Specification Corner

Colorado DOT
No significant specification changes, although we developed a Project Special Provision to allow up to 0.5% PPA. To date, it has not been used on any CDOT projects. Our default is no PPA modification.

Florida DOT
Effective in January 2017, PG 76-22 polymer modified asphalt (PMA) and PG 76-22 asphalt-rubber binders (ARB) are considered equivalent, and it will be the contractor’s choice as to which binder to use. Both binders must meet the same PG binder tests including MSCR Jnr and % recovery.

Effective in July 2017, FDOT has removed PG 82-22 (PMA) from its binder program and replaced it with a highly polymer modified binder, conventionally referred to as HiMa binder.

FDOT is considering implementing an FTIR scan of modified binders as part of being included on the Approved Products List. It will not be used in routine acceptance testing, but would be used for forensics testing and perhaps in IA sampling. This will likely happen in 2018.

Montana DOT
We are slowly moving towards implementing MSCR for our binder acceptance. We are waiting for comments from our local refineries. Our hope is to have it in place for construction season 2018.

Ohio DOT
We are currently planning on making significant changes to our 421 microsurfacing specification to include more QC related items as well as including a few more mix design tests.

South Carolina DOT
We have revised our SC-M-402 specification dealing with mix design properties. We are now using a 9.5mm surface PMA mix under our OGFC mixes, and our old 12.5mm surface PMA mix has become an intermediate mix. We are encouraging the HMA contractors to use COAC on RAP/RAS mixtures using a 0.75 availability percentage based on percent aged binder in surface and intermediate mixtures to improve mix durability.

Tennessee DOT
We will begin allowing GTR modification as an option in 2018.

Utah DOT
We added a longitudinal joint specification to our HMA this year and are evaluating it to see how things went.

Washington State DOT
We will be implementing AASHTO Standard Specification M 332 and Standard Method T 350, Multiple Stress Creep Recovery (MSCR), for PG binders in Washington State effective January 1, 2018. After several years of research and testing, WSDOT states that the implementation of this specification and test procedure will require products and processes used to modify asphalt binders in WA that ensure performance. Additional benefits of implementing M 332 and T 350 include eliminating the PG plus specification (elastic recovery) and test procedure (T 301), which WSDOT has been using since 2012. Eliminating T 301 will reduce laboratory test time, volume of RTFO aged material, as well as time spent cleaning molds, bottles, etc.