Stacey D. Diefenderfer, Ph.D., P.E.

Associate Principal Research Scientist

Research Interests:

  • Asphalt materials characterization, evaluation, performance and design
  • Balanced mix design (BMD)
  • Reclaimed asphalt pavement (RAP)
  • Warm mix asphalt (WMA)
  • Flexible pavement design and analysis

Education:

  • Ph.D., Civil Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA
  • M.S., Civil Engineering, Virginia Polytechnic Institute and State University
  • B.S., Civil Engineering, Virginia Polytechnic Institute and State University

Registration:

  • Registered Professional Engineer, Commonwealth of Virginia

Memberships:

  • FHWA Asphalt Pavement and Materials Technical Feedback Group
  • FHWA Warm Mix Technical Working Group (2009 – 2012)
  • Transportation Research Board
    • Chair - AFK30 Non-binder Components of Asphalt Mixtures (2015 – 2020)
    • Chair - AKM30 Asphalt Materials Selection and Mix Design (2020-2021)
    • Member - AFK20 Asphalt Binders (2005-2017)
    • Member - AFK30 Non-binder Components of Asphalt Mixtures (2007-2015)
    • Member - AFK50 Structural Requirements of Asphalt Mixtures (2012-2020)
    • Member - AKM30 Asphalt Materials Selection and Mix Design (2021-2022)
    • Member - AKM40 Asphalt Mixture Evaluation and Performance (2021-2022)
  • National Cooperative Highway Research Program (NCHRP)
    • Panel 09-22 Beta Testing and Validation of HMA PRS
    • Panel 09-49 Performance of WMA Technologies: Stage I -- Moisture Susceptibility
    • Panel 09-49A Performance of WMA Technologies: Stage II - Long Term Performance
    • Panel 09-50 Performance Related Specification for Asphaltic Binders Used in Preservation of Surface Treatments
    • Chair - Panel 09-55 Recycled Asphalt Shingles in Asphalt Mixtures with Warm Mix Asphalt Technologies
    • Panel DTFRS-01 TFRS Project Panel on Quality (QA) Aspects of Performance Related Specifications (PRS)
    • Chair – Panel 09-68 Recycled Asphalt Materials: Binder Availability and Its Impact on Mix Performance
    • Synthesis Panel 50-14 Practices for Fabricating Asphalt Specimens for Performance Testing in Laboratories
    • Synthesis Panel 52-17 Use of Recycling Agents in Asphalt Concrete Mixtures
  • Association of Asphalt Paving Technologists
    • Board of Directors - Director at Large
    • Board Liaison – Newer Member Committee
    • Member – Membership Committee
  • ASTM International – Member
    • Member – Committee D04 Road and Paving Materials
    • Member – Subcommittee D04.21 Specific Gravity and Density of Asphalt Mixtures
    • Member – Subcommittee D04.26 Fundamental/Mechanistic Tests
    • Member – Subcommittee D04.30 Methods of Sampling
  • International Society for Asphalt Pavements (ISAP)

Awards:

  • VTRC Jack H. Dillard Best Paper Award, "Simple and Practical Tests for Rutting Evaluation of Asphalt Mixtures in the Balanced Mix Design Process" (with I. Boz and J. Habbouche), 2023
  • VTRC Tilton E. Shelburne Award, 2022
  • VTRC Jack H. Dillard Best Paper Award, "Balanced Mix Design for Surface Asphalt Mixtures: Phase I: Initial Roadmap Development and Specification Verification" (with I. Boz and J. Habbouche), 2021
  • W. J. Eammons Award for Best Paper, Association of Asphalt Paving Technologists, 2016
  • VTRC Jack H. Dillard Best Paper Award, 2015
  • VCTIR Horizon Award for Outstanding Productivity and Achievement, 2014
  • Outstanding Young Alumni Award, Via Department of Civil and Environmental Engineering, Virginia Tech, 2013
  • VDOT Commissioner's Award for Outstanding Achievement - Innovation and Quality Improvement, 2011
  • VCTIR Horizon Award for Outstanding Productivity and Achievement, 2011
  • VTRC Jack H. Dillard Best Paper Award, 2006
  • Dean's List for Teaching Excellence, College of Engineering, Virginia Tech, Spring 2000
  • Charles E. Via Doctoral Fellowship, Charles E. Via Department of Civil and Environmental Engineering, Virginia Tech, Fall 1999 - Spring 2003
  • Dean's List for Teaching Excellence, College of Engineering, Virginia Tech, Spring 2000

Current Projects

Reports

Stacey D. Diefenderfer, Ph.D., P.E.

Stacey.Diefenderfer@VDOT.Virginia.gov

(434) 293-1933

Team Membership

Last updated: May 7, 2024

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