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Lightweight concrete with reinforcement
Plochý, Ondřej ; Hubertová,, Michala (referee) ; Hela, Rudolf (advisor)
This bachelor thesis summarizes the current knowledge regarding to the design and properties of lightweight concrete and concrete with reinforcement. Also deals with research of lightweight aggregate concrete with Liapor and its interaction with dispersed steel fibers. The work examined recipes of volume classes D1,6 and D1,8 and strength classes SFRLC 20/22 and SFRLC 25/28. Recipes are monitored by physical-mechanical and rheological properties.
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Testing of bricks intended for the repair of monuments
Lezová, Lívia ; Anton, Ondřej (referee) ; Cikrle, Petr (advisor)
The bachelor thesis is focused on methods of testing bricks, which will use to classify historic bricks into groups on usable, usable in extreme conditions, usable in limited extent and unusable for restoration of monuments or for construct new constructions. In the theoretical part, there is describe of historical development of solid fired bricks in Central Europe and an overview of methods for testing bricks, including a description of an accomplishments and their evaluation. In the practical part, there are methods applied to three visually different sets of bricks taken from 19th century construction.
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Possibilities of utilization of solid residues from fluidized bed combustion for preparation of composite Portland cements
Beranová, Denisa ; Šiler, Pavel (referee) ; Opravil, Tomáš (advisor)
The bachelor thesis deals with possibilities of utilization of solid residues from fluidized bed combustion of coal, bed and filter ash, to be used in the production of composite Portland cements. 6 ash types were investigated, of which 3 were bed ash (finely ground) and 3 were filter ash colected from Ledvice, Tisová and Poříčí K8 power plants. The chemical composition of the ash collected was determined and the progress of a hydration reaction monitored, and then samples mixed with Portland clinker were prepared. Their respective compressive strength and flexural strength were then analysed and observations made on the hydration and composition of products of the hydration reaction. Finally the results of selected mixtures were verified with prepared standardized mortars.
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Latexes modified cementitious materials
Vinter, Václav ; Krátký, Josef (referee) ; Šoukal, František (advisor)
In this thesis, the development of mechanical properties and structure of latex modified cementious materials during hydration was studied. Latex modified materials are composites of inorganic cement (portland cement) and organic polymer latex. Preparation, processing and fabrication of the polymer cement material based on portland cement was optimized with aim to reach the most compact structure of the product with the finest mechanical characters. The experimental part was pointed to observe influence of the type and amount of polymer latex with focus on mechanical characters and hydration kinetics with given filling as well as without it. In presented work, the possibility of compaction of the material by high-shear mixing within twin-roll mixer (the prototype for production of MDF composite) was verified. The second part of the labor was aimed to analysis of prepared polymer-cementitious material. For determination of influence of batching of added polymer latex on hydration of cement paste the thermal analysis (DTA/TGA) and infrared spectroscopy of composite was done. At last the microscopic observation by optical microscope was carried.
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The use of dynamic non-destructive methods for determining the strength of cement from cement plant Hranice
Procházková, Lenka ; Novosad, Petr (referee) ; Brožovský, Jiří (advisor)
Nondestructive testing methods are employed as a tool for evaluation of parameters of building materials, especially to ascertain strength properties and to determine alteration occured during durability tests. An ultrasonic pulse velocity method is one of the most used nondestructive methods. A resonance method is employed among the nondestructive methods less. The aim of this work is to establish the calibration relationships between parameters of nondestructive testing and compressive strength value and flexural tensile strength value, respectively. Moreover, applicability of the calibration relationships is also discussed.
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Study of properties of cementitious composites with fiber reinforcement from inorganic fibers
Gottwaldová, Aneta ; Novosad, Petr (referee) ; Bodnárová, Lenka (advisor)
Diploma thesis deals with study of properties of cementious composites with fiber reinforcement from glass and basalt inorganic fibers. Diploma thesis includes a theoretical and experimental part. The theoretical part deals with information about glass and basalt fibers, their durability and usage. In the experimental part we monitored properfies of cement composites with basalt and glass fibers. Fibers were exposed to an aggressive environment. The properties of composites with reference fibers were compared with composites with fibers affacted by the aggressive environment. The properties of composites were examined after 28 and 90 days. We monitored compresive strenght, bending tensile strenght, tensile strenght, surface layer strenght and SEM.
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Influence of hydration accelerators on zinc - doped cement mortars
Beneš, Pavel ; Šilerová, Iva (referee) ; Šiler, Pavel (advisor)
This work deals with monitoring the hydration of cement mortars and cement pastes made from CEM I 42.5 R cement doped with zinc oxide in an amount of 1 % wt. To eliminate the delay in the onset of hydration due to the presence of zinc oxide, the following accelerators were added to the cement mixtures in different proportions: calcium oxide, formic acids and calcium formate. Hydration was monitored using isoperibolic calorimetry. Furthermore, the mechanical properties of mixtures were investigated, namely the tensile strength after bending and the compressive strength after 7 days and after 28 days. The cement mortars were further subjected to additional analyses, such as porosimetry, DTA/TG and SEM.
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Testing of bricks intended for the repair of monuments
Lezová, Lívia ; Anton, Ondřej (referee) ; Cikrle, Petr (advisor)
The bachelor thesis is focused on methods of testing bricks, which will use to classify historic bricks into groups on usable, usable in extreme conditions, usable in limited extent and unusable for restoration of monuments or for construct new constructions. In the theoretical part, there is describe of historical development of solid fired bricks in Central Europe and an overview of methods for testing bricks, including a description of an accomplishments and their evaluation. In the practical part, there are methods applied to three visually different sets of bricks taken from 19th century construction.
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