|
|
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.
|
|
|
Color possibilities of artificial sandstones based on geopolymers
Lattenberg, Pavel ; Kalina, Lukáš (referee) ; Opravil, Tomáš (advisor)
This thesis deals with the possibility of preparing artificial sandstone based on geopolymer matrix and ways to achieve a natural appearance and good mechanical properties. The theoretical part is devoted to the current state of knowledge in the field of geopolymers and their recovery potential, but also the natural sandstone and its geographic diversity. The practical part deals with the preparation of various types of binding systems based on metakaolin, ground blast furnace slag and water glass. Their comparison, and the possibility the appearance and characteristics change in the composition of the filler.
|
|
|
Chemical wall clamp based on fast-setting geopolymeric binders
Novotný, Radoslav ; Kalina, Lukáš (referee) ; Šoukal, František (advisor)
The aim of this work is to develope fast-setting geopolymeric binders applicable in the chemical wall clamp. This clamping systems are big trend because of easy application, ability to transfer big forces and short setting time. Binders of this systems are based on polymeric resin. Their raw materials are expensive, toxic and flammable substances. Based on this consideration an anorganic fast-setting geopolymeric binder was developed. This binders consist of mixture of metakaolin and precipitated silica activated by potassium hydroxide. Binder were characterized by suitable analytic methods (XRD, SEM, DTA). The results of this metods were used for optimalization of binder properties.
|
|
|
Development and Propertied of Historic Masonry Mortar
Lišovský, Martin ; Kulísek, Karel (referee) ; Fridrichová, Marcela (advisor)
This bachelor’s thesis deals with development and propertied of historic masonry mortar, especially lime mortars and their modifications using pozzolan. In the recipe developed in the experimental part, metakaolin is used for the modification. The technological and application properties of mortars made from these formulations are then compared with the commercial mortar SCHWENK TM 5, which is modified by the suevite trass.
|
|
|
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.
|
|
|
Possibilities of using different types of admixtures in shotcrete technology
Berčík, Martin ; Brožovský, Jiří (referee) ; Hubáček, Adam (advisor)
The Bachelor’s thesis is conceived in the form of research findings on current knowledge of inert and active ingredients and their effects on the shotcrete. It focuses mainly on the composition of individual ingredients, their function executing in the concrete mix and explains how they affect the selected physical and mechanical properties. The work enlightes the importance of using co-products from the industry production as an additive to concrete in terms of both ecological and partly economical.
|
|
|
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.
|
|
|
Preparation of light composites on the basis of alkali activated fly ashes from high temperature combustion of coal
Weiglová, Jana ; Ptáček, Petr (referee) ; Havlica, Jaromír (advisor)
This thesis studies possibilities of preparation light composite materials based on solid residues from high-temperature burning. The main focus is put on potential alkaline activation by water glass and 50% sodium hydroxide solution. Further on, the thesis analyzes suitable additions which when added into alkaline environment with alkali release gas and thus enable to create light porous composites. The aim of this work is to suggest one or several recipes for preparation of light composites made from solid residues from high-temperature burning through alkaline activation. To method of XRD diffraction analysis has been used to identify the products of hydration and alkaline-siliceous reaction (phases) of alkaline activation.
|
|
|
Studying the properties of high strength concrete using micro and nano admixtures
Gabko, Miroslav ; Bodnárová, Lenka (referee) ; Hela, Rudolf (advisor)
The objective of this bachelor thesis is to examine the properties of high strength concretes with the main focus on application of mikro or nano admixtures. In theoretical part their production, the properties and the influence on fresh and hardened properties of cement composites are described. In addition, it explores the influence of plasticizer type, some properties of aggregate and cement types. The practical part focuses on testing cement mortars in which fine cements were added. The compressive and flexural strengths were examined after 7 and 28 days of curing, moreover, rheological properties and heat hydration of cements were also observed. Furthermore, the influence of high speed mixing on cement mortars properties was studied.
|
|
|
Development of Historical Universal Mortar with Blended Binder
Lišovský, Martin ; Wagner,, Štěpán (referee) ; Fridrichová, Marcela (advisor)
The diploma thesis deals with development and properties of historic mortars, evolves and optimizes recipe of historicizing universal mortar with mixture binder, which have been evolves in previous phase. Binder system is based on lime hydrate and metakaolin and is modified with fast-pacing gypsum. Thesis follow up technological properties of mixtures of historicizing mortars and modifies them for current construction industry. It also follows effect of modification to phase composition of binder system and eventually rise of AFt phases.
|
guest ::
