Development of Test Procedures to Evaluate Moisture Susceptibility of Asphalt Mixtures used in the State of Kansas, Phase I: Surface Free Energy of Binders

Moisture damage is the major distress that causes premature failure in hot mix asphalt (HMA) pavements. The loss of cohesion/adhesion and the tendency of water to displace the bond between aggregate and binder are the major mechanisms leading to the moisture damage. Therefore, it is of utmost importance to develop/enhance test methods and specification guidelines that can be used select aggregate-binder (unmodified and modified) pairs that are compatible and resistant to moisture degradation. The current state of practice at KDOT and many other agencies is to conduct mechanical tests on moisture conditioned and dry specimens to evaluate moisture susceptibility of asphalt mixtures. Despite simplicity, these tests suffer from a number of major deficiencies to the level that they may be deemed unreliable, including the following: (1) Poor correlation with the field performance, (2) Substantial variability in test results and lack of repeatability, (3) Inability to address specific failure mechanisms and the underlying root causes, (4) Extended testing time, (5) The need to repeat the tests when slight modifications are made (e.g., addition of modifiers etc.). All these deficiencies have led KDOT researchers to evaluate the efficacy of applying more fundamental lab tests and characterization methods to determine moisture susceptibility of asphalt mixtures. This proposal lays the groundwork for a much required test method to select asphalt concrete constituents that result in moisture damage-resistant asphalt mixtures. This research project will be conducted through close interaction with Prof. Dallas Little from TTI who has led a number of projects, well-received and sponsored by NCHRP, FHWA, and TXDOT, on this subject. They have shown that the surface free energy of asphalt concrete constituents could serve as a surrogate for traditional test methods to evaluate moisture susceptibility of asphalt mixtures. The PI will work closely with TTI to enhance the developed test methods, to simplify/customize them for KDOT applications, and to verify the measurements conducted independently by KU and TTI.

• Supplemental Notes:
  • Final report is pending.

Language

• English

Project

• Status: Active
• Funding: $86939
• Contract Numbers:

  RE-0771-01

  C2126

• Sponsor Organizations:

  Kansas Department of Transportation

  Eisenhower State Office Building
  700 SW Harrison Street
  Topeka, KS  United States  66603-3754
• Performing Organizations:

  University of Kansas Center for Research, Incorporated

  2291 Irving Hill Drive, Campus West
  Lawrence, KS  United States  66045
• Principal Investigators:

  Darabi, Masoud

• Start Date: 20180801
• Expected Completion Date: 20240731
• Actual Completion Date: 0

Subject/Index Terms

• TRT Terms: Asphalt mixtures; Hot mix asphalt; Moisture damage; Specifications; Surface energy; Test procedures
• Geographic Terms: Kansas
• Subject Areas: Highways; Maintenance and Preservation; Materials; Pavements;

Filing Info

• Accession Number: 01856791
• Record Type: Research project
• Source Agency: Kansas Department of Transportation
• Contract Numbers: RE-0771-01, C2126
• Files: RIP, STATEDOT
• Created Date: Aug 30 2022 3:48PM