SEM-EDX study of bentonite alteration under the influence of cement alkaline solutions

Bentonite is a key barrier for the isolation of high-level radioactive waste within Deep Geological Repository. However, bentonite may be altered by contact with cementitious materials and their alkaline pore fluids. This study offers an extensive morphological and semi-quantitative characterization...

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Authors: González Santamaría, Daniel, Justel Eusebio, Ana María, Fernández Martín, Raúl, Ruiz García, Ana Isabel, Stavropoulou, Alexandra, Rodríguez-Blanco, Juan Diego, Cuevas Rodríguez, Jaime Fernando
Format: article
Publication Date:2021
Country:España
Institution:Universidad Autónoma de Madrid
Repository:Biblos-e Archivo. Repositorio Institucional de la UAM
Language:English
OAI Identifier:oai:repositorio.uam.es:10486/700603
Online Access:http://hdl.handle.net/10486/700603
https://dx.doi.org/10.1016/j.clay.2021.106223
Access Level:Open access
Keyword:Alkaline perturbation
Bentonite
Cement
Engineered barrier system
SEM-EDX
Matemáticas
Química
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spelling SEM-EDX study of bentonite alteration under the influence of cement alkaline solutionsGonzález Santamaría, DanielJustel Eusebio, Ana MaríaFernández Martín, RaúlRuiz García, Ana IsabelStavropoulou, AlexandraRodríguez-Blanco, Juan DiegoCuevas Rodríguez, Jaime FernandoAlkaline perturbationBentoniteCementEngineered barrier systemSEM-EDXMatemáticasQuímicaBentonite is a key barrier for the isolation of high-level radioactive waste within Deep Geological Repository. However, bentonite may be altered by contact with cementitious materials and their alkaline pore fluids. This study offers an extensive morphological and semi-quantitative characterization of the bentonite surface exposed to three types of alkaline pore fluids released by different cement-based materials. The bentonite surfaces were studied using a thorough scanning electron microscopy exploration and analysed using an energy-dispersive ꭕ-ray detector (SEM-EDX). In addition, statistical, element mappings, ꭕ-ray diffraction and infrared spectroscopy analyses were performed. The aim was to have a picture of the morphological and chemical alterations of bentonite at very early stages in accordance with the integrated approach necessary to address bentonite stability in the long-term. As a consequence of the reactivity, two types of morphologies stood out in the matrix of bentonite: platelets and coatings-like crusts characterized by their high Mg and Ca content. These alterations presented a different scope depending on the type of alkaline pore solution involved and suggested the precipitation of authigenic magnesium silicate hydrates (M-S-H) and/or trioctahedral clay minerals and Ca‑carbonates. The knowledge of the performance of bentonite subjected to these alkaline solutions can help in the evaluation of the most suitable cement-based materials to be used next to bentoniteThe experimental work was supported by funding from the European Union‘s Horizon 2020 Research and Training programme from EURATOM [H2020-NFRP 2014, 2015] under grant agreement n◦662147; CEBAMAElsevierDepartamento de Geología y GeoquímicaDepartamento de MatemáticasFacultad de Ciencias20212021-07-24research articlehttp://purl.org/coar/resource_type/c_2df8fbb1VoRhttp://purl.org/coar/version/c_970fb48d4fbd8a85info:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10486/700603https://dx.doi.org/10.1016/j.clay.2021.106223reponame:Biblos-e Archivo. Repositorio Institucional de la UAMinstname:Universidad Autónoma de MadridInglésengopen accesshttp://purl.org/coar/access_right/c_abf2info:eu-repo/semantics/openAccessoai:repositorio.uam.es:10486/7006032026-06-23T12:46:27Z
dc.title.none.fl_str_mv SEM-EDX study of bentonite alteration under the influence of cement alkaline solutions
title SEM-EDX study of bentonite alteration under the influence of cement alkaline solutions
spellingShingle SEM-EDX study of bentonite alteration under the influence of cement alkaline solutions
González Santamaría, Daniel
Alkaline perturbation
Bentonite
Cement
Engineered barrier system
SEM-EDX
Matemáticas
Química
title_short SEM-EDX study of bentonite alteration under the influence of cement alkaline solutions
title_full SEM-EDX study of bentonite alteration under the influence of cement alkaline solutions
title_fullStr SEM-EDX study of bentonite alteration under the influence of cement alkaline solutions
title_full_unstemmed SEM-EDX study of bentonite alteration under the influence of cement alkaline solutions
title_sort SEM-EDX study of bentonite alteration under the influence of cement alkaline solutions
dc.creator.none.fl_str_mv González Santamaría, Daniel
Justel Eusebio, Ana María
Fernández Martín, Raúl
Ruiz García, Ana Isabel
Stavropoulou, Alexandra
Rodríguez-Blanco, Juan Diego
Cuevas Rodríguez, Jaime Fernando
author González Santamaría, Daniel
author_facet González Santamaría, Daniel
Justel Eusebio, Ana María
Fernández Martín, Raúl
Ruiz García, Ana Isabel
Stavropoulou, Alexandra
Rodríguez-Blanco, Juan Diego
Cuevas Rodríguez, Jaime Fernando
author_role author
author2 Justel Eusebio, Ana María
Fernández Martín, Raúl
Ruiz García, Ana Isabel
Stavropoulou, Alexandra
Rodríguez-Blanco, Juan Diego
Cuevas Rodríguez, Jaime Fernando
author2_role author
author
author
author
author
author
dc.contributor.none.fl_str_mv Departamento de Geología y Geoquímica
Departamento de Matemáticas
Facultad de Ciencias
dc.subject.none.fl_str_mv Alkaline perturbation
Bentonite
Cement
Engineered barrier system
SEM-EDX
Matemáticas
Química
topic Alkaline perturbation
Bentonite
Cement
Engineered barrier system
SEM-EDX
Matemáticas
Química
description Bentonite is a key barrier for the isolation of high-level radioactive waste within Deep Geological Repository. However, bentonite may be altered by contact with cementitious materials and their alkaline pore fluids. This study offers an extensive morphological and semi-quantitative characterization of the bentonite surface exposed to three types of alkaline pore fluids released by different cement-based materials. The bentonite surfaces were studied using a thorough scanning electron microscopy exploration and analysed using an energy-dispersive ꭕ-ray detector (SEM-EDX). In addition, statistical, element mappings, ꭕ-ray diffraction and infrared spectroscopy analyses were performed. The aim was to have a picture of the morphological and chemical alterations of bentonite at very early stages in accordance with the integrated approach necessary to address bentonite stability in the long-term. As a consequence of the reactivity, two types of morphologies stood out in the matrix of bentonite: platelets and coatings-like crusts characterized by their high Mg and Ca content. These alterations presented a different scope depending on the type of alkaline pore solution involved and suggested the precipitation of authigenic magnesium silicate hydrates (M-S-H) and/or trioctahedral clay minerals and Ca‑carbonates. The knowledge of the performance of bentonite subjected to these alkaline solutions can help in the evaluation of the most suitable cement-based materials to be used next to bentonite
publishDate 2021
dc.date.none.fl_str_mv 2021
2021-07-24
dc.type.none.fl_str_mv research article
http://purl.org/coar/resource_type/c_2df8fbb1
VoR
http://purl.org/coar/version/c_970fb48d4fbd8a85
dc.type.openaire.fl_str_mv info:eu-repo/semantics/article
format article
dc.identifier.none.fl_str_mv http://hdl.handle.net/10486/700603
https://dx.doi.org/10.1016/j.clay.2021.106223
url http://hdl.handle.net/10486/700603
https://dx.doi.org/10.1016/j.clay.2021.106223
dc.language.none.fl_str_mv Inglés
eng
language_invalid_str_mv Inglés
language eng
dc.rights.none.fl_str_mv open access
http://purl.org/coar/access_right/c_abf2
dc.rights.openaire.fl_str_mv info:eu-repo/semantics/openAccess
rights_invalid_str_mv open access
http://purl.org/coar/access_right/c_abf2
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Elsevier
publisher.none.fl_str_mv Elsevier
dc.source.none.fl_str_mv reponame:Biblos-e Archivo. Repositorio Institucional de la UAM
instname:Universidad Autónoma de Madrid
instname_str Universidad Autónoma de Madrid
reponame_str Biblos-e Archivo. Repositorio Institucional de la UAM
collection Biblos-e Archivo. Repositorio Institucional de la UAM
repository.name.fl_str_mv
repository.mail.fl_str_mv
_version_ 1869419165637410816
score 15,300724

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