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The possibilities regulation of production hydration heat of concrete with plasticizer
Hermann, Radek ; Halas, Vladimír (referee) ; Sedlmajer, Martin (advisor)
This thesis studies the problematics of water reducing and high range water reducing admixtures and their influence on the process of hydration of cement pastes. The process of hydration is examined in this thesis both in terms of hydration heat and hydration temperature rise. Attention is also paid to the influence of plasticizers in combination with retarding admixture regarding rheological properties of modified fresh cement pastes and their mechanical properties after 3 and 7 days from mixing.
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Development of masonry systems with utilization in flood areas
Fabiánková, Aneta ; Sedlmajer, Martin (referee) ; Zach, Jiří (advisor)
Thesis describes the system of masonry structures in floodareas. It is based on liteature review of floods, mapping mansonry load during floods, dyinig after the passage of the flood wave solutions and water impermeability construction to prevent degradation and destruction. The main part is the design of the wall, which connectes hydrophobic individual elements of construction to provide resistence during floods. The diploma thesis includes practical verification of the functionality of a complete proposal to ensure the smallest possible water absorption caúitaly of the structure.
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Possibilities of utilizing lightweight autoclaved silicate based materials for insulation of building structures
Novák, Jakub ; Sedlmajer, Martin (referee) ; Zach, Jiří (advisor)
This bachelor´s thesis deals with the issue of thermal insulation for building structures using autoclaved aerated concrete on silicate based with density up to 200 kg/m3. The theoretical part presents the knowledge of the thermal protection of buildings and thermal insulation materials. Thereafter are distributed insulation systems. Production of aerated concrete and its properties is described in detail. In thesis were evaluated possibilities of use this material. The materiál is proved to be suitable for the production of thermal insulating wall, insulated foundation slabs or composite external panels. In the practical part were find out the values of physical and mechanical properties of aerated concrete product. Test results showed that the product can be used as an alternative to standard insulation systems. Component of the practical part was also to compare various insulation materials on the present market. In the conclusion is performed an overall assessment that includes the overall findings and the results.
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Current development of UHPC concrete and verification of selected properties
Panenková, Monika ; Sedlmajer, Martin (referee) ; Křížová, Klára (advisor)
This bachelor thesis deals with current developments and research in the field of ultra high performance concrete – UHPC. Theoretical part of this work is focused on the composition and properties of UHPC compared to normal strength concretes. It describes design principles, constructions in the world and also in the Czech Republic and other use of this material. Experimental part describes the design of UHPC, manufacture of test specimens and testing for certain physical and mechanical properties such as compressive strength, tensile strength, bending strength, water impermeability, frost resistance, resistance to chemical de-icing substances and abrasiveness of the material.
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Possibilities of using lightweight aggregate of the foam glass bonded with cement
Jahn, Jeroným ; Křížová, Klára (referee) ; Sedlmajer, Martin (advisor)
In the theoretical part of bachelor thesis are findings about use of lightweight aggregate from foam glass. Part of this work is a description of production , raw materials for production , and especially the properties of aggregates. The work deals possibilities of interconnection and the use of foam glass aggregates in building industy . There is describe a risk of alkali-silica reactions in combination with cement. In the practical part are verified application possibilities and properties of cement composite with lightweight aggregate foam glass .
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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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Methods for Monitoring of Volume Changes of Cement and Polymer-modified Mortars
Vrablová, Simona ; Sedlmajer, Martin (referee) ; Žižková, Nikol (advisor)
Bachelor thesis is focused on monitoring of volume changes in polymer-modified mortars. Using Czech and foreign literature searches are processed, in which mortars in general and ongoing chemical and physical processes are described. Thesis is further concerned with description of polymer-modified mortars and with explanation of polymer-matrix forming mechanisms. The following are noticed volume changes and experimental methods of their investigation. Experiment is performed by monitoring the volume changes in polymer-modified mortars using two selected methods. For comparison volume changes in gypsum are also measured.
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Effect of partial replacement of Portland cement by diatomaceous earth on selected parameters of cement mortar
Rousková, Jana ; Sedlmajer, Martin (referee) ; Rovnaníková, Pavla (advisor)
The subject of this thesis is selected parameters cement mortars with partial replacement of Portland cement diatomaceous earth. This work provides information on the basic properties of diatomaceous earth and its deposits with a focus on deposit in Borovany. From the properties is very important pozzolanic activity due to the high content of amorphous silica of this soil. The main use of diatomaceous earth is in the area filtration and is used widely as a nutritional supplement. In the building industry, diatomite can be applied as an admixture to mortar and concrete, where it can, with its abilities, improve some physical mechanical properties. In the experimental part was diatomaceous earth, in its raw and calcined form, tested as admixture for cement pastes and mortars. The main criterion for evaluating these composites was bulk density, flexural and compressive strength. It was also investigated mineralogical composition, microstructure, freeze–thaw resistance and sulfate resistance.
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Properties of Zeolites and Their Use in Building Binders
Rousková, Jana ; Sedlmajer, Martin (referee) ; Rovnaníková, Pavla (advisor)
Zeolites, such as natural or synthetic aluminosilicates, have a wide range of applications. Their application in the construction industry tends to use zeolites as impurity type II. However, it has to prove their reactivity and affect the content of calcium hydroxide in the concrete. The aim is to determine the effect of zeolite as a partial replacement of cement in different concentrations on the mechanical properties of fine-grained concrete and consumption of calcium hydroxide.
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