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Development of Grouts for Ceramic Tiles
Coufal, Daniel ; Gazdič, Dominik (referee) ; Fridrichová, Marcela (advisor)
The bachelor thesis deals with the development of grout for filling of wide joints of ceramics tiles. The theoretical part is devoted to individual types of jointing materials, their properties and application. The practical part deals with proposed mixtures with focus on the influence of the filler as ground limestone and his substitution with silica sand and the effect of the subsequent modification of these mixtures by the expansion additive.
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Latex Modified Cement Composites
Kunc, Michal ; Rovnaníková, Pavla (referee) ; Kuřitka, Ivo (referee) ; Havlica, Jaromír (advisor)
The subject of dissertation is a study of physic-mechanical properties and development of self-leveling polymer-cement composite of the ternary binder system PC-CAC-CS modified with chemical additives and polymeric substances. The dissertation systematically describes a four-step optimalization of the composite considering its key properties. Experimental part has been focused on monitoring the impact of composite components on selected final properties. Basic physico-mechanical, structural properties and its relations (compressive strength, porosity, flow abilities, setting times) have been analyzed for deeper understanding of the effects of individual composite components. Methods which quantify the existence of the newly formed hydration product – ettringite (XRD, SEM with EDS, calorimetry, dilatometry) has been chosen as additional study methods on selected combinations. A working prototype of self-leveling polymer-cement composite was successfully developed based on systematic process and using of testing procedures and measuring methods.
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The development of grouting for additional sealing of embankment dams
Michalčíková, Magdaléna ; Klablena,, Petr (referee) ; Drochytka, Rostislav (advisor)
Seal of sand or gravel by chemical injection is known and used for a long time. Chemical grouting are however expensive and sometimes the use of cement does not lead to desire effects. So it is trying to find new materials and methodologies injection arrangement works. To achieve savings of chemical products are added to a mixture clay and cement. Clay-cement grouting mix are used not only in order that they are better quality, but also because in this way proposed mixtures have a tendency to penetrate better into incoherent sediments that need additional sealant of chemical injection. For further possible reductions of economic terms the mixture is trying to replace the classic clay. As a suitable substitute for classic clay is to a certain extent the use of secondary raw materials. Above all it is fly ash. As a part of my thesis I deal with the appropriateness use of these materials and examining their properties in the mixture. It was found that by using fly ash were improving consistency of the fresh mixture, reducing the amount of water-cement ratio and reduce shrinkage of the mixture. On the other hand, by using fly ash has been increasing decantation, permeability atc. In the next stage of my work was examined the influence of the quality of cement, lime and liquefaction in the mixture. The aim of thesis is to propose the optimal injection mixture for additional sealing earth dams.
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Effect of Cement Bypass Dust on Cracking Tendency of Alkali-Activated Slag during Drying
Krejčová, Marie ; Švec, Jiří (referee) ; Bílek, Vlastimil (advisor)
This bachelor thesis deals with the influence of bypass cement dust on cracking of alkali activated slag. Significant shrinkage and cracking prevent greater use of alkali activated slag. The length changes and strength of the mixtures with different amount of bypass cement dust were measured at various curing conditions. In these mixtures, cracks were observed and their amount was evaluated by image analysis. It has been found that the addition of dust can reduce the amount of cracks. Treating the prisms in a humid environment leads to a reduction of cracks, especially during long-term treatment. In order to improve flexural and compressive strength, it is preferable to use dust as a replacement for part of aggregates and not as a partial slag replacement.
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Waterproof concrete structures and regulations for the design and implementation
Křenek, Daniel ; Brožovský, Jiří (referee) ; Hubáček, Adam (advisor)
This thesis covers the issues of design, production, and property testing in regards to waterlight concrete structures. The testing conducted on the properties fit in accordance to the Czech Republic and international regulations. This thesis covers the issues of design, production, and property testing in regards to waterlight concrete structures. The experimental part focused on the design of the concrete mix, which stems from previous knowledge of individual, and speific regulations. Various types of cement were particularly examined along with studying the effects of admixtures that were partially replaced by cement with propoerties of watertight concrete
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Study of the properties of cement composites with polypropylene fiber modified low-temperature plasma
Žižková, Lucie ; Herka, Petr (referee) ; Bodnárová, Lenka (advisor)
Plasma treatment of polypropylene fibers presents a new progressive method, how to increase the utility properties of these fibers. The thesis is focused on verifying the effect of surface treatment of polypropylene fibers in concrete with low-temperature plasma discharge in the normal atmosphere. The paper describes the procedure for treatment of polypropylene fibers with low-temperature plasma and evaluate the impact of this adjustment on the volume changes of cement composites. It should also be emphasized that the thesis is focused on the initial volume changes, ie volume changes in the early stages of solidification and only for your own mixture, which is not considered an external load. Subsequently, the experimental verification of the effect of the addition made commercially available fibers and fibers treated plasma volume changes to a selected physico-mechanical properties of the test compounds.
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Volume changes of concrete based on reactive powder components and possibilities of their regulation with chemical admixtures
Hlaváček, Jaroslav ; Kalinová, Helena (referee) ; Opravil, Tomáš (advisor)
Very high strength of RPC allows them to an unusual extreme possibilities of their applications. Volume change (shrinkage) negatively affects their relatively broad range of applications, particularly in applications which are used for filling tubes or other components. In today's advanced time with plenty of chemical ingredients and additives on the market (such as the expansion component) could be a side effect of this largely eliminated, or removed entirely. Only some components of the expansion will be appropriate for RPC cements. This reaserch investigates the expansion of ingredients on the basis of sulfates and monitors not only volume changes, but also the strength characteristics and tolerability of the tested anchors tested with a matrix component of the expansion.
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Issues of design and testing of waterproof concrete fot tunnel lining
Merta, Michael ; Voves, Jiří (referee) ; Hubáček, Adam (advisor)
The diploma thesis deals with the issue of waterproof concrete and testing its properties. The theoretical part is conceived through research on existing knowledge relating to waterproof concrete. Emphasis is placed on the possibility of using a waterproof concrete for structures, such is e.g. tunnel lining. The experimental part is focused on the laboratory testing of waterproof concrete. Particulary examined was the effect of various admixtures as a partial replacement of cement. Monitored was the development of compressive strength and flexural strength, development of temperature during hydration in the early stages of maturation of concrete, water resistance of concrete, concrete surface resistance to water and chemical de-icing agents, as well as development of shrinkage during concrete maturation.
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The Combustion of Organic Lightweighting Agents in the Chamotte Materials
Smékalová, Veronika ; Keršner, Štěpán (referee) ; Sokolář, Radomír (advisor)
Lightweight chamotte products are popular building material. There are many types of lightweight chamotte on the market, but the most popular lightening options are organic ingredients. This brings some problems to the production of these products. This thesis deals with the burning of various types of lighters from shards of fireclay materials. In the theoretical part are summarized raw materials, which are necessary for production of lightweight chamotte. The results of the published research studies on the topic of lightening of organic lightening products are being described here. The practical part deals with properties of products made of clay or kaolin with the addition of a certain amount of lighter. These added lighters are spruce sawdust, beech sawdust, peat, bran, paper slurry and anthracite. All these lighters are direct. For comparison, the cenospheres, which represent indirect lightweights, were also included in the research. For all specimens, the temperature interval of burnout of specimens, refractoriness, classification temperature, bulk density, thermal conductivity coefficient and other properties were defined.
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Injection moulding
Heralt, Aleš ; Balej, Zdeněk (referee) ; Žák, Ladislav (advisor)
This Bachelor´s thesis is focused on construction forms for injection of thermoplastic matters. The technology for plastic products production is technology that participate more and more in production of all sorts of products - from technical components over kitchenware after as much as toys. Main part of this thesis is focused on description of the injection valve, ejector, annealing and ventilation system forms for injection with the main structural principles.
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