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Changes of slag particles during its alkaline activation
Petrů, Ludmila ; Hrubý, Petr (referee) ; Bílek, Vlastimil (advisor)
This bachelor thesis deals with changes of slag particles during its alkaline activation. The altered parts of the slag as well as the course of the alkaline activation varies depending on the activator used, and therefore suspensions of blast furnace slag in sodium hydroxide, water glass, sodium carbonate and, for comparison, in water were prepared. Slag particles were isolated from these suspensions at selected time intervals (5 min, 30 min, 1 h, 2 h, 5 h and 24 h) for particle size analysis and evaluation of BET specific surface. After solidification, the microstructure of the samples was observed using an electron microscope. To better assess the reaction processes, the pore solution was isolated from the suspensions and its composition was analyzed using optical emission spectrometry in inductively coupled plasma. The hydration process was monitored using isothermal calorimetry.
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The binder based on the high-calcium ash - the influence of the alkali activator
Šichnárek, Vojtěch ; Kotrla, Jan (referee) ; Koplík, Jan (advisor)
The aim of this thesis was examination of the influence of different alkali activators to final properties of binders based on fluidized bed combustion fly ash. There were prepared mixtures containing sodium waterglass or sodium carbonate. Curing time, consistence, and strengths after 2, 7, 14 and 28 days were measured. X-ray diffraction and X-ray fluorescence were used to find out the composition of samples. There were taken images and element spectra using scanning electron microscope and isothermal calorimetry was used to determine the heat flow during the time of curing. The results indicate that the use of water glass achieves better initial workability and pressure strengths are higher than besides sodium carbonate. However, when sodium carbonate is used, pressure strengths are lower, but they are less dependent on the amount of the activator and do not change as much with time. Crystallographic composition is dependent to the activator used – by using sodium waterglass there was more of ettringite and portlandite in the sample.
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Changes of slag particles during its alkaline activation
Petrů, Ludmila ; Hrubý, Petr (referee) ; Bílek, Vlastimil (advisor)
This bachelor thesis deals with changes of slag particles during its alkaline activation. The altered parts of the slag as well as the course of the alkaline activation varies depending on the activator used, and therefore suspensions of blast furnace slag in sodium hydroxide, water glass, sodium carbonate and, for comparison, in water were prepared. Slag particles were isolated from these suspensions at selected time intervals (5 min, 30 min, 1 h, 2 h, 5 h and 24 h) for particle size analysis and evaluation of BET specific surface. After solidification, the microstructure of the samples was observed using an electron microscope. To better assess the reaction processes, the pore solution was isolated from the suspensions and its composition was analyzed using optical emission spectrometry in inductively coupled plasma. The hydration process was monitored using isothermal calorimetry.
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The binder based on the high-calcium ash - the influence of the alkali activator
Šichnárek, Vojtěch ; Kotrla, Jan (referee) ; Koplík, Jan (advisor)
The aim of this thesis was examination of the influence of different alkali activators to final properties of binders based on fluidized bed combustion fly ash. There were prepared mixtures containing sodium waterglass or sodium carbonate. Curing time, consistence, and strengths after 2, 7, 14 and 28 days were measured. X-ray diffraction and X-ray fluorescence were used to find out the composition of samples. There were taken images and element spectra using scanning electron microscope and isothermal calorimetry was used to determine the heat flow during the time of curing. The results indicate that the use of water glass achieves better initial workability and pressure strengths are higher than besides sodium carbonate. However, when sodium carbonate is used, pressure strengths are lower, but they are less dependent on the amount of the activator and do not change as much with time. Crystallographic composition is dependent to the activator used – by using sodium waterglass there was more of ettringite and portlandite in the sample.
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