Looking Good at 20MM ESALs

Mar 20, 2012

NCAT held the 4th Test Track Conference to summarize all of the findings from the 2009 research cycle. Mike O’Leary, Lance Brooks, and I were able to attend the conference and take a tour of the track. We checked out the Evotherm WMA pavement which was placed in 2005. It is the oldest WMA section to be placed on a test track in the world. This section has now had over 20 MM ESALs on it and it still looks great, with hardly any rutting or cracking.  Hopefully, we will see the same great performance after another 20 MM ESALs!

This research cycle included sections with WMA, high RAP, OGFC, high polymer mix, and ground tire rubber.  The Evotherm section, produced at 250F, was very comparable to the HMA control, produced at 335F, in terms of rutting with less than 1/6-inch of difference.  The total rutting was below the half-inch and no cracking was observed in either section.

The next research cycle will have a larger focus on pavement preservation. Traffic will continue on some of the 2009 test sections until trigger distresses are reached. At that time, a consensus pavement preservation treatment will be applied. This research will also extend to an offsite county road so that several different treatments and pavement conditions can be studied. It sounds like new and exciting things are in NCAT’s future. 


Author: Jenna Michael