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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.
51

Construção e testes de um penetrômetro de queda livre para caracterização do perfil de resistência ao cisalhamento de solos marinhos

Baldez, Anderson Lena January 2010 (has links)
Dissertação(mestrado) - Universidade Federal do Rio Grande, Programa de Pós-Graduação em Engenharia Oceânica, Escola de Engenharia, 2010. / Submitted by Lilian M. Silva (lilianmadeirasilva@hotmail.com) on 2013-04-15T00:06:33Z No. of bitstreams: 1 baldez,a.l.pdf: 8426528 bytes, checksum: 47e41efbe0e6ba9d1074f9667287d13a (MD5) / Approved for entry into archive by Bruna Vieira(bruninha_vieira@ibest.com.br) on 2013-06-10T18:46:55Z (GMT) No. of bitstreams: 1 baldez,a.l.pdf: 8426528 bytes, checksum: 47e41efbe0e6ba9d1074f9667287d13a (MD5) / Made available in DSpace on 2013-06-10T18:46:55Z (GMT). No. of bitstreams: 1 baldez,a.l.pdf: 8426528 bytes, checksum: 47e41efbe0e6ba9d1074f9667287d13a (MD5) Previous issue date: 2010 / Este trabalho tem por objetivo o desenvolvimento, construção e testes preliminares de um penetrômetro de queda livre para a caracterização de solos marinhos. O aparelho tem por finalidade medir as características de resistência do solo oceânico, através da medição e analise da desaceleração imposta ao penetrômetro após o seu impacto com o fundo. Este tipo de equipamento evita os elevados custos envolvidos em outros tipos de ensaios e na obtenção de amostras do fundo em condições de elevado risco e dificuldades naturais impostas pelas condições locais do mar. O dispositivo tem o formato de um aerofólio Joukowski simétrico (formato de gota), que consiste de duas partes: a primeira onde fica o acelerômetro e o chumbo granulado e a segunda onde há um conector que liga o acelerômetro a um cabo de dados e daí a um computador portátil que realiza a aquisição de dados. O penetrômetro pode ser lançado de certa altura acima da superfície da água, entra na água e mobiliza resistência hidrodinâmica durante a queda livre. Após choca-se contra o fundo marinho mobilizando resistências ao cisalhamento do solo sendo desacelerado até o repouso. Para os testes de funcionamento do equipamento foi utilizada a marina do Rio Grande Yacht Club localizado na cidade de Rio Grande - RS. Nos testes foram obtidos sinais de desaceleração registrados pelo acelerômetro que foram integrados numericamente duas vezes, a primeira obtendo dados de velocidade e na segunda dados de deslocamento percorrido pelo penetrômetro. Os dados assim coletados permitiram uma estimativa do perfil de resistência ao cisalhamento do solo marinho ao longo do comprimento penetrado,observando que o penetrômetro adquiriu a velocidade terminal sendo mensurada em torno de 5,7 m/s e o deslocamento máximo registrado obtido na marina foi de 5 metros. / This study aims at developing, constructing and testing a free fall penetrometer for the characterization of marine soils. The objective of this device is to measure the strength characteristics of the marine soil, through the measurement and the analysis of the deceleration imposed by its impact on the bottom.This kind of equipment reduces high costs involved in other tests and in the collection ofsamples on the bottom under bad sea conditions regarding risks and natural obstacles. The device was shaped as a symmetric Joukowski airfoil (the shape of a drop) which consists of two parts: one of them holds the accelerometer and the granulated lead and the other one has a connector that links the accelerometer to a data cable, and then, to a portable computer which collects the data. The penetrometer can be launched from a certain height above the water surface, and then penetrates into the water and mobilizes hydrodynamic resistance during the free fall. When it hits the bottom of the sea, it mobilizes shear strength and decelerates until it rests. The tests with the equipment were carried out in the marina at the Rio Grande Yacht Club located in Rio Grande, RS, Brazil. The tests got deceleration signals which wererecorded by the accelerometer and were integrated twice numerically in order to collectdata on the velocity and on the displacement of the penetrometer. These data enabled the estimate of the shear strength profile of the marine soil along the length in which penetration occurred. The datashow that the velocity of the penetrometer reached about 5.7 m/s and thatthe maximum displacement recorded in the marina was 5 meters.
52

Etude expérimentale des ruptures de digues fluviales par surverse / Experimental study of river dikes breaching by overtopping

Charrier, Gregory 10 April 2015 (has links)
Le réseau de digues français s'étend sur 9000 km et protège moult enjeux humains et socio-économiques. Les surverses se produisent lorsque le niveau d'eau dépasse la crête de la digue et sont responsables de nombreuses ruptures d'ouvrages. La prévision des caractéristiques des brèches (vitesse de développement, taille finale et hydrogramme) reste délicate, d'autant que les effets de la dynamique de la rivière n'ont jamais été étudiés.Cette étude expérimentale est basée sur cinq essais réalisés en canal sur des modèles physiques de digue cohésifs. Les phases classiques du développement de brèches ainsi que le mécanisme de headcutting ont été observés. L'érosion s'est manifestée à trois échelles spatiales (grain, mm et cm) et la durée des essais a varié entre 1h30 et 10 jours selon les sols. Nous avons constaté que le développement d'une brèche et de la fosse d'érosion devient asymétrique en présence d'une vitesse longitudinale amont. Des essais géotechniques originaux menés à l'IRPHE ont permis de relever des différences importantes sur le mode et la cinétique d'érosion entre les sols testés, toujours en bon accord avec les observations menées sur les modèles de digues.Des essais en brèche de largeur fixe nous ont mis à jour l'émergence d'une hydraulique particulière dans la brèche lorsque le vitesse longitudinale incidente augmente (ressauts, recirculations) qui a un impact sur l'hydrogramme de brèche.Enfin, des simulations menées sous RUBAR20 ont permis de retrouver de nombreuses observations expérimentales tant sur le fonctionnement hydraulique des brèches que sur la sensibilité de la cinétique d'érosion à la contrainte critique d'érosion et à l'érodibilité. / France's embankment network stretches over 9000~km, protecting people and infrastructures. Overtopping occurs when water level rises above the embankment's crest, often leading to breach development. Reliable forecasting of breaches' characteristics (widening rate, final geometry and breach hydrograph) remains a challenging task. Furthermore, the effects of river dynamics have never been studied.This work is based on a campain of five overtopping tests performed on scaled homogeneous cohesive model embankments, carried out in an eight meters recirculated flume. The classical steps of dike breaching were observed, as wall as headcutting. Depending on soil type and water content, erosion occured at three distinct scales (sand grain, mm, cm) while the experiments' durations ranged from 1h30 to 250~h. Evidence was brought that river dynamics can result in a completely asymmetric development of both the breach and scour pit. Simple geotechnical tests showed notable differences on erosion modes and rates among tested soils, consistently with the flume experiments.The study of fixed-width breaches showed that distinguish hydraulic phenomena such as hydraulic jumps and recirculations arise when lateral flow speed increases on the river side, which comes with an important drop in breach flow.In addition, bidimensional numerical simulations offered a practical and satisfying way of modelling breach hydraulics. In particular, the strong surface deformation and important velocity gradients in the vicinity of the breach were well-rendered. Elements relative to breach formation sensitivity to erosion parameters (threshold stress and erodibility coefficient) are also provided.
53

Návrh sanace sesuvu Nedašova Lhota / The Design of Nedašova Lhota Landslide Securing

Janík, Michal January 2012 (has links)
The thesis called The Design of Nedašova Lhota Landslide Securing concentrates on the basic analysis of the problems connected with landslides and safety factors needed for the slopes stability. At the same time it presents a concrete solution to the given practical task, where the slope stability, the causes leading to the landslide and the subsequent redevelopment in view of financial requirements are discussed.
54

Návrh založení polyfunkčního domu v Brně / Foundation design of multi-functional building in Brno

Pospíšil, Jan January 2015 (has links)
The objective of thesis is to design and evaluate suitable foundation pit and in the establishment of multi-functional building on the street Smetanova 19 in Brno. The part of this thesis is also to describe the technological process of implementing the designed constructions and the preparation of relevant design documentation.
55

Análisis del comportamiento de barreras flexibles mediante la variabilidad de parámetros de energía y localización como medida de diseño para la contención de flujo de detritos en la quebrada primero de mayo –Lurigancho Chosica

Cornejo Falcon, Brenda Anapaula, Mañuico Pérez, Bryan Aarón 26 February 2021 (has links)
La presente tesis aplica un análisis de tendencias asociados a la variación de la energía de impacto y localización que tienen las barreras flexibles ante eventos de flujos de detritos. Esto para establecer y considerar la variabilidad anteriormente mencionada como un parámetro de diseño para barreras flexibles y, por consiguiente, desarrollar una propuesta de ingeniería eficaz que permita maximizar el comportamiento de las barreras flexibles y sea aplicable a diferentes proyectos que consideren como propuesta estructuras de contención dinámica para frenar el impacto de los flujos de detritos. Todo esto tomando en cuenta los parámetros geotécnicos e hidro morfológicos de la zona, con principal importancia en la pendiente y la precipitación como desencadenante de eventos de flujos de detritos. El estudio se desarrolló en la quebrada Primero de Mayo ubicado en el distrito de Lurigancho, departamento de Lima, Perú. Tomando en cuenta que es una quebrada sin presencia de estructuras de contención previas y con un crecimiento poblacional no controlado que aumenta el riesgo de pérdidas económicas y sociales en la zona. Las simulaciones del comportamiento de las barreras flexibles ante diferentes situaciones de energía y localización se desarrollaron en el software Rocfall para establecer el número de barreras necesario para contener el flujo de detritos de la zona y plantear cuatro diferentes iteraciones para el estudio. / The proposal of a probabilistic factor is presented to determine the percentage of failure that can occur in shallow foundations, in our case footings. In this article we will present a comparison between the safety factor (F.S), defined by the standard E050 Soils and Foundations, and the probability of failure. This method will be executed through the simulation of input data, such as specific weight, cohesion, angle of friction and load stress. For this simulation process, the Monte Carlo method will be applied. Once the soil resistance values ​​have been obtained, considering its normal distribution and the stress, the probabilities of failure will begin to be analyzed using the strength and stress density curves. Finally, we will analyze the relationship that will occur between the F.S and the probability of failure to observe the behavior when increasing the parameters for resistance. / Trabajo de investigación
56

Evaluación del riesgo de deslizamiento de un depósito de relave inoperativo en la Cabecera de cuenca del Río Rímac, Chicla – Huarochirí – Lima considerando variables geotécnicas en el proceso de análisis jerárquico / Risk assessment of an inoperative tailings deposit in the Rímac River Basin Head, Chicla - Huarochirí - Lima considering the incorporation of geotechnical variables

De La Cruz Gutiérrez, Yoselin Teresa, Valderrama Ninanya, Edith Marleni 10 November 2021 (has links)
El fin de este trabajo es evaluar el riesgo de un depósito de relave inoperativo, el cual se encuentra en el cauce de una quebrada altoandina en la sierra central del Perú, por lo que es probable que se encuentre saturado debido a las precipitaciones y escorrentías, lo que genera una inestabilidad física. Esta investigación se desarrollará bajo los lineamientos del Manual para la Evaluación de Riesgos originados por fenómenos Naturales del CENEPRED, el cual hace un análisis jerárquico para la ponderación de parámetros que evalúe el origen natural y la vulnerabilidad para el cálculo del riesgo de manera subjetiva, adicionalmente las matrices que introduzcan información de análisis geotécnicos cuantitativos. Lo que permitirá tener una comparación de ambos enfoques como primera aproximación a una eficiencia en el sistema nacional de evaluación de riesgos de depósitos de relaves mineros. Por esta razón, esta tesis parte de la siguiente pregunta: ¿Cuál es el riesgo de deslizamiento del depósito de relave inoperativo aledaño a la cabecera de cuenca del Río Rímac?, esta interrogante conlleva al desarrollo de seis capítulos: El capítulo uno comprende el plan de tesis. El capítulo dos está conformado por el marco teórico para el objeto de estudio. Por otro lado, el capítulo tres recopila la información de estudios previos. Seguidamente, el capítulo cuatro da paso a las matrices de peligro, riesgo y vulnerabilidad basado en la metodología del CENEPRED. El capítulo cinco ubica las matrices con variables objetivas basadas en análisis geotécnicos. Finalmente, luego de tener claro estos capítulos previos, el capítulo seis comparará los resultados obtenidos de la evaluación de riesgo entre ambos enfoques. Con esta tesis se podrá obtener alternativas que se puedan incorporar y complementar a nuevas investigaciones que incluyan la gestión de riesgos. / The purpose of this work is to assess the risk of an inoperative tailings deposit, which will find itself in the bed of a high Andean stream in the central Sierra of Peru, so it is likely that it will be saturated due to rainfall and runoff, which that generates physical instability. This research will be developed under the guidelines of the Manual for the Evaluation of Risks originated by Natural Phenomena of CENEPRED, which makes a hierarchical analysis for the weighting of parameters that evaluates the natural origin and the vulnerability of the submind the calculation of the matrices that introduce information quantitative geotechnical analysis. What could have a comparison of both approaches as a first approximation to an efficiency in the national system of risk assessment of mining tailings deposits. For this reason, this thesis starts from the following question: What are the risks of the inoperative tailings deposit adjacent to the headwaters of the Rímac River This question leads to the development of six chapters: Chapter one. Chapter two is made up of the theoretical framework for the object of study. On the other hand, chapter three compiles the information from previous studies. Next, chapter four gives way to the hazard, risk and vulnerability matrices based on the CENEPRED methodology. Chapter five locates the matrices with objective variables based on geotechnical analysis. Finally, after having clarified these previous chapters, chapter six will compare the results obtained from the risk assessment between both approaches. With this thesis it will be possible to obtain alternatives that can be incorporated and complemented to new investigations that include risk management. / Tesis
57

Diseño de la cimentación de torres de alta tensión mediante pernos de anclaje para su fundación sobre macizo rocoso ubicado en el distrito de Chorrillos-Lima-Perú / Design of the foundation of high voltage towers by anchoring bolts for foundation on rock masses located in the district of chorrillos-lima-peru

More Torres, Alexander Nilson, Taipicuri Santiago, Luzmery 06 April 2021 (has links)
El diseño de cimentaciones para torres de alta tensión en el Perú actualmente no tiene una regulación o normativa específica que indique las distintas consideraciones técnicas a tener en cuenta en el diseño (en nuestro país basadas en el Código Nacional de Electricidad y la NORMA E.030), por lo que usualmente este es realizado usando métodos convencionales poco óptimos. La primera parte de esta investigación realiza el estudio geotécnico para un punto de referencia específico en la formación “La Herradura” del distrito de Chorrillos, Lima, Perú. De este estudio se obtienen las características y parámetros del lugar como la Resistencia a la Compresión Simple de las Rocas, Peso Específico de la roca y estado en el que se encuentra el macizo rocoso a través de métodos prácticos que permiten estudiar cualquier tipo de terreno. La segunda parte se enfoca en el diseño geotécnico de una cimentación para torres de alta tensión usando pernos de anclaje, para lo que se toma en cuenta la Especificación CFE JA100-64 (México), la IEEE (Guide for Transmission Structure Foundation Design and Testing) y Reglamento Nacional de Edificaciones (Perú). La tercera parte desarrolla un análisis paramétrico (proceso que evalúa la variabilidad de ciertos parámetros con respecto a valores “naturalmente” constantes definidos a través de diversos análisis de laboratorio e investigaciones científicas obtenidas de fuentes bibliográficas) en función del procedimiento que se ha establecido para el diseño de cimentaciones de torres de alta tensión usando pernos de anclaje. La finalidad de este análisis es determinar correlaciones que puedan ser significativas o no, a la par de identificar tendencias de comportamientos de acuerdo con la variabilidad de parámetros especificados previo a cada proceso iterativo y así poder proponer un método de diseño optimizado. La cuarta parte de la investigación desarrolla la propuesta de una metodología de diseño teniendo en cuenta el diseño geotécnico que se realizó y el análisis paramétrico con el fin de optimizar el diseño, cuantificando las ventajas y desventajas de asumir valores mayores o menores a los expuestos en la parte del diseño geotécnico. A la vez, se describe el aporte de la técnica y algunos motivos por los cuales sería conveniente usarla. Finalmente, se desarrollan las distintas conclusiones que generaron los cálculos y pruebas realizadas, de acuerdo con el alcance y objetivos del tema de investigación y se brindan recomendaciones que futuros investigadores deberían tomar en cuenta cuando se busque ampliar el estudio de la técnica y así establecer una normativa más orientada a las condiciones naturales y/o típicas de nuestro país. / The design of foundations for high voltage towers in Peru does not currently have a specific regulation or regulation that indicates the different technical considerations to take into account in the design, so this is usually done using unconventional conventional methods. The first part of this investigation carries out the geotechnical study for a specific reference point in the “La Herradura” formation of the Chorrillos district, Lima, Peru. From this study the characteristics and parameters of the place are obtained such as the Resistance to the Simple Compression of the Rocks, Specific Weight of the rock and state in which the rock mass is located. The second part focuses on the geotechnical design of a foundation for high voltage towers using anchor bolts, for which the Especificación CFE JA100-64 (Mexico), the IEEE (Guide for Transmission Structure Foundation Design and Testing) and Reglamento Nacional de Edificaciones (Peru) ) are taken into account. The third part develops a parametric analysis based on the procedure that has been established for the design of foundations of high-voltage towers using anchor bolts. The purpose of this analysis is to determine correlations that may be significant or not, while identifying behavioral trends according to the variability of parameters specified prior to each iterative process. This part provides practical expressions that can be used to have a previous design perspective and choose to make certain improvements. The fourth part of the research develops the proposal of a design methodology taking into account the geotechnical design that was carried out and the parametric analysis in order to optimize the design, quantifying the advantages and disadvantages of assuming values greater or less than those exposed in the part of geotechnical design. Finally, the different conclusions that generated the calculations and tests performed are developed, according to the scope and objectives of the research topic and recommendations that future researchers should take into account when seeking to expand the study of the technique. / Tesis
58

Geostatistical three-dimensional modeling of the subsurface unconsolidated materials in the Göttingen area / The transitional-probability Markov chain versus traditional indicator methods for modeling the geotechnical categories in a test site.

Ranjineh Khojasteh, Enayatollah 27 June 2013 (has links)
Das Ziel der vorliegenden Arbeit war die Erstellung eines dreidimensionalen Untergrundmodells der Region Göttingen basierend auf einer geotechnischen Klassifikation der unkosolidierten Sedimente. Die untersuchten Materialen reichen von Lockersedimenten bis hin zu Festgesteinen, werden jedoch in der vorliegenden Arbeit als Boden, Bodenklassen bzw. Bodenkategorien bezeichnet. Diese Studie evaluiert verschiedene Möglichkeiten durch geostatistische Methoden und Simulationen heterogene Untergründe zu erfassen. Derartige Modellierungen stellen ein fundamentales Hilfswerkzeug u.a. in der Geotechnik, im Bergbau, der Ölprospektion sowie in der Hydrogeologie dar. Eine detaillierte Modellierung der benötigten kontinuierlichen Parameter wie z. B. der Porosität, der Permeabilität oder hydraulischen Leitfähigkeit des Untergrundes setzt eine exakte Bestimmung der Grenzen von Fazies- und Bodenkategorien voraus. Der Fokus dieser Arbeit liegt auf der dreidimensionalen Modellierung von Lockergesteinen und deren Klassifikation basierend auf entsprechend geostatistisch ermittelten Kennwerten. Als Methoden wurden konventionelle, pixelbasierende sowie übergangswahrscheinlichkeitsbasierende Markov-Ketten Modelle verwendet. Nach einer generellen statistischen Auswertung der Parameter wird das Vorhandensein bzw. Fehlen einer Bodenkategorie entlang der Bohrlöcher durch Indikatorparameter beschrieben. Der Indikator einer Kategorie eines Probepunkts ist eins wenn die Kategorie vorhanden ist bzw. null wenn sie nicht vorhanden ist. Zwischenstadien können ebenfalls definiert werden. Beispielsweise wird ein Wert von 0.5 definiert falls zwei Kategorien vorhanden sind, der genauen Anteil jedoch nicht näher bekannt ist. Um die stationären Eigenschaften der Indikatorvariablen zu verbessern, werden die initialen Koordinaten in ein neues System, proportional zur Ober- bzw. Unterseite der entsprechenden Modellschicht, transformiert. Im neuen Koordinatenraum werden die entsprechenden Indikatorvariogramme für jede Kategorie für verschiedene Raumrichtungen berechnet. Semi-Variogramme werden in dieser Arbeit, zur besseren Übersicht, ebenfalls als Variogramme bezeichnet. IV Durch ein Indikatorkriging wird die Wahrscheinlichkeit jeder Kategorie an einem Modellknoten berechnet. Basierend auf den berechneten Wahrscheinlichkeiten für die Existenz einer Modellkategorie im vorherigen Schritt wird die wahrscheinlichste Kategorie dem Knoten zugeordnet. Die verwendeten Indikator-Variogramm Modelle und Indikatorkriging Parameter wurden validiert und optimiert. Die Reduktion der Modellknoten und die Auswirkung auf die Präzision des Modells wurden ebenfalls untersucht. Um kleinskalige Variationen der Kategorien auflösen zu können, wurden die entwickelten Methoden angewendet und verglichen. Als Simulationsmethoden wurden "Sequential Indicator Simulation" (SISIM) und der "Transition Probability Markov Chain" (TP/MC) verwendet. Die durchgeführten Studien zeigen, dass die TP/MC Methode generell gute Ergebnisse liefert, insbesondere im Vergleich zur SISIM Methode. Vergleichend werden alternative Methoden für ähnlichen Fragestellungen evaluiert und deren Ineffizienz aufgezeigt. Eine Verbesserung der TP/MC Methoden wird ebenfalls beschrieben und mit Ergebnissen belegt, sowie weitere Vorschläge zur Modifikation der Methoden gegeben. Basierend auf den Ergebnissen wird zur Anwendung der Methode für ähnliche Fragestellungen geraten. Hierfür werden Simulationsauswahl, Tests und Bewertungsysteme vorgeschlagen sowie weitere Studienschwerpunkte beleuchtet. Eine computergestützte Nutzung des Verfahrens, die alle Simulationsschritte umfasst, könnte zukünftig entwickelt werden um die Effizienz zu erhöhen. Die Ergebnisse dieser Studie und nachfolgende Untersuchungen könnten für eine Vielzahl von Fragestellungen im Bergbau, der Erdölindustrie, Geotechnik und Hydrogeologie von Bedeutung sein.
59

Finite element limit analysis of offshore foundations on clay

Dunne, Helen P. January 2017 (has links)
Capacity analysis is a common preliminary step in the design of offshore foundations. Inaccuracies in traditional capacity analysis methods, and the advancement of numerical modelling capabilities, have increasingly led designers to optimise foundations using more complex methods. In this thesis, the ultimate limit state capacity of a range of foundation types is investigated using finite element limit analysis. Novel three-dimensional finite element limit analysis software is benchmarked against analytical solutions and conventional displacement finite element analysis. It is then used to find lower and upper bounds of foundation capacity, with adaptive mesh refinement used to reduce the bound gap over successive iterations of the solution. Rigid foundations subjected to short term loading on clay soil are analysed. The undrained soil is modelled as a rigid--plastic von Mises material, and attention is given to modelling any normal and/or shear stress limits at the foundation/soil interface. Shallow foundations, suction anchor foundations, and hybrid mudmat/pile foundations are considered. Realistic six degree-of-freedom load combinations are applied and results are reported in the form of normalised design charts, and tables, that are suitable for use in preliminary design. Relationships between loading combinations and failure mechanisms are also explored. A number of case studies based on authentic foundation designs are analysed. The results suggest that finite element limit analysis could provide an attractive alternative to displacement finite element analysis for preliminary foundation design calculations.
60

Uso do agregado calcário na fabricação de concreto asfáltico. / Use of the limestone aggregate in the manufacture of asphalt concrete.

COÊLHO, Rosa Maria Gonçalves. 09 November 2018 (has links)
Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-11-09T16:57:24Z No. of bitstreams: 1 ROSA MARIA GONÇALVES COÊLHO - DISSERTAÇÃO PPGECA 1995..pdf: 23915263 bytes, checksum: 4e9195023b290e36631b4c43b7d4cbea (MD5) / Made available in DSpace on 2018-11-09T16:57:24Z (GMT). No. of bitstreams: 1 ROSA MARIA GONÇALVES COÊLHO - DISSERTAÇÃO PPGECA 1995..pdf: 23915263 bytes, checksum: 4e9195023b290e36631b4c43b7d4cbea (MD5) Previous issue date: 1995-12-18 / CNPq / Esta dissertação apresenta os resultados de uma pesquisa desenvolvida com o objetivo de se utilizar o agregado graúdo não convencional calcário, de formações calcítica e dolomítica, como agregado alternativo em substituição ao agregado convencionalmente usado na fabricação dos concretos betuminosos usinados à quente, como forma de redução de custos de obras rodoviárias, em regiões onde as rochas calcárias são predominantes. Para que pudessem ser comprovadas as características que mostram a resistência da mistura betuminosa, foi utilizado o Ensaio Marshall. Foram feitos ensaios físicos e mecânicos de forma a comprovar suas características na pavimentação. São apresentados alguns resultados de serviços executados na pavimentação da cidade de Mossoró-RN, com resultados satisfatórios de uso nas diferentes camadas do pavimento. Os resultados obtidos nesta pesquisa permitiram concluir que devido a resistência satisfatória e propriedades similares as da brita granítica além de menores custos de extração e britagem, o agregado calcário pode substituí-la com muita propriedade, quando empregado no uso de concreto betuminoso usinado à quente como revestimento em rodovias, reduzindo-se o custo final da obra. / This thesis presents the results of an investigation carried out to study the performance of a non conventional aggregate, calcareous aggregate of the dolomitic and calcitic formation, in substitution to the dolomitic and calcitic aggregate. used to fabricate hot-mix bituminous concrete. The predominant characteristics of the bituminous mixtures were evaluated using the traditional Marshall test. In order to determine the quality of the mixture, physic and mechanic tests were applied. The results obtained in this investigation in regard to existing pavement, named airport of Mossoró-RN city, constructed with calcareous aggregate in the bituminous mixtures, revealed that the altermative mixture made with calcareous aggregate, is a valid one. Also, the results from laboratory tests, showed that the strength property of the bituminous mixture made with the normal granitic aggregate. Therefore, based on these results, it can concluded that the calcareous aggregate is an alternative aggregate that can be used to fabricate bituminous mixtures, in replacement of the conventional granitic aggregate.

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