AN OCCURRENCE OF A HYDRATED FORM OF CALCIUM CARBONATE IN DETERIORATED CONCRETE

MANY CRYSTALLINE FORMS OF CALCITE HAVE BEEN IDENTIFIED AS SECONDARY PRODUCTS IN CONCRETE. THE RARE OCCURRENCE OF A MONOCLINIC CRYSTAL, IDENTIFIED AS CALCITE, LED TO A LABORATORY INVESTIGATION INVOLVING THE STUDY OF THE HEXAHYDRATE OF CALCIUM CARBONATE WHICH IS MONOCLINIC AND FORMS NEAR O C, BUT CHANGES TO NORMAL HEXAGONAL CALCITE AT HIGHER TEMPERATURES. THE HEXAHYDRATE OF CALCIUM CARBONATE HAS BEEN IDENTIFIED IN FROZEN CONCRETE, THEREFORE THE RELICT MONOCLINIC CRYSTALS OF CALCITE OBSERVED AS SECONDARY DEPOSITS IN CONCRETE ARE CONSIDERED TO BE PSEUDOMORPHS AFTER THE HEXAHYDRATE. RELICT MONOCLINIC CRYSTALS ARE RARE, BECAUSE DEHYDRATION OF THE HEXAHYDRATE TO CALCITE I INVOLVES A VOLUME INCREASE THAT USUALLY DESTROYS ALL EVIDENCE OF THE ORIGINAL MONOCLINIC CRYSTAL FORM. /AUTHOR/

  • Corporate Authors:

    Assoc Engr Geologists Bull

    ,    
  • Authors:
    • Pattengill, M G
    • Crumpton, C F
    • Badgley, W A
  • Publication Date: 1972-1

Media Info

  • Features: Figures; References;
  • Pagination: p. 47-56
  • Serial:
    • Volume: 9
    • Issue Number: 1

Subject/Index Terms

Filing Info

  • Accession Number: 00214141
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jul 9 1972 12:00AM