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Development of Self-leveling Screed Based on the Ternary Binder System
Běťák, Rostislav ; Vojtek, Miroslav (referee) ; Gazdič, Dominik (advisor)
The thesis deals with the development of self-leveling cement screed with compensated shrinkage. It is a ternary binder system with the majority of portland cement, that in the beginning of setting and hardening form an expandable folder ettringite. At first there was a background research of volume changes of hydrating cement composites and methods for measuring these changes. Various sort of expansion additives were also introduced, the main emphasis was on concepts of calculated formation of ettringite, which are typical for self-leveling underlayment. Background research included the issues of formation of ettringite, influences on it’s nucleation and it’s stability. The practical development of the screed began by measuring volume changes of different pastes on a ternary composition. Selected formulations suitable for use are verified together with additives to semi-application tests. After the final configuration of the screed mixture, there was a test in real application of an representative area. Individual formulations were tested in terms of long-term stability of ettringite in dry and moist environments.
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Development of phase composition in silicate systems by available methods and their optimalization
Opravilová, Lenka ; Palou, Martin (referee) ; Škvára, František (referee) ; Havlica, Jaromír (advisor)
One of the most prominent measurable parameters of the development of phases and phase transformations in inorganic systems are undoubtedly the volume changes of silicate matrix. The study of volume changes is crucial in the terms of usable durability of final product. They represent shrinkage or expansion of the material and may lead to significant decrease of technological and ecological parameters and often to complete destruction of these materials. Most often the volume changes can be observed when cement is used as a binder and in concretes, mortars, artificial aggregates and other similar materials. There are many methods to detect, define and determine the volume changes qualitatively or quantitatively. The development of phases was investigated as a part of the dissertation thesis and hence the volume changes were observed under the conditions closest to the real state in the construction industry. The raw materials and admixtures were selected which model the content of hazardous components present in conventional materials (both natural and secondary), used in construction and the relationship with volume changes was searched and demonstrated. The contacts for measuring the volume changes were attached to test surfaces of specimens and the physical - mechanical tests (volume changes, phase changes, strength, etc.), chemical analysis and ecotoxicity tests depending on the length of hydration were performed.
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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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Study of mutual influences of volume changes and internal stresses of flow floor screeds
Mikeš, Vít ; Štenko,, Miroslav (referee) ; Šťastník, Stanislav (advisor)
This thesis deals with the comparison of volumetric and stress variations in different formulations of cast floor self-leveling screeds during maturation. These changes were measured by several methods. Furthermore, the strength parameters of the test materials were compared. The test specimens were cured in metallic and elastic forms. The microstructure of these samples were monitored by scanning electron microscopy. In conclusion, the suitability of the tested methods for the given type of flooring materials was evaluated.
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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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The research of cause of failure of concrete elements Face Block
Eger, Lukáš ; Husařík, Petr (referee) ; Dufka, Amos (advisor)
This master thesis focus on the analysis of effects that cause defects in concrete blocks. Experiences show that the defect of the blocks are often manifested in the form of cracks. Great rate of occurrence of defects is attributed to volume changes of poor quality concrete filler. The aim of this master thesis is to analyze the finding from the practical use and exploration of the requirements for the actual blocks and especially the concrete filler which is used to make monolithic structures built from these blocks. The attention will be paid to the interaction between the block and the concrete filler. Here we focus mainly on the volume changes caused by a change of moisture level and especially the cyclic moisture.
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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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Study of mutual influences of volume changes and internal stresses of flow floor screeds
Mikeš, Vít ; Štenko,, Miroslav (referee) ; Šťastník, Stanislav (advisor)
This thesis deals with the comparison of volumetric and stress variations in different formulations of cast floor self-leveling screeds during maturation. These changes were measured by several methods. Furthermore, the strength parameters of the test materials were compared. The test specimens were cured in metallic and elastic forms. The microstructure of these samples were monitored by scanning electron microscopy. In conclusion, the suitability of the tested methods for the given type of flooring materials was evaluated.
|
|
|
Development of Self-leveling Screed Based on the Ternary Binder System
Běťák, Rostislav ; Vojtek, Miroslav (referee) ; Gazdič, Dominik (advisor)
The thesis deals with the development of self-leveling cement screed with compensated shrinkage. It is a ternary binder system with the majority of portland cement, that in the beginning of setting and hardening form an expandable folder ettringite. At first there was a background research of volume changes of hydrating cement composites and methods for measuring these changes. Various sort of expansion additives were also introduced, the main emphasis was on concepts of calculated formation of ettringite, which are typical for self-leveling underlayment. Background research included the issues of formation of ettringite, influences on it’s nucleation and it’s stability. The practical development of the screed began by measuring volume changes of different pastes on a ternary composition. Selected formulations suitable for use are verified together with additives to semi-application tests. After the final configuration of the screed mixture, there was a test in real application of an representative area. Individual formulations were tested in terms of long-term stability of ettringite in dry and moist environments.
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Development of phase composition in silicate systems by available methods and their optimalization
Opravilová, Lenka ; Palou, Martin (referee) ; Škvára, František (referee) ; Havlica, Jaromír (advisor)
One of the most prominent measurable parameters of the development of phases and phase transformations in inorganic systems are undoubtedly the volume changes of silicate matrix. The study of volume changes is crucial in the terms of usable durability of final product. They represent shrinkage or expansion of the material and may lead to significant decrease of technological and ecological parameters and often to complete destruction of these materials. Most often the volume changes can be observed when cement is used as a binder and in concretes, mortars, artificial aggregates and other similar materials. There are many methods to detect, define and determine the volume changes qualitatively or quantitatively. The development of phases was investigated as a part of the dissertation thesis and hence the volume changes were observed under the conditions closest to the real state in the construction industry. The raw materials and admixtures were selected which model the content of hazardous components present in conventional materials (both natural and secondary), used in construction and the relationship with volume changes was searched and demonstrated. The contacts for measuring the volume changes were attached to test surfaces of specimens and the physical - mechanical tests (volume changes, phase changes, strength, etc.), chemical analysis and ecotoxicity tests depending on the length of hydration were performed.
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