Determine Impact of Field Sands on Workability and Engineering Properties of Superpave Mixtures in Texas

Field sands have been used in hot mix asphalt (HMA) pavements to reduce binder requirement since they are readily available and are less expensive than crushed materials. Considering their adverse effects on the performance, field sands are limited to 10% to 15% of the aggregates. The most common feature of field sand that can have a significant detrimental effect on the Asphalt Concrete (AC) performance is the presence of harmful clay particles. Understanding the impact of these clay particles on AC performance is the subject of this research. The upper limit of specific field sand, given the amount of active clay present in it, the process to determine the clay content, and how they affect the performance of AC mixes shall be evaluated. Since field sands are more round compared to the crushed aggregates, mixes containing more field sands can be compacted to a given density at lower binder contents. Given the less particle to particle interlocking of such mixes, however, they are more suspect to excessive rutting. Thus, this research shall investigate the effect of clay minerals as well as the sand properties independently on the performance of AC mixes (with a focus on Superpave mixtures) and evaluate their combined/interactive effects, as the natural sands are a combination of both. To that end, the research team will provide interaction plots and/or charts that can be used to select the maximum allowable percentage of a given field sand.

Language

  • English

Project

  • Status: Active
  • Funding: $500,002
  • Contract Numbers:

    0-7111

  • Sponsor Organizations:

    Texas Department of Transportation

    125 E. 11th Street
    Austin, TX  United States  78701-2483
  • Managing Organizations:

    Texas Department of Transportation

    125 E. 11th Street
    Austin, TX  United States  78701-2483
  • Project Managers:

    Schwerdt, Tom

  • Performing Organizations:

    The University of Texas at El Paso

    500 W University Ave
    El Paso, TX  United States  79902

    Texas A&M Transportation Institute

    Texas A&M University System
    3135 TAMU
    College Station, TX  United States  77843-3135
  • Principal Investigators:

    Abdallah, Imad

  • Start Date: 20210901
  • Expected Completion Date: 20240831
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01782681
  • Record Type: Research project
  • Source Agency: Texas Department of Transportation
  • Contract Numbers: 0-7111
  • Files: RIP, STATEDOT
  • Created Date: Sep 23 2021 9:52AM