EFFECT OF ZINC OXIDE ON SETTING AND HARDENING OF PORTLAND CEMENT

THE SETTING OF CEMENT IS MUCH RETARDED BY ZNO, WHICH ACTS ONLY ON THE C3S TO INHIBIT INITIALLY ITS HYDRATION AND HYDROLYSIS. THE RETARDING ACTION IS INVERSELY PROPORTIONAL TO CEMENT FINENESS AND C3S CONTENT. THE INITIAL COMBINATION OF SULPHATE WITH ALUMINATE AND FERRITE PHASES IMMEDIATELY AFTER GAUGING A RETARDED CEMENT WITH WATER IS UNAFFECTED BY THE RETARDING ACTION, ONLY THE SUBSEQUENT REACTION OF THE GYPSUM IS RETARDED. THERE IS FORMED DURING RETARDATION A CA HYDROXYAQUO ZINCATE WHICH IS SUBSEQUENTLY DECOMPOSED, THE ZINC APPARENTLY ENTERING THE CRYSTAL LATTICE OF THE SILICATE HYDRATES, WHICH ARE DEVELOPING INTO THE HIGH-LIME FIBROUS PHASES. FINAL STRENGTHS OF ZNO-CONTAINING CEMENTS ARE HIGHER THAN THOSE OF ZNO-FREE CEMENTS. /AUTHOR/

  • Supplemental Notes:
    • Vol 20,no 3,PP 91-95
  • Authors:
    • Lieber, W
  • Publication Date: 1967

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  • Accession Number: 00212484
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jan 24 1994 12:00AM