The contents of this web site are to promote the understanding of warm-mix asphalt during its research and development phase in the United States. This web site cannot be used to promote or single out any one specific asphalt technology.

Warm-Mix Asphalt Takes Off

Warm-mix asphalt technologies allow the producers of asphalt pavement material to lower the temperatures at which the material is mixed and placed on the road. Reductions of 50° to 100° Fahrenheit have been documented. Such drastic reductions have the obvious benefits of cutting fuel consumption and decreasing the production of greenhouse gases. In addition, engineering benefits include better compaction on the road, the ability to haul paving mix for longer distances, and extending the paving season by being able to pave at lower temperatures.

In 2013, the Construction Innovation Forum awarded warm-mix asphalt a NOVA Award for Construction Innovation.

Warm-Mix Usage Reaches New Heights

The latest NAPA/FHWA survey of asphalt producers' use of recycled materials and warm-mix asphalt find that nearly a quarter of all asphalt produced during the 2012 construction season was produced using warm-mix asphalt technologies.

The survey, conducted by NAPA under contract to FHWA, found that about 86.7 million tons of WMA in 2012. This is a 26 percent increase since 2011 and a 416 percent increase in the use of warm mix since the survey was first conducted in 2009. Full results from the survey are available at

New Edition of Warm-Mix Asphalt: Best Practices

Warm-Mix Asphalt: Best Practices, 3rd EditionThe definitive publication on warm-mix asphalt has been expanded and updated with its third edition. The 68-page third edition of Warm-Mix Asphalt: Best Practices, published in 2012, presents the state of the practice for warm-mix asphalt. Warm-mix technologies have rapidly developed and evolved, and information is included on 22 processes and products (versus eight in the first edition). Thirty U.S. states now have specifications for warm mix. The section on best practices for production has been expanded, providing both short- and long-term recommendations to address potential production issues. Data is provided supporting improvements in emissions and working conditions as well as performance. Summaries are also provided of ongoing research. This document is designed to be used by both agency and contractor personnel. Learn more. Arrow image to denote a link

2nd International Conference on Warm-mix Asphalt
October 11–13, 2011 — St. Louis, Missouri

The 2nd International Conference on Warm-mix Asphalt was held October 11–13, 2011, in St. Louis. This event brought more than 550 attendees from 45 states and 24 countries together for two-and-a-half days of plenary sessions, technical presentations, and exhibits. FHWA Deputy Administrator Greg Nadeau and NIOSH Director Dr. John Howard kicked off the proceedings. NAPA 2011 Chairman Kim Snyder of Eastern Industries Inc. in Pennsylvania welcomed the attendees. Plenary sessions provided perspectives on warm mix from the U.S., Europe, and South Africa. Forty-five papers were presented in breakout sessions, covering topics ranging from health, environment, and performance to RAP and WMA. With 35 exhibitors, attendees were also able to learn about many of the warm-mix products, processes, and technologies. Following the conference was a plant and paving tour provided by Pace Construction Co. Inc. of St. Louis, the Missouri Asphalt Pavement Association, and the Missouri DOT.

Key takeaways from the conference: Warm-mix is the future of asphalt, providing both construction benefits and enhanced working conditions; implementation is proceeding rapidly in the U.S.; and interest in other countries is very keen.

Proceedings of the 2nd International Conference on Warm-Mix Asphalt can be purchased through the NAPA StoreArrow image to denote a link

Divider Recently Added Title
Warm-Mix and Recycled asphalt a cost-saving combo that should be used whenever possible Arrow image to denote a link by Chris Hill [Get Link]
Brookhaven warms to use of cooler asphalt for road paving Arrow image to denote a link by William Murphy [Get Link]
Proposed Guide Spec for WMA Arrow image to denote a link by Ray Brown [Get Link]
Status of Implementation Arrow image to denote a link by Ray Brown [Get Link]
Performance of WMA Arrow image to denote a link by Ray Brown [Get Link]

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