Synthesis and characterization of fly ash hybrid cements with limestone

  • G. Millán
  • J. González
  • L. Zamorano
  • A. Zaldívar
  • M. Figueroa
Keywords: Alkaline activation, hybrid cement, limestone, fly ash

Abstract

In this work, the alkaline activation of hybrid fly ash cements with additions of up to 30% Portland cement and limestone activated with NaOH, Na2CO3, Na2SO4 and (COONa)2 is presented. Different activator modules (Na2O/SiO2) of 0.1 to 0.3 and a w/c ratio of 0.45. The results of the compression strengths tests at 28 days of curing in samples activated with Na2SO4 showed the highest strength, 31 MPa, with a weight proportion of fly ash: Portland cement: limestone of 60:30:10. The test cements with lower strength development were those activated with NaOH and (COONa)2 with 2.4 MPa and 7.4 MPa, respectively. The limestone particle could be observed by scanning electron microscopy as the nucleation center for the reaction products and the way that the fly ash reacted by means of the alkaline activation process to form part of the reaction products.

Published
2017-06-21
How to Cite
Millán, G., González, J., Zamorano, L., Zaldívar, A., & Figueroa, M. (2017). Synthesis and characterization of fly ash hybrid cements with limestone. Academic Journal of Civil Engineering, 35(2), 352-355. https://doi.org/10.26168/icbbm2017.53