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Proposition of new type of injection material with electrically conductive function
Uher, Vojtěch ; Černý, Vít (referee) ; Drochytka, Rostislav (advisor)
The bachelor thesis deals with the design of a new type of grouting material with electrically conductive function suitable for connecting cracks and gaps in building protection systems against lightning strikes and surges. The theoretical part summarizes the important knowledge about the grouting and grouting materials, introduces the current state of knowledge in the field of lightning and surge protection of buildings and also the preconditions of electrical conductivity of cement-based composite materials. In the practical part are summarized selected properties, which the electrically conductive grouting material should have and the relevant standards tests for experimental verification of selected properties are described. A wide range of primary and secondary fillers are studied and the most suitable ones are chosen to achieve a low electrical resistivity value. At the end of the thesis, there are recipes based on amassed knowledge and using secondary fillers to reduce the environmental impact of the developed materials during mass production. Reduced resistivity has been demonstrated in recipes using waste carbon and chopped carbon fibers, but has failed to fully meet standard requirements. The result of the work are new recipes and knowledge that can serve as a basis for further research.
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Experimental testing of hydroinsulating injection screens efficiency in dependance on properties of building materials
Červenka, Martin ; Černý, Vít (referee) ; Drochytka, Rostislav (advisor)
The most of the buildings are almost always faced with moisture in our climate. In the past, the humidity was reduced and conducted only by mechanical methods. Over time, chemical wet masonry method also known as chemical infusion curtain was invented and introduced into practice. This method involves the creation of boreholes at a selected height of humid masonry. These boreholes are impregnated with special solutions. These solutions in humid masonry fill pores in the field of boreholes and thanks to this subsequence the monolithic waterproofing curtain is created. The objective of this work is to determine the methodology for verifying effectiveness of various types of waterproofing injection curtains depending on the properties of the various types of building materials.
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Business Plan
Žůrková, Lenka ; Černý, Vít (referee) ; Sládková, Jitka (advisor)
Bachelor’s thesis presents the prerequisites for producing a business aim of establishing and operation the cultural facilities. It analyses problems, which are related to creation of business plan and establishment of new cultural facilities. It contains suggestions of organizational, marketing and financial plan that can be applied within creation and activity of this company. The work expresses how the project should be undertaken.
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Advanced material based on secondary raw materials for construction of subgrade layer
Hrubý, Jakub ; Luňáček,, Martin (referee) ; Černý, Vít (advisor)
The diploma thesis deals with the development of a new material for the establishment of a layer of the ground body of a railway undercarriage purely on the basis of secondary raw materials. The theoretical part presents the characteristics of structural layers, materials used for bonded substrates, including their requirements. The following are the general conditions for the creation of base layers from purely secondary raw materials and previous experience with the issue. The introduction of the experimental part of the thesis sets out the basic parameters of secondary raw materials (construction recyclates, waste from railway bed cleaning, dust from cement plant) and energy by-products (fly ash, coal slag and municipal waste incinerator), which together form the raw material base. Grain size, absorbency, moisture, bulk density, chemical analysis and pollutant content were determined on the raw materials. Bulk densities and compressive strengths of the bonded mixtures were determined. The optimum humidity of all mixtures was determined by the Proctor standard test. Experimental verification was performed on testing of bonded mixtures in order to verify the effect of cement dose, when the original dose of 8% was optimized for construction recycled and slag from municipal waste incinerator to 4%, due to high strengths ranging from 4.5 to 6.0 MPa. Further optimization also included the addition of an energy by-product in a proportion of 10% of the weight of the secondary raw material. At the end of the experimental part, two optimal recipes were selected (recycled concrete with 4% cement and 10% fluid fly ash; slag from a municipal waste incinerator with 3% cement and 10% fluid fly ash), which underwent advanced testing in the form of frost resistance and resistance to water and a functional sample was designed. The final functional sample is recycled concrete with cement and 10% addition of fluid fly ash, which is suitable for core layers without frost loading.
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New possibilities of using superabsorbent polymers in cement composites
Holubová, Petra ; Melichar, Jindřich (referee) ; Černý, Vít (advisor)
The work deals with the influence of superabsorbent polymers (SAP) on the structure and properties of cement composites. SAPs excel in their unique ability to hold large amounts of water. This property can be used in hydration processes for internal curing of concrete. Two types of mixtures were tested in cement paste, which were further modified by two types of SAP. SAPs were always used in two dosing modes (dry, in suspension). The samples were then stored for 28 days in a laboratory conditions, respectively. in an conditions with a temperature of 30 °C. Physical and mechanical properties, such as compressive strength, flexural tensile strength and bulk density, were determined. The addition of SAP to the mixture resulted in an increase in tensile strength of almost twofold. It can therefore be concluded that SAP helped with hydration processes.
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