Propriedades reológicas na detecção do caráter coeso em solos
Autor(a) principal: | |
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Data de Publicação: | 2021 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Manancial - Repositório Digital da UFSM |
Texto Completo: | http://repositorio.ufsm.br/handle/1/24374 |
Resumo: | The cohesive character has been evaluated primarily in the field, where a pedologist is capable to recognize it rather easily. However, there is a problem of subjectivity and lack of metrics for characterization, so research has been done in order to address this doubt with quantitative methods measured so far in the meso-scale. It is known that adhesion and cohesion processes originate at the micro scale, that is, in the interactions between particles, and a useful method to analyze the micro scale but not yet tested, is through rheometry. The objective of this study was then to evaluate whether rheological properties, obtained in amplitude sweep tests under oscillatory shear conditions, are able to detect the cohesive character and thus contribute to improve the understanding of cohesiveness in these soils. In a rotational rheometer, samples of six soil types were evaluated at three different positions in the profile (top, middle, and bottom), with and without cohesive character. Several soil rheological properties were determined: strain at the end of the linear viscoelastic range, LVR range (γLVR), shear stress at the end of the LVR range (τLVR), strain at the yield point (YP) (γYP), storage and loss modulus at YP (G'G”YP), maximum shear stress (τmax), strain at maximum shear stress (γ τ max), and z integral (Iz). In this study, only a few rheological properties had a significant effect on detecting the cohesive character of the soil, in general with higher values for cohesive soils compared to non-cohesive soils, indicating that cohesive soils are more stable. While cohesion affected only the γ base position of the rheological properties at the end of the LVR range, it had a significant effect on the τmax and γ τ max properties, in the top and middle positions, respectively. In addition, three materials did not reach the pour point. For the integral z, cohesive soils showed both lower and higher values than non-cohesive soils. Greater Iz in non-cohesive soils seems to be linked to a small expansion, a consequence of the high friction between the particles. In this sense, τmax and Iz were the properties that had a significant double interaction between the factors analyzed. The type of soil had the greatest effect on the rheological properties, being, in general, the PVAd soil with the highest values. Within the other soil properties studied, iron, organic carbon and clay content, density, and normal force at test initiation had the greatest impact on rheology. The evaluated mesoscale property, tensile strength, showed the closest relationship with γ τ max and τmax. It is concluded that rheometry can help identify the cohesive character supporting other analyses, but for an independent evaluation, more tests, especially at different water contents, are needed. |
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Propriedades reológicas na detecção do caráter coeso em solosReological properties in detection of the cohesiveness character in soilsReometriaSolo coesoCisalhamento oscilatórioSolos intemperizadosSolos hardsettingRheometryCohesive soilOscillatory shearWeathered soilsHardsetting soilsCNPQ::CIENCIAS AGRARIAS::AGRONOMIA::CIENCIA DO SOLOThe cohesive character has been evaluated primarily in the field, where a pedologist is capable to recognize it rather easily. However, there is a problem of subjectivity and lack of metrics for characterization, so research has been done in order to address this doubt with quantitative methods measured so far in the meso-scale. It is known that adhesion and cohesion processes originate at the micro scale, that is, in the interactions between particles, and a useful method to analyze the micro scale but not yet tested, is through rheometry. The objective of this study was then to evaluate whether rheological properties, obtained in amplitude sweep tests under oscillatory shear conditions, are able to detect the cohesive character and thus contribute to improve the understanding of cohesiveness in these soils. In a rotational rheometer, samples of six soil types were evaluated at three different positions in the profile (top, middle, and bottom), with and without cohesive character. Several soil rheological properties were determined: strain at the end of the linear viscoelastic range, LVR range (γLVR), shear stress at the end of the LVR range (τLVR), strain at the yield point (YP) (γYP), storage and loss modulus at YP (G'G”YP), maximum shear stress (τmax), strain at maximum shear stress (γ τ max), and z integral (Iz). In this study, only a few rheological properties had a significant effect on detecting the cohesive character of the soil, in general with higher values for cohesive soils compared to non-cohesive soils, indicating that cohesive soils are more stable. While cohesion affected only the γ base position of the rheological properties at the end of the LVR range, it had a significant effect on the τmax and γ τ max properties, in the top and middle positions, respectively. In addition, three materials did not reach the pour point. For the integral z, cohesive soils showed both lower and higher values than non-cohesive soils. Greater Iz in non-cohesive soils seems to be linked to a small expansion, a consequence of the high friction between the particles. In this sense, τmax and Iz were the properties that had a significant double interaction between the factors analyzed. The type of soil had the greatest effect on the rheological properties, being, in general, the PVAd soil with the highest values. Within the other soil properties studied, iron, organic carbon and clay content, density, and normal force at test initiation had the greatest impact on rheology. The evaluated mesoscale property, tensile strength, showed the closest relationship with γ τ max and τmax. It is concluded that rheometry can help identify the cohesive character supporting other analyses, but for an independent evaluation, more tests, especially at different water contents, are needed.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESO caráter coeso tem sido avaliado primeiramente à campo, onde o pedólogo faz o seu reconhecimento rápido, no entanto, há o problema da subjetividade e a falta de métricas para a caracterização. Por isso, pesquisas vêm sendo feitas no sentido de sanar essa dúvida com métodos quantitativos medidos até então na mesoescala. Conhecido é que os processos de adesão e coesão possuem origem na microescala, isto é, nas interações entre partículas, e um método útil para analisar a microescala e ainda não testado, é por meio reometria. O objetivo deste estudo foi então avaliar se as propriedades reológicas, obtidas em testes de varredura de amplitude sob condições de cisalhamento oscilatório, são capazes de detectar o caráter coeso e, assim, contribuir para melhorar o entendimento da coesividade nesses solos. Em um reômetro rotacional, foram avaliadas amostras de seis tipos de solos, em três posições diferentes no perfil (topo, meio e base), com e sem caráter coeso. Várias propriedades reológicas do solo foram determinadas: deformação no final do intervalo viscoelástico linear, faixa do LVR (γLVR), tensão de cisalhamento no final da faixa do LVR (τLVR), deformação no ponto de escoamento (“yield point”, YP) (γYP), módulos de armazenamento e perda em YP (G'G”YP), tensão máxima de cisalhamento (τmax), deformação na tensão máxima de cisalhamento (γ τ max) e integral z (Iz). Neste estudo, apenas algumas propriedades reológicas apresentaram efeito significativo na detecção do caráter coeso do solo, em geral com valores maiores para solos coesos em comparação com os não coesos, indicando que os solos coesos são mais estáveis. Enquanto que a coesão afetou somente na posição base da γ das propriedades reológicas no fim da faixa LVR, ela teve um efeito significativo nas propriedades τmax e γ τ max, nas posições topo e meio, respectivamente. Além disso, três materiais não atingiram o ponto de escoamento. Para a integral z, solos coesos apresentaram ambos menores e maiores valores que solos não coesos. Iz maior em solos não coesos parece estar ligado a uma pequena dilatação, consequência do atrito alto entre as partículas. Nesse sentido, a τmax e a Iz foram as propriedades que tiveram interação dupla significativa entre os fatores analisados. O tipo de solo teve maior efeito nas propriedades reológicas, sendo, em geral, o solo PVAd com maiores valores. Dentro das demais propriedades dos solos estudados, o teor de ferro, carbono orgânico e de argila, a densidade e a força normal no início do teste tiverem o maior impacto na reologia. A propriedade da mesoescala avaliada, a resistência tênsil, apresentou a relação mais estreita com a γ τ max e a τmax. Conclui-se que a reometria pode ajudar a identificar o caráter coeso apoiando outras análises, mas para uma avaliação independente, mais testes, especialmente em diferentes teores de água, são necessários.Universidade Federal de Santa MariaBrasilAgronomiaUFSMPrograma de Pós-Graduação em Ciência do SoloCentro de Ciências RuraisReichert, José Miguelhttp://lattes.cnpq.br/0910765178697312Holthusen, DörtheBatistão, Alan CarlosMota, Jaedson Cláudio AnunciatoSobucki, Viviane2022-05-19T20:28:58Z2022-05-19T20:28:58Z2021-03-05info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://repositorio.ufsm.br/handle/1/24374porAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/info:eu-repo/semantics/openAccessreponame:Manancial - Repositório Digital da UFSMinstname:Universidade Federal de Santa Maria (UFSM)instacron:UFSM2022-05-19T20:28:58Zoai:repositorio.ufsm.br:1/24374Biblioteca Digital de Teses e Dissertaçõeshttps://repositorio.ufsm.br/ONGhttps://repositorio.ufsm.br/oai/requestatendimento.sib@ufsm.br||tedebc@gmail.comopendoar:2022-05-19T20:28:58Manancial - Repositório Digital da UFSM - Universidade Federal de Santa Maria (UFSM)false |
dc.title.none.fl_str_mv |
Propriedades reológicas na detecção do caráter coeso em solos Reological properties in detection of the cohesiveness character in soils |
title |
Propriedades reológicas na detecção do caráter coeso em solos |
spellingShingle |
Propriedades reológicas na detecção do caráter coeso em solos Sobucki, Viviane Reometria Solo coeso Cisalhamento oscilatório Solos intemperizados Solos hardsetting Rheometry Cohesive soil Oscillatory shear Weathered soils Hardsetting soils CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::CIENCIA DO SOLO |
title_short |
Propriedades reológicas na detecção do caráter coeso em solos |
title_full |
Propriedades reológicas na detecção do caráter coeso em solos |
title_fullStr |
Propriedades reológicas na detecção do caráter coeso em solos |
title_full_unstemmed |
Propriedades reológicas na detecção do caráter coeso em solos |
title_sort |
Propriedades reológicas na detecção do caráter coeso em solos |
author |
Sobucki, Viviane |
author_facet |
Sobucki, Viviane |
author_role |
author |
dc.contributor.none.fl_str_mv |
Reichert, José Miguel http://lattes.cnpq.br/0910765178697312 Holthusen, Dörthe Batistão, Alan Carlos Mota, Jaedson Cláudio Anunciato |
dc.contributor.author.fl_str_mv |
Sobucki, Viviane |
dc.subject.por.fl_str_mv |
Reometria Solo coeso Cisalhamento oscilatório Solos intemperizados Solos hardsetting Rheometry Cohesive soil Oscillatory shear Weathered soils Hardsetting soils CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::CIENCIA DO SOLO |
topic |
Reometria Solo coeso Cisalhamento oscilatório Solos intemperizados Solos hardsetting Rheometry Cohesive soil Oscillatory shear Weathered soils Hardsetting soils CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::CIENCIA DO SOLO |
description |
The cohesive character has been evaluated primarily in the field, where a pedologist is capable to recognize it rather easily. However, there is a problem of subjectivity and lack of metrics for characterization, so research has been done in order to address this doubt with quantitative methods measured so far in the meso-scale. It is known that adhesion and cohesion processes originate at the micro scale, that is, in the interactions between particles, and a useful method to analyze the micro scale but not yet tested, is through rheometry. The objective of this study was then to evaluate whether rheological properties, obtained in amplitude sweep tests under oscillatory shear conditions, are able to detect the cohesive character and thus contribute to improve the understanding of cohesiveness in these soils. In a rotational rheometer, samples of six soil types were evaluated at three different positions in the profile (top, middle, and bottom), with and without cohesive character. Several soil rheological properties were determined: strain at the end of the linear viscoelastic range, LVR range (γLVR), shear stress at the end of the LVR range (τLVR), strain at the yield point (YP) (γYP), storage and loss modulus at YP (G'G”YP), maximum shear stress (τmax), strain at maximum shear stress (γ τ max), and z integral (Iz). In this study, only a few rheological properties had a significant effect on detecting the cohesive character of the soil, in general with higher values for cohesive soils compared to non-cohesive soils, indicating that cohesive soils are more stable. While cohesion affected only the γ base position of the rheological properties at the end of the LVR range, it had a significant effect on the τmax and γ τ max properties, in the top and middle positions, respectively. In addition, three materials did not reach the pour point. For the integral z, cohesive soils showed both lower and higher values than non-cohesive soils. Greater Iz in non-cohesive soils seems to be linked to a small expansion, a consequence of the high friction between the particles. In this sense, τmax and Iz were the properties that had a significant double interaction between the factors analyzed. The type of soil had the greatest effect on the rheological properties, being, in general, the PVAd soil with the highest values. Within the other soil properties studied, iron, organic carbon and clay content, density, and normal force at test initiation had the greatest impact on rheology. The evaluated mesoscale property, tensile strength, showed the closest relationship with γ τ max and τmax. It is concluded that rheometry can help identify the cohesive character supporting other analyses, but for an independent evaluation, more tests, especially at different water contents, are needed. |
publishDate |
2021 |
dc.date.none.fl_str_mv |
2021-03-05 2022-05-19T20:28:58Z 2022-05-19T20:28:58Z |
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 |
http://repositorio.ufsm.br/handle/1/24374 |
url |
http://repositorio.ufsm.br/handle/1/24374 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.rights.driver.fl_str_mv |
Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Universidade Federal de Santa Maria Brasil Agronomia UFSM Programa de Pós-Graduação em Ciência do Solo Centro de Ciências Rurais |
publisher.none.fl_str_mv |
Universidade Federal de Santa Maria Brasil Agronomia UFSM Programa de Pós-Graduação em Ciência do Solo Centro de Ciências Rurais |
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_ |
1805922138958331904 |