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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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Reactive powder concretes (RPC) with polymer latexes
Petrů, Ludmila ; Koplík, Jan (referee) ; Šoukal, František (advisor)
This thesis deals with the effect of polymeric latexes on the properties of concrete based on reactive powders. Three types of commercial latexes were used for the preparation of the samples, namely Revacryl, Duvilax and Plextol. Revacryl AE 2091 is an aqueous dispersion of styrene-acrylate copolymer with a high content of solids. Duvilax BD-20 is a homopolymer polyvinyl acetate dispersion that does not contain fillers with plasticizers. Plextol X 4002 is an aqueous, self-setting acrylic emulsion with a high content of solids. These latexes were added to the samples at concentrations of 0,20; 0,40; 0,60; 1,20 and 2,50 %. To determine the effect of latex on processability, the flow rate of the fresh mixture was measured. The main objective was to determine the ballistic resistance of modified concretes based on reactive powders. The DOP test was used for the determination. Furthermore, the change in mechanical properties was determined by adding a polymer to concrete based on reactive powders. The improvement in properties is expected to be due to the formation of a polymer film and a polymer-cement co-matrix. To demonstrate the film formation, the microstructure of the samples was observed by a raster electron microscope.
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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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