Scientific Innovations in Micro-surfacing and Slurry Seal Mixture Design TR-755

In recent years, focus on pavement preservation implementation has been renewed as agencies face budget challenges and aging road infrastructure. Microsurfacing and slurry seals have shown great potential as fast, cost-effective pavement preservation and minor rehabilitation strategies. Microsurfacing and slurry seals can be used in high traffic areas and in areas with high traffic demands, which require rapid repairs and completion of work (Asphalt Institute 2008). A recent analysis completed by Iowa State University (ISU) researchers of Iowa Department of Transportation (DOT) data has shown that the application of microsurfacing and slurry seals are providing improvements to roadway characteristics; however, based on survey results sent to county engineers, guidance of pavement preservation is still needed. A large part of understanding microsurfacing and slurry seals is knowledge of the mixture design processes. In general, the understanding of design processes for emulsion-based mixtures needs to be improved so proper field adjustments can be made in real time. This proposal aims to improve and incorporate chemistry-based measurements for microsurfacing and slurry seals to provide a quantitative metric to formulate and tweak designs both in the lab and in the field. This research project will provide seed funding to explore a scientific approach to microsurfacing mixture design using zeta potential. Zeta potential measurements are the electrical forces that influence particle stability, repulsion, and attraction in the microsurfacing/slurry seal mixture design. The zeta potential of an asphalt-water emulsion system is the measure of the potential difference between emulsifiers adsorbed on the surface of the asphalt droplets and the conducting liquid suspension (water). If mixture components could be engineered with zeta potential, the breaking and setting of the emulsion could be more precisely controlled and scientifically adjusted. The mixture components with more negative zeta potential are holding the mixture in suspension while the components with more positive zeta potential are inducing flocculation. The point at which these components work together to chemically break the emulsion in the mixture is called the isoelectric point. The objective of this research is to investigate the use of zeta potential as a measurement to predict setting behavior and performance of micro-surfacing mixtures. Results and comparisons between mechanical testing, methylene blue values for aggregates, and zeta potential testing will be performed. (1) Use zeta potential to incorporate scientific measurements into micro-surfacing mixture design. (2) Research will provide recommendations about improving micro-surfacing/slurry seal materials. (3) Research will investigate how zeta potential titrations can be used to better formulate a slurry/micro mixture for improved adhesion properties and/or a faster setting rate to quickly return traffic to a roadway.

  • Supplemental Notes:
    • Contract to a Performing Organization has not yet been awarded.


  • English


  • Status: Active
  • Funding: $50000
  • Contract Numbers:

    Add 669


  • Sponsor Organizations:

    Iowa Department of Transportation

    800 Lincoln Way
    Ames, IA  United States  50010
  • Managing Organizations:

    Iowa State University, Ames

    Center for Transportation Research and Education
    2711 South Loop Drive, Suite 4700
    Ames, IA  United States  50010-8664
  • Project Managers:

    Goetz, Vanessa

  • Principal Investigators:

    Buss, Ashley

  • Start Date: 20180915
  • Expected Completion Date: 20190930
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01682034
  • Record Type: Research project
  • Source Agency: Iowa Department of Transportation
  • Contract Numbers: Add 669, TR-755
  • Files: RIP, STATEDOT
  • Created Date: Sep 26 2018 2:54PM