PRACTICAL LABORATORY MEASUREMENT AND APPLICATION OF STIFFNESS OR RESILIENT PROPERTIES OF SOILS AND GRANULAR BASE MATERIALS FOR IDAHO FLEXIBLE PAVEMENT DESIGN PROCEDURES

The results of this study indicate that the fine grained subgrade soils tested at the Idaho R-value water contents and densities give resiliences, i.e. resilient moduli (M sub R), that, when used with the elastic layered computational methods and reasonable design criteria, produce base thickness requirements which can be larger than the requirements from the Idaho R-value method. The first 2 phases of the study were concerned with Idaho R-value modification and measurement of pavement deflection on pavements that showed premature cracking, and the analysis of the causes of cracking and high pavement deflection. The Idaho laboratory determination of R-value of subgrade soils was modified to measure R-value when the soil is less compacted and wetter than in the previous Idaho method, thus giving lower R-values and hence thicker pavements for some fine-grained soils. Pavement deflection measurements and analyses were accomplished on several pavements but, the data that was gathered were not sufficient to specify definite pavement deflection limits for various soils in order to minimize fatigue cracking. The soil testing device and the soil tests are described, and details are given of the soil specimen preparation, testing and resilient modulus determination. The application of resilient modulu to flexible pavement thickness design is detailed, and recommendations are presented.

  • Supplemental Notes:
    • This report was prepared for the Division of Highways, Idaho Transportation Department.
  • Corporate Authors:

    University of Idaho, Moscow

    College of Engineering
    Moscow, ID  USA  83843
  • Authors:
    • Lottman, R P
  • Publication Date: 1976-10

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: 106 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00163566
  • Record Type: Publication
  • Report/Paper Numbers: ITD Res. Project 76 Final Rpt.
  • Files: TRIS
  • Created Date: Mar 14 1978 12:00AM