NCDOT has updated the WMA allowances to include any state route and interstates (when using PG76-22), for technologies that have been used in over 250,000 mix tons. Over the last 18 months, NCDOT has made a targeted effort to promote and track warm mix usage across the state. In doing so, they have also been able to monitor WMA performance. During this time period, Evotherm has been the most widely used warm mix product on the market. This represents a major shift for a state that was nearly 90% foam three years ago for any WMA that was produced.
Aside from the normal HMA mix design and JMF approval processes, there are no special requests needed for a contractor to utilize an approved WMA technology on major interstate projects. Evotherm is the only additive-based technology to achieve this threshold.
Author: David Newton