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Characterization of portland cement hydration products by thermal dilatometric analysis
Dvořáková, Tereza ; Švec, Jiří (referee) ; Šoukal, František (advisor)
The paper presents the results of thermal dilatometric analysis of cement pastes during the heating at high temperatures. Volume changes were observed in samples of cement paste at selected time intervals during the hydration. Based on the measured data the dTDAc urves course has been described and the results have been compared with the curves of differential thermal analysis. To characterize the microstructure of the cement paste during the considerable shrinkage at higher temperatures the images by scanning electron microscope have been acquired.
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Effect of cement by-pass dust on properties alkali-activated slag
Janíčková, Vlasta ; Kalina, Lukáš (referee) ; Bílek, Vlastimil (advisor)
This masters thesis deals with influence of cement bypass kiln dust on physico-mechanical properties of alkali activated slag and influence of chosen compounds of cement bypass kiln dust on alkali activated slag. Using alkali activated slag is limited by its shrinkage. The setting time with different amount of cement bypass kiln dust and its chosen compounds (CaO, KCl and K2SO4) were measured by isotermal and isoperibolic calorimetry too. The strength and length changes of the mixtures with different amount of cement bypass kiln dust were measured. Samples were analysed by X-Ray diffraction analysis and scanning electron microscopy. It has been found that the increasing addition of dust reduce setting time, flexural and compresive strength and shrinkage. Presence of free CaO was found being one of the reasons for accelerated setting. KCl and K2SO4 have retarding effect but influece of free CaO prevails even for its lower contents. Long-term properties evolution is strongly dependent on curing regime due to potential volume expansion.
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Effect of cement by-pass dust on properties alkali-activated slag
Janíčková, Vlasta ; Kalina, Lukáš (referee) ; Bílek, Vlastimil (advisor)
This masters thesis deals with influence of cement bypass kiln dust on physico-mechanical properties of alkali activated slag and influence of chosen compounds of cement bypass kiln dust on alkali activated slag. Using alkali activated slag is limited by its shrinkage. The setting time with different amount of cement bypass kiln dust and its chosen compounds (CaO, KCl and K2SO4) were measured by isotermal and isoperibolic calorimetry too. The strength and length changes of the mixtures with different amount of cement bypass kiln dust were measured. Samples were analysed by X-Ray diffraction analysis and scanning electron microscopy. It has been found that the increasing addition of dust reduce setting time, flexural and compresive strength and shrinkage. Presence of free CaO was found being one of the reasons for accelerated setting. KCl and K2SO4 have retarding effect but influece of free CaO prevails even for its lower contents. Long-term properties evolution is strongly dependent on curing regime due to potential volume expansion.
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Characterization of portland cement hydration products by thermal dilatometric analysis
Dvořáková, Tereza ; Švec, Jiří (referee) ; Šoukal, František (advisor)
The paper presents the results of thermal dilatometric analysis of cement pastes during the heating at high temperatures. Volume changes were observed in samples of cement paste at selected time intervals during the hydration. Based on the measured data the dTDAc urves course has been described and the results have been compared with the curves of differential thermal analysis. To characterize the microstructure of the cement paste during the considerable shrinkage at higher temperatures the images by scanning electron microscope have been acquired.
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