|
|
The effect of the shrinkage reducing additives on rheological properties of high-strength concrete
Červenka, Jiří ; Kucharczyková, Barbara (referee) ; Daněk, Petr (advisor)
Master’s thesis examines the effect of the shrinkage reducing additives on rheological properties of high-strength concrete. The first part is focused on high-strength concrete in terms of their composition and properties. The second part contains a detailed analysis of the cementitious composites shrinkage problems. Total shrinkage is divided into individual elementary shrinkages. For each of them there is a detailed description of causes and factors that affect their sizes. The next part describes the basic additives used to reduce the shrinkage of cementitious composites. The experimental part is focused on verifying the effectiveness of the shrinkage reducing additives during preparation of high-strength concrete. Usage of shrinkage drains for relative strain measurement enables to determine the process of shrinkage immediately after placing the concrete in the form and to obtain the overall curve of the hight-strength concrete volume changes during its setting and hardening. At the end of the thesis, there are overall analysis and summary of the results of the performed experiments.
|
|
|
The verification of durability of surface layer by pull-off testing
Fujačková, Hedvika ; Komárková, Tereza (referee) ; Kocáb, Dalibor (advisor)
The theoretical part of this bachelor's thesis defines the basic properties, categorization, and use of the individual components of concrete and presents the properties of fresh and hardened concrete, especially the tensile strength. Furthermore, the thesis addresses the problem of durability assessment of concrete, which depends directly on the quality of the surface layer. The experimental part of the thesis focuses on executing of a pull-off test and examines the surface layer tensile strengths of various concrete mix designs. The thesis examines how the results of the measurements correspond with other published results.
|
|
|
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
|
|
|
Influence of input materials for quality architectural concrete
Ondryášová, Veronika ; Novosad, Petr (referee) ; Hela, Rudolf (advisor)
This diploma thesis focuses on the influence of properties of feedstocks for the production of quality surfaces of architectural concrete. The introductory part describes the definition of architectural concrete with the advantages and disadvantages of its implementation. In the following chapters, the characteristics, the dosage or the chemical composition of the input materials are given. Besides the design of the mixture, important parameters for the creation of a quality surface of concrete are compaction, precise placement in formwork and subsequent treatment of the surface. Individual types of architectural concrete, their method of production with the examples belonging to concrete constructions are also given. In the practical part, 4 mixtures were designed, whose type or dosage of feedstocks was changed. In creating mixtures, emphasis was placed on minimal segregation of fresh concrete and the formation of pores on the surface of hardened concrete.
|
|
|
Research on the Preparation of Masonry Mortars
Koláček, Tomáš ; Dvořák, Karel (referee) ; Gazdič, Dominik (advisor)
This thesis deals with development in the preparation of masonry mortars. The theoretical part focuses on basic knowledge of mortars, individual types of mortar, preparation methods and individual components from which the mortar is composed. The practical part deals with the proposed reference and modified mortar mixtures and compares their technological properties.
|
|
|
Analysis of filler types onto the wood plastics composites
Blaha, Lukáš ; Pospíšil,, Ladislav (referee) ; Vaněrek, Jan (advisor)
Wood polymer composite (WPC) is a material that combines the wood material and the thermoplastic matrix. As filler to be used as wood flour and thermoplastic matrix will be used in primary or recycled polypropylene. WPC will be made by injection molding. The aim of the thesis is to find the optimal ratio between primary and recycled polymer in which the result will be the best physical and mechanical properties.
|
|
|
Effect of admixtures on the properties of metakaolin geopolymer
Halasová, Kristýna ; Vyšvařil, Martin (referee) ; Rovnaník, Pavel (advisor)
Geopolymers are amorphous to semi-crystalline aluminosilicate polymers which are formed from inorganic polycondensation reaction of a solid aluminosilicate precursor with an alkaline sodium hydroxide or silicate. The resulting materials exhibit high durability, resistance to aggressive environments, high temperature resistance and many other properties that make them have received much attention in recent years, not only in construction. This thesis describes the influence of additives commonly used in concrete and mortar (water reducing, superplasticizer, air-entraining, foamer and defoamer, anti-shrinkage, stabilization) on the behavior of metakaolin in geopolymer fresh and hardened state. It describes metakaolin geopolymer effect on rheological properties of fresh mixtures, compressive strength and flexural strength after 28 days and a density in the fresh and hardened state.
|
|
|
Influence of input materials for quality architectural concrete
Ondryášová, Veronika ; Novosad, Petr (referee) ; Hela, Rudolf (advisor)
This diploma thesis focuses on the influence of properties of feedstocks for the production of quality surfaces of architectural concrete. The introductory part describes the definition of architectural concrete with the advantages and disadvantages of its implementation. In the following chapters, the characteristics, the dosage or the chemical composition of the input materials are given. Besides the design of the mixture, important parameters for the creation of a quality surface of concrete are compaction, precise placement in formwork and subsequent treatment of the surface. Individual types of architectural concrete, their method of production with the examples belonging to concrete constructions are also given. In the practical part, 4 mixtures were designed, whose type or dosage of feedstocks was changed. In creating mixtures, emphasis was placed on minimal segregation of fresh concrete and the formation of pores on the surface of hardened concrete.
|
|
|
Research on the Preparation of Masonry Mortars
Koláček, Tomáš ; Dvořák, Karel (referee) ; Gazdič, Dominik (advisor)
This thesis deals with development in the preparation of masonry mortars. The theoretical part focuses on basic knowledge of mortars, individual types of mortar, preparation methods and individual components from which the mortar is composed. The practical part deals with the proposed reference and modified mortar mixtures and compares their technological properties.
|
|
|
Effect of admixtures on the properties of metakaolin geopolymer
Halasová, Kristýna ; Vyšvařil, Martin (referee) ; Rovnaník, Pavel (advisor)
Geopolymers are amorphous to semi-crystalline aluminosilicate polymers which are formed from inorganic polycondensation reaction of a solid aluminosilicate precursor with an alkaline sodium hydroxide or silicate. The resulting materials exhibit high durability, resistance to aggressive environments, high temperature resistance and many other properties that make them have received much attention in recent years, not only in construction. This thesis describes the influence of additives commonly used in concrete and mortar (water reducing, superplasticizer, air-entraining, foamer and defoamer, anti-shrinkage, stabilization) on the behavior of metakaolin in geopolymer fresh and hardened state. It describes metakaolin geopolymer effect on rheological properties of fresh mixtures, compressive strength and flexural strength after 28 days and a density in the fresh and hardened state.
|
guest ::
