|
|
Geopolymers based on fly ashes and brick body
Řezník, Bohuslav ; Lang,, Karel (referee) ; Příhoda,, Jiří (referee) ; Žižková, Nikol (referee) ; Rovnaníková, Pavla (advisor)
In line with the current focus on utilizing side products of various production processes, this dissertation thesis analyzes the process of alkali activation of particular side products: fly ash and brick fragments. This activation produces geopolymeric materials widely used in civil engineering. The thesis aims to optimize the geopolymerization process so that the resulting geopolymer is both ecologically and economically viable. To that end, the thesis studies the course of geopolymeric reaction between the alkali activator and fly ash from: (i) the Chvaletice power plant, (ii) the Dětmarovice power plant, and (iii) biomass combustion, as well as (iv) fluid fly ash from the Hodonín power plant. All experiments of geopolymeric reaction have focused on the factors influencing the synthesis of geopolymers—that is: composition of the alkali activator, the ratio of alumino-silicate to the activator, and the impact of temperature on structure of the synthesized geopolymer. Further, the thesis analyzed the synthesized polymer’s microstructure, phase composition, resistance against corrosive conditions, and compressive strength, as well as mechanical-fracture properties of selected fly-ash geopolymers. The thesis finds that the most suitable for geopolymeric synthesis appears to be the fly ash from the Chvaletice power plant in which case the obtained geopolymers showed best properties in the studied areas. The fly ash from the Dětmarovice power plant, biomass fly ash, and fluid fly ash have failed to reach acceptable properties. Separately, the thesis studies the geopolymerization of brick body that could be suitable input for alkali activation. The geopolymers synthesized from brick fragments resulted in materials of supperior mechanical strength. A mixed use of fly ash and brick fragments failed to show a synergetic effect. Properties of the resulting geopolymers have been inferior to the properties of geopolymers produced using just fly ash or just brick body.
|
|
|
Color Changing of the Ceramic brick.
Kocmánek, Tomáš ; Zach, Jiří (referee) ; Nevřivová, Lenka (advisor)
The bachelor’s thesis is focused on color correction of brick body. There are examples of pigments commonly used in various industrial fields, as well as studies on the use of waste products as additives in brickmaking industry, altering, among other things, the color of the brick body. In the experimental part of the thesis the effect of three selected ferric pigments and two selected correction clays on the color and selected physico-mechanical properties of the brick body was investigated.
|
|
|
The effect of fibres addition on the properties of brick body
Novotný, David ; Stančík,, Hynek (referee) ; Sokolář, Radomír (advisor)
This diploma thesis will discuss possibilities of using inorganic fibers to improve the mechanical properties of the resulting physical body bricks. Assessment of the effect of fiber length, fiber thickness is in the order of micrometers. In this work we were used fibers which are commercially produced for the purpose of reinforcement, but also waste fibers, which mainly serves as an insulator.
|
|
|
Lime Mortars Modified by Fine Ground Brick Body
Šmerdová, Ludmila ; Vyšvařil, Martin (referee) ; Rovnaníková, Pavla (advisor)
Natural pozzolanic materials played an important role in Ancient architecture. In the last decades and nowadays it is artifical pozzolan which especially finds its use as an additive to mortar and concrete to improve some, especially the mechanical properties. This master thesis deals with study of pozzolan type of fine brick powder which is a by-product of the production of calibrated bricks. Along with studying pozzolanic activity of brick powder, lime mortar with different proportions of brick powder as an additive or replacement of lime dust are investigated. What is observed is its impact on the consistency of these mortar, water absorption, strength in time or fracture-mechanical parameters of mortar. The results may indicate the possible potential use of this source of pozzolanic admixture in lime mortar and plaster which are nowadays mainly used for the restoration of facades of historic buildings.
|
|
| |
|
| |
guest ::
