Crack Resistance and Durability of RAS Asphalt Mixtures

Recent national sustainability efforts by such organizations as the Federal Highway Administration (FHWA) and state legislatures and departments of transportation (DOTs) have led to increased use of reclaimed asphalt shingles (RAS) and higher reclaimed asphalt pavement (RAP) contents. In addition, state DOTs spend over 20% of their budgets on asphalt and can receive substantial cost savings by increasing use of RAS and RAP. This occurs by decreasing the amount of virgin asphalt binder (derived from crude oil) required in RAS and RAP asphalt mixes. Virgin asphalt binder is the most expensive component of asphalt mixtures even though used in small amounts by weight. There is, however, a point of diminishing returns. As asphalt mixtures have less and less virgin binder an increase in durability issues become evident resulting in increased maintenance costs and lower expected life. The way most DOTs deal with this is to put higher amounts of RAS and RAP in lower asphalt layers and lower amounts in surface asphalt mixtures Recent Ohio Department of Transportation (ODOT) project work with RAS suggest current methods and limits may exceed what is desired for performance. Historically, performance benefits of RAS and RAP have been quantified by measuring rutting resistance, which will always improve with harder aged binders and less amounts of softer virgin binders. However, durability performance entails far more than rutting. It also entails crack propagation resistance, fatigue resistance, moisture damage resistance and raveling resistance as well as performance in freeze/thaw conditions in northern climates such as Ohio. The researcher's goals and objectives will include determining suitable test methods and equipment for testing of RAS, RAP and virgin mixtures in order to distinguish expected crack propagation resistance and durability performance of each. Phase 1 of the work will be to evaluate, with ODOT liaison concurrence, available methods and equipment to determine which is best suited for further work. Phase 2, with written authorization from ODOT's research office, will perform extended testing using the selected method to prove its suitability and allow recommendations for specification limits and test standards to be made. If Phase 2 is authorized, the researcher will be asked to develop a proposal for the approved solution(s) and an addendum to the contract will be issued by the Research Section.


  • English


  • Status: Active
  • Contract Numbers:



  • Sponsor Organizations:

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Project Managers:

    Nye, Kelly

  • Performing Organizations:

    Auburn University

    National Center for Asphalt Technology
    310 Sanford Hall
    Auburn, Alabama  United States  36849-5131
  • Start Date: 20160106
  • Expected Completion Date: 20170906
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01584017
  • Record Type: Research project
  • Source Agency: Ohio Department of Transportation
  • Contract Numbers: 135305, 27267
  • Files: RiP, STATEDOT
  • Created Date: Dec 23 2015 9:59AM