The California bearing ratio (CBR) test for road materials has remained popular for over 50 years. It is a lengthy and relatively expensive test and attempts have been made over the years to substitute it with mathematical or graphical models that utilize soil classification parameters such as grading and Atterberg limits to predict the CBR. This paper details an investigation in which archival data were used to evaluate the existing models for some selected Natal soils, and describes how the relationships between CBR and various classification parameters (in both simple and multivariate forms) were further examined when these models were found to be generally unsatisfactory. The lack of any correlations suitable for use in a universally applicable prediction model is discussed, the good relationship between CBR and maximum swell is examined, further research into the influence of the clay fraction on CBR prediction is reported and the interim use of the shrinkage and grading moduli to obtain minimum CBR values for shrinking and non-shrinking soils respectively is proposed. (Author/TRRL) (Author/TRRL)

  • Availability:
  • Corporate Authors:

    South African Institution of Civil Engineers

    P.O. Box 62129
    Marshalltown 2107,   South Africa 
  • Authors:
    • Stephens, D J
  • Publication Date: 1990-12


  • English

Media Info

  • Features: References;
  • Pagination: p. 523-7
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00623808
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Jul 31 1992 12:00AM