Alkali-activated fly ash. Relationship between mechanical strength gains and initial ash chemistry

G. Kovalchuk; A. Fernández-Jiménez; A. Palomo

doi:10.3989/mc.2008.v58.i291.101

Autores/as

G. Kovalchuk V.D. Glukhovskiy Scientific Research Institute on Binders and Materials, Kyiv
A. Fernández-Jiménez Instituto de Ciencias de la Construcción "Eduardo Torroja", CSIC, Madrid
A. Palomo Instituto de Ciencias de la Construcción "Eduardo Torroja", CSIC, Madrid

DOI:

https://doi.org/10.3989/mc.2008.v58.i291.101

Palabras clave:

ceniza volante, activación alcalina, cementos alcalinos, zeolitas

Resumen

Las cenizas volantes activadas alcalinamente constituyen la base de una nueva generación de cementos con muy interesantes propiedades mecánicas, adherentes y durables (a veces incluso mejores que las de los cementos Portland tradicionales). Adicionalmente el desarrollo de estos cementos podría contribuir a mitigar las emisiones de CO₂ a la atmósfera, ya que el material base de los mismos puede estar formado por subproductos industriales. En la presente investigación se realizó un estudio para determinar la influencia de la composición de los materiales iniciales (ratios SiO₂/Al₂O₃ y Na₂O/Al₂O₃) en las propiedades mecánicas y en la naturaleza y composición de los productos de reacción. Los resultados obtenidos indican que no existe una relación lineal de dichas ratios con las resistencias mecánicas, sino que existen unos valores óptimos, por encima y debajo de los cuales las resistencias mecánicas disminuyen. En el caso concreto de las ratios estudiadas en el presente trabajo estos valores serian: SiO₂/Al₂O₃= 4,0 y Na₂O/Al₂O₃= 1,0 (relaciones molares)

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