PREDICTED AND FIELD PERFORMANCE OF A THIN FULL DEPTH ASPHALT PAVEMENT PLACED OVER A WEAK SUBGRADE. SIXTH INTERNATIONAL CONFERENCE, STRUCTURAL DESIGN OF ASPHALT PAVEMENTS, VOLUME I, PROCEEDINGS, UNIVERSITY OF MICHIGAN, JULY 13-17, 1987, ANN ARBOR, MICHIGAN

The mechano-lattice method of analysis method, which assumes elastoplastic material behaviour, is described and details are provided of both the bound and unbound options. Prior to this paper the method has been used successfully with a variety of flexible pavements, but this was the first opportunity for the method to be used on an asphatl pavement for which testing was particularly adapted to the requirements of the analysis procedure. The asphalt pavement was 100 mm thick and overlay a weak imported subgrade, having four day soaked CBR values between 2% and 4%. Both the pavement and pavement materials were extensively evaluated during construction. Following construction, the pavement has been monitored and the results of rut depth determinations, roughness, and periodic visual assessment are presented. Using the load/deformation behaviour of the constituent materials as input the mechano-lattice predictions were compared with the field performance after the passage of the equivalent of 350,000 standard axles (esa). Two prediction runs were performed. One was based on an asphalt modulus determined from a one second loading time and a relatively dry imported subgrade and the other based on an asphalt modulus determined from a one-tenth second loading time and a relatively wet imported subgrade. The permanent deformation was overpredicted by approximately 50% for the dry imported subgrade condition and low asphalt modulus, and was close to the field value for the wet imported subgrade condition and high asphalt modulus. In both cases the absolute rut depth was predicted as 18 mm. The field survey data did not allow for the absolute rut depth to be determined. Output from mechano-lattice analysis and the asphalt moduli were used to predict the onset of cracking using the Shell method. In each case the onset of cracking was predicted to occur at about 100,000 esa. Initial cracking was noted in the outer wheelpath during a visual assessment after the equivalent of 105,000 esa.

• Corporate Authors:

  University of Michigan, Ann Arbor

  Department of Civil Engineering
  Ann Arbor, MI  United States  48109
• Authors:
  • SMITH, R B
  • Yandell, W O
• Publication Date: 1987

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 443-454
• Serial:
  • Publication of: Michigan University, Ann Arbor
  • Publisher: University of Michigan, Ann Arbor

Subject/Index Terms

• TRT Terms: Alternatives analysis; Asphalt pavements; Conferences; Deformation; Elastoplasticity; Forecasting; Full-depth asphalt pavements; Pavement cracking; Pavement performance; Performance; Roughness; Rutting; Subgrade (Pavements); Surveying
• Uncontrolled Terms: Elastic plastic analysis; Field performance; Rut depth; Visual surveys
• Old TRIS Terms: Mechano-lattice method
• Subject Areas: Design; Highways; Pavements; I22: Design of Pavements, Railways and Guideways;

Filing Info

• Accession Number: 00485614
• Record Type: Publication
• Files: TRIS
• Created Date: Jul 31 1989 12:00AM