Caltrans Drafts Updated RAP/RAS Specification

Jun 16, 2014

Caltrans is catching up to other states throughout the US with regards to the use of high percentages of recycled asphalt pavement (RAP). Now that the State has completed the effort to implement the use of the gyratory compactor as well as the Hamburg Wheel Rut Test, Caltrans is reviewing draft specifications for the use of increased percentages of RAP as well as recycled asphalt shingles (RAS). The highlights of the latest effort include the following:

  • Specifications focused on binder replacement
  • RAP Only: Allows as much as 40% binder replacement (25% maximum binder replacement for surface lifts)
  • RAS Only: 25% maximum binder replacement (0-5% RAS)
  • RAP & RAS: 30% maximum binder replacement (5% RAS maximum)
  • Require mix binder grade check when using RAS
  • Identify a discount value for the asphalt contribution from RAS
  • Allow the use of additives in mixes to obtain required binder/mix properties.

The last key provision allows contractors to capture the full value of the EvoFlex and Evotherm technologies. The final Caltrans specification will be available for use by contractors through a Standard Special Provision in 2014. The RAP Only portion of the specification is intended for incorporation in the 2015 Standard Specifications.

Author: Brandon Milar