Carbonatação da camada de cobrimento de protótipos de concreto com cinza volante e cal
Autor(a) principal: | |
---|---|
Data de Publicação: | 2005 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Manancial - Repositório Digital da UFSM |
Texto Completo: | http://repositorio.ufsm.br/handle/1/7940 |
Resumo: | When the armed concrete of the point of view of the durability is observed, observes heterogeneous zone from mold, known as cover concrete that possess distinct characteristics of the zones deepest of the structural parts. It is through the same one that the transport mechanisms act that allow the interaction with the environment through the fluid flow that stream for the pores. Between the properties, that more are affected to leave of this layer, it is the carbonation, mainly when one uses high texts of mineral additions, especially pozzolans, that consume the calcium hydroxide of the alkaline reserve and speed up the neutralization process. When the carbonated depth reaches the armor, this suffers process from depassivation for the fall of pH and is available for the beginning of the corrosion, case the ambient conditions will be propitious. The pozzolans, in special the fly ash, beyond the ecological advantages that its job in concrete brings, produce significant alterations in the improvement of the microstructure of the folder but, on the other hand, it consumes great part of CH, speeding up the carbonation process. The present inquiry deals with the study of cured archetypes of concrete in ambient conditions, of where had been extracted certifications from the surface of the concrete and, after, the 2,5 and 5,0 cm of depth, with intention to study the influence of the distance to the external surface on the process of carbonatação, pH and CH. Mixtures with cement Portland (reference) and its substitution had been used, in mass, for 50% of fly ash, with and without addition of hydrated lime. Climatized chamber was used to carry through the assays of sped up carbonation, determining the depths neutralized in 4, 8 and 12 weeks. To leave of these data the carbonatação coefficients had been calculated, of where it can be concluded that the cement substitution for 50% of fly ash increased, in average, in 100% the speed of the carbonation, while that the addition of 20% of lime to these traces made with that increase it to me average lowered for 20%, in average. Also it can be concluded that layer 3, 50 mm of the surface, was the one that more was benefited with the addition of lime in relation to the reference concrete therefore presented coefficient of carbonation of only 40% greater, content of higher CH 5.8%, agreed water content 4% greater and, finally, text of 10 lesser pores of nm raised 10.6% more. |
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Carbonatação da camada de cobrimento de protótipos de concreto com cinza volante e calCarbonation of cover concrete of prototipe with fly ash and limeEngenharia civilConcretoMaterial de construçãoCarbonataçãoCinza volanteCalCNPQ::ENGENHARIAS::ENGENHARIA CIVILWhen the armed concrete of the point of view of the durability is observed, observes heterogeneous zone from mold, known as cover concrete that possess distinct characteristics of the zones deepest of the structural parts. It is through the same one that the transport mechanisms act that allow the interaction with the environment through the fluid flow that stream for the pores. Between the properties, that more are affected to leave of this layer, it is the carbonation, mainly when one uses high texts of mineral additions, especially pozzolans, that consume the calcium hydroxide of the alkaline reserve and speed up the neutralization process. When the carbonated depth reaches the armor, this suffers process from depassivation for the fall of pH and is available for the beginning of the corrosion, case the ambient conditions will be propitious. The pozzolans, in special the fly ash, beyond the ecological advantages that its job in concrete brings, produce significant alterations in the improvement of the microstructure of the folder but, on the other hand, it consumes great part of CH, speeding up the carbonation process. The present inquiry deals with the study of cured archetypes of concrete in ambient conditions, of where had been extracted certifications from the surface of the concrete and, after, the 2,5 and 5,0 cm of depth, with intention to study the influence of the distance to the external surface on the process of carbonatação, pH and CH. Mixtures with cement Portland (reference) and its substitution had been used, in mass, for 50% of fly ash, with and without addition of hydrated lime. Climatized chamber was used to carry through the assays of sped up carbonation, determining the depths neutralized in 4, 8 and 12 weeks. To leave of these data the carbonatação coefficients had been calculated, of where it can be concluded that the cement substitution for 50% of fly ash increased, in average, in 100% the speed of the carbonation, while that the addition of 20% of lime to these traces made with that increase it to me average lowered for 20%, in average. Also it can be concluded that layer 3, 50 mm of the surface, was the one that more was benefited with the addition of lime in relation to the reference concrete therefore presented coefficient of carbonation of only 40% greater, content of higher CH 5.8%, agreed water content 4% greater and, finally, text of 10 lesser pores of nm raised 10.6% more.Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorQuando se observa o concreto armado do ponto de vista da durabilidade, percebe-se uma zona heterogênea a partir das fôrmas, conhecida como camada de cobrimento que possui características distintas das zonas mais profundas das peças estruturais. É através da mesma que atuam os mecanismos de transporte que permitem a interação com o meio ambiente através do fluxo de fluidos que percolam pelos poros. Entre as propriedades, que mais são afetadas a partir desta camada, está a carbonatação, principalmente quando se utiliza altos teores de adições minerais, especialmente pozolanas, que consomem o hidróxido de cálcio da reserva alcalina e aceleram o processo de neutralização. Quando a profundidade carbonatada atinge a armadura, esta sofre processo de despassivação pela queda do pH e fica disponível para o início da corrosão, caso as condições ambientais forem propícias. As pozolanas, em especial a cinza volante, além das vantagens ecológicas que traz o seu emprego em concreto, produzem alterações significativas na melhoria da microestrutura da pasta mas, em contrapartida, consome grande parte de CH, acelerando o processo de carbonatação. A presente investigação trata do estudo de protótipos de concreto curados em condições ambientais, de onde foram extraídos testemunhos a partir da superfície do concreto e, após, a 2,5 e 5,0 cm de profundidade, com o intuito de estudar a influência da distância à superfície externa sobre o processo de carbonatação, pH e CH. Foram empregadas misturas com cimento Portland (referência) e com sua substituição, em massa, por 50% de cinza volante, com e sem adição de cal hidratada. Empregou-se câmara climatizada para realizar os ensaios de carbonatação acelerada, determinando-se as profundidades neutralizadas em 4, 8 e 12 semanas. A partir destes dados foram calculados os coeficientes de carbonatação, de onde pode-se concluir que a substituição de cimento por 50% de cinza volante aumentou, em média, em 100% a velocidade da carbonatação, enquanto que a adição de 20% de cal a estes traços fez com que o acréscimo médio baixasse para 20%, em média. Também pode-se concluir que a camada 3, a 50 mm da superfície, foi a que mais se beneficiou com a adição de cal em relação ao concreto de referência pois apresentou coeficiente de carbonatação de apenas 40% superior, teor de CH 5,8% mais alto, teor de água combinada 4% maior e, finalmente, teor de poros menores de 10 nm 10,6% mais elevados.Universidade Federal de Santa MariaBREngenharia CivilUFSMPrograma de Pós-Graduação em Engenharia CivilIsaia, Geraldo Cechellahttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4787985U6Gastaldini, Antonio Luiz Guerrahttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4797846A8Molin, Denise Carpena Coitinho Dalhttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4787790J0Lana, Elinor Fernando Dalla2017-01-302017-01-302005-03-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfapplication/pdfLANA, Elinor Fernando Dalla. CARBONATION OF COVER CONCRETE OF PROTOTIPE WITH FLY ASH AND LIME. 2005. 138 f. Dissertação (Mestrado em Engenharia Civil) - Universidade Federal de Santa Maria, Santa Maria, 2005.http://repositorio.ufsm.br/handle/1/7940porinfo:eu-repo/semantics/openAccessreponame:Manancial - Repositório Digital da UFSMinstname:Universidade Federal de Santa Maria (UFSM)instacron:UFSM2022-03-09T18:27:24Zoai:repositorio.ufsm.br:1/7940Biblioteca Digital de Teses e Dissertaçõeshttps://repositorio.ufsm.br/ONGhttps://repositorio.ufsm.br/oai/requestatendimento.sib@ufsm.br||tedebc@gmail.comopendoar:2022-03-09T18:27:24Manancial - Repositório Digital da UFSM - Universidade Federal de Santa Maria (UFSM)false |
dc.title.none.fl_str_mv |
Carbonatação da camada de cobrimento de protótipos de concreto com cinza volante e cal Carbonation of cover concrete of prototipe with fly ash and lime |
title |
Carbonatação da camada de cobrimento de protótipos de concreto com cinza volante e cal |
spellingShingle |
Carbonatação da camada de cobrimento de protótipos de concreto com cinza volante e cal Lana, Elinor Fernando Dalla Engenharia civil Concreto Material de construção Carbonatação Cinza volante Cal CNPQ::ENGENHARIAS::ENGENHARIA CIVIL |
title_short |
Carbonatação da camada de cobrimento de protótipos de concreto com cinza volante e cal |
title_full |
Carbonatação da camada de cobrimento de protótipos de concreto com cinza volante e cal |
title_fullStr |
Carbonatação da camada de cobrimento de protótipos de concreto com cinza volante e cal |
title_full_unstemmed |
Carbonatação da camada de cobrimento de protótipos de concreto com cinza volante e cal |
title_sort |
Carbonatação da camada de cobrimento de protótipos de concreto com cinza volante e cal |
author |
Lana, Elinor Fernando Dalla |
author_facet |
Lana, Elinor Fernando Dalla |
author_role |
author |
dc.contributor.none.fl_str_mv |
Isaia, Geraldo Cechella http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4787985U6 Gastaldini, Antonio Luiz Guerra http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4797846A8 Molin, Denise Carpena Coitinho Dal http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4787790J0 |
dc.contributor.author.fl_str_mv |
Lana, Elinor Fernando Dalla |
dc.subject.por.fl_str_mv |
Engenharia civil Concreto Material de construção Carbonatação Cinza volante Cal CNPQ::ENGENHARIAS::ENGENHARIA CIVIL |
topic |
Engenharia civil Concreto Material de construção Carbonatação Cinza volante Cal CNPQ::ENGENHARIAS::ENGENHARIA CIVIL |
description |
When the armed concrete of the point of view of the durability is observed, observes heterogeneous zone from mold, known as cover concrete that possess distinct characteristics of the zones deepest of the structural parts. It is through the same one that the transport mechanisms act that allow the interaction with the environment through the fluid flow that stream for the pores. Between the properties, that more are affected to leave of this layer, it is the carbonation, mainly when one uses high texts of mineral additions, especially pozzolans, that consume the calcium hydroxide of the alkaline reserve and speed up the neutralization process. When the carbonated depth reaches the armor, this suffers process from depassivation for the fall of pH and is available for the beginning of the corrosion, case the ambient conditions will be propitious. The pozzolans, in special the fly ash, beyond the ecological advantages that its job in concrete brings, produce significant alterations in the improvement of the microstructure of the folder but, on the other hand, it consumes great part of CH, speeding up the carbonation process. The present inquiry deals with the study of cured archetypes of concrete in ambient conditions, of where had been extracted certifications from the surface of the concrete and, after, the 2,5 and 5,0 cm of depth, with intention to study the influence of the distance to the external surface on the process of carbonatação, pH and CH. Mixtures with cement Portland (reference) and its substitution had been used, in mass, for 50% of fly ash, with and without addition of hydrated lime. Climatized chamber was used to carry through the assays of sped up carbonation, determining the depths neutralized in 4, 8 and 12 weeks. To leave of these data the carbonatação coefficients had been calculated, of where it can be concluded that the cement substitution for 50% of fly ash increased, in average, in 100% the speed of the carbonation, while that the addition of 20% of lime to these traces made with that increase it to me average lowered for 20%, in average. Also it can be concluded that layer 3, 50 mm of the surface, was the one that more was benefited with the addition of lime in relation to the reference concrete therefore presented coefficient of carbonation of only 40% greater, content of higher CH 5.8%, agreed water content 4% greater and, finally, text of 10 lesser pores of nm raised 10.6% more. |
publishDate |
2005 |
dc.date.none.fl_str_mv |
2005-03-01 2017-01-30 2017-01-30 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
LANA, Elinor Fernando Dalla. CARBONATION OF COVER CONCRETE OF PROTOTIPE WITH FLY ASH AND LIME. 2005. 138 f. Dissertação (Mestrado em Engenharia Civil) - Universidade Federal de Santa Maria, Santa Maria, 2005. http://repositorio.ufsm.br/handle/1/7940 |
identifier_str_mv |
LANA, Elinor Fernando Dalla. CARBONATION OF COVER CONCRETE OF PROTOTIPE WITH FLY ASH AND LIME. 2005. 138 f. Dissertação (Mestrado em Engenharia Civil) - Universidade Federal de Santa Maria, Santa Maria, 2005. |
url |
http://repositorio.ufsm.br/handle/1/7940 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf application/pdf |
dc.publisher.none.fl_str_mv |
Universidade Federal de Santa Maria BR Engenharia Civil UFSM Programa de Pós-Graduação em Engenharia Civil |
publisher.none.fl_str_mv |
Universidade Federal de Santa Maria BR Engenharia Civil UFSM Programa de Pós-Graduação em Engenharia Civil |
dc.source.none.fl_str_mv |
reponame:Manancial - Repositório Digital da UFSM instname:Universidade Federal de Santa Maria (UFSM) instacron:UFSM |
instname_str |
Universidade Federal de Santa Maria (UFSM) |
instacron_str |
UFSM |
institution |
UFSM |
reponame_str |
Manancial - Repositório Digital da UFSM |
collection |
Manancial - Repositório Digital da UFSM |
repository.name.fl_str_mv |
Manancial - Repositório Digital da UFSM - Universidade Federal de Santa Maria (UFSM) |
repository.mail.fl_str_mv |
atendimento.sib@ufsm.br||tedebc@gmail.com |
_version_ |
1805922137069846528 |