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Effect of plasticizers on the behaviour and properties of alkali activated materials
Langová, Markéta ; Koplík, Jan (referee) ; Kalina, Lukáš (advisor)
Alkali activated materials could be suitable alternative to construction materials based on ordinary Portland cement (OPC). Therefore, it is advisable to pursue these binders further on. Aim of this thesis is to clarify the effect of lignosulfonate-based plasticizer and polycarboxylate-based superplasticizer on the behaviour and nature of alkali activated materials. For the purposes of studying the efficiency of plasticizing additives, the change of workability of alkali activated blast furnace slag in dependence on time, effect of additives on mechanical properties as well as, with usage of isothermal calorimetry, their impact on kinetics of solidification and hardening had been observed. The stability of the plasticizing admixtures in a high alkaline environment such as water glass and sodium hydroxide had been studied using infrared spectrometry. As a last step, X-ray photoelectron spectroscopy (XPS) had been used while clarifying the chemical changes in the structure of plasticizing additives after adsorption to blast furnace slag.
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Technology design watertight concrete
Skřivánek, Michal ; Hubertová,, Michala (referee) ; Hela, Rudolf (advisor)
My work describes technology design of pervious concrete. The theoretical part contains a research about this kind of concrete usually from foreign authors. In general, I focused on the composition of the PC, aggregate grading curve, behaviour of concrete in fresh state, storing and compaction of concrete. A critical part is the aggregate grading curve – it plays the main role in the final level of water permeability. Further, we will go through the real world scenarios where we can use this type of concrete and also through the associated drawbacks. A substantial part of this work is about development of water-permeability test. The practical part shows variety of recipes with a list of measured and observed characteristics (compressive strength, frost resistence and water-permeability). The conclusion includes evaluation of the results and suggestions for future development in this area.
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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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Effect of chemical additives on the process hydration temperature of cement pastes
Knotová, Kateřina ; Halas, Vladimír (referee) ; Sedlmajer, Martin (advisor)
Chemical additives, especially plasticizers and super plasticizers, are necessary components of nearly every concrete. These additives improve the workability of grout and concrete mixes thereby reducing vibration intensity during process of compaction. Advantages of these additives are associated with reduction of the amount of gauging water which leads to decrease water-cement ratio, increase strength and durability of concrete, eventually improve other attributes. The aim of this thesis is to observe the effect of plasticizers and their dosage on the rheology and development of hydration temperatures in simpler systems, which are the cement pastes. The thesis also considers compressive, tensile and flexural strength of concrete.
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Systems of self-setting foundry mixtures on the base portland cements
Janíčková, Petra ; Cupák, Petr (referee) ; Rusín, Karel (advisor)
The project elaborated in frame of engineering studies branch N2332-00. The project is submitting design of technology production sand mixture with cement binder – Portland binder CEM I 42,5 N. Pursuant to of the literary pursuit a problem of the sand mixture with cement binder was tested few sand mixture. As optimal composition it turned out application sand mixture with 2 % CaCl2 content and 1 – 2 % Dextrin content. Sand mixture with cement has good moulder and regenerating.
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The issue of increasing the proportion of reclaimed asphalt in asphalt mixtures
Urbanec, Luboš ; Mondschein,, Petr (referee) ; Hýzl, Petr (advisor)
The subject of this Ing. thesis is asphalt mixture with increasing RAP (Reclaimed Asphalt Pavement). The theoretical part defines the terms of recycling and RAP and types of recycling. The practical part is devoted to the production and testing of asphalt mixtures with different volume RAP. The proposed asphalt mixture is asphalt concrete for base layer ACP22 +. Content of RAP in mixtures is 0%, 30%, 50% and 70%. As a special additive to soften the asphalt from RAP is used ingredient STORFLUX. For each mixture are established modulus stiffness of asphalt mixture and determined fatigue characteristics of asphalt mixture. The identified properties are compared for the different representation of RAP.
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Design of asphalt mixtures with the use of higher amount of RAP
Pavličík, Petr ; Matoušek, David (referee) ; Varaus, Michal (advisor)
In the introduction of the Master’s thesis describes for obtaining and processing of reclaimed asphlalt. Major point of the thesis is design of asphalt mixtures with use of higher amount of RAP for asphalt binder course. Asphalt mixtures were designed with contents of 0%, 30%, 50% and 70% of RAP. On each asphalt mixtures were compared parameters set out by functional tests – resistence to permanent deformation and resistence to water.
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Binders on the base alumina cements and their properties
Morávková, Jitka ; Cupák, Petr (referee) ; Burianová, Klára (advisor)
The Bachelor Thesis describes chemical and mineralogical structure, as well as alumina cements manufacture and some of their physical and techno-logical properties. It takes accelerators or plasticizers induced changes by search method. An illustrative laboratory measurement of mixture with accel-erator and plasticizer is complementary to theoretical knowledge in fluidity, air permeability and strength of mixture with aluminium silicate cement binder.
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High-valueable gypsum binder based on secondary raw materials
Rybová, Alexandra ; Dvořák,, Karel (referee) ; Fridrichová, Marcela (advisor)
The thesis is oriented on preparation of high – valuable gypsum binder using secondary raw materials with emphasis on technological properties and their improvement by aplication of selected modifier aditives. The first part of the task is dedicated to a teoretical knowledge in the field of gypsum binders, especially to the raw materials, properties and possibilities of utilization. Second part is focused on experimental works that test properties of gypsum and effectivness of selected modifier aditives.
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