by Tom Kuennen
ALDOT HiMA Application on Busy Highway Driven
by Persistent Rutting, Experience at Close-By Test Track
The Alabama Department of Transportation (ALDOT) leveraged pavement research from the National Center for Asphalt Technology (NCAT) to validate the use of a new, high-performance, highly modified asphalt pavement mix that it anticipates will stand up to brutal truck traffic.
The highly modified asphalt (HiMA) mix, placed as an intermediate or binder course on U.S. 231 in mid-2012, contains a much higher percentage of polymer modifier than conventional modified mixes. The HiMA binder contained 7.5 percent SBS (styrene-butadiene-styrene) polymer, more than twice that used in conventional polymer-modified binders.