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Modeling Dissolution–Precipitation Kinetics of Alkali-Activated Metakaolin

[Image: see text] The numerical model HydratiCA was used to simulate the reaction kinetics of alkali-activated metakaolin, a material belonging to a class of sustainable binders alternative to Portland cement. The full chemistry of the system, including solid phases and aqueous species, is taken int...

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Autor principal: Valentini, Luca
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2018
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6643674/
https://www.ncbi.nlm.nih.gov/pubmed/31458395
http://dx.doi.org/10.1021/acsomega.8b02380
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author Valentini, Luca
author_facet Valentini, Luca
author_sort Valentini, Luca
collection PubMed
description [Image: see text] The numerical model HydratiCA was used to simulate the reaction kinetics of alkali-activated metakaolin, a material belonging to a class of sustainable binders alternative to Portland cement. The full chemistry of the system, including solid phases and aqueous species, is taken into account in these simulations. Specifically, metakaolin dissolution, reaction product nucleation and growth, and ion speciation, and diffusion in solution are simulated. The sodium aluminosilicate (N–A–S–H), formed by the reaction of metakaolin in alkaline solution, is implemented in the model as a combination of co-precipitating pseudo-zeolitic phases, with variable stoichiometry. The results show how variations of the reaction pathways, occurring when alkaline activators of different composition and concentration are used, can be associated with different macroscopic behaviors in terms of mechanical performance and durability. Reconciling these macroscopic properties with the basic chemical processes will be a fundamental technological challenge for the deployment of sustainable technologies in the construction industry.
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spelling pubmed-66436742019-08-27 Modeling Dissolution–Precipitation Kinetics of Alkali-Activated Metakaolin Valentini, Luca ACS Omega [Image: see text] The numerical model HydratiCA was used to simulate the reaction kinetics of alkali-activated metakaolin, a material belonging to a class of sustainable binders alternative to Portland cement. The full chemistry of the system, including solid phases and aqueous species, is taken into account in these simulations. Specifically, metakaolin dissolution, reaction product nucleation and growth, and ion speciation, and diffusion in solution are simulated. The sodium aluminosilicate (N–A–S–H), formed by the reaction of metakaolin in alkaline solution, is implemented in the model as a combination of co-precipitating pseudo-zeolitic phases, with variable stoichiometry. The results show how variations of the reaction pathways, occurring when alkaline activators of different composition and concentration are used, can be associated with different macroscopic behaviors in terms of mechanical performance and durability. Reconciling these macroscopic properties with the basic chemical processes will be a fundamental technological challenge for the deployment of sustainable technologies in the construction industry. American Chemical Society 2018-12-24 /pmc/articles/PMC6643674/ /pubmed/31458395 http://dx.doi.org/10.1021/acsomega.8b02380 Text en Copyright © 2018 American Chemical Society This is an open access article published under a Creative Commons Attribution (CC-BY) License (http://pubs.acs.org/page/policy/authorchoice_ccby_termsofuse.html) , which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited.
spellingShingle Valentini, Luca
Modeling Dissolution–Precipitation Kinetics of Alkali-Activated Metakaolin
title Modeling Dissolution–Precipitation Kinetics of Alkali-Activated Metakaolin
title_full Modeling Dissolution–Precipitation Kinetics of Alkali-Activated Metakaolin
title_fullStr Modeling Dissolution–Precipitation Kinetics of Alkali-Activated Metakaolin
title_full_unstemmed Modeling Dissolution–Precipitation Kinetics of Alkali-Activated Metakaolin
title_short Modeling Dissolution–Precipitation Kinetics of Alkali-Activated Metakaolin
title_sort modeling dissolution–precipitation kinetics of alkali-activated metakaolin
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6643674/
https://www.ncbi.nlm.nih.gov/pubmed/31458395
http://dx.doi.org/10.1021/acsomega.8b02380
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