Subcommittee on Materials

FHWA in Lakewood, CO along with NM DOT, WY DOT, and NV DOT have found that their results for tests performed on binder that has been aged in the RTFO does not correlate well with laboratory results at lower elevations. 

 

FHWA has requested that the following wording be added in a note after section 7.6 to allow laboratories to extend the time in the oven so that they get equivalent aging to those labs at lower elevations.  Since a note is not mandatory language, it allows the laboratories that are having problems to investigate and detemine times that help them correlate with the other laboratories at lower elevations without everyone else having to adjust their operations.

This is the wording suggested by FHWA in Lakewood, CO:

"Note 3-For laboratories at high elevations, the use of aging times greater than 85 minutes may be used.  Individual laboratories may develop the appropriate time."