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...

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Detalles Bibliográficos
Autores: Marfil, Silvina Andrea, Maiza, Pedro
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:1993
País:Argentina
Institución:Comisión de Investigaciones Científicas de la Provincia de Buenos Aires
Repositorio:CIC Digital (CICBA)
Idioma:inglés
OAI Identifier:oai:digital.cic.gba.gob.ar:11746/10235
Acceso en línea:https://digital.cic.gba.gob.ar/handle/11746/10235
Access Level:acceso abierto
Palabra clave:Geología
concrete
alkali-aggregate reaction
XRD analysis
Descripción
Sumario: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.