Asphalt Pavement Industry Survey on Recycled Materials and Warm-Mix Asphalt Usage: 2014

A shared goal of the Federal Highway Administration (FHWA) and the National Asphalt Pavement Association (NAPA) is to support and promote sustainable practices, such as pavement recycling and warm-mix asphalt (WMA). The use of recycled materials, primarily reclaimed asphalt pavement (RAP) and reclaimed asphalt shingles (RAS), in asphalt pavements reduces the amount of new materials required to produce asphalt mixes, as well as the stream of material going to landfills. This is vital to the mission of environmental stewardship and extending the service life of the nation’s infrastructure while lowering overall costs. WMA technologies have been introduced to reduce the production and compaction temperatures for asphalt mixtures as a means of reducing the energy needed and emissions associated with mix production. Additional benefits include improved compaction of asphalt mixtures leading to improved pavement performance, as well as a longer paving season. As part of FHWA’s Every Day Counts initiative, WMA was chosen for accelerated deployment in federal-aid highway, state department of transportation (DOT), and local road projects. It is important for the industry to document the deployment of these technologies to understand where they are being used and where they may be underutilized. FHWA has established a mechanism for tracking the use of recycled materials and WMA in asphalt pavements. This mechanism has established a baseline for RAP, RAS, and WMA usage and has tracked the growth of the use of these sustainable practices in the highway industry since 2009. The objective of this tracking is to quantify the use of recycled materials and WMA produced annually by the asphalt pavement industry. Results show significant growth in the use of RAP, RAS, and WMA technologies from 2009 through 2014. The asphalt industry remains the country’s most diligent recycler by recycling asphalt pavements at a rate of over 99 percent. The average percentage of RAP used in asphalt mixtures has increased from 15.6 percent in 2009 to 20.4 percent in 2014. In 2014, the estimated RAP tonnage used in asphalt mixes was 71.9 million tons. Assuming 5 percent liquid asphalt in RAP, this represents over 3.6 million tons (20 million barrels) of asphalt binder conserved along with replacing some 68 million tons of virgin aggregate. The combined saving of asphalt binder ($550/ton) and aggregate ($9.50/ton) by using RAP and RAS in asphalt mixes is more than $2.8 billion. This keeps asphalt pavement mixture costs competitive and allows owners to achieve more roadway maintenance and construction activities within limited budgets. In 2014, WMA was about one-third of the total asphalt mixture market. WMA use increased by nearly 7 percent from 2013 to 2014, and about 577 percent since 2009. Plant foaming is used most often in producing WMA, with over 84 percent of the market. WMA additives accounted for about 16 percent of the market.