ACCELERATION AND RETARDATION OF PORTLAND CEMENT HYDRATION BY ADDITIVES

THE MECHANISM OF ACCELERATOR AND RETARDER ACTION UPON SETTING AND HARDENING OF PORTLAND CEMENT WAS INVESTIGATED. TESTS WERE CONDUCTED ON CEMENT AND ON A SYNTHETIC SILICATE BINDER, USING ANHYDROUS CALCIUM CHLORIDE AS THE ACCELERATOR AND THE CITRIC ACID AS THE RETARDER. FINDINGS SHOWED THAT THE RATE OF HYDRATION OF THE SILICATE PHASE /I.E. RATE OF FORMATION OF TOBERMORITE GEL/ IS CHANGED BY ADDITIVES. /PREVIOUS HYPOTHESES HAD STRESSED THAT THE SILICATE PHASE REMAINED UNAFFECTED./ INSOLUBLE COMPOUNDS WITH CLINKER ALUMINATES ARE FORMED DURING THE PROCESS. THERMAL AND HEAT-ON-SETTING EXPERIMENTS ARE CONSISTENT WITH THESE CONSIDERATION. THE EFFECT OF MIXING SEQUENCE USING RETARDERS AND ACCELERATORS IS EXPLAINED.

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  • Corporate Authors:

    Highway Research Board (HRB)

    Washington, DC   
  • Authors:
    • Tamas, Ferenc D
  • Publication Date: 1966

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 392-397
  • Monograph Title: Symposium on structure of Portland cement paste and concrete
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00212290
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Nov 18 1994 12:00AM