Zeolite crystallization in portland cement concrete due to alkali-aggregate reaction

Concrete used in works and altered by alkali-aggregate reaction was studied in order to identify the reaction products. For this purpose, the methods of petrographic microscopy, XRD and SEM were employed. The crystalline forms observed by SEM were later determined through the petrographic microscope...

ver descrição completa

Detalhes bibliográficos
Autores: Marfil, Silvina Andrea, Maiza, Pedro
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:1993
País:Argentina
Recursos:Comisión de Investigaciones Científicas de la Provincia de Buenos Aires
Repositório:CIC Digital (CICBA)
Idioma:inglês
OAI Identifier:oai:digital.cic.gba.gob.ar:11746/10235
Acesso em linha:https://digital.cic.gba.gob.ar/handle/11746/10235
Access Level:Acceso aberto
Palavra-chave:Geología
concrete
alkali-aggregate reaction
XRD analysis
Descrição
Resumo:Concrete used in works and altered by alkali-aggregate reaction was studied in order to identify the reaction products. For this purpose, the methods of petrographic microscopy, XRD and SEM were employed. The crystalline forms observed by SEM were later determined through the petrographic microscope, as being zeolites on the basis of their optical properties and confirmed by XRD. In order to obtain a minimum amount (10 mg) of the reaction product, many thin sections were prepared. The product was isolated under the microscope for XRD analysis, through which it was identified as being a zeolite (heulandite-clinoptilolite group). With the aim of determining the minimum limits capable of being registered by XRD, tests with the addition of 1, 5 and 10 % of a similar natural zeolite (clinoptilolite) were also performed on a concrete sample, showing that 5 % is about the minimum.