Hot Mix Asphalt Technology - January/February 2008 - (Page 22)

Warm Mix: The Lights are Green continued drew a standing-room-only crowd, and interest in the subject has zoomed ever since. “Warm mix has been tried on stone-matrix asphalt (SMA), opengraded friction courses and densegraded mixes, all with success,” says David Newcomb, Ph.D., NAPA vice president of research and technology. “Warm mix is progressing very rapidly,” says Newcomb. “The whole technology has taken off very quickly, and the implementation will be much wider than with SMA, for example.” Federal and regional air quality regulations already limit emissions in non-attainment areas. “Warm mix gives contractors in these (nonattainment) areas opportunities to produce asphalt and avoid problems with emissions regulations,” said Randy West, director of the National Center for Asphalt Technology (NCAT). Moreover, West says, warm mix offers reduced energy costs because less fuel is needed to produce a ton of asphalt. That will give contractors an incentive to use warm-mix additives or processes on their own. Under sponsorship by NAPA and the State Asphalt Pavement Associations, NCAT undertook the first U.S. research on warm mix. Since then, NCAT has published reports on a number of the warm-mix technologies. These research reports are available at www.ncat.us. “People are looking at the lowered emissions and fuel savings as two of the benefits, but now contractors are looking at how they can use warm Rosphalt Protection That Protects and Performs in Tough Environments ROSPHALT – A “Dry Mix” additive offering superior results. Over 3.5 times more life than standard HMA designs based on AASHTO’s Beam Fatigue along with independent testing. If you need a product that lasts and lasts you can count on a Rosphalt solution with over 23 years’ practical field experience offering: • Better long term durability • Best resistance to rutting or shoving • Best waterproofing system (R50) • Fast track construction solver • Cost competitive and long term cost effectiveness. Bridge Deck overlays (most cost effective solution when considering traffic control) Interstate access ramps Bus Turn-arounds Truck – Weigh Scales Heavy traffic intersections Solutions for reflective cracking Airports • Rehab over existing stable base • Excellent solution over concrete in failure mode Motor Speedways “Because warm mix reduces emissions, we might be able to use it for paving even on days when the air quality is not the best.” mix as part of the paving process,” said Larry Michael, an asphalt consultant who represents warm-mix additive manufacturer Sasol Wax. “Contractors are looking for ways to improve workability with RAP or with polymer mixes, for a way to run more RAP, and ways to improve density.” Long-term performance has not been proven in this country, but there are new studies under way to do that. And as Newcomb points out, a mix design procedure needs to be developed that incorporates warm-mix temperatures. That too is happening, under NCHRP 9-43. (NCHRP is the National Cooperative Highway Research Program.) “None of the warm-mix technologies are a cure for everything,” cautions Michael. “If you have a very stiff RAP you can’t Doug Zuberer • (508) 341-4961 • dzuberer@chasecorp.com 22 • Hot Mix Asphalt Technology – JANUARY/FEBRUARY 2008 http://www.ncat.us

Table of Contents Feed for the Digital Edition of Hot Mix Asphalt Technology - January/February 2008

Hot Mix Asphalt Technology - January/February 2008 Contents Chairman's Commentary President's Perspective A Conversation with the New NCAT Director NCAT Test Track: Real-Time Testing for Real-World Results Warm Mix: The Lights are Green Illinois Tollway Tests RAP in Fast Forwarded Research Big Creek Teams with TxDOT to Pave Using Innovative Asphalt Mix Diamond Achievement Commendation Issues a Call for Quality Calendar of Events CONEXPO-CON/AGG Product Review Index of Advertisers Advertisers.com

Hot Mix Asphalt Technology - January/February 2008

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.