Report from NAPA also finds an increase in use of warm mix.
The National Asphalt Pavement Association (NAPA) reports that a survey of the U.S. asphalt pavement industry finds that close to 25 percent of the asphalt mixtures manufactured in the 2012 construction season were produced using warm-mix asphalt (WMA) technologies.
The survey, conducted by NAPA under contract to the Federal Highway Administration (FHWA), found that the 1,141 U.S. asphalt plants queried produced about 86.7 million tons of WMA during the 2012 construction season, a 416 percent increase in the use of warm mix since the survey was first conducted in 2009.
Because WMA is produced at a lower temperature than traditional asphalt mixes it uses less energy to produce, reduces emissions, improves worker safety and offers construction benefits, according the NAPA.
In a statement made during the 2014 Transportation Research Board’s annual meeting, U.S. Secretary of Transportation Anthony Foxx said that the use of WMA is expected to save $3.6 billion in energy costs alone by 2020.
The NAPA also notes that asphalt pavements also continue to use increasing amounts of recycled and reclaimed materials. The survey found that about 68.3 million tons of reclaimed asphalt pavement (RAP) and 1.86 million tons of recycled asphalt shingles (RAS) were used in new asphalt pavement mixes in the United States during the 2012 construction season. For the first time since the start of this survey in 2009, the amount of RAP and RAS used by producers exceeded the amount collected, the NAPA notes.
“Ensuring high performance roads at a cost-effective price has always been a goal for the asphalt pavement industry. It has spurred us to continue to look for new solutions and to put innovations into practice,” says NAPA President Mike Acott. “This survey reflects how the industry is rapidly putting sustainable innovations, such as warm-mix asphalt, to use to ensure that drivers get the smooth, dependable roads they want at a price taxpayers can afford.”
In 2012, RAS usage reached 1.86 million tons — a 56 percent increase over 2011, and a 165 percent increase since 2009. Since 2009, RAS usage has been reported in 37 states. RAS includes both manufacturer scrap shingles and post-consumer roofing shingles.
RAP usage also continued to climb, increasing to 68.3 million tons in 2012, a nearly 22 percent increase from 2009. According to NAPA, more than 99 percent of asphalt pavement reclaimed from roads went back into new roads. In the survey, 98 percent of producers reported using RAP in their mixes.
The 2012 survey also asked for the first time about the use of ground tire rubber, steel and blast furnace slags, and other recycled materials. Although national estimates of these products’ usage were not calculated, more than 1 million tons of other recycled materials was reported as being incorporated into asphalt mixtures.
The survey was conducted in the middle of 2013. Results from 213 companies with 1,141 plants in 48 states and Puerto Rico, along with data from 36 state asphalt pavement associations, were used to calculate industry estimates for total tonnage.