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Reactivity of Gypsum-Based Materials Subjected to Thermal Load: Investigation of Reaction Mechanisms
The thermal stability of gypsum-based materials, and in this context, especially their long-term behavior, is the background of our current research activities. A comprehensive investigation program was compiled in which detailed examinations of various model materials exposed to thermal loads were...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7142976/ https://www.ncbi.nlm.nih.gov/pubmed/32245074 http://dx.doi.org/10.3390/ma13061427 |
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author | Krause, Felix Renner, Bernhard Coppens, Frederik Dewanckele, Jan Schwotzer, Matthias |
author_facet | Krause, Felix Renner, Bernhard Coppens, Frederik Dewanckele, Jan Schwotzer, Matthias |
author_sort | Krause, Felix |
collection | PubMed |
description | The thermal stability of gypsum-based materials, and in this context, especially their long-term behavior, is the background of our current research activities. A comprehensive investigation program was compiled in which detailed examinations of various model materials exposed to thermal loads were carried out. The understanding of the partly not entirely consistent state of knowledge shall be sharpened especially by in situ observations of the thermally induced conversion reaction of gypsum into hemihydrate. The temporal course of the reaction was investigated non-destructively by in situ investigations in a high-resolution X-ray computed tomography setup, and the experiment was accompanied by detailed characterizations of the microstructure and composition. In this contribution, selected results of experiments with a high-purity natural gypsum rock as the model substance are presented. Studying the influence of temperature on the reaction showed that, even under supposedly dry conditions, the reaction could take place at much lower temperatures than usually reported in the literature. It was demonstrated that the transformation of gypsum into hemihydrate could take place at a temperature of already 50 °C. The results indicated that even under “classical” heating conditions in a conventional oven, the dissolution and crystallization processes in water films on the mineral surfaces could be suggested to be a driving force for the reaction. A corresponding reaction model, which took these aspects into account, was proposed in this work. |
format | Online Article Text |
id | pubmed-7142976 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-71429762020-04-14 Reactivity of Gypsum-Based Materials Subjected to Thermal Load: Investigation of Reaction Mechanisms Krause, Felix Renner, Bernhard Coppens, Frederik Dewanckele, Jan Schwotzer, Matthias Materials (Basel) Article The thermal stability of gypsum-based materials, and in this context, especially their long-term behavior, is the background of our current research activities. A comprehensive investigation program was compiled in which detailed examinations of various model materials exposed to thermal loads were carried out. The understanding of the partly not entirely consistent state of knowledge shall be sharpened especially by in situ observations of the thermally induced conversion reaction of gypsum into hemihydrate. The temporal course of the reaction was investigated non-destructively by in situ investigations in a high-resolution X-ray computed tomography setup, and the experiment was accompanied by detailed characterizations of the microstructure and composition. In this contribution, selected results of experiments with a high-purity natural gypsum rock as the model substance are presented. Studying the influence of temperature on the reaction showed that, even under supposedly dry conditions, the reaction could take place at much lower temperatures than usually reported in the literature. It was demonstrated that the transformation of gypsum into hemihydrate could take place at a temperature of already 50 °C. The results indicated that even under “classical” heating conditions in a conventional oven, the dissolution and crystallization processes in water films on the mineral surfaces could be suggested to be a driving force for the reaction. A corresponding reaction model, which took these aspects into account, was proposed in this work. MDPI 2020-03-20 /pmc/articles/PMC7142976/ /pubmed/32245074 http://dx.doi.org/10.3390/ma13061427 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Krause, Felix Renner, Bernhard Coppens, Frederik Dewanckele, Jan Schwotzer, Matthias Reactivity of Gypsum-Based Materials Subjected to Thermal Load: Investigation of Reaction Mechanisms |
title | Reactivity of Gypsum-Based Materials Subjected to Thermal Load: Investigation of Reaction Mechanisms |
title_full | Reactivity of Gypsum-Based Materials Subjected to Thermal Load: Investigation of Reaction Mechanisms |
title_fullStr | Reactivity of Gypsum-Based Materials Subjected to Thermal Load: Investigation of Reaction Mechanisms |
title_full_unstemmed | Reactivity of Gypsum-Based Materials Subjected to Thermal Load: Investigation of Reaction Mechanisms |
title_short | Reactivity of Gypsum-Based Materials Subjected to Thermal Load: Investigation of Reaction Mechanisms |
title_sort | reactivity of gypsum-based materials subjected to thermal load: investigation of reaction mechanisms |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7142976/ https://www.ncbi.nlm.nih.gov/pubmed/32245074 http://dx.doi.org/10.3390/ma13061427 |
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