This report begins with a review of previously published findings on stone sand used as a fine aggregate in portland cement concrete, including production, gradation, particle shape, and the proportioning of mixes made with it. Based on this current state of knowledge, a laboratory test program was planned to study effects of variations in gradation and particle shape of manufactured stone sand, and variations in coarse aggregate factor and maximum size of coarse aggregate, on properties of freshly mixed and hardened air-entrained portland cement concretes. Using a range of fixed cement contents, mixing water was varied as needed to obtain a single specified slump for all mixes. Results show that satisfactory air-entrained portland cement concrete can be produced in normal strength range with manufactured stone sands containing considerably more "microsand" than has been previously allowed by standard specifications such as ASTM C 33. These concretes have reduced bleed water, acceptable freeze-thaw durability, adequate strengths, and about the same shrinkage as those made with minimum amounts of microsand. Variations of particle shape of sands below 53.4% voids (NCSA Shape Index) had little or no appreciable effect on compressive and flexural strengths, freezing and thawing durability, and shrinkage. More angular or flanky sands (void content above 53 percent) required more water in the concrete mixes, and contributed to somewhat lower strengths. Limited study indicated that water reducing admixtures could effectively counteract this tendency. It is evident from the results of this study that stone sands, carefully produced to have consistent gradings, can be used with confidence in concretes that are properly proportioned for any of a wide variety of applications. /Author/

  • Corporate Authors:

    National Crushed Stone Association

    1415 Elliot Place, NW
    Washington, DC  United States  20007
  • Authors:
    • Kalcheff IV
  • Publication Date: 1977-7

Media Info

  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 20 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00183149
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Dec 3 1978 12:00AM