MOISTURE-DENSITY RELATIONS OF SOIL-AGGREGATE MIXTURES AS AFFECTED BY THE GEOMETRIC CHARACTERISTICS AND GRADATION OF COARSE AGGREGATES

This paper summarizes the results of a laboratory study concerning the effects of the geometric characteristics and gradation of coarse aggregates on the moisture-density relations of soil-aggregate mixtures. Six coarse aggregate materials with discernible geometric characteristics, including both gravel and crushed stone materials, were used in the investigation. The geometric characteristics of these aggregates were determined by the particle index test and expressed quantitatively as particle index values for positive identification. Each coarse aggregate material was combined with various percentages of fines aggregate and soil materials to form nine different and fully controlled gradations according to a mathematical expression. The moisture-density relations of these mixtures were determined according to AASHO Designation: T-99-57. The results of this investigation show that the percentage of voids in a compacted soil-aggregate mixture of a given gradation increases more or less linearly with increasing values of the particle index of the coarse aggregate; that is, as the coarse aggregate particles become more irregular in shape, angular, and roughly surfaced. For the soil-aggregate mixture containing coarse aggregates of given geometric characteristics, there is an optimum gradation at which maximum dry density is achieved. The optimum moisture content is also a minimum for this gradation. These results indicate convincingly that both the geometric characteristics and the gradation of the coarse aggregate materials deserve consideration in the construction control of soil-aggregate road materials. /Author/

  • Corporate Authors:

    Michigan Technological University, Houghton

    Houghton, MI  USA  49931
  • Authors:
    • Huang, E Y
  • Publication Date: 1966

Media Info

  • Pagination: 23 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00264420
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jan 29 1975 12:00AM