Using Recycling Agents in Balanced Mix Design with High Recycled Materials Content

Asphalt Academy


Environmental sustainability and economic benefits motivate increased use of recycled asphalt materials, including reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS), in asphalt pavements. However, adequate cracking performance initially and with time when these stiff, brittle, aged materials are added to virgin asphalt-aggregate mixtures must be maintained by engineering each unique materials combination of virgin and recycled materials. Recycling agents can be added to partially restore rheology and improve cracking performance of mixtures with high recycled materials contents, but performance must be balanced between rutting and cracking.
This webinar will summarize a forthcoming draft AASHTO Standard Practice for the use of recycling agents in asphalt mixtures with high recycled materials contents and provide: (1) component materials selection guidelines for virgin binders, recycling agents, and recycled materials (RAP and RAS) and their proportions; (2) a recycling agent dose selection method; (3) a binder availability factor for recycled materials for use in mix design; and (4) binder blend and mixture evaluation tools that include aging protocols, recycling agent incorporation methods, and laboratory tests and corresponding thresholds for balanced rutting and cracking performance.


Professional Development Hours:

  • 60 Minutes, 1.0 PDHs

A PDH Certificate is available upon request after you complete the session by sending an email to with the name of the webinar and full name you used to register.


  • Dr. Amy Epps Martin
    Bio: Dr. Amy Epps Martin has more than 22 years of experience teaching civil engineering materials courses and conducting research on safe, sustainable asphalt technologies at Texas A&M University and the Texas A&M Transportation Institute where she is a professor and researcher. She received her education at the University of California at Berkeley.

Who Should Attend:

This webinar is intended for an audience of technicians and engineers who are relatively new to the field of asphalt materials and are interested in learning the basic steps and tests used in an asphalt mix design. Sales and marketing students will also benefit from the overview of the asphalt mix design process.


  • Registration is per individual. Only the registered person will receive emails about the webinar and will be recognized for a PDH certificate. See below for group registration.
  • We would encourage you to visit to ensure your system is compatible with our webinar system before you register or as soon as possible afterward.
  • We also highly recommend that you go to: and join a test meeting to load the client and test your system.

Group Registration & PDH Certificate Policy

For more information contact: