|
|
Physical and mechanical properties of Carboniferous arkoses from Březín natural stone deposit
Čada, Martin ; Přikryl, Richard (advisor) ; Krutilová, Kateřina (referee)
The aim of the thesis is to determine the levels of the physical and mechanical properties of chosen sedimentary (siliciclastic) rocks and also to describe their microstructural nature. With respect to the intended use of the studied material (building stone raw material) the laboratory testing methods are presented. The samples were taken from the drill cores and also from the surface blocks in locality "Zlatý lom" Březín situated in western Bohemia. The microstructural phenomena in the samples were studied using optical microscopy and digital image analyses. According to Folk's classification (1980) the name of the rock was lithic arkose. The strength testing methods were represented by unconfined compressive strength and the Brazilian test. The rest of the mechanical parameters were determined in form of Young's modulus, shear modulus and Poisson's ratio. Special emphasis was given to the hydric expansion (after full immersion) test. The other physical methods were used in order to describe the pore space and real density of samples. For this purposes the absorption test, mercury intrusion porosimetry and helium pycnometry were performed. Besides the porosity value, the pore-size distribution histograms were obtained. In order to calculate the theoretical density of the rock MINLITH and MODES...
|
|
|
Weathering forms of brick-wall surrounding Regional Maternity Hospital in Prague and their interpretation
Jablonský, Jakub ; Přikryl, Richard (advisor) ; Krutilová, Kateřina (referee)
This diploma thesis focuses on the weathering of firing bricks used for construction of the walls at the Regional Maternity Hospital U Apolináře in Prague. This wall shows significant marks of weathering, such as black crusts of gypsum on the original bricks surface, blistering, spalling and powdering in the worst cases. The poor quality of the bricks is caused by a low firing temperature (aprox. 800 - 900řC). This leads to a lack of pores bigger than 3 μm, which have positive influence on high performance of bricks against freeze-thaw cycles and effect of water soluble salts. This thesis aims to find the source of raw material for production of bricks, determination of their mineralogical composition and their basic geotechnical survey, as well as determination of weathering forms and their intensity by detailed field study of the wall. The relationship between properties of bricks and weathering forms will be studied by optical microscopy, XR diffraction, which allows to estimate mineralogal composition of bricks and their firing temperature. Ion changing chromatography identifies concentration of water soluble salts in the wall and their relationship to porosity of surface area and cores of bricks which will be detected by mercury intrusion porosimetry. Results will be useful for restoration...
|
|
|
Modification of rock fabric of clastic sedimentary rocks due to the Schmidt hammer test
Snížek, Petr ; Přikryl, Richard (advisor) ; Vavro, Martin (referee)
iv Summary Schmidt hammer is the instrument which is used for the assessment of rock mechanical properties and this instrument is classified as the indirect method. This method is based on the assessment of rebound value (R) of the Schmidt hammer, which is measurred by the amount of rebound of the impact plunger from the surface of tested rock. Schmidt hammer is called as the non-destructive method of rock assessment and it is called as in situ testing method as well. The main objective of this work is provement, that Schmidt hammer testing is destructive method and define degree of damage which is caused in the rock mass. Sedimentary rocks were used for the testing, mostly sandstones and arkose sandstones with different types of cement. This made it possible to test the fraction of the rock mass and the relation between fraction and type of cement. The clasts of the rocks had different properties than it was possible to find the relation between grain size and fraction of the rock. Already in procedure of the testing by Schmidt hammer it was obvious, that this metod is definitely destructive. Rock surface after hitting by plunger of Schmidt hammer gains macroscopically observeable destruction. On the surface is the circular track of the plunger and the surface is grinded. It is possible to wipe the small...
|
|
|
Mineralogical and technological characteristics of Cyprus bentonites
Ppalos, Christodoulos ; Přikryl, Richard (advisor) ; Jelínek, Emil (referee)
The Cypriot deposits of bentonite, Phiti, Statos and Pedakomo are located in an autochthon sediment zone, which represents sediments during the marine regression in the period Upper Cretaceous - Pleistocene (67 Ma to 0.0117 Ma). The goal of this thesis is to suggest potential applications of bentonite, through the study of mineralogical composition and analysis of selected properties (chemical, physical and mechanical). The mineralogical study of Cypriot bentonite using X-ray diffraction analysis has proven the existence of clay mineral belonging to the group of smectite (montmorillonite), as well as the existence of minority illite and kaolinite. From non-clay minerals, the majority of the samples contained zeolite (clinoptilolite), quartz, feldspar and in some samples calcite. The semiquantitative representation of crystalline phases, found during the mineralogical study, was calculated through the chemical analysis. The calculations suggest that Cypriot bentonite is composed of 47 - 58 % smectite, 3 - 19 % kaolinite, 3 - 11 % illite, 3 - 10 % clinoptilonite, 8 - 17 % quartz and 2 - 5 % feldspar. From the physicochemical properties, the cation exchange capacity and specific surface area were studied. The values of cation exchange capacity fluctuate in a range 15.8 - 64.3 meq/100g for individual...
|
|
|
Comprehensive study of the sandstone rock forms deterioration (Case study: Pravčická brána Arch, Bohemian Switzerland National Park)
Vařilová, Zuzana ; Přikryl, Richard (advisor) ; Vilímek, Vít (referee) ; Mikuláš, Radek (referee)
This PhD thesis contains the results of comprehensive research into the Pravčická brána Arch and surrounding sandstone massifs with focus on gaining more knowledge about natural dynamics and evolution of this rock formation, its current level of stability and the weathering processes it displays. Non-destructive methods were used for this comprehensive study; these ranged from detailed field documentation to monitoring temperature regime of the rock and included application of a geophysical survey and control monitoring of the course of arch body deformation. Laboratory testing was carried out for strength parameters and salt efflorescences together with weathered sandstones were analysed for chemical compounds. Main operating factors were monitored simultaneously, which particularly involved changes in external temperature, degree of sunlight and chemical composition of rainfall. Conventional as well as entirely new assessment procedures were used in synthesis and interpretation of the data collected, including knowledge of nonlinear dynamics of complex systems. The survey was designed to fully respect the protective conditions of the site, to make follow-up activities possible in future and to monitor any possible negative changes in the rock massif. The main results incorporate description of...
|
|
|
Rare Earth Elements deposits in the World and their indications at Czech Republic
Pechar, Tomáš ; Zachariáš, Jiří (advisor) ; Přikryl, Richard (referee)
Rare earth metals are a strategic raw material (the material of the 21st century), whose economic importance greatly increased significantly over the past few years. There are currently required to produce a modern electrotechnology and for the use of renewable resources (such as permanent magnet in generators for wind turbines). They are also used in metallurgy, glass and automotive industries (carrier catalysts). Rare earth elements are contained in more than 200 minerals, but few of them are economically important. Increased accumulation of these elements are related mainly to the peralkaline igneous rocks, carbonatites, placer and laterite deposits. The world's largest exporter of this commodity is China, for which currently accounts for 97% of world production. China gets rare earths mainly from Bayan Obo deposit, which in itself account for 70% of world reserves of this raw material. Due to high demand for this commodity, both in China and around the world, the Chinese government introduced a new pricing tariffs and export controls. In 2011 world production was 133 000 tons of oxides of rare earths, while expected, will be in demand in 2015 amount to 210 000 tons of oxides of rare earths. Due to that situation are greatly increased interests of advanced economies to provide new sources of...
|
|
|
Experimental study of Palaeozoic limestones of the Barrandian and their possible use for burning of hydraulic limes and natural cement
Kozlovcev, Petr ; Přikryl, Richard (advisor) ; Vavro, Martin (referee)
54 Summary In this experimental study, selected Devonian limestones of the Prague Basin (i.e. samples from the historic quarry of Branické skály) were examined to find their suitability for production of hydraulic limes or for natural cement. Four representative samples of the dvorecko-prokopské limestone were sampled in the form of blocks weighing approximately 10 kg each, from the layer of the quarry wall that had been chosen based on literature research. A detailed mineralogical-petrographic examination of samples was the first step, in an attempt to obtain their mineralogical composition, microstructure and texture. Samples were analysed by polarizing microscopy and cathodoluminescence of thin sections, and X-ray diffraction of insoluble residues determined by treatment with both the hydrochloric acid and the acetic acid solution. Mineralogical composition of the insoluble residuals was illite, kaolinite, quartz and Na-plagioclase (albite). Two samples contained among above mentioned mineral phases also chlorite. The utility of studied limestones for the production of hydraulic binders (hydraulic limes and natural cement) was derived from both the calculations based on obtained chemical analyses (included standard cement and lime indexes and modules) and the firing experiments. The firing experiments...
|
|
|
Utilization of waste material from the glass-sand production
Zach, Jaroslav ; Přikryl, Richard (advisor) ; Vavro, Martin (referee)
The presented diploma thesis is focused on possible use of waste from glass and foundry sands deposits of Provodín. The mineralogical and chemical composition, mechanical and physical properties, the specific surface area and parameters of pore area were studied. X-ray analysis proved the presence of kaolinite, illite, quartz and accessory microclin. Silicate analysis shows dominant presence of SiO2 80.52%, then Al2O3 11.36% and K2O 2.14%. This diploma thesis is focused on a possible use of studied material at three main areas: the potential use as a clay component in a raw material mixture for making of hydraulic lime, the use as a kaolinite absorbent and the potential use as a geotechnical material. The studied material was experimentally mixed with limestone in a ratio of 10; 15; 20 a 25 wt %. This mixture was subsequently burnt in the temperature range from 850 to 1,200řC. New phases were identified by an X-ray diffraction analysis. The results prove the presence of characteristic phases for hydraulic limes (C2S, C3A, C4AF). The formation of new phases depend on the temperature. The most of them are formed at a temperature of 1050řC and higher. For the characterization of a specific surface area and parameters of pore areas there were used simple studied material and thermally modified samples...
|
|
|
Relationship between petrographic parameters and technological properties of clastic sedimentary rocks used for crushed stone
Čermák, Martin ; Přikryl, Richard (advisor) ; Krutilová, Kateřina (referee)
This diploma thesis is focused on the finding and describing of the relationships between petrological parameters and technological properties of rocks used for the production of aggregates (crushed stone). Rock specimens were selected from a geological area of Culm (Lower Carboniferous age) in the area of Nízký Jeseník Mts. and Drahanská vrchovina uplands in the Czech Republic. Studied localities were selected on the basis of the current quarrying operations and also to represent the different strata. The six studied localities encompass Kobylí, Chabičov, and Bělkovice where Horní Benešov formation of Nízký Jeseník is exposed. Locality Valšov represents Andělské Hory formation and locality Nová Ves and Loštice represent Protivanov formation of Drahanská vrchovina uplands. Two specimens were taken from the locality Loštice (one from the second cut because there are produced low-grade aggregates and the third cut where high quality crushed stone is produced). A detailed mineralogical-petrographic examination of the samples was the first step, in an attempt to obtain their mineralogical composition and to identify the major rock-forming clasts. Thin sections were examined by standard polarizing microscopy. The auxiliary UV lamp and thin sections saturated by fluorescent substance were used for the...
|
|
|
Pumic in the Sokolov basin: genesis and possible use
Harenčáková, Irma ; Přikryl, Richard (advisor) ; Kuchařová, Aneta (referee)
In this work was to bring newly discovered volcanic porous rocks in the Czech Republic. These rocks have been found by Dr. Peter Rojíkem who is employed as a geologist in the Sokolov coal and The rocks are of volcanic origin, and therefore occur in the Sokolov Basin in refractive Druzhba. Macroscopic appearance of found rocks and store them in the terrain resembled the character of pumice rock, and therefore the studies addressed the comparison and verification of whether these rocks are actually a pumice stone or not. Geological position of porous volcanic rock is characterized by its deposit base in the bentonite clay in the form of a lahar, and can be attributed to the so-called epiklastickým deposits. Collected rock samples were subjected to analysis petrografickému. Researching, it became clear that these rocks in the initial stage of the research considered pumice from it in some cases differ. Identifying four basic categories of rocks according to macroscopic criteria. Silicate analysis identified according to their chemical composition as the samples trachyandesites, fonotefrit to basaltic trachyandesites, trachybasalts and tefrifonolit. Using other laboratory methods to deal with microscopy was observed in thin sections and holokrystalická hemikrystalická structure and a typical porphyritic...
|
guest ::
RSS feed.