A NOTE ON THE OCCURANCE OF CRYSTALS OF CALCIUM CHLORIDE AND ETTRINGITE IN VOIDS IN HARDENED PORTLAND CEMENT PASTE

THE OCCURRENCE OF CRYSTALS OF CALCIUM HYDROXIDE AND OF ETTRINGITE (CALCIUM SULPHOALUMINATE) IN HARDENED PORTLAND CEMENT, REPORTED PREVIOUSLY BY OTHERS IS CONFIRMED. SAMPLES OF HARDENED PORTLAND CEMENT PASTE PREPARED HALF A CENTURY AGO AT ONE OF CANADAS EARLIEST CEMENT PLANTS WERE, ON EXAMINATION, FOUND TO CONTAIN VOIDS IN WHICH WELL DEVELOPED CRYSTALS HAD FORMED. THE CRYSTALS OCCURRED AS THIN PLATES AND NEEDLES THAT WERE IDENTIFIED BY OPTICAL MICROSCOPY AND X-RAY DIFFRACTION AS CALCIUM HYDROXIDE AND ETTRINGITE, RESPECTIVELY. IT IS OF INTEREST THAT THE CALCIUM HYDROXIDE HAD NOT BEEN ALTERED TO CARBONATE EVEN THOUGH THE CEMENT SAMPLES HAD BEEN STORED FOR A LONG TIME UNDER CONDITIONS THAT WOULD BE EXPECTED TO PROMOTE THIS CHANGE. /AUTHOR/

• Supplemental Notes:
  • Vol 17, No 50, PP 3-4
• Authors:
  • Gillotz, J E
  • Ritchie, T
• Publication Date: 1965-3

Media Info

• Serial:
  • Magazine Concrete Research /UK/

Subject/Index Terms

• TRT Terms: Calcium compounds; Diffraction; Ettringite; Hydroxides; Microscopes; Pastes; Portland cement; Rock crystals; X rays
• Uncontrolled Terms: Optical microscopes; X-ray diffraction
• Old TRIS Terms: Determination; Hardened
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 00212333
• Record Type: Publication
• Files: TRIS
• Created Date: Feb 15 1994 12:00AM