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

Rutting and 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 (PGs) have been used. With the record summer temperatures in recent years, several surface rutting and shear failures have occurred with hot mix asphalt (HMA) mixes that had passed the Hamburg wheel tracking test (HWTT) criterion. In an effort to mitigate these surface rutting and shear failure distresses, Texas Department of Transportation (TxDOT) project 0-6744 New HMA Shear Resistant and Rutting Tests for Texas Mixes proposed several key modifications to the HWTT protocol to improve 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, 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 and screening of HMA mixes. This implementation project verified and refined the modified HWTT protocol and the proposed SPST test for screening HMA mixtures susceptible to rutting, permanent deformation, and shear failure. Specifically, the study involved performing the SPST and the traditional HWTT tests on HMA at both the standard (50°C) and elevated test temperatures (i.e., 60°C) and validated the laboratory test results with field performance data. The scope of work for the validation and implementation process included assisting the TxDOT districts, such as Laredo, with their routine mix-design screening and HMA shear strength testing.

• Record URL:
  http://tti.tamu.edu/documents/5-6744-01-R1.pdf
• Summary URL:
  https://library.ctr.utexas.edu/Presto/catalogid=36751
• Record URL:
  https://rosap.ntl.bts.gov/view/dot/59036
• Supplemental Notes:
  • Project Title: Implementation of the HMA Shear Test for Routine Mix-Design and Screening.
• Corporate Authors:

  Texas A&M Transportation Institute, College Station

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

  Texas Department of Transportation

  Research and Technology Implementation Office
  125 E 11th Street
  Austin, TX  United States  78701-2483

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Walubita, Lubinda F
  • Nyamuhokya, Tito
  • Lee, Sang Ick
  • Prakoso, Adrianus
• Publication Date: 2019-2

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Technical Report
• Features: Appendices; Figures; Photos; References; Tables;
• Pagination: 78p

Subject/Index Terms

• TRT Terms: Flexible pavements; Hot mix asphalt; Mix design; Rutting; Shear strength; Shear tests; Temperature
• Uncontrolled Terms: Shear failure; Simple punching shear tests; Wheel tracking tests
• Subject Areas: Highways; Materials; Pavements;

Filing Info

• Accession Number: 01696584
• Record Type: Publication
• Report/Paper Numbers: FHWA/TX-18/5-6744-01-R1, Report 5-6744-01-R1
• Contract Numbers: Project 5-6744-01
• Files: NTL, TRIS, ATRI, USDOT, STATEDOT
• Created Date: Feb 27 2019 5:21PM