Alkali activation of fly ash. Part III: Effect of curing conditions on reaction and its graphical description

The micro- and nano-structural characteristics of the reaction products of fly ash alkali activation depend, among others, on the curing conditions used: temperature, time and relative humidity. The present study focuses primarily on relative humidity. When the material is cured in air-tight contain...

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Detalhes bibliográficos
Autores: Criado Sanz, María, Fernández-Jiménez, Ana, Palomo, Ángel
Tipo de documento: artigo
Estado:Versión aceptada para publicación
Data de publicação:2010
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositório:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/32658
Acesso em linha:http://hdl.handle.net/10261/32658
Access Level:Acceso aberto
Palavra-chave:Alkali activated
Fly ash
Relative humidity
Microscopic and nanostructural model
Descrição
Resumo:The micro- and nano-structural characteristics of the reaction products of fly ash alkali activation depend, among others, on the curing conditions used: temperature, time and relative humidity. The present study focuses primarily on relative humidity. When the material is cured in air-tight containers, the silicon content of the initial aluminium-rich material gradually increases. This end product is dense and compact. When samples are in direct contact with the atmosphere, however, early age carbonation takes place, resulting in water loss and persistence of a high-aluminium content. This resulting material is granular and develops lower mechanical strength than the paste cured under high RH conditions. The main nano- and micro-structural differences observed in the materials as a result of different curing conditions have been shown through a graphical description of the reactions.