Resistividade elétrica de concretos contendo diferentes teores de cinza de casca de arroz
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/1/7671 |
Resumo: | The durability of reinforced concrete structures derives from the protective effect provided by the concrete cover over the steel rebars. When the passivation of the steel is compromised, the whole structure is liable to corrosion phenomena, whose rate of propagation is mainly controlled by the electrical resistivity of the concrete between the anode and cathode and by the availability of oxygen at the cathode. The electrical resistivity of concrete is highly dependent on its physical and chemical characteristics. This study aimed at to investigate the influence of the content of rice husk ash (RHA) on the electrical resistivity of concrete and identify any correlations between electrical resistivity and compressive strength properties and changes in pore solution and pore structure. The mixtures in this study were prepared with water/binder ratios (w/b) of 0.35, 0.50 and 0.65 with RHA substitutions of 10%, 20% and 30% for cement. Samples with 50% blast furnace slag, 35% fly ash and a reference sample with 100% cement were also investigated. Electrical resistivity was determined using the four electrode method (Wenner s Method adapted for concrete). Tests of compressive strength, pore solution composition, pH e electrical condutivity, and mercury porosimetry were also performed. These indicate that that the age of the sample, the w/b ratio used and the mineral additions have a expressive effect on the electrical resistivity of concrete because of changes in the concrete pore structure and in the composition and volume of pore solution. Results show there is a exponential increase in concrete resistivity as the content of RHA grows. This is confirmed by the smaller size of the pore network and the lower specific conductivity of the pore solution, which show a sound correlation. The best results in electrical resistivity were obtained with content of 30% of RHA. The best cost/benefit ratio for compressive strength values of 65MPa and electrical resistivity of 30kΩ.cm was obtained with the use of 10% RHA and for compressive strength values of 65MPa and electrical resistivity of 60kΩ.cm, the best results were obtained with 20% RHA. |
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2007-12-072007-12-072005-10-21HOPPE, Tiago Fernandes. ELECTRICAL RESISTIVITY OF CONCRETE COMPOSITIONS WITH DIFFERENT CONTENTS OF RICE HUSK ASH. 2005. 147 f. Dissertação (Mestrado em Engenharia Civil) - Universidade Federal de Santa Maria, Santa Maria, 2005.http://repositorio.ufsm.br/handle/1/7671The durability of reinforced concrete structures derives from the protective effect provided by the concrete cover over the steel rebars. When the passivation of the steel is compromised, the whole structure is liable to corrosion phenomena, whose rate of propagation is mainly controlled by the electrical resistivity of the concrete between the anode and cathode and by the availability of oxygen at the cathode. The electrical resistivity of concrete is highly dependent on its physical and chemical characteristics. This study aimed at to investigate the influence of the content of rice husk ash (RHA) on the electrical resistivity of concrete and identify any correlations between electrical resistivity and compressive strength properties and changes in pore solution and pore structure. The mixtures in this study were prepared with water/binder ratios (w/b) of 0.35, 0.50 and 0.65 with RHA substitutions of 10%, 20% and 30% for cement. Samples with 50% blast furnace slag, 35% fly ash and a reference sample with 100% cement were also investigated. Electrical resistivity was determined using the four electrode method (Wenner s Method adapted for concrete). Tests of compressive strength, pore solution composition, pH e electrical condutivity, and mercury porosimetry were also performed. These indicate that that the age of the sample, the w/b ratio used and the mineral additions have a expressive effect on the electrical resistivity of concrete because of changes in the concrete pore structure and in the composition and volume of pore solution. Results show there is a exponential increase in concrete resistivity as the content of RHA grows. This is confirmed by the smaller size of the pore network and the lower specific conductivity of the pore solution, which show a sound correlation. The best results in electrical resistivity were obtained with content of 30% of RHA. The best cost/benefit ratio for compressive strength values of 65MPa and electrical resistivity of 30kΩ.cm was obtained with the use of 10% RHA and for compressive strength values of 65MPa and electrical resistivity of 60kΩ.cm, the best results were obtained with 20% RHA.A durabilidade das estruturas de concreto armado é resultado da ação protetora do concreto sobre o aço. Quando a passivação do aço deixa de existir, a estrutura torna-se vulnerável ao fenômeno da corrosão, cuja propagação, após iniciada, é essencialmente controlada pela resistividade elétrica do concreto entre o ânodo e o cátodo e pela disponibilidade de oxigênio no cátodo. A resistividade elétrica do concreto é uma propriedade extremamente sensível às características físicas e químicas do mesmo. O presente trabalho buscou investigar a influência do teor de cinza de casca de arroz (CCA) na resistividade elétrica do concreto, bem como correlacionar os resultados obtidos com a resistência à compressão axial e alterações na composição da solução aquosa e estrutura dos poros. Foram investigadas misturas com relações água/aglomerante (a/ag) 0,35 , 0,50 e 0,65 com teores de substituição em massa de 10%, 20% e 30% de CCA. Para comparar os resultados, misturas com 50% de escória de alto forno, 35% de cinza volante e uma mistura de referência com 100% de cimento foram simultaneamente investigadas. A resistividade elétrica foi determinada utilizando o método dos quatro eletrodos (método de Wenner, adaptado para uso em concreto). Paralelamente, foram realizados ensaios de resistência à compressão axial, composição, pH e condutividade elétrica específica da solução aquosa dos poros e porosimetria por intrusão de mercúrio. Verificou-se que a idade, a relação a/ag e as adições minerais mostraram uma influência expressiva na resistividade elétrica do concreto, em virtude principalmente das alterações na estrutura dos poros e na quantidade e composição da solução dos mesmos. Os resultados mostraram um crescimento exponencial na resistividade do concreto com o aumento do teor de CCA. Tal fato foi confirmado pelo maior refinamento dos poros e menor condutividade específica da solução dos mesmos, mostrando haver uma ótima correlação entre estes fatores. Assim, os melhores resultados na resistividade elétrica foram obtidos com o teor de 30% de CCA. A melhor relação CUSTO/BENEFÍCIO, para 65MPa de resistência à compressão e 30kΩ.cm de resistividade elétrica, foi obtida com 10% de CCA e, para 65MPa e 60kΩ.cm, os melhores resultados foram atingidos com 20% desta adição.application/pdfporUniversidade Federal de Santa MariaPrograma de Pós-Graduação em Engenharia CivilUFSMBREngenharia CivilConcretoCinza de casca de arrozAdições mineraisResistividade elétricaConcreteRice husk ashMineral additionsElectrical resistivityCNPQ::ENGENHARIAS::ENGENHARIA CIVILResistividade elétrica de concretos contendo diferentes teores de cinza de casca de arrozElectrical resistivity of concrete compositions with different contents of rice husk ashinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisGastaldini, Antonio Luiz Guerrahttp://lattes.cnpq.br/9293085240832049Isaia, Geraldo Cechellahttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4787985U6Kazmierczak, Claudio de Souzahttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4787715T4http://lattes.cnpq.br/0267879087357443Hoppe, Tiago Fernandes3001000000034003003003003006a6bd4d6-e9f2-46f6-9245-5aefb19c7a2896296198-fb8d-4901-8d68-ba5ddb7f3a1a77820f74-3115-4fb7-ad76-0c65fc11b1c915e1730c-aa0f-48ec-964e-73c3c2d36f6cinfo:eu-repo/semantics/openAccessreponame:Manancial - Repositório Digital da UFSMinstname:Universidade Federal de Santa Maria (UFSM)instacron:UFSMORIGINALTIAGO HOPPE.pdfapplication/pdf4448693http://repositorio.ufsm.br/bitstream/1/7671/1/TIAGO%20HOPPE.pdfb29d459ecffb46151af5ca7cf58ea016MD51TEXTTIAGO HOPPE.pdf.txtTIAGO HOPPE.pdf.txtExtracted texttext/plain242050http://repositorio.ufsm.br/bitstream/1/7671/2/TIAGO%20HOPPE.pdf.txtb4cae25381ac35095c1ba235dc965c43MD52THUMBNAILTIAGO HOPPE.pdf.jpgTIAGO HOPPE.pdf.jpgIM Thumbnailimage/jpeg5054http://repositorio.ufsm.br/bitstream/1/7671/3/TIAGO%20HOPPE.pdf.jpg540d2b2667549efb114bd12acc31e7b7MD531/76712021-09-28 19:15:02.174oai:repositorio.ufsm.br:1/7671Repositório Institucionalhttp://repositorio.ufsm.br/PUBhttp://repositorio.ufsm.br/oai/requestopendoar:39132021-09-28T22:15:02Manancial - Repositório Digital da UFSM - Universidade Federal de Santa Maria (UFSM)false |
dc.title.por.fl_str_mv |
Resistividade elétrica de concretos contendo diferentes teores de cinza de casca de arroz |
dc.title.alternative.eng.fl_str_mv |
Electrical resistivity of concrete compositions with different contents of rice husk ash |
title |
Resistividade elétrica de concretos contendo diferentes teores de cinza de casca de arroz |
spellingShingle |
Resistividade elétrica de concretos contendo diferentes teores de cinza de casca de arroz Hoppe, Tiago Fernandes Concreto Cinza de casca de arroz Adições minerais Resistividade elétrica Concrete Rice husk ash Mineral additions Electrical resistivity CNPQ::ENGENHARIAS::ENGENHARIA CIVIL |
title_short |
Resistividade elétrica de concretos contendo diferentes teores de cinza de casca de arroz |
title_full |
Resistividade elétrica de concretos contendo diferentes teores de cinza de casca de arroz |
title_fullStr |
Resistividade elétrica de concretos contendo diferentes teores de cinza de casca de arroz |
title_full_unstemmed |
Resistividade elétrica de concretos contendo diferentes teores de cinza de casca de arroz |
title_sort |
Resistividade elétrica de concretos contendo diferentes teores de cinza de casca de arroz |
author |
Hoppe, Tiago Fernandes |
author_facet |
Hoppe, Tiago Fernandes |
author_role |
author |
dc.contributor.advisor1.fl_str_mv |
Gastaldini, Antonio Luiz Guerra |
dc.contributor.advisor1Lattes.fl_str_mv |
http://lattes.cnpq.br/9293085240832049 |
dc.contributor.referee1.fl_str_mv |
Isaia, Geraldo Cechella |
dc.contributor.referee1Lattes.fl_str_mv |
http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4787985U6 |
dc.contributor.referee2.fl_str_mv |
Kazmierczak, Claudio de Souza |
dc.contributor.referee2Lattes.fl_str_mv |
http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4787715T4 |
dc.contributor.authorLattes.fl_str_mv |
http://lattes.cnpq.br/0267879087357443 |
dc.contributor.author.fl_str_mv |
Hoppe, Tiago Fernandes |
contributor_str_mv |
Gastaldini, Antonio Luiz Guerra Isaia, Geraldo Cechella Kazmierczak, Claudio de Souza |
dc.subject.por.fl_str_mv |
Concreto Cinza de casca de arroz Adições minerais Resistividade elétrica |
topic |
Concreto Cinza de casca de arroz Adições minerais Resistividade elétrica Concrete Rice husk ash Mineral additions Electrical resistivity CNPQ::ENGENHARIAS::ENGENHARIA CIVIL |
dc.subject.eng.fl_str_mv |
Concrete Rice husk ash Mineral additions Electrical resistivity |
dc.subject.cnpq.fl_str_mv |
CNPQ::ENGENHARIAS::ENGENHARIA CIVIL |
description |
The durability of reinforced concrete structures derives from the protective effect provided by the concrete cover over the steel rebars. When the passivation of the steel is compromised, the whole structure is liable to corrosion phenomena, whose rate of propagation is mainly controlled by the electrical resistivity of the concrete between the anode and cathode and by the availability of oxygen at the cathode. The electrical resistivity of concrete is highly dependent on its physical and chemical characteristics. This study aimed at to investigate the influence of the content of rice husk ash (RHA) on the electrical resistivity of concrete and identify any correlations between electrical resistivity and compressive strength properties and changes in pore solution and pore structure. The mixtures in this study were prepared with water/binder ratios (w/b) of 0.35, 0.50 and 0.65 with RHA substitutions of 10%, 20% and 30% for cement. Samples with 50% blast furnace slag, 35% fly ash and a reference sample with 100% cement were also investigated. Electrical resistivity was determined using the four electrode method (Wenner s Method adapted for concrete). Tests of compressive strength, pore solution composition, pH e electrical condutivity, and mercury porosimetry were also performed. These indicate that that the age of the sample, the w/b ratio used and the mineral additions have a expressive effect on the electrical resistivity of concrete because of changes in the concrete pore structure and in the composition and volume of pore solution. Results show there is a exponential increase in concrete resistivity as the content of RHA grows. This is confirmed by the smaller size of the pore network and the lower specific conductivity of the pore solution, which show a sound correlation. The best results in electrical resistivity were obtained with content of 30% of RHA. The best cost/benefit ratio for compressive strength values of 65MPa and electrical resistivity of 30kΩ.cm was obtained with the use of 10% RHA and for compressive strength values of 65MPa and electrical resistivity of 60kΩ.cm, the best results were obtained with 20% RHA. |
publishDate |
2005 |
dc.date.issued.fl_str_mv |
2005-10-21 |
dc.date.accessioned.fl_str_mv |
2007-12-07 |
dc.date.available.fl_str_mv |
2007-12-07 |
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.citation.fl_str_mv |
HOPPE, Tiago Fernandes. ELECTRICAL RESISTIVITY OF CONCRETE COMPOSITIONS WITH DIFFERENT CONTENTS OF RICE HUSK ASH. 2005. 147 f. Dissertação (Mestrado em Engenharia Civil) - Universidade Federal de Santa Maria, Santa Maria, 2005. |
dc.identifier.uri.fl_str_mv |
http://repositorio.ufsm.br/handle/1/7671 |
identifier_str_mv |
HOPPE, Tiago Fernandes. ELECTRICAL RESISTIVITY OF CONCRETE COMPOSITIONS WITH DIFFERENT CONTENTS OF RICE HUSK ASH. 2005. 147 f. Dissertação (Mestrado em Engenharia Civil) - Universidade Federal de Santa Maria, Santa Maria, 2005. |
url |
http://repositorio.ufsm.br/handle/1/7671 |
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Universidade Federal de Santa Maria |
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Engenharia Civil |
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Universidade Federal de Santa Maria |
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