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ASR potential of quartz in experimental mortar bar specimens
Kuchyňová, Markéta ; Kuchařová, Aneta (advisor) ; Vavro, Martin (referee)
The alkali-silica reaction is one of the most damaging chemical reactions taking place in concrete, which can cause fatal damage. ASR originates under following conditions: high moisture (> 80 %), sufficient amount of alkaline ions (Ca2+ , Na+ , K+ ) and use of reactive aggregates (low crystaline or deformed quartz, amorphous SiO2). Reactive aggretates react with high alkaline pore solution and produce hydrofile gels. These gels absorb water and swell. Dilatometric test methods are commonly used to evaluate the reactivity of aggregates. The principle of dilatometric test methods is simple. Mortar or concrete prisms are created in a laboratory, then they are stored in the special environment, which accelerates the inception of ASR. The creation and expansion of alkali-silica gels cause prism's length changes. The major goal of this diploma thesis was to evaluate the alkali-silica reactivity potential of quartz-rich rocks using microscopic (polarizing microscopy, scanning electron microscopy combined with SEM/BSE image analysis) and dilatometric (ASTM C1260, RILEM AAR-4.1) methods. Rocks were assessed as reactive, potentially reactive and non-reactive by the ASTM C1260 method. The reactivity of aggregates was connected with the amount of cryptocrystaline matrix, grain size, shape of grain boundaries,...
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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...
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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...
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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...
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Experimental study of alkali-silica reactivity of volcanic rocks
Seidlová, Zuzana ; Přikryl, Richard (advisor) ; Vavro, Martin (referee)
(AJ) Even today, alkali-silica reaction is a significant problem in concrete-making industry. It was first described in 1940 by Stanton and since then the study of alkali-silica reaction of aggregates has proceeded notably. Despite these findings, not everything has been resolved and not all the causes and consequences of this reaction are known. To detect the alkali-silica reaction in the aggregates many methods are used, such as petrographic methods, chemical methods, and expansion tests, which examine the expansion of concrete due to the reactivity of aggregates. Petrographic methods evaluate qualitative and quantitative characteristics of aggregates but can not guarantee whether they still do not cause the reaction. Chemical tests and expansion tests provide so- called potential response (non-reactive, reactive and potentially reactive aggregates), but even they have their errors and can not be taken as a 100% indicator of the presence of alkali-silica reaction of aggregates. The thesis describes the general characteristics of alkali-silica reaction of aggregates, the mechanisms and the factors influencing its formation. It describes the fraction of the concrete in which some volcanic rocks have been used, and which are in some works identified as potentially reactive by the alkali-silica...
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Preliminary evaluation of sites for long-term safety - a detailed factual and timetable of work
Havlová, V. ; Pertoldová, J. ; Mixa, P. ; Uhlík, J. ; Vavro, Martin ; Maryška, J. ; Černík, M. ; Vašíček, R.
Tato zpráva obsahuje Podrobný věcný a časový harmonogram prací ZL Předběžné hodnocení lokalit z hlediska dlouhodobé bezpečnosti, zaměřeného na hodnocení vhodnosti lokalit pro umístění hlubinného úložiště VJP a RAO na základě archivních informací, , také na základě průběžných výsledků ze probíhajících projektů a geologického průzkumu prováděného pomocí metod prováděných z povrchu. \nLokality budou hodnoceny podle následujících charakteristik, důležitých pro dlouhodobou bezpečnost:\n1) Popsatelnost a predikovatelnost lokality\n2) Hydrogeologické vlastnosti horninového prostředí\n3) Stabilita lokality (seismické, klimatické, vertikální pohyby, postvulkanické jevy)\n4) Pravděpodobnost intruze/invaze člověka do úložiště\n5) Transportní vlastnosti horninového prostředí\n6) Slučitelnost horninového prostředí s navrženým systémem inženýrských bariér\nŘešení bude probíhat v 5 etapách\n1) Podrobný věcný a časový plán řešení projektu \n2) Hodnocení lokality Čihadlo (první fáze)\n3) Hodnocení ostatních lokalit (první fáze)\n4) Hierarchie kritérií či indikátorů vhodnosti lokalit a způsob hodnocení lokalit \n5) Hodnocení lokalit (druhá fáze)\nŘešení projektu je zajištěno účastí širokého týmu řešitelů, kteří buď participují na řešení probíhajícího projektu Výzkumná podpora hodnocení lokality, nebo splňují vysokou kvalitu odborné erudice.\n
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Underground research site Bukov - geotechnical characterization of the site
Souček, Kamil ; Vavro, Martin ; Vavro, Leona ; Staš, Lubomír ; Georgiovská, Lucie
Podzemní výzkumné pracoviště Bukov (PVP) je navrženo jako testovací lokalita pro zhodnocení vlastností a chování horninového masivu, typově blízkého vybraným kandidátním lokalitám, v hloubce odpovídající předpokládané úložné hloubce finálního hlubinného úložiště vysoce aktivních odpadů v České republice. PVP Bukov, jehož výstavba byla zahájena v roce 2013, je realizováno v jižním křídle uranového ložiska Rožná, na severovýchodním okraji strážeckého moldanubika, poblíž jeho styku se svrateckým krystalinikem. Důlní díla pracoviště jsou situována na 12. patře jámy Bukov-1, v hloubce přibližně 600m pod povrchem.
Fulltext: content.csg -  PDF
Plný tet: UGN_0465530 - PDF
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Summary of foreign knowledge about the origin and development of EDZ in crystalline rocks - research
Vavro, Martin ; Souček, Kamil ; Staš, Lubomír ; Vavro, Leona
Presented search summarizes findings of foreign research oriented on the origin and evolution of the excavation damaged zone in crystalline rocks with a particular focus on the essential results of experimental projects which were performed in Canada, Sweden, Finland, and Switzerland. The study is divided, excluding the introduction, into seven main chapters of the text, which gradually deal with: (1) definition of key terms, (2) overview of the main underground research laboratories in the world where EDZ assessment was conducted, (3) methods suitable for EDZ description and characterization, (4) main factors influencing the origin of failure around the excavations and time-dependent evolution of EDZ. An overview of important outcomes of EDZ experiments, focusing on the European hard rock laboratories (Stripa, Äspö, Onkalo/Olkiluoto and Grimsel), and their summary are presented in the final two chapters.\nThe review summarizing the published key findings and results of in situ experiments shows, that for rock in lower stress state, i.e. in no spalling environment, the extent and character of rock mass damage is typically dependent on the excavation method. Using mechanical excavation, rock damage zone with thickness less than 3 centimeters can be originated. The microcracks within this zone contribute to the increase of hydraulic conductivity of the rock mass. At some test sites (Äspö, Grimsel), where the tunnel boring machine technology was used, the damage zone was already detected in depth of less than 5 mm.\nOn the contrary, openings excavated by drilling and blasting are characterized by much more extensive damage zones up to several tens of centimeters in width. The damage progressively diminishes with the distance from the opening.
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Bukov PVP underground research laboratory - geotechnical conditions of construction
Souček, Kamil ; Vavro, Martin ; Staš, Lubomír ; Koníček, Petr ; Ptáček, Jiří ; Waclawik, Petr ; Vavro, Leona ; Lednická, Markéta ; Kaláb, Zdeněk ; Šňupárek, Richard ; Vondrovic, L.
Bukov PVP Underground Research Laboratory (Bukov URL) is designed to be a test site for the evaluation of properties and behavior of the rock mass which is of similar type as selected candidate sites in the Czech Republic. It is situated at a depth corresponding to the proposed storage depth of the final locality for the national deep repository of high-level radioactive waste. The Bukov URL, the construction of which has begun in 2013, is situated in the southern part of the Rožná uranium deposit, at the northeastern periphery of the Strážek Moldanubicum close to its contact with the Svratka Unit. The rock mass is composed of relatively monotonous rock sequences primarily of a volcanosedimentary origin. They are currently represented, due to the subsequent tectonometa-morphic development, by migmatized biotite paragneisses up to stromatitic and/or oftalmitic migmatites, amphibole-biotite to biotite-amphibole gneisses, and amphibolites. The workings of the Bukov URL are situated on the level 12 of the Bukov-1 shaft, at the depth of about 600 m below the earth’s surface. The Bukov URL is still under construction and the research works by the consortium of several organizations – ÚJV Řež, a.s., Czech Geological Survey, Institute of Geonics of the CAS, v.v.i., and Arcadis CZ, a.s. - are carried out simultaneously. The research activities focus on a complex geological and geotechnical characterization of the rock mass of interest, which is vital for the realization of further research in situ. This paper briefly describes the technical solution of the Bukov URL and the process of its construction.
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Komplexní geologická charakterizace prostorů PVP Bukov
Verner, K. ; Bukovská, Z. ; Souček, Kamil ; Vavro, Martin ; Staš, Lubomír ; Kaláb, Zdeněk ; Havlová, V. ; Kučera, P.
This report summarizes results of ongoing basic and applied research related to the project "Comprehensive geological characterization of underground research facility (PVP) Bukov" (PB-2014-ZL-U2301-004-BUKOV). In the wider area of the PVP Bukov a steep NW-SE trending metamorphic foliation was identified which is partly refolded into sub-horizontal direction. Faults and extensional joints with variable mineralization are mostly steep, trending mostly NW - SE or NNE - SSW. In addition, geological map at the scale of 1 : 4 500 of this area has been processed based on new field geological mapping and archival data. Moreover, a detailed petrographic and structural analysis of boreholes S-1 to S-4 (a total length of 470 meters) has been made. On the basis of U/Pb dating the age of the protolith of prevailing migmatized amphibolic gneisses was determined at 500-600 Ma as well as the subsequent regional metamorphism associated with partial melting and deformation at around 338 Ma. Results of thermodynamic modeling revealed the P-T conditions of regional metamorphism at T: 692–727 °C and P: 5 kbar.
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