Balanced Mixture Design Implementation Support

The Wisconsin Department of Transportation (WisDOT) is in the process of implementing performance-based testing procedures for Hot Mix Asphalt (HMA) material acceptance. Performance testing allows agencies to test the end product instead of specifying HMA material/volumetric requirements. End-product testing may provide a more accurate way of accepting mixtures for flexible pavements, allow for more innovative mixture designs and increase pavement service life. In past WHRP projects, researchers have identified mixture design factors sensitive to performance properties and recommended test procedures that strongly indicate cracking and rutting resistance (projects 0092-17-06 and 0092-15-04). Despite past success, more information is needed before implementation of promising a performance testing procedures. For that reason, WisDOT does not currently have a draft specification to enforce performance-based acceptance system on WisDOT projects. Furthermore, WisDOT does not have results providing insight regarding practical constraints of performance-based acceptance methodologies. WisDOT currently provides testing specifications for HMA paving projects that assess quality and design. Quality control tests are conducted throughout the construction and production process to ensure uniformity of construction materials. Design tests are required before construction. Designers submit volumetric test results for approval and, once approved, the mixture design is permitted to be used for WisDOT work. This research project will focus on implementation of design specification requirements. Required design specifications should take into consideration of practical constraints that may affect HMA designs, such as: cost, available materials, construction practices, and others. The goal of a performance-based specification methodology should be to maximize the quality of the end product without adding excessive costs that cannot be recouped during added pavement life. The prevailing framework for performance-based specifications is typically presented as “Balanced Mixture Design” (BMD) methods. Multiple tests are required to target different levels of performance: rutting, fatigue cracking, thermal cracking and others. Designs that overall improve the specified performance properties are called “balanced” designs. There are three concepts for implementation of the BMD methods: • Volumetric design with performance testing validation, • Performance-modified volumetric mix design and • Performance design. Researchers will be asked to develop a rational BMD specification that takes into consideration all potential constraints in the mixture design process.The objective of this research is to assess and test performance-based methodologies with the intent of developing an implementable BMD specification for WisDOT projects. There are multiple factors that contribute to the decision-making process of a mixture design: economics, availability of materials, specification requirements, construction considerations, additives and others must be considered. One question the research team must address during the development of the research project is: How are design considerations prioritized in the BMD process? Researchers are expected to recommend a methodology to set rational performance limits so that available materials can be used without cost prohibitive consequences.

• Record URL:
  https://wisconsindot.gov/documents2/research/rfp-ffy20-flexible-bmd.pdf
• 

Language

• English

Project

• Status: Active
• Funding: $150000
• Contract Numbers:

  0092-20-04

• Sponsor Organizations:

  Wisconsin Department of Transportation

  4802 Sheboygan Avenue
  Madison, WI  United States  53707
• Project Managers:

  Hefel, Steven

• Performing Organizations:

  National Center for Asphalt Technology

  277 Technology Pkwy
  Auburn, AL  United States  36830
• Principal Investigators:

  West, Randy

• Start Date: 20190624
• Expected Completion Date: 20201224
• Actual Completion Date: 0

Subject/Index Terms

• TRT Terms: Flexible pavements; Hot mix asphalt; Materials; Mix design; Performance based specifications
• Subject Areas: Design; Highways; Materials; Pavements;

Filing Info

• Accession Number: 01722042
• Record Type: Research project
• Source Agency: Wisconsin Department of Transportation
• Contract Numbers: 0092-20-04
• Files: RIP, STATEDOT
• Created Date: Nov 12 2019 11:52AM