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Evaluation of long-term performance of sodium silicate grouted in embankment damsFu, Jenny January 2019 (has links)
Embankment dams is the most common type of dams in operation inSweden today. Due to the nature of embankment dams, seepage throughthem will always occur. If the seepage velocity exceeds a critical velocity,internal erosion is initiated, which could lead to damage in form of pipingand sinkholes. To treat this problem, remedial grouting has beenperformed involving a combination of conventional grouts, i.e. cement andcement-bentonite as well as sodium silicate, which is a chemical grout thatalso known as water glass. Regarding the sodium silicate grout, there isconcern about the long-term permanence.The aim of this thesis has been to study the potential performance ofsodium silicate grouted in embankment dams. The first part of this thesisis a literature review of the general behavior of sodium silicate as a grout,its degradation processes and the factors that could induce degradation.The second part suggests monitoring methods to control and evaluate theperformance of the treated dam and the grout if degradation has occurred.Findings from literature generally indicates a high risk of instability andlow permanence of sodium silicate when grouted in an embankment dam.This type of grout will undergo degradation mainly in two forms: syneresisinduced shrinkage and leaching due to grout erosion or dissolution. As thedegradation has developed, an increase in permeability of the repaireddam core is a potential consequence.How the potential degradation of sodium silicate will affect the treateddams is suggested to be observed by monitoring the permeability of thegrouted core. Applicable monitoring methods for this purpose aremeasurements of pore pressure and temperature using piezometers. Thesecond direct method of monitoring a changed dam behavior is suggestedto be leakage analysis, in order to detect potentially increased leakagebecause of the grout degradation. An indirect way to investigate the damperformance is suggested to be monitoring of the grout state. Measurementof ion concentration of sodium and silicon respectively in leakage waterusing selective-ion electrodes will reveal any increase in ion concentrationdue to the potential grout dissolution or leaching.
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Modelový výzkum účinnosti separačních technologií úpravy vody / Model research on the effectiveness of separation technologies for water treatmentHofmanová, Lucie January 2019 (has links)
This diploma thesis deals with the effectiveness of separation technologies for water treatment. The first theoretical part mentions types of pollution that can be found in surface water. Furthermore, the interparticle interactions affecting the stability of colloidal dispersions are discussed. The following is a description of the principle, procedure, mechanisms of coagulation and factors influencing this process. The chapter dealing with types of water treatment is followed by a more detailed description of the individual separation technologies used in the water treatment plants. The important passage in the theoretical part is the description of materials and reagents used in laboratory experiments. The coagulants nanoiron and sodium water glass are characterized, as well as Bayoxide E33, CFH 0818, FILTRASORB 100 activated charcoal and DORSILIT silicate sand. The experimental part of the thesis analyses the jar test procedure. The flocculation tester intended for the jar test was used for laboratory coagulation using nanoiron and sodium water glass. The effectiveness of selected coagulants in the removal of turbidity from water during sedimentation of flakes produced in reaction vessels was investigated. In addition, the effectiveness of individual filtering materials in the removal of turbidity from water containing nanoiron/sodium water glass was investigated. In the end, the results of laboratory tests are compared and evaluated, including photos taken during experiments.
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Možnosti inovace procesu úpravy vody / Water Treatment Plants Innovation OpportunitiesZelený, Zdeněk January 2014 (has links)
This master´s thesis deals with the possibilities of innovation process water treatment. Specifically, to explore the use of sodium water glass and nanoiron in removing heavy metals from raw water at the drinking water treatment. For the comparison was used traditionally used coagulant, particularly liquid aluminum sulfate. The introductory part deals with the possibility of modifying the surface water during the treatment process such water into potable water. This chapter is a description of the quality of raw water used, then the description of currently used separation processes. Furthermore, they are described and commonly used types of treatment plants. Conclusion The introductory section deals with traditional coagulants and form a suspension. Another part of this master´s thesis has been devoted to the possibilities of innovation in the treatment of raw waters as drinking water, describes the options and features of the use of water glass and nanoiron. The following section describes the experimental part of this thesis. It is followed by the experimental results. The last chapter summarizes the acquired knowledge and commented on the measured values of the experimental part. This work also shows several specific projects using innovative technologies presented.
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Kompozitní materiály na bázi alkalicky aktivované vysokopecní strusky s přídavkem elektrárenských popílků / Composite materials based on alcali activated blast furnace slag with admixture of fly ashIndra, Ivo January 2010 (has links)
This thesis concerns on substitution of blast furnace slag or its part with fly ash in alkali-activated systems based on aluminosilikates. Classic, fluid bottom and fluid filter fly ashes will be tested. The goal is to prepare geopolymer with required mechanical properties, but with maximal admixture of alternative raw materials. In composites with substitutioned slag or its part the thesis focuses mainly on workabilityof fresh mixture, pressure and bending strenght. Use of secondary raw materials has advantages in the economic point of view and it´s friendly to enviroment, too.
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Vývoj kompozitů na bázi alkalicky aktivovaných matric odolných vůči působení extrémních teplot / The development of composites based on alkali-activated matrices resistant to extreme temperaturesŠevčík, Marek January 2021 (has links)
The diploma thesis is focused on the development of composites from alkali activated materials (AAM) and their resistance to extreme temperatures. The theoretical part describes alkaline activation and precursors for the production of AAM. Furthermore, the problem of the effect of extreme temperatures on these materials is described. In the experimental part, the optimal silicate modulus with respect to the properties of AAM was gradually determined, and the effect of extreme temperatures on the AAM matrix was verified. In the next stage, the effect of the filler with respect to the behavior at extreme temperatures was tested and then the final formulation was optimized.
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Možnosti využití slévárenských odprachů / The possibilities of using of foundry filter ashSolik, Jaroslav January 2012 (has links)
This thesis explores the posibility of using of foundry filter ash for production of inorganic composite materials, that could be used primary in the construction industry. The thesis is divided into theoretical and experimental section, where theoretical section contain literature review of used materials and the experimental section summarizes the results of laboratory tests performed on tested mixture based on portland and alumina cement with various content of foundry filter ash. For comparison was also used another foundry waste - foundry sand. Prepared test bodies with dimension of 40 x 40x 160 mm was subjected to mechanical strength tests and the influence of amount of foundry waste on the strenght of the prepared mixtures was monitored. Next the thesis deals with possibilities of alkaline activation of foundry waste, where sodium water glass, sodium hydroxide and commercially supplied baucis L 160 component B were used as alkaline activator. These test mixtures were also subjected to mechanical strenght tests and the influence of amount of foundry waste on the strenght was observed too. The analysis of input materials were performed by XRF, TG – DTA – EGA and XRD powder diffraction methods. All strength tests were tested by testing equipment desttest 4310.
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Možnosti využití odpadních písků z výroby vodního skla ve stavebnictví / Possibilities of the utilization of the waste sand from the water glass production in building industryBílek, Vlastimil January 2013 (has links)
Nowadays, the waste sands from the water glass production have no utilization and due to high alkali content are considered as a dangerous waste. So the aim of this thesis is to find and study some possibilities of their utilization in the building industry. First of all, some necessary analysis of these sands were performed and then some advantages and disadvantages of their application for production of materials based on portland cement and alkali activated materials were studied. Characteristics of fresh and hardened pastes, mortars and concretes containing these waste sands were determined. The most tested properties were their workability and their compressive and flexural strength. Close attention for the risks of alkali-silica reaction and for options of its suppressing by the mineral admixtures was paid.
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Tepelné vlastnosti forem v závislosti na použitém ostřivu / Thermoproperties of foundry moulds in dependence on different used foundry sandsŠuráň, Jiří January 2012 (has links)
The project elaborated in frame of engineering studies is submitting the study of thermal properties of holding mixtures using different types of sand. Were tested a total of 5 sands: zirkon, ŠH22, chromite, olivine and dunite. Molding compounds were tested for thermal capacity, thermal conductivity and heat accumulation. The highest heat capacity was achieved in dunite sand. The largest heat accumulation had mixture with chromite sand and the best thermal conductivity was found in a mixture with olivine sand.
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Vývoj kompozitů na bázi anorganických pojiv určených pro extrémní aplikace / The development of composites based on inorganic binders designed for the extreme applicationsJanoušek, Petr January 2013 (has links)
The topic of this master's thesis is the development of composite materials based on inorganic binders for use in extreme conditions. It means especially geopolymeric or alkali activated materials (AAM) based composites. The theoretical part of this thesis summarizes knowledges about the development and use of alkali-activated materials, their structure and mechanisms of their formation. It also deals with the applicable raw materials for AAM and their exciters, which are in particular water glass and sodium hydroxide. There also have been a summary of the effects of high temperatures and chemicals on the mechanical properties of AAM and the requirements of standard EN 1504-3 for repairing materials. The task of the practical part was to develop a repair mortar for concrete structures based on AAM so that its production was as simple as possible, ie one-component materials. Gradually six recipes have been develeoped. Test specimens made from these recipes have been putted to selected tests according to the requirements of ČSN EN 1504-3.
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Vývoj injektážních směsí pro dodatečné těsnění sypaných hrází / The development of grouting for additional sealing of embankment damsMichalčíková, Magdaléna January 2015 (has links)
Seal of sand or gravel by chemical injection is known and used for a long time. Chemical grouting are however expensive and sometimes the use of cement does not lead to desire effects. So it is trying to find new materials and methodologies injection arrangement works. To achieve savings of chemical products are added to a mixture clay and cement. Clay-cement grouting mix are used not only in order that they are better quality, but also because in this way proposed mixtures have a tendency to penetrate better into incoherent sediments that need additional sealant of chemical injection. For further possible reductions of economic terms the mixture is trying to replace the classic clay. As a suitable substitute for classic clay is to a certain extent the use of secondary raw materials. Above all it is fly ash. As a part of my thesis I deal with the appropriateness use of these materials and examining their properties in the mixture. It was found that by using fly ash were improving consistency of the fresh mixture, reducing the amount of water-cement ratio and reduce shrinkage of the mixture. On the other hand, by using fly ash has been increasing decantation, permeability atc. In the next stage of my work was examined the influence of the quality of cement, lime and liquefaction in the mixture. The aim of thesis is to propose the optimal injection mixture for additional sealing earth dams.
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