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Bigots Curve for the Determination of Plastic Body Properties
Suk, Vojtěch ; Nevřivová, Lenka (referee) ; Sokolář, Radomír (advisor)
This bachelor thesis is focused on the use of the Bigot curve as a tool for assessing the performance of plastic ceramic materials. The theoretical thesis is a form of research of available literature. It elaborates a general view on the Bigot curve and possible application properties which derive from it for some specific soil. In the experimental part were determined properties of plastic ceramic material from location Jirčany from which were formed samples made of plastic dough with different moisture content, with the addition of grog and additives. Properties such as shape of Bigot curve, critical moisture value, size of drying shrinkage and drying sensitivity of the soil were monitored on the samples.
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Influence of ionts on the efficiency of shrinkage reducing admixtures in alkali activated systems
Vašíčková, Kateřina ; Bílek, Vlastimil (referee) ; Kalina, Lukáš (advisor)
Alkali activated materials, especially when activated with waterglass, are subjected to substantial drying shrinkage that hinders their broader industrial application. The effect of shrinkage reducing admixtures (SRA), based on poly(propylene glycol), on drying shrinkage of alkali activated blast furnace slag (BFS) mortars was studied. The aim of this thesis is to determine the efficiency of SRA as well as the influence of different type of alkali activator with varying silicate modulus on drying shrinkage characteristics. It was observed that the high amount of alkalis positively influenced the effect of SRA. The higher the amount of alkalis, the lower the drying shrinkage was. It also caused more water to be incorporated in the alkali activated structure and prevent it from evaporation. Thus, the weight change of such mortars was the lowest. Reduced effect of SRA on mechanical strength properties was observed in mortars with low amount of alkalis which was connected with delayed hydration resulting in insufficient amount of created C-S-H gel. The presented thesis further discussed and underlines the role of different kinds of alkali ions as well as their amount on the properties of alkali activated BFS systems.
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Study of possibilities of reduction of volume changes and development of hydration temperatures in concrete
Pikna, Ondřej ; Ťažký, Tomáš (referee) ; Hela, Rudolf (advisor)
Volume changes are one of the priority characteristics of concrete that plays an important role place mainly in the durability of structures as such. These low volume changes are required especially for structures as: industrial concrete floors, massive structures and waterproof structures. One of the possibilities in reducing these changes is the use of mineral admixtures with suitable grain curve of aggregate. Another possibility is the use of shrinkage reducing admixtures. There can occur problem with efficiency (long term age) with other components of the mixture. Therefore, the effort of this work is to use the avaible processes for maximum reduction of shrinkage and hydration temperatures.
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Study of possibilities of reduction of volume changes and development of hydration temperatures in concrete
Pikna, Ondřej ; Ťažký, Tomáš (referee) ; Hela, Rudolf (advisor)
Volume changes are one of the priority characteristics of concrete that plays an important role place mainly in the durability of structures as such. These low volume changes are required especially for structures as: industrial concrete floors, massive structures and waterproof structures. One of the possibilities in reducing these changes is the use of mineral admixtures with suitable grain curve of aggregate. Another possibility is the use of shrinkage reducing admixtures. There can occur problem with efficiency (long term age) with other components of the mixture. Therefore, the effort of this work is to use the avaible processes for maximum reduction of shrinkage and hydration temperatures.
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Influence of ionts on the efficiency of shrinkage reducing admixtures in alkali activated systems
Vašíčková, Kateřina ; Bílek, Vlastimil (referee) ; Kalina, Lukáš (advisor)
Alkali activated materials, especially when activated with waterglass, are subjected to substantial drying shrinkage that hinders their broader industrial application. The effect of shrinkage reducing admixtures (SRA), based on poly(propylene glycol), on drying shrinkage of alkali activated blast furnace slag (BFS) mortars was studied. The aim of this thesis is to determine the efficiency of SRA as well as the influence of different type of alkali activator with varying silicate modulus on drying shrinkage characteristics. It was observed that the high amount of alkalis positively influenced the effect of SRA. The higher the amount of alkalis, the lower the drying shrinkage was. It also caused more water to be incorporated in the alkali activated structure and prevent it from evaporation. Thus, the weight change of such mortars was the lowest. Reduced effect of SRA on mechanical strength properties was observed in mortars with low amount of alkalis which was connected with delayed hydration resulting in insufficient amount of created C-S-H gel. The presented thesis further discussed and underlines the role of different kinds of alkali ions as well as their amount on the properties of alkali activated BFS systems.
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Bigots Curve for the Determination of Plastic Body Properties
Suk, Vojtěch ; Nevřivová, Lenka (referee) ; Sokolář, Radomír (advisor)
This bachelor thesis is focused on the use of the Bigot curve as a tool for assessing the performance of plastic ceramic materials. The theoretical thesis is a form of research of available literature. It elaborates a general view on the Bigot curve and possible application properties which derive from it for some specific soil. In the experimental part were determined properties of plastic ceramic material from location Jirčany from which were formed samples made of plastic dough with different moisture content, with the addition of grog and additives. Properties such as shape of Bigot curve, critical moisture value, size of drying shrinkage and drying sensitivity of the soil were monitored on the samples.
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