|
|
Possibilities of recycling in the sand aerated concrete technology
Kostura, Patrik ; Kulísek, Karel (referee) ; Drochytka, Rostislav (advisor)
Waste of the aerated concrete is generated directly from the production of aerated concrete or from the constructions. The options for handling aerated concrete are two. We can deal with it as a light aggregate or as a material for the production of aerated concrete. Based on the physico-mechanical properties, the decision was made that aerated concrete is suitable as a light aggregate. The brash as a light aggregate was tested in two variants of the softness (0-2 mm, 0.25-2 mm). Evaluation of the brash as a suitable material for the production of aerated concrete consisted of the creation of laboratory-autoclaved composites. The brash was tested in different ratios (10%, 20%, 30%, 40%), two variants of fineness (0-2 mm, 0-0.25 mm) and two formulations (lime base, fluffy fly ash). Silicon sand was replaced. Based on physico-mechanical properties and microstructural analysis (XRD, SEM), was found that aerated concrete as a material is suitable for 40% sand substitution.
|
|
|
Study of microstructure of autoclaved aerated concrete with using of secondary raw materials
Martanová, Jana ; Suchý, Peter (referee) ; Kulísek, Karel (advisor)
Autoclaved aerated concrete is a used building material, especially for its thermal insulating properties. During autoclaving, an aerated concrete microstructure produces crystalline CSH phases, primarily tobermorite. The ingoing substances are calcium oxide and silica. In addition to commonly used raw materials, secondary raw materials rich in silicon dioxide can be used for production. The use of secondary raw materials gives the opportunity for the construction industry to be more environmentally friendly. Another benefit is the reduction of financial costs. The work explores the influence of individual secondary raw materials on the microstructure. High-temperature fly ash, fluid fly ash, cinder, ground glass and zeolite were used The raw materials were mixed with unalloyed lime at a molar ratio of calcium oxide to silicon dioxide of 0.73 and 1.0. Autoclaving capsules were used to synthesize tobermorite under laboratory conditions. Autoclave was performed at 170 °C and 190 °C with hydrothermal durations of 4, 8 and 16 hours. The most important influence on the microstructure was high-temperature fly ash, on the contrary, the greatest influence on the mechanical properties is attributed to the ground glass.
|
|
|
Development of Grouts for Ceramic Tiles
Coufal, Daniel ; Gazdič, Dominik (referee) ; Fridrichová, Marcela (advisor)
The bachelor thesis deals with the development of grout for filling of wide joints of ceramics tiles. The theoretical part is devoted to individual types of jointing materials, their properties and application. The practical part deals with proposed mixtures with focus on the influence of the filler as ground limestone and his substitution with silica sand and the effect of the subsequent modification of these mixtures by the expansion additive.
|
|
|
The effect of fly ash aerated concrete production technology to formation of tobermoritic phases
Fleischhacker, Ján ; Kulísek, Karel (referee) ; Drochytka, Rostislav (advisor)
Autoclaved aerated concrete is long-time ecological building material with usefull properties. There needs to be done research of its mineralogical compound for reengineering the production. The main mineral compound of AAC is tobermorite, it increases its mechanical properties. In the presence study, we examine the usage of nature and artificial silicious materials. Also, we investigate the influence of sulfate and alumina admixtures, as well as fluidized bed combustion ash, which can be used as the lime and gypsum replacement. Closure of the study is design of the optimal raw material composition, also hydrothermal treatment of autoclaved aerated concrete. In relation to its mechanical properties, mineralogical composition and cost.
|
|
|
Evaluation of local filler sources suitability for anhydrite-based screeds
Šikral, Martin ; Kaláb, Michal (referee) ; Drochytka, Rostislav (advisor)
Goal of this thesis is to evaluate suitability of local filler sources for anhydrite based screed floor covers. The theoretical part is mostly aimed at summarization of general findings about flooring constructions and about anhydrite itself. The thesis also includes description of primary and secondary raw materials. The goal of this work is to suggest suitable fillers for anhydrite based screed floor covers in accordance with distance from Sika CZ, s.r.o with residence in Brno – Modrice. At the same time this thesis explores possibility of secondary raw materials usage as a replacement of primary fillers. In conclusion the thesis focuses on the laboratory test of chosen fillers, summarization and discussion of discovered findings.
|
|
|
Development of high quality autoclaved aerated concrete using alternative resources
Kostura, Patrik ; Janovský, Radek (referee) ; Drochytka, Rostislav (advisor)
With the growing trend of construction, the demand for building materials is growing steadily. Porous concrete is widely used in the building industry, that makes efforts to discount production and simultaneously save the environment. The aim of this thesis is to develop high-quality porous concrete by using alternative raw materials as a substitute for silicate sand. As a possible substitute were chosen: Silica masonry, foundry sand and fireclay boulders. The influence of two key parameters - the specific surface (130, 240 and 350 m2·kg-1) and the amount of silica sand substitution (10, 30 and 50 %) were monitored. Two autoclaving modes (7 and 12 hours of isothermal durations at 190 ° C) were tested. Based on the physico-mechanical and mineralogical characteristics of the porous concrete composites was chosen the ideal surface area of 240 m2·kg-1 and time of isothermal endurance was determined at 7 hours (temperature 190 ° C, pressure 1,4 MPa). From the optimal intentions were created samples with a macroporous structure, using an aluminum powder. Physical-mechanical properties and microstructural analysis (XRD, SEM) were subsequently determined on the samples. Ideal recipes were proposed with 50% sand substitution of fireclay boulders and 10% substitution of foundry sand. This was due to a 10% higher compressive strenght and an increase of the coefficient of constructiveness, compared to the reference sample.
|
|
|
Utilization of alternative raw materials in sand aerated concrete technology
Ondříčková, Pavlína ; Kulísek, Karel (referee) ; Drochytka, Rostislav (advisor)
The presented work deals with the problems about silica sand replacement for alternative raw materials in the production of autoclaved aerated concrete. The work describes technology of production and creating structures of autoclaved aerated concrete. The main part of the work is the study scientific articles dealing with alternative materials in autoclaved silicate materials. The object of work is to find the most suitable domestic alternative materials for supplement or replacement for silica sand in production of autoclaved aerated concrete.
|
|
|
Desin of new technologies for invert grouting of masonry sewer
Dolák, Martin ; Melichar, Tomáš (referee) ; Drochytka, Rostislav (advisor)
The subject of this work is to find optimal grouting mixture for repairing existing brick sewer with insistence on ecological modesty. Secondary raw and waste materials will be evaluated as a partial replacement of good-quality materials, that are commonly used. Production wastes for which is after necessary adjustment found usage in another sphere of production are named secondary raw materials. In the end will be made a selection of appropriate secondary raw materials for a project of new technology of back grouting identified for repairing currently used brick sewers.
|
|
|
Desin of new technologies for invert grouting of masonry sewer
Dolák, Martin ; Melichar, Tomáš (referee) ; Drochytka, Rostislav (advisor)
The subject of this work is to find optimal grouting mixture for repairing existing brick sewer with insistence on ecological modesty. Secondary raw and waste materials will be evaluated as a partial replacement of good-quality materials, that are commonly used. Production wastes for which is after necessary adjustment found usage in another sphere of production are named secondary raw materials. In the end will be made a selection of appropriate secondary raw materials for a project of new technology of back grouting identified for repairing currently used brick sewers.
|
|
|
Development of high quality autoclaved aerated concrete using alternative resources
Kostura, Patrik ; Janovský, Radek (referee) ; Drochytka, Rostislav (advisor)
With the growing trend of construction, the demand for building materials is growing steadily. Porous concrete is widely used in the building industry, that makes efforts to discount production and simultaneously save the environment. The aim of this thesis is to develop high-quality porous concrete by using alternative raw materials as a substitute for silicate sand. As a possible substitute were chosen: Silica masonry, foundry sand and fireclay boulders. The influence of two key parameters - the specific surface (130, 240 and 350 m2·kg-1) and the amount of silica sand substitution (10, 30 and 50 %) were monitored. Two autoclaving modes (7 and 12 hours of isothermal durations at 190 ° C) were tested. Based on the physico-mechanical and mineralogical characteristics of the porous concrete composites was chosen the ideal surface area of 240 m2·kg-1 and time of isothermal endurance was determined at 7 hours (temperature 190 ° C, pressure 1,4 MPa). From the optimal intentions were created samples with a macroporous structure, using an aluminum powder. Physical-mechanical properties and microstructural analysis (XRD, SEM) were subsequently determined on the samples. Ideal recipes were proposed with 50% sand substitution of fireclay boulders and 10% substitution of foundry sand. This was due to a 10% higher compressive strenght and an increase of the coefficient of constructiveness, compared to the reference sample.
|
guest ::
