FORMATION OF ETTRINGITE IN PASTES CONTAINING CALCIUM ALUMINOFERRITES AND GYPSUM

THE RELATIONSHIP BETWEEN SULFATE RESISTANCE AND THE FERRITE PHASE IN LOW TRICALCIUM ALUMINATE CEMENTS IS ANALYZED. ALITE AND FERRITE PHASE ARE THE TWO ALUMINA BEARING PHASES IN ZERO-TRICALCIUM ALUMINATE CEMENTS. NO TRISULFATE HYDRATE WAS FORMED IN THE HYDRATED ALITE-GYPSUM MIXTURES, THEREBY INDICATING THAT ALUMINUM OXIDE PRESENT IN ALITE IS NOT LIBERATED FOR PARTICIPATION IN THE REACTIONS INVOLVING SULFATES AND ALUMINATES. THE AMOUNT OF TRISULFATE HYDRATE FORMED BY REACTION OF THE FERRITE PHASE WITH SULFATE UNDER THE TEST CONDITIONS WAS OBSERVED TO BE GREATLY INFLUENCED BY A/F RATIO. ALKYLIES WERE FOUND TO ACCELERATE THE REACTIONS, BUT ALTERED NEITHER THE NATURE NOR THE AMOUNTS OF THE HYDRATION PRODUCTS. DEPRESSED REACTIVITY OF THE FERRITE PHASE IN PRESENCE OF EXCESS CALCIUM HYDROXIDE SEEMS TO BE THE MAIN REASON FOR ABSENCE OF MONOSULFATE HYDRATE.

Media Info

  • Media Type: Print
  • Features: Figures; References;
  • Pagination: pp 36-45
  • Monograph Title: Cement hydration
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00212492
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Jan 16 1994 12:00AM