Asphalt Delivers Some Hot New Mixes
HighwayContractor
By Mike Anderson
Warm-Mix
Asphalt Rolls into Place
T
here is little doubt that even the most staid and traditional of road agencies and contractors
are at least warming to the idea of a cooled-down approach to asphalt production and
application only unveiled to the United States nine years ago. The ability to cut fuel
consumption, greenhouse emissions and employee risk has that effect.
Some industry stakeholders are even convinced warmmix asphalt (WMA), regardless of how the ever-evolving
category here is ultimately defined, will turn out to be the
equivalent to what hot-mix asphalt (HMA) has long been. In
other words, there won’t be any more HMA applications per
se; they’ll all be what we are now loosely terming as WMA.
The Federal Highway Administration (FHWA) and
National Asphalt Pavement Association (NAPA) may not be
ready for such a proclamation quite yet; the two organizations, however, continue to team up to try to get the asphalt industry’s collective head around WMA. Their Second
Annual International Warm-Mix Conference is scheduled
for Oct. 11-13 in St. Louis, Mo. A dedicated website maintained for FHWA by NAPA, www.warmmixasphalt.com acts
as an ongoing source of education, news, research and
products on the market.
More than 30 warm-mix asphalt products or technologies are being marketed and sold in the U.S., “which has
been a challenge for us,” says Mike Corrigan, FHWA program manager, “although a good challenge, because it’s
made us focus really on warm mix as a category. Instead
of focusing on individual technologies, we’ve had to take a
step back and say, ‘Let’s focus on warm mix as a material
and what the performance of that warm mix is.’”
Speaking at NAPA’s Asphalt in Depth Conference held in
June in Nashville, Corrigan did issue a disclaimer about the
products listed on the website, ranging from emulsions to
mixing systems, sourced from long-established suppliers
and market newcomers alike. “The one thing I do like to
point out is that just because it’s on warmmixasphalt.com
does not mean it’s been through any kind of large scrutiny
or evaluation whether it’s appropriate technology. A lot of
them have had a lot of successes, but the only criterion for
us to really list them on the site is the fact that they have
their own website that we can link to, to provide people
Better Roads August 2011 31