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.