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The Use of Tensograf for Optimization of the Composition of Mortars
Hrbáček, Matěj ; Melichar, Tomáš (referee) ; Žižková, Nikol (advisor)
Bachelor thesis is focused on monitoring of volume changes in concrete composites. Using Czech and foreign literature searches are processed, in which mortars in general 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. The last part describes in detail the Tensograf TGF-02. Experiment is performed by monitoring the volume changes in polymermodified mortars using Tensograf TGF-02 and it is verified its suitability for the subject matter.
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Study of the influence of aggregate composition on volume changes and mechanical properties of High Performance Concrete
Vobinušková, Kristýna ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
The master´s thesis deals with the volume changes of concrete during its concrete glow. These volume changes are generally more susceptible to high-strength concretes – HSC, which contain a bigger dose of binder. The theoretical section describes the possible reduction volume change especially in HSC, which are focused on the composition of concrete, especially on the type and particle size distribution of aggregate. Then attention is also paid to the different types of cements and their possible substitution. The part of the theoretical work describes the types of volume changes that may occur. In the experimental part are suggested the HSC by to secure informations. Different kinds of aggregates are used and a continuous or discontinuous grain curve and a different maximum grain size. Part of the sample was made only from CEM I 42,5 R and the second part of the sample from CEM I 42,5 R with the addition of very finely ground limestone. In terms of the part of the work were monitored volume changes of concrete with different composition and also their mechanical properties after 7, 28 and 90 days. Specifically, compressive strength, tensile strength, strength of the surface layers of concrete, water absorption and water-permeability test concrete. In conclusion, are listed all the results of tests.
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Multistorey administrative building
Gášek, Libor ; Bažant,, Zdeněk (referee) ; Čírtek, Ladislav (advisor)
The theme of the work is design of the administrative building with supporting concrete structure. The design must include changes of concrete cubic capacity and their additional effects on the stress of the structure. Minimization of the impact of additional stress is necessary to solve with the appropriate design of structural systems and materials.
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Quick Setting Road Cement
Coufal, Daniel ; Jiroušková, Kateřina (referee) ; Fridrichová, Marcela (advisor)
The thesis deals with the study of magnesium oxide burned by various burning regimes and his possibilities of its usage as potential expansion additive. The theoretical part of the thesis concerns mainly the volume changes and how they can be influenced. The practical part focuses on monitoring morphology, phase composition and the hydration process of magnesium oxide.
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Analysis of selected silicate based composites volume changes
Kubeš, Pavel ; Šimonová, Hana (referee) ; Keršner, Zbyněk (advisor)
This diploma thesis deals with the analysis of volume changes of selected silicate based composites. The first part introduces the issue of volume changes of concrete, especially the shrinkage process, two selected models for shrinkage prediction, describes configuration and course of performed tests, as well as the processing of measured experimental data. The second part contains input data modified by the program GTDiPS and another calculated parameters. The result of the work is the evaluation of the influence of thermal dilation on the development of shrinkage of young concrete. Another output is the comparison of accuracy of the two selected prediction models to capture the course of measured shrinkage.
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Study of possibilities of reduction of volume changes and development of hydration temperatures in concrete
Pikna, Ondřej ; Ťažký, Tomáš (referee) ; Hela, Rudolf (advisor)
Volume changes are one of the priority characteristics of concrete that plays an important role place mainly in the durability of structures as such. These low volume changes are required especially for structures as: industrial concrete floors, massive structures and waterproof structures. One of the possibilities in reducing these changes is the use of mineral admixtures with suitable grain curve of aggregate. Another possibility is the use of shrinkage reducing admixtures. There can occur problem with efficiency (long term age) with other components of the mixture. Therefore, the effort of this work is to use the avaible processes for maximum reduction of shrinkage and hydration temperatures.
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Possibilities of reducing shrinkage of concrete and development of concrete recipes with limited shrinkage.
Stoklásek, Martin ; Louda,, Pavel (referee) ; Hela, Rudolf (advisor)
The bachelor thesis deals with the issue of volume changes of concrete and their causes. The theoretical part describes the various types of volume changes in concrete and the causes of their occurrence. Influence of concrete mix design and concreting conditions on volume changes. Methods for reducing volume changes are also addressed. The experimental part is focused on the development of recipes with limited volume changes. In which the development of shrinkage is monitored from an early age up to 60 days and at the same time the development of compressive strengths at 2, 7, 28 and 60 days is also monitored.
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Numerical simulation of volume changes of selected cementitious composites
Drbušková, Magdaléna ; Veselý,, Václav (referee) ; Keršner, Zbyněk (advisor)
This thesis deals with volume changes of selected cementitious composites. They are divided into two parts, theoretical and practical. The theoretical section describes the volume changes that occur in concrete structures. The practical part is focused primarily on the initial stage of shrinkage specimens of two-component cement composite (cement paste + aggregate) and it´s numerical simulation. For analysis were used SpatiDist and FyDiK 2D computer applications. It was simulating shrinkage of specimens with and without notch to compare. The result is a parametric study which reflects the influence of type and size of grain aggregate and shrinkage degree of cementitious paste.
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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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