Nebraska Balanced Mix Design – Phase II

Typically, asphalt mixes are designed under the Superpave system, in which the proportioning of the aggregates and asphalt binder are based on the aggregate quality characteristics and mix volumetric properties such as air voids, voids in the mineral aggregate (VMA) and voids filled with asphalt (VFA). The estimation of the volumetric properties significantly depends on the accuracy of the estimated specific gravity of the mix components; however, there are still some serious concerns regarding the accuracy and variability of aggregate bulk specific gravity testing and the selection of suitable amounts of asphalt in the mix design. Mixes designed with high amounts of asphalt can be susceptible to rutting, while those with low asphalt contents are prone to cracking, raveling or other durability issues. It should be pointed out that with the incorporation of reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS), these concerns are magnified. Moreover, the effects of the binders in these recycled materials are not definitively clear with regard to volumetric properties, e.g., the amount of interaction of the recycled binders with the virgin binders. In addition, the effects of warm-mix asphalt (WMA) additives, polymers, rejuvenators, and fibers cannot be evaluated in the conventional volumetric mix design method. Therefore, performance tests should be included as part of the mix design procedure to ensure the desirable field pavement performance. We are currently performing a research project entitled “Nebraska Balanced Mix Design - Phase I” funded by Nebraska DOT to develop BMD method for Nebraska pavements. Phase I of this research project will ultimately define the Nebraska BMD method which considers 3 main distresses: rutting, fatigue cracking, moisture damage. To be able to fully implement the outcomes of this research, the field evaluation must be conducted, and field data must be collected to establish pass/fail thresholds for future quality assurance (QA) and acceptance (QC) purposes.

    Language

    • English

    Project

    • Status: Active
    • Funding: $141,914.00
    • Sponsor Organizations:

      Nebraska Department of Transportation

      1500 Nebraska 2
      Lincoln, NE  United States  68502
    • Project Managers:

      Halsey, Lieska

    • Principal Investigators:

      Haghshenas, Hamzeh

    • Start Date: 20220701
    • Expected Completion Date: 20240531
    • Actual Completion Date: 0

    Subject/Index Terms

    Filing Info

    • Accession Number: 01849038
    • Record Type: Research project
    • Source Agency: Nebraska Department of Transportation
    • Files: RIP, STATEDOT
    • Created Date: Apr 19 2022 10:32AM