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Surface treatment of cementitious systems by silicate sealers
Iliushchenko, Valeriia ; Šoukal, František (oponent) ; Kalina, Lukáš (vedoucí práce)
Silicate-based impregnations are widely used for to protect concrete against the aggressive environment. Nevertheless, understanding of the several aspect concerning to this type of impregnation is not entirely clear. This thesis presents the information about individual properties of selected silicates, more precisely potassium, sodium, lithium silicates and colloidal silica, then effectiveness in terms of water absorption, degree the effect on cement hydration, the ability of these agents to close pores and the influence on the microstructure of the cement substrate as well as penetration capability. The effectiveness of film-forming substances was assessed both on fresh cement and on more hydrated ones, applied after 1 hour and 24 hours after mixing the mixture, respectively. Instrumental methods such as mercury porosimetry, rheometry, isothermal calorimetry, X-ray diffractometry and scanning electron microscopy were used to achieve quality results. Considering to the tests performed, a certain effectiveness of the care agents was proved. The results of all tests showed a higher efficiency of these substances in the case of treatment on a more hydrated cement surface, which was probably due to a higher degree of hydration resulting in the creation of new phases with which silicates were able to react and in some way affect the microstructure.
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Thermal analysis methods application for characterisation of sol-gel binding system for ceramic materials
Cesnek, Ľuboš ; Másilko, Jiří (oponent) ; Švec, Jiří (vedoucí práce)
The master thesis deals with the study of the binder system of silica sol and its characterization mainly by methods of thermal analysis. The master thesis also uses method of rheology to determine the gelatinization time, method of TG/DTA do analyse the exo and endothermic effects during heating, the method of FT-IR to quickly determine the composition of samples, method of XRD to analyze phase composition of the samples and the method of SEM to observe the topography of the samples. MgO is used as a gelling agent, reactive alimina is used as a filler.
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Thermal analysis methods application for characterisation of sol-gel binding system for ceramic materials
Cesnek, Ľuboš ; Másilko, Jiří (oponent) ; Švec, Jiří (vedoucí práce)
The master thesis deals with the study of the binder system of silica sol and its characterization mainly by methods of thermal analysis. The master thesis also uses method of rheology to determine the gelatinization time, method of TG/DTA do analyse the exo and endothermic effects during heating, the method of FT-IR to quickly determine the composition of samples, method of XRD to analyze phase composition of the samples and the method of SEM to observe the topography of the samples. MgO is used as a gelling agent, reactive alimina is used as a filler.
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Surface treatment of cementitious systems by silicate sealers
Iliushchenko, Valeriia ; Šoukal, František (oponent) ; Kalina, Lukáš (vedoucí práce)
Silicate-based impregnations are widely used for to protect concrete against the aggressive environment. Nevertheless, understanding of the several aspect concerning to this type of impregnation is not entirely clear. This thesis presents the information about individual properties of selected silicates, more precisely potassium, sodium, lithium silicates and colloidal silica, then effectiveness in terms of water absorption, degree the effect on cement hydration, the ability of these agents to close pores and the influence on the microstructure of the cement substrate as well as penetration capability. The effectiveness of film-forming substances was assessed both on fresh cement and on more hydrated ones, applied after 1 hour and 24 hours after mixing the mixture, respectively. Instrumental methods such as mercury porosimetry, rheometry, isothermal calorimetry, X-ray diffractometry and scanning electron microscopy were used to achieve quality results. Considering to the tests performed, a certain effectiveness of the care agents was proved. The results of all tests showed a higher efficiency of these substances in the case of treatment on a more hydrated cement surface, which was probably due to a higher degree of hydration resulting in the creation of new phases with which silicates were able to react and in some way affect the microstructure.
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