Reformulation of the CBR Procedure, Report II: Design, Construction, and Behavior Under Traffic of the Pavement Test Sections

The California Bearing Ratio (CBR) procedure has been the principal method used for design of flexible pavements for both military roads and airfields since its development in the 1940s. In recent years, as the use of analytical models, such as the layered elastic and finite element models, became accepted for pavement design, the CBR design procedure was criticized as being empirical, overly simplistic, and outdated. A major criticism of the procedure was the use of a correction factor (Alpha factor) as a thickness adjustment for traffic volume. The objectives of this research were to reformulate the CBR-Alpha procedure so that design would be based on a more mechanistic methodology and to develop performance criteria for use with the reformulation. With these purposes in mind, this report details the developmental steps of the reformulation, starting with the original CBR-Alpha procedure and ending with a new procedure based on Fröhlich’s theory for stress distribution. The reformulation was verified through review of historical test data and full-scale traffic tests and analyses of an actual airfield pavement failure. The reformulation of the procedure resulted in the elimination of both the equivalent single-wheel load concept and the Alpha factor.

• Record URL:
  • http://acwc.sdp.sirsi.net/client/search/asset/1032660
• 
• Supplemental Notes:
  • The information for the appendix can be obtained by contacting the ERDC Library at 601-634-2355 or erdclibrary@usace.army.mil.
• Corporate Authors:

  U.S. Army Engineer Research and Development Center

  Geotechnical and Structures Laboratory, 3909 Halls Ferry Road
  Vicksburg, MS  United States  39180-6199

  Air Force Civil Engineer Center

  139 Barnes Drive, Suite 1
  Tyndall AFB, FL  United States  32403-5319
• Authors:
  • Gonzalez, Carlos R
  • Barker, Walter R
  • Bianchini, Alessandra
• Publication Date: 2013-12

Language

• English

Media Info

• Media Type: Web
• Features: Appendices; Figures; Photos; References; Tables;
• Pagination: 86p

Subject/Index Terms

• TRT Terms: California bearing ratio; Deformation curve; Flexible pavements; Formulations; Pavement design; Test sections
• Subject Areas: Highways; Pavements; I22: Design of Pavements, Railways and Guideways;

Filing Info

• Accession Number: 01502018
• Record Type: Publication
• Report/Paper Numbers: ERDC/GSL TR-12-16
• Files: TRIS
• Created Date: Dec 23 2013 7:53AM