Mineral phases in metakaolin-portlandite pastes cured 15 years at 60 °C. New data for scientific advancement

One of the problems addressed by the scientific community in connection with cement matrix hydration is the evolution of hydrated phases under certain, primarily temperature-related, curing conditions. Such conditions are of utmost importance when the cement generates metastable hydrated phases that...

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Detalhes bibliográficos
Autores: Frías, M., Vigil de la Villa Mencía, Raquel, Martínez-Ramírez, S., García Giménez, Rosario, Sánchez de Rojas, M. I.
Tipo de documento: artigo
Data de publicação:2019
País:España
Recursos:Universidad Autónoma de Madrid
Repositório:Biblos-e Archivo. Repositorio Institucional de la UAM
Idioma:inglês
OAI Identifier:oai:repositorio.uam.es:10486/694714
Acesso em linha:http://hdl.handle.net/10486/694714
https://dx.doi.org/10.1016/j.clay.2019.105368
Access Level:Acceso aberto
Palavra-chave:Metakaolinite
Metastable phases
Mineralogical evolution
Pozzolanic reaction
Temperature
Zeolites
Geología
Descrição
Resumo:One of the problems addressed by the scientific community in connection with cement matrix hydration is the evolution of hydrated phases under certain, primarily temperature-related, curing conditions. Such conditions are of utmost importance when the cement generates metastable hydrated phases that develop into stable phases, inducing substantial physical-mechanical changes in the matrix. One such instance arises during the pozzolanic reaction between metakaolinite and calcium hydroxide at 60 °C when metastable hexagonal phases co-exist with cubic stable phases. Such processes are well understood in the short and medium term (<5 years). Evolution at longer curing times has not been studied, however. This paper describes the evolution of the initial (stable and metastable) mineral phases in the metakaolinite / Ca(OH) reaction toward a zeolite-like phase after 15 year curing at 60 °C. An understanding of such mineralogical changes is scientifically significant, given their direct impact on the engineering properties of cement-based matrices