Implementation of the HMA Shear Test for Routine Mix-Design and Screening

In Texas, rutting or permanent deformation (PD) continues to be a flexible pavement failure mode of concern, particularly under heavy traffic loading, high temperature environments, and severe shear stress conditions such as highway intersections and urban stop-go sections, or where lower asphalt-binder performance grades (PG) have been used. In particular, with the record summer temperatures in recent years, several rutting failures have occurred with hot mix asphalt (HMA) mixes that had performed acceptably in the laboratory rutting susceptibility tests, namely the Hamburg wheel tracking test (HWTT). Texas Department of Transportation (TxDOT) Project 0-6744: New HMA Shear Resistance and Rutting Test for Texas Mixes proposed several key modifications to the HWTT protocol in the View of improving its ability to simulate field rutting conditions under extreme shear environments, including testing the HMA mixes at elevated temperatures (i.e. 60 °C). Additionally, a new supplementary HMA shear test, namely the simple punching shear test (SPST) was developed that showed good potential to be considered as a supplement or surrogate to the HWTT for shear strength evaluation of HMA mixes. The research team will perform the following objectives: 1) Assist all of the districts with their routine mix-design screening and HMA shear strength testing. 2) Conduct a pilot implementation of the findings of Project 0-6744 through assisting the districts with their routine HMA mix-designs and mix screening using the proposed SPST and modified HWTT protocols. 3) Verify and refine the proposed test procedures with field performance data from in-service highway test sections.

Language

  • English

Project

  • Status: Active
  • Funding: $404044
  • Contract Numbers:

    5-6744-01

  • Sponsor Organizations:

    Texas Department of Transportation

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

    Adams, Joe

  • Performing Organizations:

    Texas A&M Transportation Institute, College Station

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

    Walubita, Lubinda

  • Start Date: 20150901
  • Expected Completion Date: 20180831
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01634638
  • Record Type: Research project
  • Source Agency: Texas Department of Transportation
  • Contract Numbers: 5-6744-01
  • Files: RiP, STATEDOT
  • Created Date: May 11 2017 4:17PM