|
| |
|
|
Issue of taking leave for teaching and non-teaching staff
Šimonová, Hana ; Kitzberger, Jindřich (advisor) ; Svoboda, Petr (referee)
This bachelor degree thesis deals with the planning of annual leave for teaching and non-teaching staff and with their taking leave in different types of schools and educational establishments in the district of Havlíčkův Brod run by municipalities, in relation to valid legal regulations. It is based on the assumption that annual leave is planned for the purpose of using up all leave of all employees in the year when they are entitled to take it. The thesis summarizes the reasons for which not all annual leave is taken, looks at the compliance with legal regulations and tries to find out in which parts of schools and in which categories of staff the biggest problems with taking annual leave arise and how this affects the school budget. The results of the research survey could be applied in the vocational education of headmasters and headmistresses.
|
|
|
Architectural study of the sacral object Brno - Líšeň / second stage
Simonova, Hanna ; Žalmanová, Petra (referee) ; Šindlar, Jiljí (advisor)
The main theme of the diploma is the design of a new Roman Catholic church and parish within the framework of the construction of a panel residential complex in Nový Líšeň in Brno. Due to the fact that Salesian children and youth workers came to the area in 1990, it became necessary to build a church and a Salesian youth center. This proposal is based on an analysis of the urban context. The church is surrounded by prefabricated houses next to a school, a health clinic, a shopping center, and a Salesian youth center in a gently sloping area facing south with the dominant Palava hills.
|
|
|
Fracture Parameters of AAAS composites with ceramic precursor
Šimonová, H. ; Rozsypalová, I. ; Kumpová, Ivana ; Trčka, T. ; Frantík, P. ; Rovnaníková, P. ; Keršner, Z.
The paper deals with alkali-activated aluminosilicate composites based on ceramic precursors with respect to their characterization by fracture-mechanical parameters. Three composites made of brick dust as a precursor and alkaline activator with silicate modulus Ms = 1.0, 1.2 and 1.4 were investigated. After 28 days of maturation, specimens with nominal dimensions of 40 × 40 × 160 mm were provided by an initial notch to 1/3 of the body height in the middle of the span. At least 6 samples were tested from each composite. Specimens were subjected to three-point bending tests during which force vs. deflection at midspan (F–d) and force vs. crack mouth opening displacement (F–CMOD) diagrams were recorded. By processing these diagrams, the values of the static modulus of elasticity, the effective fracture toughness (including its initiating component) and the specific fracture energy were determined using the effective crack model, Work-of-Fracture method, and Double-K fracture model. After the fracture experiments had been performed, compressive strength values were determined for informational purposes from one part of each specimen that remained after testing. All evaluations included the determination of arithmetic means and standard deviations. To obtain information about the internal structure of composites before and after mechanical testing, the selected body was examined by micro-tomography. Tomographic measurements and image processing were performed for qualitative and quantitative evaluation of internal structure changes with an emphasis on the calculation of porosimetric parameters as well as visualization of the fracture process zone. The fractal dimension of fracture objects was determined.
|
|
|
Determination of Fatigue Characteristics of Concrete Using Fracture-Mechanics Parameteres
Šimonová, Hana ; Králik,, Juraj (referee) ; Terzijski, Ivailo (referee) ; Bílek,, Vlastimil (referee) ; Keršner, Zbyněk (advisor)
The topic of this PhD. thesis is the issue of determining fatigue characteristics of selected cement-based composites. First, the history of fatigue of metal is mentioned, and some basic notions related to fatigue are clarified. The thesis also summarizes current research in the field of cement-based composites fatigue, and failure mechanisms of plain concrete during static and dynamic tests are described. Furthermore, the thesis deals with the evaluation of static and dynamic experiments’ results with extensive series of C30/37 and C45/55 class concrete specimens. In order to achieve relevant fatigue test evaluation which takes into account the age of the specimens, a new correction procedure of the data measured based on the approximation of the basic fracture-mechanics parameters of tested materials over time was suggested and verified. The annexes of this thesis present complete data obtained during static and dynamic experiments.
|
|
| |
|
|
Basic features of aggregate-matrix-interface fracture of concrete: pilot modelling
Vyhlídal, M. ; Šimonová, H. ; Veselý, V. ; Keršner, Z. ; Klusák, Jan ; Malíková, Lucie
In this paper, the attention is paid to investigation of the importance of the Interfacial Transition Zone (ITZ) in concrete for the global fracture behaviour. A simplified cracked geometry (consisting matrix, ITZ and aggregate) is modelled by means of the finite element method with a crack terminating at the matrix-ITZ interface. Numerical studies assuming two various ITZ thicknesses and several various ITZ elastic moduli are performed. Based on the values of the opening stress ahead of the crack tip (its average value and stress range) a few conclusions are discussed. The pilot analyses dealing with the effect of ITZ on the stress distribution should contribute to better description of toughening mechanisms in silicate-based composites.
|
|
|
Analysis of selected silicate based composites volume changes
Kubeš, Pavel ; Šimonová, Hana (referee) ; Keršner, Zbyněk (advisor)
This diploma thesis deals with the analysis of volume changes of selected silicate based composites. The first part introduces the issue of volume changes of concrete, especially the shrinkage process, two selected models for shrinkage prediction, describes configuration and course of performed tests, as well as the processing of measured experimental data. The second part contains input data modified by the program GTDiPS and another calculated parameters. The result of the work is the evaluation of the influence of thermal dilation on the development of shrinkage of young concrete. Another output is the comparison of accuracy of the two selected prediction models to capture the course of measured shrinkage.
|
|
|
Mechanical fracture parameters of concrete after exposure to high temperatures
Bejček, Michal ; Keršner, Zbyněk (referee) ; Šimonová, Hana (advisor)
The diploma thesis is focused on the evaluation of mechanical fracture parameters of concrete after exposure to high temperatures. In the introductory theoretical part general principles of fracture mechanics with the concentration on a linear elastic fracture mechanics and non-linear fracture models for the concrete are summarized. The meaning of the three-point bending fracture test used for determination of fracture parameters is also explained. Further the influence of high temperatures on the partial components of concrete and general modeling of temperature loading is described. The practical part is concerned with the evaluation of fire experiments on the concrete panels including numerical simulations using GiD and ATENA software. The evaluation of data obtained from the three-point bending test carried out on specimens with initial stress concentrator taken from concrete panels is a main part of the diploma thesis. The values of modulus of elasticity, effective fracture toughness, work of fracture and fracture energy are determined from the measured F–d and F–CMOD diagrams after their proper corrections in the GTDiPS application. The evaluation of the selected mechanical fracture parameters was performed by StiCrack software using effective crack model and work of fracture method and DKFM_BUT software using the double-K fracture model. Finally, the attention is paid to the analysis of the obtained data.
|
|
|
Possibilities of using X ray tomography for description of damage of temperature loaded concrete
Rozsypalová, I. ; Kumpová, Ivana ; Daněk, P. ; Šimonová, H. ; Keršner, Z.
The effect of high temperatures on concrete affects the internal structure of this composite material. The paper opens the question of the possibility of using a computed X–ray tomography to quantify the degree of damage of a concrete specimen that was drilled from the selected experimental panel loaded in a fire furnace with high temperatures at the AdMaS (Advanced Materials, Structures and Technologies) research centre at Faculty of Civil Engineering Brno University of Technology. The nominal value of the maximum temperature on the heated side of the panel was 1000 °C. Advanced workstation computer X–ray tomography TORATOM at Centre of Excellence Telč (CET) is parallel imaging of an object in two spectra of X–ray radiation, that allows to highlight differences between the material components to the full X–ray spectrum similar to the attenuation of the radiation.
|
guest ::
RSS feed.