THE MITIGATING EFFECT OF POZZOLANS ON ALKALI SILICA REACTIONS

Expansion of mortar bars with and without selected pozzolans exposed to saturated calcium hydroxide and sodium chloride solutions at 50 deg C has been measured up to 20 weeks of exposure. Both fly ash and silica fume were found to prevent deleterious alkali silica reactions. The amount of pozzolan necessary to prevent expansion increased with the amount of reactive aggregate and varied with the type of pozzolan. 5% fly ash or 3% silica fume were enough to suppress deleterious reactions in the mixes with 2% synthetic cristobalite during the period of testing. 25% fly ash or 5% silica fume plus 15% fly ash were found to prevent deleterious reactions in the mixes with 6% synthetic cristobalite until 15 weeks of exposure.

• Corporate Authors:

  American Concrete Institute

  P.O. Box 19150, Redford Station, 22400 Seven Mile Road
  Detroit, MI  United States  48219
• Authors:
  • GEIKER, M
  • Thaulow, N
• Conference:
  • Fly Ash, Silica Fume, Slag, and Natural Pozzolans in Concrete. Fourth International Conference
  • Location: Istanbul, Turkey
  • Date: 1992-5-3 to 1992-5-8
• Publication Date: 1992

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 533-548
• Serial:
  • Volume: 1

Subject/Index Terms

• TRT Terms: Alkali silica reactions; Fly ash; Mortar; Pozzolan; Silica fume
• Subject Areas: Geotechnology; Highways; Materials; I32: Concrete;

Filing Info

• Accession Number: 00624320
• Record Type: Publication
• Report/Paper Numbers: SP-132
• Files: TRIS
• Created Date: Oct 15 1993 12:00AM