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Blended alkali-activated aluminosilicate binders
Mizerová, Cecílie ; Bayer, Patrik (referee) ; Rovnaník, Pavel (advisor)
The first part of the work presents a summary of the current knowledge of two-component blended alkali-activated binders based on blast furnace slag, fly ash, metakaolin and ground brick with emphasis on their workability, microstructure, mechanical properties and durability. In the experimental part the alkali-activated binders with different ratio of fly ash and metakaolin were made to compare their workability and mechanical properties. The binder structure was evaluated by means of scanning electron microscopy (SEM) and mercury intrusion porosimetry. From the literature review and my own achievements it can be concluded that the combination of single precursors has a positive effect on the majority of the assessed properties of the material.
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Plasticizers replacing lime in cement-lime mortars
Kajsrlík, Jan ; Bayer, Patrik (referee) ; Vyšvařil, Martin (advisor)
This bachelor thesis deals with the possibility of replacing lime in lime-cement plaster mortars. Considering commercially sold products, it explores the ways of replacing lime qualities by organic materials. Their influence on density, beam test and compression strength are researched; absorption capacity, frost resistance, capillary absorption coefficient are also assessed. Finally the organic materials are compared with the qualities of the lime-cement mortar
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Rehydration of alkali-activated slag after high temperature loading
Fialová, Barbora ; Bayer, Patrik (referee) ; Rovnaník, Pavel (advisor)
Ground granulated blast furnace slag is a by-product of the steel industry and is often used in combination with ordinary Portland cement as a binder in concrete. When concrete is exposed to high temperatures, physical and chemical transformations lead to significant loss of mechanical properties. This study aims to investigate the effect of high temperatures and rehydration on the mechanical properties, microstructure and phase composition of alkali activated slag. The results of the research could make an important contribution to decisions made concerning the reconstruction of structures affected by fire. In suitable cases it would be possible to regenerate parts of a structure instead of totally rebuilding it.
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Fibre coposites with alkali -activated slag matrix
Pluskalová, Barbora ; Bayer, Patrik (referee) ; Rovnaník, Pavel (advisor)
This master thesis is concerns the preparation of Alkali Activated Materials, specifically Alkali Activated Slag (AAS), with the addition of fiber reinforcement. Alkali Activated Materials have great potential for use in construction practice. However, their use is limited by certain undesirable properties, which can be diminished by adding fiber reinforcement. This thesis deals with the influence of carbon fibers (2 % by weight of the binder) and carbon nanotubes (0,2 % by weigh of the binder) on the mechanical properties, microstructure and shrinkage of AAS. The results of the experiments which were carried out correspond with the literary research. Conclusions of this thesis agree with research published in original scientific papers.
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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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Properties of alkai-activated aluminosilicates subjected to high temperatures
Halasová, Kristýna ; Bayer, Patrik (referee) ; Rovnaník, Pavel (advisor)
Currently the concept of geopolymer or alkali activated aluminosilicate is very mentioned topic. Many studies concerning utilization of these materials have already been made, but if we want to use these materials in building industry in the future, further research will be needed. This thesis deals with the influence of high temperatures on alkali-activated slag, fly ash and metakaolin-based composites. The work compares mechanical and technological properties, microstructural changes and effect off iller on the geopolymer composites heated at 200–1200 °C. In conclusion, the individual properties are compared and application possibilities of these materials are evaluated.
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Methods of Indetification of Historic Mortars
Kurfürstová, Nela ; Bayer, Patrik (referee) ; Rovnaníková, Pavla (advisor)
The thesis is describing short survey on metods to help identify individual components that was used in the history for the production of mortar. The work is focused especially for plaster whose main binder is lime. The lime was in the past used to mortatrs to improve the properties for example adhesion to the substráte, workability, hygrophobic and more. The aim of practical part was to analyze the obtained historical mortar according to the methods mentioned in the theoretical part – determining individual components contained in historical mortar, composition ratio and proposal for the composition of the repair mortars. These knowledge can to help for reconstrution of historical objects.
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Carbon nanotubes in building materials
Fialová, Barbora ; Bayer, Patrik (referee) ; Rovnaník, Pavel (advisor)
Carbon nanotubes (CNTs) has become of great interest for scientists in many disciplines. This study examines the effect of CNTs as nanosized reinforcement for metakaolin–based geopolymer. It was found out that the addition of CNTs considerably affects the compressive and flexural strength geopolymer samples. The influence of CNTs on microstructure was examined using mercury intusion porosimetry and scanning electron microscopy.
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Artificial stone - methods of preparation and properties
Pluskalová, Barbora ; Bayer, Patrik (referee) ; Rovnaník, Pavel (advisor)
The aim of the thesis „Artificial stone – Methods of preparation and it´s properties“ deals with the various methods and issues concerning the preparation of artificial stone. The thesis presents the summary of materials and various methods suitable for the preparation and points out mechanical properties, including durability of material, which serves as an alternative to natural stone. Further on, the thesis deals with the studies of binding systems based on geopolymers, which are used for the artificial stone preparation. This part of the thesis is associated with the experimental part, which is aimed at choosing the suitable mixing ratio of binder to aggregate in the artificial stone based on metakaolin geopolymer. According to the results of mechanical tests and aesthetic impression the author chose the best composition and then created a decorative element.
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