This paper which should assist engineers and designers in developing realistic specifications for granular base courses for all types of pavement construction and in maximizing the performance of materials when subjected to modern-day traffic levels and repetitions, briefly reviewes the subject of compaction and presents a "state-of-the-art" of compaction control for unbound graded aggregate materials used in pavement construction. Factors influencing compaction of granular materials are discussed and technical data that demonstrates the effect of compaction on specific properties of graded aggregate mixtures are set forth. "In-service" compaction of granular base materials by traffic is reviewed and the resulting "densities" are compared with densities that are achievable with modern-day compaction equipment. The inadequacy of many current state highway department compaction requirements for unbound granular materials is discussed. Appropriate conclusions based on sound technical data are drawn, and recommendations are made for compaction requirements for unbound granular materials. The paper concludes that compaction is essential to good base performance. Increased density achieved through compaction as the proper moisture content improves the strength and durability characteristics of granular base course materials, while increased, density obtained through the addition of excessive fines (minus 200) is detrimental to the strength characteristics of granular base materials. Graded crushed aggregate base course materials can be compacted to densities greater than 100 percent of the maximum density obtained in the laboratory using AASHO T-180 compactive effort. Further conclusions refer to the specifications based on AASHO T-99, quantitative methods of compaction control, base compaction control, strength properties, the shear strength of cohesionless materials, permanent plastic deformation, the relationship of density and strength to roller coverage, vibratory rollers, subgrade support, and traffic densification. The presentation of the paper was followed by a discussion.

  • Supplemental Notes:
    • Proceedings from a conference on Utilization of Graded Aggregate Base Materials in Flexible Pavements, March 25-26, 1974, Oak Brook Hyatt House, Oak Brook, Illinois.
  • Corporate Authors:

    National Crushed Stone Association

    1415 Elliot Place, NW
    Washington, DC  United States  20007

    National Sand and Gravel Association

    900 Spring Street
    Silver Spring, MD  United States  20910

    National Slag Association

    300 South Washington Street
    Alexandria, VA  United States  22314
  • Authors:
    • Marck, C R
    • Jones, T R
  • Publication Date: 1974

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00127534
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Apr 7 1976 12:00AM