Within processing of this paper provides basic information concerning the connective concept of purposeful formation of ettringite.
25

Sledování vývoje AFt fází ve směsných portlandských cementech s fluidním popílkem / Monitoring the Development of AFt Phases in Mixed Portland Cement with FBC Ash

Martykán, Jiří January 2016 (has links)
This diploma thesis is focused on evaluation of the possibilities of using FBC ash for production of blended cement and monitoring the hydration process, specially creation of the AFt phases.
26

Vliv oxidů těžkých kovů na tvorbu a vlastnosti portlandského slínku / Influence of heavy metal oxides on the formation and properties of Portland clinker

Kašpárková, Kateřina January 2016 (has links)
The Master’s thesis is focused on a study of the effect of increased content of heavy metals present in a raw meal on the formation and properties of prepared clinker and acquired cement. Main attention is devoted to changes on the physical, mechanical, microstructural and hydration properties. The theoretical part contains an overview of clinker minerals occurring in Portland cement including the possibility of incorporation of heavy metals into their structure and affecting the properities of the cement. In the experimental part, there is compared the effect of heavy metal oxides on the composition and hydration properties of portland clinker and physical-mechanical and microstructural properities of cement pastes prepared from this clinker.
27

Reologické vlastnosti cementových past s přídavkem amorfního SiO2 / Reological properties of cement pastes modified by amorphous SiO2

Zimmermann, Štěpán January 2017 (has links)
The subject of this thesis are the rheological properties of cement paste with the addition of amorphous silicon dioxide. The basic rheological parameters are that describe the behavior of cement pastes in the fresh state. The work also included rheological tests including measurement principle and method of evaluation. Effect of mineral admixtures with high content of amorphous SiO2 is summarized the available scientific articles. In the experimental part, the effects of impurities with a high content of amorphous SiO2 on the rheological properties of fresh cement paste. It was tested by substitution of up to 10 % by weight of cement in the cement pastes mineral admixtures of different chemical composition, particle size and pozzolanic activity. Flow measurement was measured yield value, viscosity, and flow index. The stability of cement pastes was investigated oscillatory measurements. To complement the behavior pastes in the fresh state was determined by calorimetry. Test results were compared with those determined by reference samples and compared the effect of various ingredients.
28

Možnosti využití skelného recyklátu pro přípravu směsných cementů / Possibilities of using recycled glass for the preparation of blended cements

Dobrovolný, Petr January 2015 (has links)
This work focuses on the possibility of using recycled glass in the manufacture of blended portland cements. It examines the possibilities to improve pozzolanic properties of recycled glass with new milling processes, the formation of agglomerates material during the course of grinding and their subsequent effect on the hydration process of binders. It is also the optimization of the grinding process with respect to the wear of grinding bodies, grinding energy consumption and maximize the performance of the mill.
29

Studium alkalicko křemičité reakce v hybridních systémech / Study of alkali-silica reaction in hybrid systems

Bradová, Lada January 2020 (has links)
This study evaluates question of alkali–silica reaction (ASR) in hybrid system, which was designed in the bachelor's thesis, to meet the requirements of EN 197-1 and classified to the Blastfurnace CEM III/C cements. The durability of this system is a great unknown. For this reason, the same methods (ASTM C1260, ASTM C289 and ASTM C856) were used to observer the ASR effects as the ones used to observer the Portland cement based concrete. Supplementary methods include determination of compressive strengths according to EN 196-2 and scanning electron microscopy to observe the microstructure. Hybrid system results were compared to two different types of cements, CEM I and CEM III/B. From the results of the ASR evaluation assays, it was found that the hybrid system (CEM III/C-HB) and CEM III/B showed the lowest tendency to ASR. The results of the supplementary methods showed that CEM III/C-HB compressive strength increases after 14 days within NaOH by 43 % in comparison to 28 days strength. Based on those results, it is sure that the CEM III/C-HB shows little susceptibility to ASR.
30

Možnosti využití slévárenských odprachů / The possibilities of using of foundry filter ash

Solik, Jaroslav January 2012 (has links)
This thesis explores the posibility of using of foundry filter ash for production of inorganic composite materials, that could be used primary in the construction industry. The thesis is divided into theoretical and experimental section, where theoretical section contain literature review of used materials and the experimental section summarizes the results of laboratory tests performed on tested mixture based on portland and alumina cement with various content of foundry filter ash. For comparison was also used another foundry waste - foundry sand. Prepared test bodies with dimension of 40 x 40x 160 mm was subjected to mechanical strength tests and the influence of amount of foundry waste on the strenght of the prepared mixtures was monitored. Next the thesis deals with possibilities of alkaline activation of foundry waste, where sodium water glass, sodium hydroxide and commercially supplied baucis L 160 component B were used as alkaline activator. These test mixtures were also subjected to mechanical strenght tests and the influence of amount of foundry waste on the strenght was observed too. The analysis of input materials were performed by XRF, TG – DTA – EGA and XRD powder diffraction methods. All strength tests were tested by testing equipment desttest 4310.

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