FOURTH CYCLE OF PAVEMENT RESEARCH AT THE PENNSYLVANIA TRANSPORTATION RESEARCH FACILITY, VOLUME 2, DEVELOPMENT OF AN OVERLAY DESIGN PROCEDURE FOR FLEXIBLE PAVEMENTS. FINAL REPORT

An overlay design procedure for flexible pavements was developed for the Pennsylvania Department of Transportation. The procedure assumes a 3-layer model of a pavement structure, and requires Road Rater sensor deflections for estimating remaining life and required overlay thicknesses. Linear elastic layered theory was used to develop strain-deflection relationships for direct calculation of pavement strains from measured Road Rater sensor deflections. This is believed to be a simpler and more straightforward approach than the back-calculation of layer moduli from measured surface deflections and the subsequent calculation of stresses and/or strains from elastic layered theory and the layer moduli estimates. In order to develop the strain-deflection relationships, the multi-layer linear elastic program BISAR was used in a large factorial study. The program was modified for implementation on a microcomputer, thus making the factorial study feasible. The strains calculated from the Road Rater sensor deflections are subsequently used for remaining life analysis and for determining the need for an overlay. In connection with this, the tensile strain at the bottom of the asphalt layer and the compressive strain at the top of the subgrade are used as criteria for performance evaluation of the existing pavement. A program has been written for the computerized application of the overlay design procedure developed. The interactive program, known as OVERLAY, is written in standard FORTRAN 77 language and runs on either a mainframe system or a microcomputer. (Author)

• Corporate Authors:

  Pennsylvania State University, University Park

  Pennsylvania Transportation Institute, Transportation Research Building
  University Park, PA  United States  16802

  Pennsylvania Department of Transportation

  Office of Research and Special Studies, P.O. Box 2926
  Harrisburg, PA  United States  17120
• Authors:
  • Fernando, E G
  • Luhr, D R
  • Anderson, D A
• Publication Date: 1984-12

Media Info

• Features: Appendices; Figures; References; Tables;
• Pagination: 148 p.

Subject/Index Terms

• TRT Terms: Computer aided design; Deflection; Design methods; Flexible pavements; Overlays (Pavements); Pavement design; Pavement layers; Pavements; Tension; Thickness; User interfaces (Computer science)
• Uncontrolled Terms: Interactive computing
• Old TRIS Terms: Pavement deflection
• Subject Areas: Design; Highways; Materials; Pavements; I22: Design of Pavements, Railways and Guideways;

Filing Info

• Accession Number: 00454339
• Record Type: Publication
• Report/Paper Numbers: FHWA-PA-84-024
• Contract Numbers: Res. Project 82-11
• Files: TRIS, STATEDOT
• Created Date: Jul 31 1986 12:00AM