Effect of metakaolin pozzolanic activity in the early stages of cement type II paste and mortar hydration
Autor(a) principal: | |
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Data de Publicação: | 2008 |
Outros Autores: | , , |
Tipo de documento: | Artigo de conferência |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1007/s10973-007-8749-5 http://hdl.handle.net/11449/219458 |
Resumo: | The cement industry is one which most emits polluting gases to the environment, due to the calcium carbonate calcination, as well as to the burning of fossil fuels during the manufacturing process. Metakaolin (MK), in partial substitution to cement in its applications, is having a special worldwide growing role, for the technological increment due to its pozzolanic activity and mainly to the reduction of those emissions. In the present paper, the effect of pozzolanic activity of metakaolin was analyzed by thermal analysis in pastes and mortars of type II Portland cement in the first three days of the hydration, during which, relevant initial stages of the hydration process occur. By non-conventional differential thermal analysis (NCDTA), paste and mortar samples containing 0, 10, 20, 30 and 40% of metakaolin in cement mass substitution and using a 0.5 water/(total solids) mass ratio, were evaluated. The NCDTA curves, after normalization on cement mass basis and considering the heat capacity of each reactant, indicate that the pozzolanic activity behavior of metakaolin is different in pastes and mortars. Through the deconvolution of the normalized NCDTA curve peaks, it can be seen that ettringuite formation increases as cement substitution degree (CSD) increases, in both cases. Tobermorite formation is more enhanced in mortars than in pastes by MK, with a maximum formation at 30% of CSD. In the pastes, tobermorite formation increases as CSD increases but it is practically the same at 30 and 40% of CSD. © 2008 Springer Science+Business Media, LLC. |
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Effect of metakaolin pozzolanic activity in the early stages of cement type II paste and mortar hydrationCementMetakaolinMortarsNCDTAPastesPozzolanic activityThe cement industry is one which most emits polluting gases to the environment, due to the calcium carbonate calcination, as well as to the burning of fossil fuels during the manufacturing process. Metakaolin (MK), in partial substitution to cement in its applications, is having a special worldwide growing role, for the technological increment due to its pozzolanic activity and mainly to the reduction of those emissions. In the present paper, the effect of pozzolanic activity of metakaolin was analyzed by thermal analysis in pastes and mortars of type II Portland cement in the first three days of the hydration, during which, relevant initial stages of the hydration process occur. By non-conventional differential thermal analysis (NCDTA), paste and mortar samples containing 0, 10, 20, 30 and 40% of metakaolin in cement mass substitution and using a 0.5 water/(total solids) mass ratio, were evaluated. The NCDTA curves, after normalization on cement mass basis and considering the heat capacity of each reactant, indicate that the pozzolanic activity behavior of metakaolin is different in pastes and mortars. Through the deconvolution of the normalized NCDTA curve peaks, it can be seen that ettringuite formation increases as cement substitution degree (CSD) increases, in both cases. Tobermorite formation is more enhanced in mortars than in pastes by MK, with a maximum formation at 30% of CSD. In the pastes, tobermorite formation increases as CSD increases but it is practically the same at 30 and 40% of CSD. © 2008 Springer Science+Business Media, LLC.School of Chemistry Rio de Janeiro Federal University, BlocoE do CT Sala E206, Rio de Janeiro, RJ 21 949-900Department of Technology Feira de Santana State University Campus Universitário, Av. Universitária, s/n - Km 03 da BR 116, Feira de Santana 44031-460, BAChemical Engineering Department São Paulo State University, Avenida Professor Luciano Gualberto 380, São Paulo, SP 05424-970Chemical Engineering Department São Paulo State University, Avenida Professor Luciano Gualberto 380, São Paulo, SP 05424-970Rio de Janeiro Federal UniversityFeira de Santana State UniversityUniversidade Estadual Paulista (UNESP)Cherem Da Cunha, A. L.Gonçalves, J. P.Büchler, P. M. [UNESP]Dweck, J.2022-04-28T18:55:42Z2022-04-28T18:55:42Z2008-04-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/conferenceObject115-119http://dx.doi.org/10.1007/s10973-007-8749-5Journal of Thermal Analysis and Calorimetry, v. 92, n. 1, p. 115-119, 2008.1388-6150http://hdl.handle.net/11449/21945810.1007/s10973-007-8749-52-s2.0-44849136190Scopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengJournal of Thermal Analysis and Calorimetryinfo:eu-repo/semantics/openAccess2022-04-28T18:55:42Zoai:repositorio.unesp.br:11449/219458Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T16:00:18.056748Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Effect of metakaolin pozzolanic activity in the early stages of cement type II paste and mortar hydration |
title |
Effect of metakaolin pozzolanic activity in the early stages of cement type II paste and mortar hydration |
spellingShingle |
Effect of metakaolin pozzolanic activity in the early stages of cement type II paste and mortar hydration Cherem Da Cunha, A. L. Cement Metakaolin Mortars NCDTA Pastes Pozzolanic activity |
title_short |
Effect of metakaolin pozzolanic activity in the early stages of cement type II paste and mortar hydration |
title_full |
Effect of metakaolin pozzolanic activity in the early stages of cement type II paste and mortar hydration |
title_fullStr |
Effect of metakaolin pozzolanic activity in the early stages of cement type II paste and mortar hydration |
title_full_unstemmed |
Effect of metakaolin pozzolanic activity in the early stages of cement type II paste and mortar hydration |
title_sort |
Effect of metakaolin pozzolanic activity in the early stages of cement type II paste and mortar hydration |
author |
Cherem Da Cunha, A. L. |
author_facet |
Cherem Da Cunha, A. L. Gonçalves, J. P. Büchler, P. M. [UNESP] Dweck, J. |
author_role |
author |
author2 |
Gonçalves, J. P. Büchler, P. M. [UNESP] Dweck, J. |
author2_role |
author author author |
dc.contributor.none.fl_str_mv |
Rio de Janeiro Federal University Feira de Santana State University Universidade Estadual Paulista (UNESP) |
dc.contributor.author.fl_str_mv |
Cherem Da Cunha, A. L. Gonçalves, J. P. Büchler, P. M. [UNESP] Dweck, J. |
dc.subject.por.fl_str_mv |
Cement Metakaolin Mortars NCDTA Pastes Pozzolanic activity |
topic |
Cement Metakaolin Mortars NCDTA Pastes Pozzolanic activity |
description |
The cement industry is one which most emits polluting gases to the environment, due to the calcium carbonate calcination, as well as to the burning of fossil fuels during the manufacturing process. Metakaolin (MK), in partial substitution to cement in its applications, is having a special worldwide growing role, for the technological increment due to its pozzolanic activity and mainly to the reduction of those emissions. In the present paper, the effect of pozzolanic activity of metakaolin was analyzed by thermal analysis in pastes and mortars of type II Portland cement in the first three days of the hydration, during which, relevant initial stages of the hydration process occur. By non-conventional differential thermal analysis (NCDTA), paste and mortar samples containing 0, 10, 20, 30 and 40% of metakaolin in cement mass substitution and using a 0.5 water/(total solids) mass ratio, were evaluated. The NCDTA curves, after normalization on cement mass basis and considering the heat capacity of each reactant, indicate that the pozzolanic activity behavior of metakaolin is different in pastes and mortars. Through the deconvolution of the normalized NCDTA curve peaks, it can be seen that ettringuite formation increases as cement substitution degree (CSD) increases, in both cases. Tobermorite formation is more enhanced in mortars than in pastes by MK, with a maximum formation at 30% of CSD. In the pastes, tobermorite formation increases as CSD increases but it is practically the same at 30 and 40% of CSD. © 2008 Springer Science+Business Media, LLC. |
publishDate |
2008 |
dc.date.none.fl_str_mv |
2008-04-01 2022-04-28T18:55:42Z 2022-04-28T18:55:42Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/conferenceObject |
format |
conferenceObject |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://dx.doi.org/10.1007/s10973-007-8749-5 Journal of Thermal Analysis and Calorimetry, v. 92, n. 1, p. 115-119, 2008. 1388-6150 http://hdl.handle.net/11449/219458 10.1007/s10973-007-8749-5 2-s2.0-44849136190 |
url |
http://dx.doi.org/10.1007/s10973-007-8749-5 http://hdl.handle.net/11449/219458 |
identifier_str_mv |
Journal of Thermal Analysis and Calorimetry, v. 92, n. 1, p. 115-119, 2008. 1388-6150 10.1007/s10973-007-8749-5 2-s2.0-44849136190 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Journal of Thermal Analysis and Calorimetry |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
115-119 |
dc.source.none.fl_str_mv |
Scopus reponame:Repositório Institucional da UNESP instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Repositório Institucional da UNESP |
collection |
Repositório Institucional da UNESP |
repository.name.fl_str_mv |
Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
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1808128591546810368 |