FATIGUE CHARACTERIZATION OF ALASKAN PAVING MATERIALS. FINAL REPORT

Mechanistic analysis procedures for pavement evaluation have become relatively simple with recent development in microcomputers. These procedures require pavement fatigue models to make them useful for evaluation of pavement life. Numerous models exist. However, their applicability to cold climates requires further investigation. The purpose of this study was to determine the applicability to existing fatigue models in Alaska, determine if asphalt concrete mixes used in Alaska differed in performance, and to determine whether laboratory prepared samples perform differently than field compacted samples. Testing consisted of three point bending tests with temperatures ranging from 80 deg F to minus 15 deg F. A Materials Testing System (MTS) modified for the test procedure was used in conjunction with computerized data acquisition systems. All tests were strain controlled. None of the existing fatigue relationships were adequate. As a result, new equations were developed which better fit AC 2.5 and AC 5 at temperatures below 45 deg F. This equation is much more sensitive to strain than The Asphalt Institute equations. AC 2.5 and AC 5 were found to perform similarly at temperatures below 20 deg F. At temperatures as low as minus 15 deg F, no difference in performance was noted between the two asphalts. Both the laboratory prepared samples and the field samples showed equivalent performance. The data pointed out a difference between the time at which the maximum load occurred and the time at which the maximum strain occurred. This difference or "phase lag" was greatest at the beginning of the test and almost in phase at the end of the test. This phenomenon should be explored further, since it may provide a method of determining remaining life.

• Record URL:
  • http://www.dot.state.ak.us/stwddes/research/assets/pdf/fhwa_ak_rd_88_12.pdf
• 
• Corporate Authors:

  University of Alaska, Fairbanks

  Institute of Northern Engineering, P.O. Box 755910
  Fairbanks, AK  United States  99775-5900

  Alaska Department of Transportation and Public Facilities

  2301 Peger Road
  Fairbanks, AK  United States  99701

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Coetzee, N F
  • Kaelber, K
• Publication Date: 1988-8

Media Info

• Pagination: 134 p.

Subject/Index Terms

• TRT Terms: Asphalt concrete; Bend tests; Equations; Evaluation; Fatigue (Mechanics); Frigid regions; Mathematical models; Pavement performance; Pavements; Temperature; Testing
• Old TRIS Terms: Testing temperature
• Subject Areas: Design; Highways; Materials; Pavements; I22: Design of Pavements, Railways and Guideways; I31: Bituminous Binders and Materials;

Filing Info

• Accession Number: 00489603
• Record Type: Publication
• Source Agency: Alaska Department of Transportation and Public Facilities
• Report/Paper Numbers: FHWA-AK-RD-88-12
• Contract Numbers: 64201
• Files: TRIS, USDOT, STATEDOT
• Created Date: Nov 30 1990 12:00AM