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Possibilities of using plasticizers and superplasticizers in alkali-activated systems
Langová, Markéta ; Švec, Jiří (referee) ; Kalina, Lukáš (advisor)
Bachelor thesis deals with the preparation and properties alkali activated blast furnace slag after addition of the different types of plasticizers and superplasticizers with the different weight percentage amount. The aim of this thesis is to find suitable plasticizers or superplasticizers which would improve both workability and mechanical properties of alkali activated blast furnace slag. The effect of these admixtures on compressive and flexural strength was determined. In conclusion the behaviour of plasticizing admixtures in alkaline environment through the infrared spectrometry is studied.
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The Study of Aditives and Admixture Influence on High-Performance Concrete Properties
Šiler, Pavel ; Bílek, Vlastimil (referee) ; Brandštetr, Jiří (referee) ; Havlica, Jaromír (advisor)
The aim of this work was to develop the method for the determination of the superperplasticizers (SP) content in the water solution. The method developed was then applied to study the SP adsorption on the individual components used for high-performance concrete and the influence of the temperature and pH values over this adsorption. Furthermore the influence of the water to binder ratio, SP, finely grounded granulated blast furnace slag, fly ash, silica fume, finely ground silica sand and bauxite on the hydration process was studied by means of isoperibolic, isothermal and solution calorimetry. The compressive and flexural strength of most samples used in calorimetric experiments was also determined.
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Gypsum free cements with retarded setting by plastisizer and alkali compond
Sedlařík, Tomáš ; Ptáček, Petr (referee) ; Havlica, Jaromír (advisor)
This thesis deals with preparation of gypsum free cements with retarded solidification. It focuses on their preparation by alkali activation with addition of superplasticizers and without superplasticizers. The main aim of this work is to suggest substitution of gypsum in Portland cement by other materials. Ash after fluidized combustion was chosen as a good compensatory raw material with respect to sustainable development. Milled fluidized bed ash from heating station Třinec was tested. Examined pastes were prepared by alkali activation. 50% solution NaOH and sodium water-glass were used as alkali activators. Trial specimens (20x20x100 mm) were prepared from pastes. Measurements of calorimetric properties of unprocessed pastes tested mixtures were implemented. Bending and compressive strength of pastes were also explored.
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Improving of dispersion of silica fume in high performance concrete
Janča, Martin ; Koutný, Ondřej (referee) ; Šiler, Pavel (advisor)
The goal of this work was to create a method for improving the dispersion of silica fumes for use in high performance concrete. Traditional methods used to design and manufacture high performance concrete emphasize the removal of coarse aggregates. Use of specially sorted fine aggregates at relatively low doses, the use of super-plasticizers and siliceous excrement. The low water content was achieved by using superplasticizer on a polycarboxylate basis. The standard ultrasound technology found in each laboratory was selected for the dispersion of silica fume. For experiments were we used dry silica fume powder and aqueous stabilized suspension. For comparison, were prepared different mixtures which showed the effects of the treatment prior to the use of silica fume.
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The possibilities of utilization of scoira from high-temperature combustion of coal
Dobeš, Jiří ; Švec, Jiří (referee) ; Opravil, Tomáš (advisor)
This thesis deals with the possibility of usage boiler slag in construction industry and related fields. Within this study is observed the influence of the amount of added boiler slag on the properties of pastes and mortars based on Portland cement. The influence of the addition of superplasticizer was further studied as well. The prepared samples were tested for mechanical properties such as tensile strength, bending and compression strength in the time dependence of the standard wet storage. The obtained data were further processed and evaluated.
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Improving of dispersion of silica fume in high performance concrete
Janča, Martin ; Koutný, Ondřej (referee) ; Šiler, Pavel (advisor)
The goal of this work was to create a method for improving the dispersion of silica fumes for use in high performance concrete. Traditional methods used to design and manufacture high performance concrete emphasize the removal of coarse aggregates. Use of specially sorted fine aggregates at relatively low doses, the use of super-plasticizers and siliceous excrement. The low water content was achieved by using superplasticizer on a polycarboxylate basis. The standard ultrasound technology found in each laboratory was selected for the dispersion of silica fume. For experiments were we used dry silica fume powder and aqueous stabilized suspension. For comparison, were prepared different mixtures which showed the effects of the treatment prior to the use of silica fume.
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The Study of Aditives and Admixture Influence on High-Performance Concrete Properties
Šiler, Pavel ; Bílek, Vlastimil (referee) ; Brandštetr, Jiří (referee) ; Havlica, Jaromír (advisor)
The aim of this work was to develop the method for the determination of the superperplasticizers (SP) content in the water solution. The method developed was then applied to study the SP adsorption on the individual components used for high-performance concrete and the influence of the temperature and pH values over this adsorption. Furthermore the influence of the water to binder ratio, SP, finely grounded granulated blast furnace slag, fly ash, silica fume, finely ground silica sand and bauxite on the hydration process was studied by means of isoperibolic, isothermal and solution calorimetry. The compressive and flexural strength of most samples used in calorimetric experiments was also determined.
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