GREENBELT, MARYLAND — A new industry survey conducted by the U.S.-based National Asphalt Pavement Association (NAPA) in partnership with the Federal Highway Administration found that more than 100 million tons of reclaimed asphalt pavement (RAP) was collected for re-use in the United States during 2018.
Nationally, the average amount of RAP in new asphalt pavements during 2018 was 21.1 per cent, which is the highest level reported since the survey began in 2009, stated a Sept. 17 release.
The survey found that 82.2 million tons of RAP, along with 1.05 million tons of recycled asphalt shingles (RAS), were used in 389.3 million tons of new asphalt pavement mixes in the United States during 2018.
An additional 8.8 million tons of RAP and RAS were used as aggregate, in cold-mix asphalt, and other road-building activities.
The survey also found that at year-end 2018 about 111.7 million tons of RAP and RAS was stockpiled for future use across the country.
“Over the years, we’ve seen steady advancement in the amount of RAP being used across the country. This has been the result of concerted engineering efforts by industry and road owners to research and apply best practices to ensure we maintain or improve performance while increasing the use of recycled materials,” said NAPA president and CEO Audrey Copeland in the statement.
“As interest grows in incorporating other recycled materials into pavements, we must continue to gain a solid understanding of how new materials affect pavement performance before we move to widespread deployment.”
NAPA also reported that the use of industry warm-mix asphalt (WMA) technologies, developed to save energy, continues to grow.
In 2018, 157.4 million tons of asphalt pavement mixture was produced using WMA technologies.
More than half of this tonnage was produced at reduced temperatures, meaning less energy was required in manufacturing.
“A decade ago, WMA technologies were a novel idea. In 2018, more than half the asphalt pavement mixture tonnage produced in 23 states used WMA technologies, and in six of those states, it was more than 75 per cent of the tonnage,” stated John Harper, 2019 NAPA chairman, in a statement.
“While there remains room to grow their use, WMA technologies have become just another tool we can use to produce the best asphalt mixture to meet a given project or agency need.”