RESISTANCE OF FLY ASH CONCRETE TO FREEZING AND THAWING

A study was made of the effects of Saskatchewan lignite fly ash on the resistance of concrete to freezing and thawing. The results show that the use of high percentages of fly ash in concrete reduced its resistance to freezing and thawing even though it contained about 6% air and was cured in water for 80 days. Concrete containing 20% fly ash gave satisfactory performance provided its air content and strength were comparable to control concrete which contained no fly ash. The decrease in resistance of fly ash concrete to freezing and thawing may be due to the slow migration of portlandite and ettringite crystals from the dense C-S-H zones to the air voids. Concrete with fly ash was less susceptible to the migration of portlandite, but its air voids contained more fibrous hydrates which may have led to an increase in the paste porosity.

Language

  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 205-226
  • Serial:
    • Volume: 1

Subject/Index Terms

Filing Info

  • Accession Number: 00624302
  • Record Type: Publication
  • Report/Paper Numbers: SP-132
  • Files: TRIS
  • Created Date: Oct 13 1993 12:00AM