EFFECT OF SUBSTITUTIONS OF FLY-ASH FOR PORTIONS OF THE CEMENT IN AIR-ENTRAINED CONCRETE

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

  • Supplemental Notes:
    • Vol 29, pp 225-235, 4 FIG, 6 TAB
  • Authors:
    • Larson, G H
  • Publication Date: 1950

Media Info

  • Monograph Title: Proceedings of the Twenty-Ninth Annual Meeting of the Highway Research Board Held at Washington, D.C. December 13-16, 1949.
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00213945
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Jul 25 1971 12:00AM