TENTATIVE OVERLAY DESIGN FOR MINNESOTA ASPHALT PAVEMENTS

A METHOD HAS BEEN SUGGESTED FOR DESIGNING AN OVERLAY ON AN EXISTING ASPHALT PAVEMENT FROM RECENT RESEARCH IN MINNESOTA. THIS METHOD MAKES A PREDICTION OF HOW LONG A GIVEN THICKNESS OF OVERLAY WILL LAST ON A PAVEMENT. A SPRING DEFLECTION OF THE PAVEMENT SECTION BEFORE OVERLAY IS DETERMINED BY MAKING A REBOUND DEFLECTION TEST DURING ANY NON-FROZEN PORTION OF THE YEAR, PREFERABLE IN JUNE, JULY, AUGUST, SEPTEMBER OR OCTOBER WHEN THE STRENGTH OF THE PAVEMENT IS LESS VARIABLE. THE DEFLECTIONS ARE CORRECTED TO AN 80 F DEFLECTION BY USING THE TEMPERATURE OF THE MAT. THE CORRECTION WAS FOUND TO BE A FUNCTION OF THE LEVEL OF DEFLECTION. THE FUNCTION OF TEMPERATURE FOR MINNESOTA ROADS WAS DETERMINED BY USING THE RESULTS OF THE AASHO ROAD TEST AND TEMPERATURE STUDIES MADE ON MINNESOTA TEST SECTIONS. BASED ON THE RESULTS OF A SPRING RECOVERY TEST PROGRAM OVER THE LAST FEW YEARS, IT WAS FOUND THAT THE STRENGTH OF A PAVEMENT SECTION IS DEPENDENT ON EMBANKMENT TYPE, TIME OF YEAR, AND SURFACE THICKNESS. AFTER THE SPRING DEFLECTION IS DETERMINED, A REDUCTION IN DEFLECTION IS ESTABLISHED FOR VARIOUS THICKNESSES OF OVERLAY. BEFORE AND AFTER TESTS ARE BEING CONDUCTED ON SECTIONS OVERLAID IN 1968 TO ESTABLISH THE DEFLECTION REDUCTION. THE CALCULATED LIST OF DEFLECTIONS WITH THE VARIOUS THICKNESSES OF OVERLAY CAN BE USED TO PREDICT THE NUMBER OF EQUIVALENT 18-KIP AXLE LOADS THAT A PAVEMENT SECTION CAN WITHSTAND BEFORE THE SERVICEABILITY WILL DROP TO 2.5, ASSUMING THAT THE PSI IS BROUGHT UP TO 3.9 OR 4.0 OR BETTER WITH THE ADDITION OF THE OVERLAY. THE MINNESOTA TEST SECTIONS HAVE SO FAR VERIFIED THE EQUATION DEVELOPED FROM THE AASHO ROAD TEST. A COMPUTER PROGRAM WAS DEVELOPED TO ESTIMATE TRAFFIC IN TERMS OF EQUIVALENT 18-KIP AXLE LOADS FOR 5, 10, 15, 20 AND 25 YEARS INTO THE FUTURE ON A GIVEN PAVEMENT SECTION.

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/hrr/1969/300/300-006.pdf
• Supplemental Notes:
  • Paper sponsored by Committee on Salvaging Old Pavements by Resurfacing, Maintenance of Bituminous Pavements, and Maintenance of Portland Cement Concrete Pavements and presented at the 48th Annual Meeting. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
• Authors:
  • Skok Jr, Eugene L
• Publication Date: 1969

Media Info

• Media Type: Digital/other
• Features: References; Tables;
• Pagination: pp 33-36
• Monograph Title: Design of overlays and pavement rehabilitation
• Serial:
  • Highway Research Record
  • Issue Number: 300
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Asphalt pavements; Axle load force; Computer programs; Deflection tests; Embankments; Equations; Flexible pavements; Overlays (Pavements); Pavement design; Seasons; Serviceability; Temperature; Test sections; Thickness
• Identifier Terms: AASHO Road Test
• Uncontrolled Terms: Serviceability Index
• Geographic Terms: Minnesota
• Subject Areas: Design; Highways; Maintenance and Preservation; Pavements;

Filing Info

• Accession Number: 00218569
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Feb 16 1970 12:00AM