Material Alcalinamente Ativado (MAA) de metacaulinita sintetizado a partir das espécies alcalinas do tipo sódio e potássio
Autor(a) principal: | |
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Data de Publicação: | 2021 |
Tipo de documento: | Tese |
Idioma: | por |
Título da fonte: | Biblioteca Digital de Teses e Dissertações da UFPB |
Texto Completo: | https://repositorio.ufpb.br/jspui/handle/123456789/23402 |
Resumo: | New materials have been developed seeking to minimize negative effects on the environment, especially in the field of cementitious materials, alkaline activated materials (AAM). These have been shown to be an economically viable alternative that may contribute to reducing the environmental impact of construction in general. The raw material for the production of this material must be rich in silica and alumina in amorphous form. In this work, metakaolinite was chosen because it is a locally available material, relatively easy to obtain and low production cost. The efficiency of activation depends on the chemical and mineralogical composition of the raw material, as well as the molar ratios of the components and the curing conditions. Alkaline activators were defined as sodium and potassium hydroxides and silicates. Although there are already works in this field, here the research sought to advance by studying the formation of silicoaluminous species of the (AAM) at curing temperatures of 38.5oC and 50oC, lower than those commonly indicated, and using also the molarity of alkaline activators equal to 8, which corresponds to about half of what is considered ―ideal‖ by the literature. This is to reduce the energy costs of chemicals. The behavior of MAA was evaluated when subjected to thermal curing at temperatures indicated for periods of 3, 7, 28, 56 and 91 days. The generated AAM's were sprayed and characterized by physical-chemical tests using X-ray diffraction and fluorescence techniques (DRX and FRX), as well as by thermographic tests, infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and electron microscopy by scanning (MEV). In addition to these, the mechanical performance of AAM‘s was obtained in tests of resistance to compression, whose results were analyzed statistically through ANOVA. The characterization results made it possible to know the physical-chemical and microstructural characteristics of the products, as well as their reaction process. Using Fourier transformation infrared spectroscopy it was possible to identify the reactive potential of the samples. The results of compressive strength were worked from the influence of alkaline activators (NaOH and KOH); the different temperatures (38.5 °C and 50 °C); of curing time at ages 3, 7, 28, 56 and 91 days and indicated that there was no differentiation in the variability of resistances in relation to the alkaline activators used. For NaOH, there was an oscillation from 19.88 MPa (3 days) to 6.16 MPa (91 days) at a temperature of 38.5 ºC, and 19.45 MPa to 6.03 MPa (3 days and 91 days respectively) at temperature of 50 ºC. For KOH, the variation was 12.47 MPa (28 days) to 6.62 (91 days) at 38.5 ºC and, at 50 °C, 11.88 MPa (28 days) to 9,05 MPa (91 days). Taking into account the curing times, it is noticeable that when the curing time increases, the resistance of the products tends to decrease. Finally, statistically, in the resistance associated with the temperature, the results achieved at a temperature of 50 ºC were higher than that of 38.5 ºC. In this context, the developed AAM´s present themselves as products that promise significant performance in civil construction as sealing or interlocking blocks, with the advantage of being able to be prepared with a lowest mass percentage, low temperature, in shorter curing time and with a precursor of easy and abundant access, thus becoming a product less aggressive to the environment. |
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Material Alcalinamente Ativado (MAA) de metacaulinita sintetizado a partir das espécies alcalinas do tipo sódio e potássioAtivação alcalinaMetacaulimMAAGeopolímerosMeio ambienteAlkaline activationMetakaolinAAMGeopolymersEnvironmentCNPQ::ENGENHARIASNew materials have been developed seeking to minimize negative effects on the environment, especially in the field of cementitious materials, alkaline activated materials (AAM). These have been shown to be an economically viable alternative that may contribute to reducing the environmental impact of construction in general. The raw material for the production of this material must be rich in silica and alumina in amorphous form. In this work, metakaolinite was chosen because it is a locally available material, relatively easy to obtain and low production cost. The efficiency of activation depends on the chemical and mineralogical composition of the raw material, as well as the molar ratios of the components and the curing conditions. Alkaline activators were defined as sodium and potassium hydroxides and silicates. Although there are already works in this field, here the research sought to advance by studying the formation of silicoaluminous species of the (AAM) at curing temperatures of 38.5oC and 50oC, lower than those commonly indicated, and using also the molarity of alkaline activators equal to 8, which corresponds to about half of what is considered ―ideal‖ by the literature. This is to reduce the energy costs of chemicals. The behavior of MAA was evaluated when subjected to thermal curing at temperatures indicated for periods of 3, 7, 28, 56 and 91 days. The generated AAM's were sprayed and characterized by physical-chemical tests using X-ray diffraction and fluorescence techniques (DRX and FRX), as well as by thermographic tests, infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and electron microscopy by scanning (MEV). In addition to these, the mechanical performance of AAM‘s was obtained in tests of resistance to compression, whose results were analyzed statistically through ANOVA. The characterization results made it possible to know the physical-chemical and microstructural characteristics of the products, as well as their reaction process. Using Fourier transformation infrared spectroscopy it was possible to identify the reactive potential of the samples. The results of compressive strength were worked from the influence of alkaline activators (NaOH and KOH); the different temperatures (38.5 °C and 50 °C); of curing time at ages 3, 7, 28, 56 and 91 days and indicated that there was no differentiation in the variability of resistances in relation to the alkaline activators used. For NaOH, there was an oscillation from 19.88 MPa (3 days) to 6.16 MPa (91 days) at a temperature of 38.5 ºC, and 19.45 MPa to 6.03 MPa (3 days and 91 days respectively) at temperature of 50 ºC. For KOH, the variation was 12.47 MPa (28 days) to 6.62 (91 days) at 38.5 ºC and, at 50 °C, 11.88 MPa (28 days) to 9,05 MPa (91 days). Taking into account the curing times, it is noticeable that when the curing time increases, the resistance of the products tends to decrease. Finally, statistically, in the resistance associated with the temperature, the results achieved at a temperature of 50 ºC were higher than that of 38.5 ºC. In this context, the developed AAM´s present themselves as products that promise significant performance in civil construction as sealing or interlocking blocks, with the advantage of being able to be prepared with a lowest mass percentage, low temperature, in shorter curing time and with a precursor of easy and abundant access, thus becoming a product less aggressive to the environment.NenhumaNovos materiais têm sido desenvolvidos buscando minimizar efeitos negativos no meio ambiente, destacando-se, no campo dos materiais cimentícios, os materiais alcalinamente ativados (MAA). Estes têm se mostrado uma alternativa economicamente viável que pode vir a contribuir para a redução do impacto ambiental da construção em geral. A matéria prima para a produção deste material deve ser rica em sílica e alumina na forma amorfa. Neste trabalho, optou-se pela metacaulinita por se tratar de material disponível localmente, de relativamente fácil obtenção e baixo custo de produção. A eficiência da ativação depende da composição química e mineralógica da matéria prima, assim como das razões molares dos componentes e das condições de cura. Definiu-se como ativadores alcalinos os hidróxidos e silicatos de sódio e de potássio. Embora já existam trabalhos nesse campo, aqui, porém, se procurou avançar estudando a formação de espécies silico-aluminosas do (MAA) em temperaturas de cura de 38,5 oC e 50 oC, inferiores às indicadas comumente, e também usando a molaridade dos ativadores alcalinos igual a 8, que corresponde a cerca de metade do que é considerado ―ideal‖ pela literatura. Isto para se reduzir os custos energéticos dos produtos químicos. Foi avaliado o comportamento do MAA quando submetido à cura térmica nas temperaturas indicadas por períodos de 3, 7, 28, 56 e 91 dias. Os MAA‘s gerados foram pulverizados e caracterizados por ensaios físico-químicos utilizando técnicas de difração e fluorescência de raio X (DRX e FRX), assim como por ensaios termográficos, espectroscopia na região do infravermelho (FTIR), análise termogravimétrica (TGA) e microscopia eletrônica por varredura (MEV). Além destes, o desempenho mecânico dos MAA‘s foi obtido em ensaios de resistência à compressão, cujos resultados foram analisados estatisticamente através da ANOVA. Os resultados da caracterização permitiram conhecer as características físico-químicas e microestrutural dos produtos, bem como seu processo de reação. Na espectroscopia de infravermelho por transformada de Fourier foi possível identificar o potencial reativo das amostras. Os resultados de resistência à compressão foram trabalhados a partir da influência dos ativadores alcalinos (NaOH e KOH); das distintas temperaturas (38,5°C e 50°C); do tempo de cura nas idades de 3, 7, 28, 56 e 91 dias e indicaram que não houve diferenciação na variabilidade das resistências com relação aos ativadores alcalinos utilizados. Para o NaOH, houve oscilação de 19,88 MPa (3 dias) a 6,16 MPa (91 dias) na temperatura de 38,5 ºC, e de 19,45 MPa a 6,03 MPa (3 dias e 91 dias respectivamente) na temperatura de 50 ºC. Já para o KOH, a variação foi de 12,47 MPa (28 dias) a 6,62 (91 dias) a 38,5 ºC e, na temperatura de 50 °C, 11,88 MPa (28 dias) a 9,05 MPa (91 dias). Levando em consideração o tempo de cura, é perceptível que à medida que ele aumenta, a resistência dos produtos tende a diminuir. Por fim, estatisticamente, na resistência associada à temperatura, os resultados alcançados na temperatura 50 ºC foram superiores à de 38,5 ºC. Neste contexto, os MAAs desenvolvidos se apresentam como produtos que têm potencial para serem usados na construção civil como blocos para vedação ou blocos intertravados, com a vantagem de poderem ser elaborados com menor percentual de massa, baixa temperatura, em menor tempo de cura e com um precursor de fácil acesso e abundante tornando-se, assim, um produto menos agressivo ao meio ambiente.Universidade Federal da ParaíbaBrasilEngenharia de MateriaisPrograma de Pós-Graduação em Ciência e Engenharia de MateriaisUFPBBarbosa, Normando Perazzohttp://lattes.cnpq.br/6420367558476872Silva, Kelly Cristiane Gomes dahttp://lattes.cnpq.br/0678485152961068Egito, Maria Jacy Caju do2022-07-11T17:46:59Z2022-01-102022-07-11T17:46:59Z2021-02-26info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesishttps://repositorio.ufpb.br/jspui/handle/123456789/23402porAttribution-NoDerivs 3.0 Brazilhttp://creativecommons.org/licenses/by-nd/3.0/br/info:eu-repo/semantics/openAccessreponame:Biblioteca Digital de Teses e Dissertações da UFPBinstname:Universidade Federal da Paraíba (UFPB)instacron:UFPB2022-08-09T12:42:38Zoai:repositorio.ufpb.br:123456789/23402Biblioteca Digital de Teses e Dissertaçõeshttps://repositorio.ufpb.br/PUBhttp://tede.biblioteca.ufpb.br:8080/oai/requestdiretoria@ufpb.br|| diretoria@ufpb.bropendoar:2022-08-09T12:42:38Biblioteca Digital de Teses e Dissertações da UFPB - Universidade Federal da Paraíba (UFPB)false |
dc.title.none.fl_str_mv |
Material Alcalinamente Ativado (MAA) de metacaulinita sintetizado a partir das espécies alcalinas do tipo sódio e potássio |
title |
Material Alcalinamente Ativado (MAA) de metacaulinita sintetizado a partir das espécies alcalinas do tipo sódio e potássio |
spellingShingle |
Material Alcalinamente Ativado (MAA) de metacaulinita sintetizado a partir das espécies alcalinas do tipo sódio e potássio Egito, Maria Jacy Caju do Ativação alcalina Metacaulim MAA Geopolímeros Meio ambiente Alkaline activation Metakaolin AAM Geopolymers Environment CNPQ::ENGENHARIAS |
title_short |
Material Alcalinamente Ativado (MAA) de metacaulinita sintetizado a partir das espécies alcalinas do tipo sódio e potássio |
title_full |
Material Alcalinamente Ativado (MAA) de metacaulinita sintetizado a partir das espécies alcalinas do tipo sódio e potássio |
title_fullStr |
Material Alcalinamente Ativado (MAA) de metacaulinita sintetizado a partir das espécies alcalinas do tipo sódio e potássio |
title_full_unstemmed |
Material Alcalinamente Ativado (MAA) de metacaulinita sintetizado a partir das espécies alcalinas do tipo sódio e potássio |
title_sort |
Material Alcalinamente Ativado (MAA) de metacaulinita sintetizado a partir das espécies alcalinas do tipo sódio e potássio |
author |
Egito, Maria Jacy Caju do |
author_facet |
Egito, Maria Jacy Caju do |
author_role |
author |
dc.contributor.none.fl_str_mv |
Barbosa, Normando Perazzo http://lattes.cnpq.br/6420367558476872 Silva, Kelly Cristiane Gomes da http://lattes.cnpq.br/0678485152961068 |
dc.contributor.author.fl_str_mv |
Egito, Maria Jacy Caju do |
dc.subject.por.fl_str_mv |
Ativação alcalina Metacaulim MAA Geopolímeros Meio ambiente Alkaline activation Metakaolin AAM Geopolymers Environment CNPQ::ENGENHARIAS |
topic |
Ativação alcalina Metacaulim MAA Geopolímeros Meio ambiente Alkaline activation Metakaolin AAM Geopolymers Environment CNPQ::ENGENHARIAS |
description |
New materials have been developed seeking to minimize negative effects on the environment, especially in the field of cementitious materials, alkaline activated materials (AAM). These have been shown to be an economically viable alternative that may contribute to reducing the environmental impact of construction in general. The raw material for the production of this material must be rich in silica and alumina in amorphous form. In this work, metakaolinite was chosen because it is a locally available material, relatively easy to obtain and low production cost. The efficiency of activation depends on the chemical and mineralogical composition of the raw material, as well as the molar ratios of the components and the curing conditions. Alkaline activators were defined as sodium and potassium hydroxides and silicates. Although there are already works in this field, here the research sought to advance by studying the formation of silicoaluminous species of the (AAM) at curing temperatures of 38.5oC and 50oC, lower than those commonly indicated, and using also the molarity of alkaline activators equal to 8, which corresponds to about half of what is considered ―ideal‖ by the literature. This is to reduce the energy costs of chemicals. The behavior of MAA was evaluated when subjected to thermal curing at temperatures indicated for periods of 3, 7, 28, 56 and 91 days. The generated AAM's were sprayed and characterized by physical-chemical tests using X-ray diffraction and fluorescence techniques (DRX and FRX), as well as by thermographic tests, infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and electron microscopy by scanning (MEV). In addition to these, the mechanical performance of AAM‘s was obtained in tests of resistance to compression, whose results were analyzed statistically through ANOVA. The characterization results made it possible to know the physical-chemical and microstructural characteristics of the products, as well as their reaction process. Using Fourier transformation infrared spectroscopy it was possible to identify the reactive potential of the samples. The results of compressive strength were worked from the influence of alkaline activators (NaOH and KOH); the different temperatures (38.5 °C and 50 °C); of curing time at ages 3, 7, 28, 56 and 91 days and indicated that there was no differentiation in the variability of resistances in relation to the alkaline activators used. For NaOH, there was an oscillation from 19.88 MPa (3 days) to 6.16 MPa (91 days) at a temperature of 38.5 ºC, and 19.45 MPa to 6.03 MPa (3 days and 91 days respectively) at temperature of 50 ºC. For KOH, the variation was 12.47 MPa (28 days) to 6.62 (91 days) at 38.5 ºC and, at 50 °C, 11.88 MPa (28 days) to 9,05 MPa (91 days). Taking into account the curing times, it is noticeable that when the curing time increases, the resistance of the products tends to decrease. Finally, statistically, in the resistance associated with the temperature, the results achieved at a temperature of 50 ºC were higher than that of 38.5 ºC. In this context, the developed AAM´s present themselves as products that promise significant performance in civil construction as sealing or interlocking blocks, with the advantage of being able to be prepared with a lowest mass percentage, low temperature, in shorter curing time and with a precursor of easy and abundant access, thus becoming a product less aggressive to the environment. |
publishDate |
2021 |
dc.date.none.fl_str_mv |
2021-02-26 2022-07-11T17:46:59Z 2022-01-10 2022-07-11T17:46:59Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/doctoralThesis |
format |
doctoralThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
https://repositorio.ufpb.br/jspui/handle/123456789/23402 |
url |
https://repositorio.ufpb.br/jspui/handle/123456789/23402 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.rights.driver.fl_str_mv |
Attribution-NoDerivs 3.0 Brazil http://creativecommons.org/licenses/by-nd/3.0/br/ info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
Attribution-NoDerivs 3.0 Brazil http://creativecommons.org/licenses/by-nd/3.0/br/ |
eu_rights_str_mv |
openAccess |
dc.publisher.none.fl_str_mv |
Universidade Federal da Paraíba Brasil Engenharia de Materiais Programa de Pós-Graduação em Ciência e Engenharia de Materiais UFPB |
publisher.none.fl_str_mv |
Universidade Federal da Paraíba Brasil Engenharia de Materiais Programa de Pós-Graduação em Ciência e Engenharia de Materiais UFPB |
dc.source.none.fl_str_mv |
reponame:Biblioteca Digital de Teses e Dissertações da UFPB instname:Universidade Federal da Paraíba (UFPB) instacron:UFPB |
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Universidade Federal da Paraíba (UFPB) |
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UFPB |
institution |
UFPB |
reponame_str |
Biblioteca Digital de Teses e Dissertações da UFPB |
collection |
Biblioteca Digital de Teses e Dissertações da UFPB |
repository.name.fl_str_mv |
Biblioteca Digital de Teses e Dissertações da UFPB - Universidade Federal da Paraíba (UFPB) |
repository.mail.fl_str_mv |
diretoria@ufpb.br|| diretoria@ufpb.br |
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1801842995932168192 |