Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-30T18:08:23Z No. of bitstreams: 1 DIS_SERGIO_ROBERTO_DA_SILVA_COMPLETO.pdf: 2644731 bytes, checksum: 207623c4aecda0de23cefed577f3f2d6 (MD5) / Made available in DSpace on 2017-06-30T18:08:23Z (GMT). No. of bitstreams: 1 DIS_SERGIO_ROBERTO_DA_SILVA_COMPLETO.pdf: 2644731 bytes, checksum: 207623c4aecda0de23cefed577f3f2d6 (MD5) Previous issue date: 2017-03-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Nowadays, searching for alternatives materials for the construction industry has become imperative. Construction and demolition waste (CDW) and by-products from the thermoelectric industries, such as fly ash, are the subject of studies in several segments of the construction industry. Their use can be one of many significant efforts to achieve a more sustainable construction. This paper studies the influence of the interactions and incorporations of CDW and fly ash on the concrete properties. X-ray diffraction (XRD), X-ray Fluorescence Spectrometry (XRF) and particle size distribution analysis were used to characterize the investigated materials. The mechanical properties (compressive strength and splitting strength) and durability (water absorption and carbonation depth) of concrete with different CDW contents (25%, 50%, 75%, and 100%) were investigated as a coarse aggregate (10%, 15%, 25% and 30%) replacing Portland cement in different water/binder ratios (0.40, 0.45, 0.50, 0, 55 and 0.65). Based on the results, it was observed that the addition of fly ash replacing the Portland cement in concretes with CDW causes a reduction in mechanical properties and durability of concretes in the early ages. However, as the fly ash content increases in concretes with CDW there is an increase in the compressive strength ratio (fc91/fc28), and as the time of exposure to CO2 advances the carbonation coefficient tends to decrease. / A busca de novos materiais para o emprego na ind?stria da constru??o civil se faz necess?rio nos dias atuais. O res?duo da constru??o e demoli??o (RCD) e os subprodutos das ind?strias termoel?tricas como a cinza volante s?o objetos de estudos em diversos segmentos da ind?stria da constru??o civil, e a adi??o destes materiais pode ser um dos esfor?os significativos para se alcan?ar uma constru??o mais sustent?vel. Neste trabalho foram estudadas a influ?ncia das intera??es e incorpora??es de RCD e cinza volante nas propriedades dos concretos. Para a caracteriza??o dos materiais investigados foram utilizadas as t?cnicas de Difra??o de raios X (DRX), an?lise qu?mica por Espectrometria de Fluoresc?ncia de raios X (FRX) e an?lise de distribui??o granulom?trica ? laser. Foram investigadas as propriedades mec?nicas (compress?o axial e tra??o por compress?o diametral) e de durabilidade (absor??o d??gua e resist?ncia ? carbonata??o) dos concretos com diferentes teores de RCD (25%, 50%, 75% e 100%) como agregado gra?do reciclado em substitui??o ao gra?do natural e adi??o de cinza volante (10%, 15%, 25% e 30%) em substitui??o ao cimento Portland em diferentes rela??es ?gua/aglomerante (0,40, 0,45, 0,50, 0,55 e 0,65). Com base nos resultados observou-se que a adi??o de cinza volante em substitui??o ao cimento Portland em concretos com RCD causa uma redu??o nas propriedades mec?nicas e de durabilidade nos concretos nas primeiras idades. Entretanto, ? medida que o teor de cinza volante aumenta nos concretos com RCD h? um aumento na taxa de resist?ncia ? compress?o axial (fc91/fc28), e ? medida que o tempo de exposi??o ao CO2 vai se avan?ando o coeficiente de carbonata??o tende a diminuir.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-08-27T00:37:00Z No. of bitstreams: 1 CleberMedeirosDeLucena_DISSERT.pdf: 9013175 bytes, checksum: 75f16c8bb3ea98fef072367d6efcb73d (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-09-02T21:26:23Z (GMT) No. of bitstreams: 1 CleberMedeirosDeLucena_DISSERT.pdf: 9013175 bytes, checksum: 75f16c8bb3ea98fef072367d6efcb73d (MD5) / Made available in DSpace on 2016-09-02T21:26:23Z (GMT). No. of bitstreams: 1 CleberMedeirosDeLucena_DISSERT.pdf: 9013175 bytes, checksum: 75f16c8bb3ea98fef072367d6efcb73d (MD5) Previous issue date: 2016-05-05 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Esta pesquisa foi pautada no projeto e constru??o de uma c?mara de carbonata??o acelerada, em quatro etapas distintas, capaz de equipar um laborat?rio destinado a estudar a durabilidade das edifica??es, principalmente no tocante ?s pesquisas relacionadas ?s an?lises de materiais ciment?cios. A primeira etapa foi determinada no projeto propriamente dito, onde se pensou em dimens?es e materiais a ser utilizado. A segunda etapa destinou-se a constru??o da c?mara de carbonata??o e finalizou com o teste de estanqueidade com o intuito de garantir sua veda??o. A pesquisa teve continuidade em sua terceira etapa, com a automa??o e microcontrole da c?mara de carbonata??o atrav?s de um algoritmo desenvolvido e programado, capaz de interagir com a programa??o presente nos sensores e v?lvulas adquiridos comercialmente. Esta etapa, ainda contou com a calibra??o do sensor, utilizando padr?es rastre?veis internacionalmente e a realiza??o de pr?-testes em modelo reduzido, antes da instala??o definitiva na c?mara de carbonata??o. A quarta etapa foi submeter ao ensaio de carbonata??o acelerada, amostras cil?ndricas de concreto com dimens?es de 100mm x 200mm, no interior da c?mara de carbonata??o acelerada, conforme os padr?es da Laborat?rio Nacional de Engenharia Civil - LNEC E-391 (1993) e especifica??o FINAL DRAFT FprCEN/TS 12390-12, da European Committee Standardization de novembro de 2010. As amostras foram submetidas ao ensaio de carbonata??o acelerada aos 7, 14, 28, 42 e 56 dias de exposi??o e obtiveram respectivamente, profundidades m?dias de carbonata??o de 0,00mm, 1,62mm, 2,65mm, 3,35mm e 3,72mm. Por fim, a pesquisa cumpriu seus objetivos em projetar e construir uma c?mara de carbonata??o acelerada em laborat?rio, bem como teve sua efici?ncia avaliada atrav?s da calibra??o de seus dispositivos avaliadores de CO2 e sua estanqueidade, e garantiu sua funcionalidade atrav?s do ensaio de carbonata??o acelerada em um concreto convencional com 365kg/m? de cimento. / The carbon dioxide present in the atmosphere penetrates into the porous matrix of concrete internally and dissolves altering the chemical balance of the means. Due to this CO2 dissociation occurs a gradual lowering of the pH, which likely contributes to corrosion of the reinforcement. This research was based on the design and construction of chamber accelerated carbonation, automatically, in four steps, able to equip a laboratory for studying the durability of buildings, especially as regards research related to analysis of cementitious materials. The first step was the realization of the project itself, which is defined dimensions and materials to be used. The second step is intended construction of the carbonation chamber and submitted to the tightness test in order to ensure its sealing. The research continued in its third stage, with automation and microcontroller carbonation chamber through an algorithm developed and programmed, able to interact with the programming present on the sensors and valves commercially available. This stage also included the sensor calibration using internationally traceable standards and conducting pre-tests in reduced model before final installation in the carbonation chamber. The fourth step was to submit the test of accelerated carbonation, cylindrical samples of concrete with dimensions of 100mm x 200mm, inside the accelerated carbonation chamber, according to the standards of the National Laboratory of Civil Engineering - LNEC E-391 (1993) and specification FINAL DRAFT FprCEN / TS 12390-12, the European Committee of Standardization November 2010. The samples were subjected to accelerated carbonation test at 7, 14, 28, 42 and 56 days of exposure and obtained respectively mean depths carbonation 0,00mm, 1,62mm, 2.65mm, 3,35mm and 3,72mm. Finally, the study met its goals with project execution and construction of accelerated carbonation chamber in the laboratory and had their assessed efficiency through calibration of its evaluators devices CO2 and its tightness, and secured its functionality by test accelerated carbonation in a conventional concrete with 365kg / m? cement CP V ARI and factor a / c 0.50.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-14T22:33:05Z No. of bitstreams: 1 ThiagoVieiraFonseca_DISSERT.pdf: 2958142 bytes, checksum: c66f334f99f3044869ebf39752984389 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-16T19:54:31Z (GMT) No. of bitstreams: 1 ThiagoVieiraFonseca_DISSERT.pdf: 2958142 bytes, checksum: c66f334f99f3044869ebf39752984389 (MD5) / Made available in DSpace on 2017-03-16T19:54:31Z (GMT). No. of bitstreams: 1 ThiagoVieiraFonseca_DISSERT.pdf: 2958142 bytes, checksum: c66f334f99f3044869ebf39752984389 (MD5) Previous issue date: 2016-12-15 / O concreto autoadens?vel (CAA) possui elevado teor de materiais finos e vem sendo bastante utilizado devido as suas caracter?sticas de alta fluidez e coes?o. Os finos provindos de res?duos ou subprodutos industriais podem vir a ser usados em prol da sustentabilidade, minimizando consideravelmente o consumo de cimento associado ? possibilidade de manter, ou melhorar, as propriedades mec?nicas ou de durabilidade. Desta forma, o presente trabalho investigou a viabilidade do desenvolvimento de CAA?s confeccionados com elevados teores de adi??es minerais e cal hidratada. Para isso, o cimento foi substitu?do por adi??es minerais (pozolana da casca do arroz, metacaulim e f?ler calc?rio) no teor de 60%, com base no tra?o de refer?ncia com consumo de 451,1 kg/m? de cimento, originando novos tra?os com consumos de cimento entre 167,7 kg/m? e 173,3 kg/m?. A cal hidratada foi incorporada como adi??o em tr?s tra?os no teor de 5% sobre a massa total dos materiais finos. Os CAA?s foram caracterizados no estado fresco pelos ensaios de espalhamento, T500, anel-J, funil-V e caixa-L. Para avalia??o do desempenho mec?nico dos CAA?s foram realizados ensaios de resist?ncia ? compress?o, velocidade do pulso ultrass?nico e m?dulo de elasticidade est?tico, bem como propriedades de transporte relacionadas ? durabilidade: absor??o por capilaridade, difus?o de ?ons cloreto, resistividade el?trica e carbonata??o. Os CAA?s com adi??es minerais apresentaram desempenho mec?nico satisfat?rio, embora inferiores ao do tra?o de refer?ncia. As resist?ncias ? compress?o aos 28 dias dos concretos com adi??es minerais apresentaram redu??o de 15 a 60% em rela??o ao tra?o de refer?ncia, mas todos os resultados foram compat?veis com concretos estruturais de acordo com os requisitos da NBR 6118 (ABNT, 2014). Com rela??o a durabilidade, os concretos com adi??es minerais apresentaram redu??o do coeficiente de difus?o de ?ons cloreto que variaram entre 25,4% e 74,8%. As resistividades el?tricas do concreto de refer?ncia foram bastante inferiores ?s dos concretos com adi??es minerais, mas todas as composi??es estudadas foram classificadas como prov?vel taxa de corros?o desprez?vel. As resistividades el?tricas sofreram grande redu??o quando analisadas em amostras carbonatadas. J? a an?lise da carbonata??o acelerada mostrou que a substitui??o do cimento por adi??es minerais em elevados teores torna os CAA?s bastante suscet?veis a carbonata??o. Quanto a adi??o de cal hidratada, n?o foi verificada influ?ncia positiva no desempenho mec?nico dos CAA?s estudados, mas observou-se que sua utiliza??o proporcionou redu??o da profundidade de carbonata??o nos CAA?s devido a reposi??o da reserva alcalina. / Self-compacting concrete (SCC) has a high content of fine materials and has been widely used due to its characteristics of high fluidity and cohesion. Fines from industrial waste or by-products may be used for the sake of sustainability, considerably reducing the consumption of cement associated with the possibility of maintaining or improving mechanical or durability properties. In this way, the present work investigated the feasibility of the development of SCC's made with high levels of mineral additions and hydrated lime. For this purpose, the cement was replaced by mineral additives (rice husk pozzolan, metakaolin and limestone filer) in the 60% content, based on the reference mixture with consumption of 451.1 kg / m? of cement, giving rise to new mixtures with consumption of cement between 167.7 kg / m? and 173.3 kg / m?. The hydrated lime was incorporated as an addition in three mixtures in the content of 5% on the total mass of the fine materials. The SCC's were characterized in the fresh state by the slump flow test, T500, J-ring, V-funnel and L-box. To evaluate the mechanical performance of the SCC's, tests of compressive strength, ultrasonic pulse velocity and static modulus of elasticity, as well as transport properties related to durability were performed: capillary absorption, chloride ion diffusion, electrical resistivity and carbonation. The SCC's with mineral additions presented satisfactory mechanical performance, although lower than the reference mixture. The compressive strength at 28 days of the concretes with mineral additions showed a reduction of 15 to 60% in relation to the reference mixture, but all the results were compatible with structural concretes according to the requirements of NBR 6118 (ABNT, 2014). Regarding the durability, the concrete with mineral additions presented reduction of the diffusion coefficient of chloride ions that varied between 25.4% and 74.8%. The electrical resistivities of the reference concrete were much lower than those of the concretes with mineral additions, but all the studied compositions were classified as probable negligible corrosion rates. The electrical resistivities suffered great reduction when analyzed in carbonated samples. The analysis of the accelerated carbonation showed that the substitution of cement by mineral additions at high levels makes the SCC very susceptible to carbonation. As for the addition of hydrated lime, there was no positive influence on the mechanical performance of the SCC's studied, but it was observed that its use provided a reduction of the carbonation depth in the SCC's due to the alkaline reserve.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-05-31T20:47:35Z No. of bitstreams: 1 AlmirMarianoDeSousaJunior_TESE.pdf: 3946108 bytes, checksum: 2bc096f2c4d458f0f8b935b7ab096360 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-06-01T21:12:03Z (GMT) No. of bitstreams: 1 AlmirMarianoDeSousaJunior_TESE.pdf: 3946108 bytes, checksum: 2bc096f2c4d458f0f8b935b7ab096360 (MD5) / Made available in DSpace on 2017-06-01T21:12:03Z (GMT). No. of bitstreams: 1 AlmirMarianoDeSousaJunior_TESE.pdf: 3946108 bytes, checksum: 2bc096f2c4d458f0f8b935b7ab096360 (MD5) Previous issue date: 2016-12-29 / A mudan?a da matriz energ?tica ? algo ainda muito longe da realidade atual, surgindo o armazenamento geol?gico como alternativa contra o aquecimento global, adotando a t?cnica de captura de CO2 e CH4 antes de sua emiss?o para a atmosfera. Destacam-se como ambientes de armazenamento dos gases, os campos de explora??o maduros de petr?leo e abandonados, contudo, surge a necessidade de desenvolver pastas de ciment?cias sustent?veis para tamponamento de po?os que possuam baixa permeabilidade, buscando minimizar a emiss?o dos referidos gases para a atmosfera. Estas foram desenvolvidas com adi??o de filler do res?duo do polimento do porcelanato (RPP) e dispers?o aquosa de poliuretana, objetivando analisar o seu efeito na redu??o de permeabilidade em pastas de cimento para tamponamento de po?os de petr?leo. Para identificar o melhor comportamento, realizou-se ensaios de permeabilidade, resist?ncia ? compress?o axial, estabilidade, densidade e carbonata??o de acordo com as especifica??es da Associa??o Brasileira de Normas T?cnicas (ABNT) e do American Petroleum Institute (API). Os resultados obtidos nos ensaios foram satisfat?rios e verificou-se que as adi??es do Res?duo do Polimento do Porcelanato e da Poliuretana contribu?ram para redu??o da permeabilidade em pastas de cimento, possuem uma boa resist?ncia a compress?o e conseguem resistir a condi??es carbon?tica com 60 dias de exposi??o em ambiente supercr?tico. / The change in the energy matrix is still far from the current reality, then, the geological storage appears as an alternative against the Global Warming, adopting the technique of capturing CO2 and CH4 before their emission into the atmosphere. They stand out as gas storage environments: the mature and abandoned oil fields. However, there is the necessity to develop sustainable cement pastes for the wells cementation with low permeability, in order to minimize the emission of these gases into the atmosphere. These pastes were developed with the addition of filler from the porcelain polishing waste and Water-borne polyurethane in order to analyze theirs effect on the reduction of the permeability in cement pastes for oil wells. To identify the best behavior, permeability, axial compressive strength, stability, density and carbonation, experiments were performed according to the Brazilian Association of Technical Standards (ABNT) and the American Petroleum Institute (API) specifications. The results obtained in the tests were satisfactory and it was verified that the additions of the porcelain polish residue and the Polyurethane contributed to the reduction of the permeability in cement pastes, they have a good resistance to compression and they are able to withstand the carbonate conditions with 60 days of exposure in a supercritical environment.

Submitted by PPG Engenharia e Tecnologia de Materiais (engenharia.pg.materiais@pucrs.br) on 2018-03-16T11:25:56Z No. of bitstreams: 1 Rafael _ Goularte _ Ortiz _ TES.pdf: 9521284 bytes, checksum: c69cc2ad925316be0c15638aac8f5999 (MD5) / Approved for entry into archive by Tatiana Lopes (tatiana.lopes@pucrs.br) on 2018-03-28T12:56:52Z (GMT) No. of bitstreams: 1 Rafael _ Goularte _ Ortiz _ TES.pdf: 9521284 bytes, checksum: c69cc2ad925316be0c15638aac8f5999 (MD5) / Made available in DSpace on 2018-03-28T13:06:35Z (GMT). No. of bitstreams: 1 Rafael _ Goularte _ Ortiz _ TES.pdf: 9521284 bytes, checksum: c69cc2ad925316be0c15638aac8f5999 (MD5) Previous issue date: 2017-12-21 / Carbon geological storage in depleted wells has been identified as an important solution to mitigate the environmental impacts caused by the release of CO2 into the atmosphere. However, the degradation of the materials used in the construction of the wells over the years has been one of the major concerns of the application of this technology, due the possibility of CO2 escape to the surface. The most susceptible region of CO2 leakage is through the wellbore at the interface between the cement paste and rock formation. The degradation of the cement paste occurs due to the presence of CO2 and water or brine, occurring acid carbonation that causes loss on mechanical resistance and increase in porosity. This work aims to study the chemical alteration of the class G cement paste in the presence of arenite rock of the Rio Bonito Formation (Paran? Basin-Brazil) by humid CO2, CO2 saturated water and brine saturated with CO2, simulating the geological storage conditions with a depth of 1,500 m, corresponding to a temperature of 70?C and the pressure of 15MPa. For the degradation test, samples were made by pouring a cement into the hole of an arenite cylinder. The tests were performed in two exposure times, 28 and 180 days, and the chemical degradation of the cement phases was evaluated by Scanning Electron Microscopy (SEM / FEG) and X-Ray Diffraction. The density of cement and rock before and after exposure to CO2 was obtained by pycnometry and the surface area of the rock pores and the diameter of them were evaluated by the BJH method. In addition, the percentage of inorganic carbon present in the rock was determined before and after the degradation tests. The carbonation of the cement was less accelerated in the samples exposed to the saline solution than in the supercritical environment of CO2 and CO2 saturated water, probably due to the decreasing of CO2 solubility in the aqueous medium in the presence of salts and also due to the higher precipitation of carbonate in the pores of the rock that make difficult the CO2 percolation. The density measurements showed that there was an increase in the density of rock and cement (near the interface with the rock) after exposure to CO2 and the density increased with the time of exposure. The surface area of the rock pores, for both times and all mediums, increased after expusure to CO2 due the precipitation of CaCO3, while the radius of the pore have a tendence to decrease. In addition, an increase in the amount of carbon present in the rock after CO2 exposure was observed for the three studied environment and the two exposure times, and a higher amount of carbon was observed for the rock samples exposed to the saline solution, and in this case the carbon content significantly increased from exposure time from 28 days to 180 days. / O armazenamento geol?gico de carbono em po?os depletados tem sido apontado como uma solu??o importante para a mitiga??o de impactos ambientais causados pela libera??o do CO2 na atmosfera. No entanto, a degrada??o dos materiais utilizados na constru??o dos po?os ao longo dos anos tem sido uma das maiores preocupa??es da aplica??o desta tecnologia, uma vez que pode favorecer o vazamento do CO2 para a superf?cie. A regi?o do po?o mais suscet?vel ? fuga de CO2 ? a interface da pasta de cimento com a forma??o rochosa. A degrada??o da pasta de cimento se d? devido a presen?a de CO2 e ?gua ou salmoura, ocorrendo a carbonata??o ?cida que gera perda de resist?ncia mec?nica e aumento da porosidade. Este trabalho tem como objetivo estudar a altera??o qu?mica da pasta de cimento classe G em presen?a da rocha sedimentar arenosa da Forma??o de Rio Bonito (Bacia do Paran?-Brasil) nos meios de CO2 ?mido, ?gua saturada com CO2 e solu??o salina saturada com CO2, simulando as condi??es de armazenamento geol?gico com profundidade de 1.500m, correspondendo a uma temperatura de aproximadamente 70?C e a press?o de 15MPa. Para os ensaios de degrada??o foram confeccionados corpos de prova constitu?dos de rocha e cimento. Os ensaios tiveram dura??o de 28 ou 180 dias e a degrada??o qu?mica das fases do cimento foi avaliada por meio de microscopia eletr?nica de varredura (MEV/FEG) e difra??o de raios X. A densidade do cimento e da rocha antes e ap?s exposi??o ao CO2 foi obtida por picnometria e a ?rea superficial dos poros da rocha o di?metro m?dio dos mesmos foram avaliados pelo m?todo BJH. Al?m disso, foi determinado o percentual de carbono inorg?nico presente na rocha antes e ap?s os testes de degrada??o. A carbonata??o do cimento foi menos acelerada para os corpos de provas expostos ? solu??o salina que nos meios de CO2 supercr?tico ?mido e ?gua saturada com CO2, provavelmente devido a presen?a de sais diminuir a solubilidade do CO2 no meio aquoso e tamb?m devido a maior precipita??o de carbonato nos poros da rocha que dificultaram a percola??o do CO2. As medidas de densidade mostraram que houve um aumento na densidade da rocha e do cimento (pr?ximo ? interface com a rocha) ap?s exposi??o ao CO2 e a densidade aumentou com o tempo de exposi??o ao CO2. A ?rea superficial dos poros da rocha medidas, para ambos os tempos e todos os meios, aumentou com a precipita??o de CaCO3 enquanto que o raio m?dio do poro tendeu a diminuir para a maioria dos casos. Adicionalmente, observou-se um aumento na quantidade de carbono presente na rocha ap?s exposi??o ao CO2 para os tr?s meios estudados e os dois tempos de exposi??o, sendo que uma maior quantidade de carbono foi observada para as amostras de rocha expostas ? solu??o salina, sendo que neste caso o teor de carbono aumentou significativamente do tempo de exposi??o de 28 dias para 180 dias.

Made available in DSpace on 2014-12-17T14:07:10Z (GMT). No. of bitstreams: 1 CarinaGMMB_TESE.pdf: 4060316 bytes, checksum: 4ffd1d674b7bda144d5cd732432d8bfb (MD5) Previous issue date: 2012-12-14 / One of the major challenges faced nowadays by oil companies is the exploration of pre-salt basins. Thick salt layers were formed in remote ages as a consequence of the evaporation of sea water containing high concentrations of NaCl and KCl. Deep reservoirs can be found below salt formations that prevent the outflow of oil, thus improving the success in oil prospection. The slurries used in the cement operations of salt layers must be adequate to the properties of those specific formations. At the same time, their resulting properties are highly affected by the contamination of salt in the fresh state. It is t herefore important to address the effects of the presence of salt in the cement slurries in order to assure that the well sheath is able to fulfill its main role to provide zonal isolation and mechanical stability. In this scenario, the objective of the present thesis work was to evaluate the effect of the presence of NaCl and KCl premixed with cement and 40% silica flour on the behavior of cement slurries. Their effect in the presence of CO2 was also investigated. The rheological behavior of slurries containing NaCl and KCl was evaluated along with their mechanical strength. Thermal and microstructural tests were also carried out. The results revealed that the presence of NaCl and KCl affected the pozzolanic activity of silica flour, reducing the strength of the hardened slurries containing salt. Friedel?s salt was formed as a result of the bonding between free Cl- and tricalcium aluminate. The presence of CO2 also contributed to the degradation of the slurries as a result of a process of carbonation/bicarbonataion / Atualmente, um dos grandes desafios para as empresas petrol?feras ? a explora??o de petr?leo em bacias dominadas por estruturas salinas, mais conhecidas por zonas evapor?ticas. A camada de sal ? formada pela evapora??o da ?gua do mar, cuja composi??o qu?mica inclui altas concentra??es de cloreto de s?dio (NaCl). Reservat?rios profundos s?o encontrados abaixo de espessas camadas de sal que vedam o fluxo de ?leo para fora da rocha, aprisionando hidrocarbonetos e aumentando, assim, a probabilidade de sucesso na prospec??o de ?leo e g?s. Atendendo ?s condi??es de po?o, s?o utilizadas pastas de cimento do tipo Portland para isolar, promover resist?ncia mec?nica ao po?o e impedir a intercomunica??o zonal das forma??es rochosas produtoras. Deste modo, as pastas de cimento devem atender ? natureza dos sais, pois estes se encontram na natureza com distintas caracter?sticas. Assim, este trabalho teve como objetivo avaliar o comportamento da adi??o de sais NaCl e KCl em sistemas de pastas de cimento contendo 40% de s?lica flour e avaliar o comportamento dessas pastas frente a presen?a de CO2. As propriedades foram avaliadas atrav?s de ensaios de reologia, resist?ncia ? compress?o pelo m?todo ultrass?nico (UCA) e resist?ncia mec?nica pelo m?todo destrutivo, bem como com o uso de t?cnicas de caracteriza??o t?rmica (TG/DTG), difra??o de raios X (DRX), microscopia eletr?nica de varredura (MEV) e an?lise de EDS em microanalisadores de sonda eletr?nica (EPMA). Os resultados mostraram que a presen?a do NaCl e KCl, interferem na atividade pozol?nica da s?lica, reduzindo a resist?ncia das pastas quando adicionado altas concentra??es dos sais. Essa interfer?ncia foi comprovada devido a forma??o do sal de Friedel, resultado da liga??o dos cloretos livres ao aluminato tric?lcico, incorporado ?s fases s?lidas do cimento hidratado. Para o estudo da influ?ncia de meios ricos em CO2 em pastas de cimento, foi observada a degrada??o das pastas atrav?s do processo de carbonata??o seguido da bicarbonata??o, resultando na perda da resist?ncia mec?nica

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-10T20:59:54Z No. of bitstreams: 1 RafaelAugustoVentura_DISSERT.pdf: 2403506 bytes, checksum: 03833598c2b497f4e7cd05ae5e4c1bf1 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-05-12T20:33:13Z (GMT) No. of bitstreams: 1 RafaelAugustoVentura_DISSERT.pdf: 2403506 bytes, checksum: 03833598c2b497f4e7cd05ae5e4c1bf1 (MD5) / Made available in DSpace on 2016-05-12T20:33:13Z (GMT). No. of bitstreams: 1 RafaelAugustoVentura_DISSERT.pdf: 2403506 bytes, checksum: 03833598c2b497f4e7cd05ae5e4c1bf1 (MD5) Previous issue date: 2015-07-27 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Em um po?o de petr?leo, a cimenta??o dos revestimentos tem grande import?ncia, pois ela garante a seguran?a do po?o, para que este n?o colapse, como tamb?m promove o isolamento das forma??es rochosas para que n?o ocorra comunica??o entre os fluidos adjacentes. Desta forma, ? importante que a matriz de cimento possua estabilidade estrutural e qu?mica. O di?xido de carbono tem sido um agente que tem comprometido essa estabilidade, pois em determinados campos petrol?feros, ele pode ser encontrado em grandes quantidades e em condi??es ideais para a carbonata??o e posterior degrada??o da matriz de cimento, de forma a comprometer o selo hidr?ulico entre as forma??es, podendo tamb?m formar caminhos preferenciais de sa?da de fluidos da forma??o para o espa?o anular do po?o de petr?leo. A s?lica flour tem sido utilizada com grande frequ?ncia em po?os que est?o sujeitos a altas temperaturas, sejam os de elevadas profundidades ou no caso daqueles onde s?o injetados vapor como alternativa para recupera??o avan?ada em reservat?rios de ?leo pesado. Com base no exposto, o presente trabalho tem como objetivo avaliar a influ?ncia de ambientes ricos em CO2 na estabilidade qu?mica da matriz do cimento contendo s?lica flour. Foram preparadas pastas contendo s?lica flour e curadas por 30 dias sob temperatura de 65?C e 3000psi de press?o. Ap?s a cura, parte das amostras foram analisadas quimicamente e outra parte submetida ? atmosfera de CO2 em uma autoclave, por 30 e 60 dias, e posteriormente analisadas ap?s este processo de carbonata??o. As amostras foram caracterizadas por difra??o de raios x (DRX), microscopia eletr?nica de varredura (MEV), espectroscopia de infravermelho por transformada de Fourier (FTIR) e termogravimetria (TG). As pastas ciment?cias curadas por 60 dias foram as que apresentaram uma maior ?rea carbonatada. As amostras curadas em ambiente de CO2 saturado sofreram uma maior carbonata??o em rela??o as amostras curadas em ambiente supercr?tico, o que est? diretamente relacionado ? concentra??o de CO2 do meio. Os espectros de infravermelho apresentaram bandas caracter?sticas dos produtos de carbonata??o da matriz do cimento, com estiramento do grupo carbonato no comprimento de onda de 875cm-1, que ? caracter?stico da calcita. Nas imagens obtidas por MEV pode-se observar a presen?a de cristais de aragonita (CaCO3). O efeito da carbonata??o em po?os petrol?feros pode afetar consideravelmente a microestrutura da matriz de cimento podendo comprometer o selo hidr?ulico do po?o. / In oil well cementation casing is very important because in addition to ensuring the safety of the well so that it does not collapse, it also promotes the isolation of the rock formations so that there is communication between the adjacente fluids. Thus, it is important that the cement matrix has structural and chemical stability. Carbon dioxide has been an agent that this stability is compromised. In particular oil fields, it can be found in large quantities and in ideal conditions for carbonation and subsequent degradation of the cement matrix, in order to compromise the hydraulic seal between the formations, and may also form preferential paths of fluid to exit the formation the annular space of the oil well. The silica flour has been used frequently in wells that are subjected to high temperatures, be the case in very deep or those which are injected steam as an alternative for enhanced recovery of heavy oil reservoirs. Based on the above, this study aims to evaluate the influence of environments rich in CO2 in the chemical stability of the cement matrix containing silica flour. Pastes containing silica flour and cured for 30 days under temperature of 65?C and pressure of 3000psi (20,7MPa) were prepared. After curing, some of the samples were analyzed chemically and part subjected to CO2 atmosphere in an autoclave for 30 and 60 days and analyzed after this carbonation process. The samples were characterized by Xray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy by Fourier transform (FTIR) and thermogravimetry (TG). The cement pastes cured for 60 days showed the greater carbonated area. The samples cured in saturated CO2 environment suffered greater carbonation compared to samples cured in supercritical environment, which is directly related to CO2 concentration in the environment. Infrared spectra showed characteristic bands of carbonation products cement matrix, with stretch carbonate group at a wavelength of 875cm-1, which is characteristic of calcite. The images obtained by SEM it can be observed the presence of crystal of aragonite (CaCO3). The effect of carbonation in oil wells can greatly affect the microstructure of the cement matrix may compromise the hydraulic seal the well.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-02-21T21:14:12Z No. of bitstreams: 1 BrunoLeonardoDeSenaCosta_TESE.pdf: 4089487 bytes, checksum: fcfd3987ed1c7e1dfaa97685067e032e (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-02-22T20:55:45Z (GMT) No. of bitstreams: 1 BrunoLeonardoDeSenaCosta_TESE.pdf: 4089487 bytes, checksum: fcfd3987ed1c7e1dfaa97685067e032e (MD5) / Made available in DSpace on 2018-02-22T20:55:45Z (GMT). No. of bitstreams: 1 BrunoLeonardoDeSenaCosta_TESE.pdf: 4089487 bytes, checksum: fcfd3987ed1c7e1dfaa97685067e032e (MD5) Previous issue date: 2018-01-15 / Neste trabalho o fen?meno da carbonata??o do cimento Portland ? investigado por diferentes abordagens, por?m convergindo para o mesmo objetivo: aprofundar o conhecimento dos processos e os efeitos do CO2 na matriz ciment?cia. Esse fen?meno ocorre atrav?s de rea??es qu?micas entre o ?cido carb?nico, formado pela rea??o do CO2 com a ?gua, e alguns produtos hidratados do cimento. Em subsuperf?cie, devido ao incremento de temperatura e press?o o meio se torna mais danoso, sendo assim, na ?rea de petr?leo e g?s, principalmente a cimenta??o, tem um grande interesse por esta problem?tica. Frente ao exposto, neste trabalho foram desenvolvidos e publicados tr?s artigos intitulados: [Artigo I] Efeitos do di?xido de carbono no cimento Portland: uma rela??o entre a sedimenta??o est?tica e a carbonata??o, [Artigo II] Carbonata??o em cimento Portland para po?os de petr?leo: influ?ncia do tempo de hidrata??o antes do contato com o CO2 e [Artigo III] Estudo sobre a carbonata??o em uma matriz de cimento Portland classe G em ambientes supercr?tico e saturado. No primeiro estudo foi proposto um modelo para o comportamento da sedimenta??o e da carbonata??o ocorrido em uma pasta inst?vel, onde a sedimenta??o est?tica baseia-se na mec?nica dos fluidos. No segundo estudo foram investigadas tr?s pastas com a mesma formula??o, por?m curadas durante per?odos de tempos de 8 horas, 7 dias e 28 dias antes do contato com o CO2. Os resultados mostraram processos distintos, mas com efeitos similares de carbonata??o ao final. E no ?ltimo estudo as amostras foram expostas ao mesmo tempo em CO2 supercr?tico e saturado. As an?lises mostraram resultados significativamente distintos, onde as amostras expostas ao meio saturado sofreram um ataque 35% superior ?quelas submetidas ao CO2 supercr?tico. Este trabalho apresenta estudos que buscam promover uma maior compreens?o da fenomenologia da a??o do CO2 e ao mesmo tempo dar subs?dios para o desenvolvimento de tecnologias que combatam a carbonata??o. / In this study the phenomenon of Portland cement carbonation is investigated by different approaches, but converging towards the same objective: to deepen the knowledge of the processes and the effects in the cement matrix. The phenomenon occurs through chemical reactions between carbonic acid, formed by the reaction of CO2 with water, and some hydrated products of cement. In subsurface due to the increase of temperature and pressure the medium becomes more damaging, being therefore, in the area of oil and gas, mainly cementing, has a great interest by this problematic. In view of the above, in this study three articles were developed and published entitled: [Article I] Effects of carbon dioxide in Portland cement: a relation between static sedimentation and carbonation, [Article II] Carbonation in oil well Portland cement: Influence of hydration time prior to contact with CO2 and [Article III] Study of carbonation in a class G Portland cement matrix at supercritical and saturated environments. In the first study, a model was proposed for sedimentation and carbonation behavior in an unstable slurry, the static sedimentation based on fluid mechanics. In another study, three slurries of the same formulation were investigated, but were cured for periods of 8 hours, 7 days and 28 days before CO2 contact. The results showed distinct processes, but with similar carbonation effects at the end. In addition, in one last study samples were exposed at the same time in supercritical and saturated CO2. The analyzes showed significantly different results, where the samples exposed to the saturated medium suffered a 35% higher attack. This work presents studies that seek to promote a greater understanding of phenomenology and give subsidies for the development of technologies that combat carbonation.