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Reactive Powder Concrete
Gabko, Miroslav ; Klečka,, Tomáš (referee) ; Hela, Rudolf (advisor)
Reactive powder composites (RPC) have been recently a subject of many researches of modern concrete technology. This type of concrete is very fine and its behaviour exceeds the other types of concrete, therefore there are new possibilities of its use. The design and production of RPC is complex technology process which needs to gain new results in RPC research to get the best features regarding its higher price. This thesis is focused on design of reactive powder concrete (RPC200), which compressive strength is between 200 – 300 MPa. Next goal is to prove the influence of curing regimes like high temperature or pressure, and also check the possibilities of production of low cement reactive powder composite (LCRPC).
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The development of ultra-high strength (UHPC) and reactive powder (RPC) composites
Rundt, Lukáš ; Hela,, Vlastimil (referee) ; Hela, Rudolf (advisor)
Bachelor’s thesis studies ultra-high strength concrete and reactive powder composites. In theoretical part there are researched and described properties of raw materials used for their production, mainly additions. Design methodology, processing and types of curing are also studied. Psychical mechanic and durability properties of fresh and hardened concrete are described. In practical part 4 mixtures were designed and prepared and their rheological properties, strengths after 7 and 90 days in case of UHPC and strengths after 7, 28 and 60 days in case of RPC were tested.
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Bonding of composite materials in precise applications
Schubert, Vojtěch ; Zouhar, Jan (referee) ; Kupčák, Radim (advisor)
This work is focused on the bonding of composite materials. Related research dealing with technology of production and bonding of these materials was additionally conducted. Practical part of this thesis was set to find out what the optimal bond line thickness was for the bonding of the composites. Thus, the strength of single-lap joints (SLJ) in series of various bond line thicknesses was therein tested. A model of samples (and design of their production by wet lay-up) for the experiment is also provided in this thesis.
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Effect of curing conditions on the properties of alkali activated slag
Rypák, Peter ; Bayer, Patrik (referee) ; Rovnaník, Pavel (advisor)
Combination of fine ground granulated slag with proper alkaline activator gives alkali-activated slag – a material with remarkable properties. Theoretical part of the thesis deals with summarizing basic informations about alkali-activated slag, its properties, production and utilization. It also follows research devoted to effects of curing of alkali activated slag and shrinkage-reducing admixtures on its properties. Objective of the experimental part is to determine the influence of curing conditions on the mechanical properties and microstructure of alkali-activated slag. These properties are also monitored in alkali-activated slag with carbon nanotubes and hydroxypropylmethylcellulose as an shrinkage-reducing admixtures.
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Phosphate binders
Kalina, Lukáš ; Ptáček, Petr (referee) ; Šoukal, František (advisor)
The work deals with the preparation and study of polyphosphate composites. Aluminum phosphates provide some unusual properties like high-heat resistance in terms of inorganic binders. The addition of chromium in the form of Cr2O3 or directly the bond with the aluminum-chromium-phosphate can improve the properties of this binder. Highly viscous Al2Cr(H2PO4)9 and Al3Cr(H2PO4)12 binders were prepared by dissolving Al(OH)3 and CrO3 in 85% phosphoric acid, and mixed with Al2O3 and Cr2O3 fillers. The composites were cured in the furnace at 150 °C for 24 h under pressure of 10 MPa. During the annealing at temperatures up to 1 500 °C changes in chemical structure of the cured composites were observed, leading to the understanding of the creation of crystalline phases and their eventual changes. The characterization of binders was mainly based on FT-IR, EDAX, TG-DTA and optical microscopy analyses.
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Polymer matrix based on epoxydized oils
Kvasničková, Lucie ; Tocháček, Jiří (referee) ; Přikryl, Radek (advisor)
The theoretical part of this bachelor thesis deals with a current state in the field polymer matrix based on vegetable oils and their epoxidation. Subsequently it deals with epoxy resins – particularly their structure, crosslinking and a curing. The experimental part of this research focuses on the amine curing of epoxy resins. A curing of epoxidized soybean oil with various amine curing agents was tested and also a curing of a blend containing comercial epoxy resin and epoxidized soybean oil. Testing pieces were prepared from selected mixtures and a tensile test was performed on them.
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Modern treatments by powder paints
Turek, Tomáš ; Kovář, Petr (referee) ; Kubíček, Jaroslav (advisor)
The thesis deals with the process of powder coating paint, a description of the individual steps and types of used equipment. Thesis also includes the distribution of powder paints and overview of basic information, color chart systems and the description of color tone perception. At the end of the thesis are summary of quality standards of deposited surface and technologic process of coating using in the powder coating in paintshop.
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Surface treatments of material
Tichý, Jan ; Kolář, Ladislav (referee) ; Fiala, Zdeněk (advisor)
This thesis deals with surface treatment materials, focusing on the process of plastic powder coating. The thesis describes several exclusive finishes that are entirely recommended as pre-treatment for powder coating. The thesis also provides information gained through market research, focusing specifically on powder plastics and technical equipment for powder coating. Technical equipment for the existing powder coating plant of the company KOVOT Invest Ltd. is also suggested.
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The study of hydration of RPC (Reactive Powder Concretes) in hydrothermal condition
Dvořáková, Tereza ; Koplík, Jan (referee) ; Šoukal, František (advisor)
The diploma thesis deals with the study of hydration of reactive powder concrete under hydrotermal conditions. The theoretical part describes the properties of materials and additives used for the preparation of mixtures. The following describes the principles and requiments for the materials for preparing the reactive powder concrete. The practical part is studied design method mix and the impact of materials to the consistency of paste. The effect of cample placement on flexural and compressive strength of the prepared mixtures was observed. The samples were stored under standart laboratory conditions and under hydrothermal conditions. The phase composition of the samples was monitored by X-ray diffraction analysis and the mocrostructure by scanning electron microscopy.
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Study of the influence of composition and curing of self-leveling cement screeds on their properties in the early stage of maturation
Powetz, Dominik ; Štenko,, Miroslav (referee) ; Šťastník, Stanislav (advisor)
The diploma thesis deals with the study of the influence of composition and curing of self-leveling cement screeds on their properties in the early stage of maturation. Within this work, various concepts of ensuring the volume stability of cement self-leveling screeds were verified. An anti-shrink additive based on neopentyl glycol and an expansion additive based on hard-burnt lime were used as modifiers. The reduction of plastic and overall shrinkage using various types of liquid membrane-forming compounds was verified on the most volume-stable screed using the optical dilatometry method. The effectiveness of the individual solutions was monitored by continuous measurement of the intensity of evaporation from the screed surface. Subsequently, the effect of membrane-forming compounds on the residual moisture of the cured treated cement self-leveling screed was measured by the carbide method and also the effect of this curing on the adhesion of bonded ceramic tiles.
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