|
|
Lightweight mortars with content of alternative raw materials and resistant to adverse effects
Morkusová, Kristýna ; Jakubík, Aleš (referee) ; Bydžovský, Jiří (advisor)
This diploma thesis describes research and following development of lightweight cement mortars with alternative raw materials. Attention was focused on study of the effects of extreme influences such as high temperature (up to 1200 °C), freeze-thaw and agressive sulfur dioxide. Verification of durability of developed mortars was realized using physical and mechanical tests (density and strength), physical and chemical methods (computed tomography) and scanning electron microscopy. Assessment of durability was realized in a longer period of time (90 days).
|
|
|
The development of fire-resistant repair mortars with fine-grained filler
Záruba, Jiří ; Gross,, Tomáš (referee) ; Bydžovský, Jiří (advisor)
The diploma thesis is focused on fire-resistant repair mortar with fine-grained filler. The aim of this work is the research and development of fine-grained Mortars resistant to high temperatures, which are characteristic at the beginning of the fire. The theoretical knowledge with subsequently realized laboratory verification was used. At-tention was paid to the masses based on the mixed binder comprising cement and blast furnace slag, respectively. high-temperature ash. Cellulose fibres were used as the dis-persed reinforcement. Two kinds of aggregate were assessed - fly ash agloporit and am-phibolite incl. combinations thereof. Laboratory tests were carried out via determination of basic material properties (density, strength, consistency, dimensional changes etc.) after exposure to extreme temperatures. A substantial part of the research was also study of different cooling conditions - slow and fast (water and air). Selected formulations were subjected to temperatures up to 1200 ° C. In the conclusion is selected several recipes that have been found to be optimal for continuing research on the basis of the results and findings.
|
|
|
The study of the influence of the composition of the lightweight fiber concrete physical and mechanical properties
Šindelek, David ; Bodnárová, Lenka (referee) ; Hela, Rudolf (advisor)
This bachelor thesis deals with a study of light construction concrete with an addition of steel fibre which monitors its impact of the physical mechanical properties. The work is divided into two parts, theoretical and practical. The theoretical part is focused on characteristics and a design of light concrete within the class 35MPa and over with the density within the class of D1,8. Furthermore, it focuses on the increase of toughness of cementitious composites with the form of application of steel fibre in different doses and lengths. In the practical part, formulas of two strength classes 35/38 D 1,8 and 45/50 D1,8 were designed with the help of the steel fibre Krampeharex in doses of 25 and30 kg/m3, and where there were both its impact of the working diagram as well as the compressive strength monitored for the duration of twenty-eight days
|
|
|
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.
|
|
|
Development of ultra lightweight concretes
Popelková, Adéla ; Hubertová,, Michala (referee) ; Hela, Rudolf (advisor)
This bachelor thesis deals with the technology of production of ultralight concretes using direct lighten cementing compound and at the same time indirect lighten using lightweight aggregate. Further work deals with the choice of suitable raw materials for these concretes. The practical part consists of a proposal of several different recipes, experimental verification and by comparing their properties in a fresh or hardened state.
|
|
|
The Influence of Moisture of Lightweight Aggregate on the Concrete Properties
Pešek, Lukáš ; Lišovský, Martin (referee) ; Kocáb, Dalibor (advisor)
The bachelor thesis deals with the influence of moisture of lightweight aggregate on the concrete properties. In the experiment, test specimens from two different lightweight aggregate, and two different input moisture states of lightweight aggregate were tested. The tests were performed to determine the basic properties of lightweight concrete after 7, 28 and 90 days of maturing. Compressive strength, tensile splitting strength and depth of penetration of water under pressure were determined on cubic specimens. On the test prisms were performed tests to determine the flexural strength and dynamic modulus of elasticity. The results were processed and evaluated in tabular and graphical form to determine statistical data and formulate a conclusion.
|
|
|
Study of the properties of fillers to the composites requiring high temperature resistance
Vovesný, Václav ; Gross,, Tomáš (referee) ; Bydžovský, Jiří (advisor)
The diploma thesis is focused on the behaviour of natural and synthetic aggregates and their behaviour in polymer – cement composites, while being exposed to high temperature. The processes, happening in aggregates and mortar under the thermal load, were described in the theoretical part of the thesis same as the testing of heat effects on the aggregates and mortar. Further, the influence of high temperature on each component of concrete was described, followed by the suggestion of the appropriate components for concrete exposed to high temperature. Various aggregates were tested in the experimental part of the thesis. The basic physical and mechanical properties of aggregates were examined same as their mineralogical composition with using XRD, DTA and SEM methods. At the mortar, the influence of high temperature on the concrete density, compressive strength and tensile strength was defined. The gained knowledge was evaluated in the final part of the thesis
|
|
|
Ultralight concrete with high utility properties
Popelková, Adéla ; Hubertová,, Michala (referee) ; Hela, Rudolf (advisor)
This diploma thesis deals with the technology of production of ultralight concretes using direct lighten cementing compound and at the same time indirect lighten using lightweight aggregate. Further work deals with the choice of suitable raw materials for these concretes. The practical part consists of a proposal of several different recipes, experimental verification and by comparing their properties in a fresh or hardened state.
|
|
|
Development of pelletization conditions for secondary energy products
Burešová, Eliška ; Batelka,, Michal (referee) ; Sokolář, Radomír (advisor)
This thesis deals with the use of secondary energy products. The teorethical part describes methods of separation of fine particles, characteristics and properties of secondary energy products and equipment suitable for pelletizing. On the basis of the theoretical part, the practical part designed and created suitable conditions for pelletizing two types of secondary energy products, namely brick dust and fly ash. These suggestions have been verified and both feedstocks and resulting pellets were tested. In accordance with the results, it is possible to say that the pelletized raw material has better properties than the raw material in its original powder state.
|
|
|
The Influence of Moisture of Lightweight Aggregate on the Concrete Properties
Pešek, Lukáš ; Lišovský, Martin (referee) ; Kocáb, Dalibor (advisor)
The bachelor thesis deals with the influence of moisture of lightweight aggregate on the concrete properties. In the experiment, test specimens from two different lightweight aggregate, and two different input moisture states of lightweight aggregate were tested. The tests were performed to determine the basic properties of lightweight concrete after 7, 28 and 90 days of maturing. Compressive strength, tensile splitting strength and depth of penetration of water under pressure were determined on cubic specimens. On the test prisms were performed tests to determine the flexural strength and dynamic modulus of elasticity. The results were processed and evaluated in tabular and graphical form to determine statistical data and formulate a conclusion.
|
guest ::
