Valorisation of "La Palma" Volcanic Ash for Making Portland-Blended, Alkaline and Hybrid Portland&-Alkaline Cements Articles uri icon

authors

  • MARTIN RODRIGUEZ, PABLO
  • FERNANDEZ JIMENEZ, ANA
  • ALONSO, MARIA DEL MAR
  • PALOMO, ANGEL
  • GARCIA LODEIRO, INES

publication date

  • January 2024

start page

  • 1

end page

  • 20

issue

  • 1

volume

  • 17

International Standard Serial Number (ISSN)

  • 1996-1944

abstract

  • The present work evaluates the feasibility of using volcanic fly ash (VFA) generated by
    the eruption of the Tajogaite volcano on the island of La Palma (Spain) in 2021, as a precursor in the
    preparation of cementitious materials with different Portland cement (PC) replacement levels (0%,
    30%, 70% and 100%), in the absence (Blended Cement, BC) and presence of an alkaline activator (Hybrid Alkaline Cement, HAC, and Alkaline Cements, AC). Hydration kinetics (isothermal conduction
    calorimetry), paste mechanical strengths and reaction products were characterised by XRD, FTIR,
    TG/DTG and BSEM/EDX. The results obtained indicate that the strengths developed by the hybrid
    alkaline cements (HAC) are higher than those of the blended cements (BC), especially at the age of
    2 days, where 25 MPa were obtained with the replacement of 70% PC by VFA. Alkaline cements (AC,
    100% VFA) that were prepared with 8 M NaOH solution as the activator reached 40 MPa after 2 days.
    It was observed that in all the binders, depending on the initial composition of the binder mixture
    and the percentage of replacement and/or activator, VFA reacts to form cementitious gels, C-A-S-H
    and N-A-S-H type, which supports its use as a mineral addition to blended cement or as a precursor
    in the preparation of alkaline and hybrid alkaline cements.

subjects

  • Chemistry

keywords

  • volcanic fly ash; blended cement; hybrid alkaline cement; alkaline cement