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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Propuesta de metodología de trabajo para la preparación e inyección de lechada en los sistemas de anclajes de muros pantalla para suelos gravosos de la ciudad de Lima / Proposal of work methodology for the preparation and injection of grout in the systems of anchors of walls for loamy soils of the city of lima

Mazuelos De la Cruz, Victor Manuel, Mercado Chávez, Ramiro Antonio 22 October 2021 (has links)
En nuestro país, actualmente no se cuenta con una norma estandarizada ni con normas técnicas que involucren los procesos de preparación e inyección de lechada cementicia en sistemas de anclajes de muros. Además, las empresas están teniendo problemas de desempeño en la prueba de carga del anclaje, el cual se relaciona directamente con la lechada. Para ello, se presenta una propuesta de metodología para uniformizar los procesos de preparación, inyección en los sistemas de anclajes de muros pantalla con suelo gravoso y control de calidad de lechada cementicia en obra. La investigación incluye visitas a obras para recopilar información sobre la calidad de mano de obra, procesos de aplicación de lechada y toma de muestras para el control de calidad. Asimismo, incluye la evaluación de la reología y propiedades mecánicas a escala de laboratorio según dosificaciones requeridas por las especificaciones técnicas de los reglamentos UNE y ACI. / In our country, there is currently no standardized nor technical norms that involve the processes of preparation and injection of cementitious grout in wall anchor systems. In addition, companies are having performance problems in the anchor load test, which is directly influenced by the grout. For this, a proposal of methodology is presented to standardize the processes of preparation, injection in the systems of anchors of screen walls with loamy ground and quality control of cementitious grout in building. The research includes visits to buildings to collect information on the quality of labor, grout application processes and sampling for quality control. It also includes the evaluation of rheology and mechanical properties on a laboratory scale according to dosages required by the technical specifications of the UNE and ACI regulations. / Tesis
102

Příprava a organizace výstavby souboru bytových domů ve Štětí / Project planning and management of construction residential houses in the file Štětí

Sládek, Lukáš January 2014 (has links)
The subject of this thesis is the preparation and organization of construction of residential buildings in Štětí. In the technological regulations deal with all the layers of flooring from the ceiling construction in residential buildings. The objects are hard floors. For floor coverings will be used PVC roofing, ceramic tiles and concrete coating. It will be used for machining of concrete. Next, I will discuss technological instruction, timing, valuation of all technological stages, construction site equipment, health and safety at work. Also here describe the proper allocation of construction processes into sub-processes to technological stage of completion of work most effectively achieve the objective.
103

Vývoj injektážních směsí pro dodatečné těsnění sypaných hrází / The development of grouting for additional sealing of embankment dams

Michalčíková, 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.
104

Energetické využití netradiční biomasy / Utilization of unconventional biomass for energy production

Boumová, Markéta January 2010 (has links)
Tato diplomová práce se zabývá netradičními druhy biomasy využitelnými v České republice a Španělsku a jejich srovnáním. V prvních kapitolách jsou popsány netradiční druhy biomasy, mezinárodní projekty, smlouvy a legislativa. V následujích kapitolách je rozbor netradičních druhů biomasy zejména vznikajících z potravinářského průmyslu každé země s detailním rozborem a srovnáním zbytků z průmyslového zpracování slunečnice a oliv. V závěru je uděláno celkové srovnání těchto druhů biomasy České republiky a Španělska z aspektů výkupních cen, výhřevností, vlhkosti a množství popelovin.
105

Asfaltocementový beton / Open-graded asphalt concrete filled with a special cement grout

Hruška, Lukáš January 2012 (has links)
Aim of this thesis is the usage of the open-graded asphalt concrete filled with a special cement grout in the road structures. Thesis defines the main concrete properties and explains related legislation and norms that apply. In addition, laboratory design of asfalt mixtures and a tree kind mortal filler and possibilities of mortal filler pigmentation are dealth with. Finally, thesis evaluates the results from various laboratory tests that were performed on the specimens made from final mixtures.
106

Analýza chování kořene kotvy v jemnozrnných zeminách / Behavior analysis of a ground anchor fixed length in fine grained soils

Chalmovský, Juraj January 2016 (has links)
Ground anchors represent an important structural element in the area of ground engineering. Despite an extensive usage of these elements, their design is usually performed using simple empirical and semi-empirical methods. An application of these procedures brings to the design a number of simplifying assumptions. The goal of the dissertation is to refine the computational design of ground anchors, analysis and quantification of selected factors significantly affecting their load displacement behavior. Firstly, the finite element method is applied. Two novel constitutive models are used: Multilaminate Constitutive Model for Stiff Soils (Schädlich, 2012) involving post peak shear softening of overconsolidated cohesive soils and Shotcrete Model (Schädlich, 2014) involving tension softening after tensile strength is reached. First constitutive model was used in order to simulate progressive decrease of skin friction along the anchor fixed length. Second constitutive model was applied for the grout material. In the next step, experimental program including several anchor load tests was carried out. The goal of the experimental program was to confirm conclusions from numerical studies and to obtain relevant data for further back – analysis. A newly developed application, in which all the findings from numerical computations and experimental measurements are incorporated, is described afterwards. The application is based on the use of so-called load-transfer functions. The program verification was conducted through series of back analysis of investigation anchor load tests realized on four different construction sites in two different types of fine-grained soils. The verification of the application is followed by series of parametric studies in which an influence of input parameters values is analyzed. Dissertation is concluded by the summarization of the most important findings.
107

Vývoj speciálních sanačních hmot na beton pro extrémní namáhání s využitím druhotných surovin / DEVELOPMENT OF SPECIAL REHABILITATION MATERIALS FOR CONCRETE FOR EXTREME STRESS WITH USE OF SECONDARY RAW MATERIALS

Hodul, Jakub January 2019 (has links)
The doctoral thesis deals with finding the use of some waste and secondary raw materials in the production of special polymer remediation materials for concrete, which could be applied even in constructions, where extreme mechanical and chemical load is occurred. The aim of this doctoral thesis is experimental examination of the possibility of using selected types of waste, including hazardous waste which represent the highest risk to environment, and secondary raw materials as a substitute for the currently used primary fillers in order to reduce the ecological footprint of the product itself. Some types of secondary raw materials, such as filter fly ash contaminated by flue gas denitrification process, are no longer used as a concrete admixture or partial cement substitution due to unwanted release of toxic ammonia (NH3). Mainly for this reason, the thesis deals with the progressive utilization of such types of secondary raw materials as well as with another currently unused waste into polymeric patching, grouting and anchoring materials while preserving or improving the final properties compared to reference materials using only primary raw materials. The result of this thesis is to find out suitable formulations for efficient preparation of special polymeric remediation materials for concrete containing waste and secondary raw materials as fillers. The partial aim of the thesis and a the scientific contribution is an observation of the developed materials internal structure using a modern device, CT tomography, an influence of the filler type on the long-term durability, and last but not least the observation of the rate of pollutants incorporation, found in hazardous waste, into the polymeric matric with the aid of EDX and FTIR analysis.

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