Minnesota Department of Transportation

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Road Research

NRRA Flexible Team

Orange barrels on a highway

Mix Rejuvenator Test Sections (Phase II)

Status: Active
Project Start Date: August 24, 2020
Project End Date: August 31, 2024

Project objectives

Asphalt rejuvenators are used to incorporate higher amounts of Reclaimed Asphalt Pavement (RAP) in Hot Mix Asphalt (HMA) without detrimentally impacting the long-term performance of the pavement. Rejuvenating agents (RAs) are relatively new in the HMA industry and there are many different products marketed to transportation agencies. However, most of these products have limited field and laboratory test data available to support their effectiveness over time. Several recent research efforts have shown that some products, while effective immediately after production, show rapid decrease in effectiveness with aging. Therefore, there is a need for a better understanding of how various RAs perform over time through both laboratory and field evaluations to help guide engineers on appropriate usage of these materials.

The National Road Research Alliance (NRRA) Flexible Team constructed field test sections as part of a mill and overlay project on Trunk Highway 6 (TH6) located in Emily, MN in August of 2019. These field sections include wearing courses with 40% RAP that incorporate seven different RA products, with the dosage determined by the supplier to meet a target extracted and recovered performance grade (PG) of XX-34. In addition to the RA test sections, there are control sections with 40% RAP and 30% RAP (the maximum level allowed on remainder of this project).

The objective of this research project is to evaluate the effectiveness of the seven RA products over time and evaluate their performance as compared to the control mixtures. This will be accomplished through a combination of binder and mixture characterization and performance testing using different laboratory aging levels, field core testing, and performance monitoring of the field sections over time.

Project tasks

Task 1: State of the art review, determination of additional laboratory long-term mixture conditioning method

Task 2: Summary of construction information and binder testing results

Task 3: Summary of mixture testing results

Project team

Principal Investigator: Jo Sias, University of New Hampshire, jo.sias@unh.edu
Technical Liaison: Michael Vrtis, MnDOT, michael.vrtis@state.mn.us
Project Technical Advisory Panel (TAP) – email the TAP
Contact us to join this TAP

  • Jim Arduino, Georgia Pacific
  • Jason Bausano, Ingevity
  • Andy Cascione, Flint Hills
  • Curt Dunn, NDDOT
  • Mohamed Elkashef, UC Davis
  • John Garrity, MnDOT
  • Jerry Geib, MnDOT
  • Andrew Hanz, Mathy
  • Brian Hill, Iowa DOT
  • Bob Kluttz, Kraton
  • Ryan Lynch, Georgia-Pacific Chemicals
  • Alex McCurdy, Poet
  • Pete Montenegro, Collaborative Aggregates
  • Nathan Moore, NCAT
  • Terry Naidoo, Asphalt and Wax Innovations
  • Paul Nolan, MnDOT
  • Dan Oesch, MoDOT
  • Barry Paye, WisDOT
  • Raghu Shrestha, Caltrans
  • Hassan Tabatabaee, Cargill
  • Nam Tran, NCAT
  • Michael Vrtis, MnDOT (TL)
  • Randy West, NCAT
  • Chris Williams, Iowa Sate University
  • Tyler Wollmuth, NDDOT

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