Development of a Database on Surface Free Energy of Asphalt Binders to Evaluate Moisture Susceptibility of Asphalt Mixtures Used in the State of Kansas

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 Kansas Department of Transportation (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, including poor correlation with the field performance, lack of repeatability, inability to address failure mechanism and the underlying root causes to name a few. 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. In a recent project sponsored by KDOT, the research team measured surface free energy of a number of modified and virgin asphalt binders. The results showed that the surface free energy of asphalt binders could serve as a surrogate for traditional test methods to evaluate moisture susceptibility of asphalt mixtures. This research aims at conducting surface free energy test on a comprehensive set of asphalt binders to create a much-needed database. The number of binders to be tested will be selected via collaboration with KDOT researchers. The binders selected will be tested at KU using Wilhelmy Plate method using a force tensiometer equipment. From the selected binders, 20% will be tested at KDOT as well using the Sessile drop method which is based on the contact angles. The created database will achieve two goals: First, the overlap between the testing will determine the variability between results using the two methods and different equipment and provide data on which equipment could be use more efficiently to determine different components of surface free energy of asphalt binders. Second, the database can be used to evaluate the moisture susceptibility of asphalt binder/aggregate pairs and to determine the asphalt binder that results in the least moisture susceptible asphalt mixture. This research project will be conducted through close interaction with KDOT personnel. A large number of binders will be tested to create a database. The database can be used effectively to quickly and efficiently determine whether the mixture made with a specific binder/aggregate pair is susceptible to moisture damage.

Language

• English

Project

• Status: Active
• Funding: $92761
• Contract Numbers:

  RE-0886-01

  C2219

• 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: 20230613
• Expected Completion Date: 20250215
• Actual Completion Date: 0

Subject/Index Terms

• TRT Terms: Aggregates; Asphalt mixtures; Binders; Databases; Free energy; Moisture damage
• Geographic Terms: Kansas
• Subject Areas: Data and Information Technology; Highways; Maintenance and Preservation; Materials; Pavements;

Filing Info

• Accession Number: 01894770
• Record Type: Research project
• Source Agency: Kansas Department of Transportation
• Contract Numbers: RE-0886-01, C2219
• Files: RIP, STATEDOT
• Created Date: Sep 27 2023 11:59AM