Field Performance of Asphalt Mixtures Based on Flexibility Index Results

This document presents the continuous effort to develop mechanical tests that can relate to the expected performance of asphalt mixtures once placed in the field. During a previous research project, asphalt mixtures of different compositions were collected from different locations across the state of Utah. Based on the tests, it was found that asphalt mixtures sampled at the plant had a flexibility index, FI, between 3.0 and 20.0. This means that some mixtures were likely to show premature fatigue cracking. To verify if the laboratory predicted performance matched the field performance, the locations where five different mixtures were placed were surveyed and their level of distresses was documented. It was found that out of the 5 sections surveyed, the one that had the lowest flexibility index showed premature fatigue cracking. A different section also shows significant low-temperature cracking. Based on the results, it is concluded that the proposed mechanical testing at intermediate temperatures can be used to identify mixtures that might have poor cracking performance in the field. However, since no other section showed any distresses, it is not known if a specific minimum FI can be developed at this time.

  • Record URL:
  • Record URL:
  • Supplemental Notes:
    • This document was sponsored by the U.S. Department of Transportation, University Transportation Centers Program.
  • Corporate Authors:

    University of Utah, Salt Lake City

    Department of Civil and Environmental Engineering
    Salt Lake City, UT  United States 

    Mountain-Plains Consortium

    North Dakota State University
    Fargo, ND  United States  58108

    Office of the Assistant Secretary for Research and Technology

    University Transportation Centers Program
    Department of Transportation
    Washington, DC  United States  20590
  • Authors:
    • Romero, Pedro
  • Publication Date: 2022-7

Language

  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Figures; Photos; References; Tables;
  • Pagination: 19p

Subject/Index Terms

Filing Info

  • Accession Number: 01855176
  • Record Type: Publication
  • Report/Paper Numbers: MPC 22-466, MPC-611
  • Files: UTC, NTL, TRIS, ATRI, USDOT
  • Created Date: Aug 22 2022 9:35AM