The latest NAPA/FHWA survey of asphalt producers’ use of recycled materials and warm-mix asphalt finds that nearly a third of all asphalt produced during the 2013 construction season was produced using warm mix asphalt technologies.
The survey, conducted by NAPA under contract to FHWA, found that 106.4 million tons of WMA was produced in 2013. This is a 23% increase in the use of warm mix from 2012 and a greater than 533% increase since the survey was first conducted in 2009. In the 2009 survey less than 5% of asphalt pavement mix tonnage was produced using warm-mix technologies; in 2013, it was more than 30%.
The survey also found that about 73.5 million tons of reclaimed asphalt pavement (RAP) and 1.7 million tons of reclaimed asphalt shingles (RAS) were used in new asphalt pavement mixes in the United States during 2013.
Producers were also asked about ground tire rubber, steel and blast furnace slag, and other waste material repurposed into pavements. Although national estimates of usage were not calculated, survey respondents reported using nearly 1.2 million tons of these materials in 2013 in the production of more than 6.6 million tons of asphalt pavement mixes.
The tons of asphalt pavement mixtures produced using recycled and reclaimed materials was predominately flat from 2012 to 2013, despite a 2.5% drop in total tons of asphalt produced during 2013 compared to 2012. However, the percentage of tons produced using these materials was slightly greater in 2013 than 2012.
The survey was conducted in mid-2014. Results from 249 companies with 1,281 plants in all 50 states, the District of Columbia, and Puerto Rico, along with data from State Asphalt Pavement Associations for 38 states, were used to compile the report. A full copy of the survey, including state-by-state appendixes, may be downloaded here.