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The influence of heavy metal oxides on the properties of cement pastes
Kašpárková, Kateřina ; Rovnaníková, Pavla (referee) ; Vyšvařil, Martin (advisor)
The Bachelor´s thesis is focused on study of the effect of increased content of heavy metals in cement production on the properties of this cement and the effect of addition of heavy metal oxides in cement pastes production. The thesis also deals with structural changes in particular components of cement in the presence of heavy metals. The effect of addition of heavy metal oxides on the properties of cement pastes is demonstrated in the experimental part by determining their mechanical properties, pore structure, and observation of the progress of hydration.
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The influence of zinc oxide on the cement composite with silica fume.
Dobiáš, Jiří ; Koutný, Ondřej (referee) ; Šiler, Pavel (advisor)
The aim of this work was to investigate the influence of zinc oxide on the properties of blended Portland cement mixed with silica fume. On the pastes were monitored flow properties and by using of isoperibolic calorimetry process of the hydration. On the prepared samples were studied mechanical properties of obtaining values of compressive and flexural strength after 1, 7 and 28 days. By using of XRD were measured phase composition and microstructure development war observed by SEM. The elemental composition of cement leaches was measured by using of ICP-OES.
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Rheology in Technology of Inorganic Binders
Kosár, Petr ; Másilko, Jiří (referee) ; Zmrzlý, Martin (advisor)
This final thesis deals with the study of rheological behaviour of cement pastes. The introductory part describes the composition of Portland cement. Next, a detailed description of mutual interaction between cement and water and the principle of superplasticizer affection follows. The thesis includes a description of properties and interaction of alumina cement with water as well as rheological properties of suspensions and cement pastes. Finally, the theoretical part provides a survey of the elementary methods and equipment for the evaluation of rheological properties of cement materials. The experimental part includes measurement and evaluation of rheological properties (flow curves, plastic viscosity and yield stress) of cement pastes with different composition. The influences of water-cement ratio, amount of superplasticizer and the kind of cement on rheological properties of cement pastes are compared here.
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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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Effect of the currently used plasticizers for concrete hydration temperature
Knotová, Kateřina ; Halas, Vladimír (referee) ; Sedlmajer, Martin (advisor)
Plasticizing and superplasticizing admixtures are the key components of nearly every concrete. These admixtures improve workability of mortar and fresh concrete which lead to facilitation of depositing and compaction. Adding of plasticizers or superplasticizers enables to change properties of fresh and hardened concrete, especially to reduce water-cement ratio, thereby increasing strength and durability of concrete or to improve other properties. The main aim of this thesis is to monitor the effect of plasticizing admixtures and their dosage on the rheology and hydration of concrete with emphasis on the development of hydration temperature. The other goal is to examine their strength qualities. Behaviour of plasticizing admixtures is analysed at first on cement pastes, as simple systems, and then verified on concrete.
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Effect of chemical additives on the process hydration temperature of cement pastes
Knotová, Kateřina ; Halas, Vladimír (referee) ; Sedlmajer, Martin (advisor)
Chemical additives, especially plasticizers and super plasticizers, are necessary components of nearly every concrete. These additives improve the workability of grout and concrete mixes thereby reducing vibration intensity during process of compaction. Advantages of these additives are associated with reduction of the amount of gauging water which leads to decrease water-cement ratio, increase strength and durability of concrete, eventually improve other attributes. The aim of this thesis is to observe the effect of plasticizers and their dosage on the rheology and development of hydration temperatures in simpler systems, which are the cement pastes. The thesis also considers compressive, tensile and flexural strength of concrete.
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Effect of the currently used plasticizers for concrete hydration temperature
Knotová, Kateřina ; Halas, Vladimír (referee) ; Sedlmajer, Martin (advisor)
Plasticizing and superplasticizing admixtures are the key components of nearly every concrete. These admixtures improve workability of mortar and fresh concrete which lead to facilitation of depositing and compaction. Adding of plasticizers or superplasticizers enables to change properties of fresh and hardened concrete, especially to reduce water-cement ratio, thereby increasing strength and durability of concrete or to improve other properties. The main aim of this thesis is to monitor the effect of plasticizing admixtures and their dosage on the rheology and hydration of concrete with emphasis on the development of hydration temperature. The other goal is to examine their strength qualities. Behaviour of plasticizing admixtures is analysed at first on cement pastes, as simple systems, and then verified on concrete.
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Effect of chemical additives on the process hydration temperature of cement pastes
Knotová, Kateřina ; Halas, Vladimír (referee) ; Sedlmajer, Martin (advisor)
Chemical additives, especially plasticizers and super plasticizers, are necessary components of nearly every concrete. These additives improve the workability of grout and concrete mixes thereby reducing vibration intensity during process of compaction. Advantages of these additives are associated with reduction of the amount of gauging water which leads to decrease water-cement ratio, increase strength and durability of concrete, eventually improve other attributes. The aim of this thesis is to observe the effect of plasticizers and their dosage on the rheology and development of hydration temperatures in simpler systems, which are the cement pastes. The thesis also considers compressive, tensile and flexural strength of concrete.
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