Asphalt paving increases use of recycled materials
Thanks to broad adoption of sustainable construction practices by the asphalt pavement industry, many asphalt roads are getting greener, conserving natural resources and saving taxpayers money.
In 2011 alone, recycling America's roads saved about 21.2 million barrels of liquid asphalt binder worth some $2.2 billion.
According to a survey conducted by the National Asphalt Pavement Association (NAPA) under contract to the Federal Highway Administration (FHWA), record-high levels of recycled materials were used in the construction of new pavements and the use of energy-saving warm-mix asphalt also reached a new high during the 2011 construction season.
"Asphalt pavements are the sustainable option for paving our nations' roads and highways. With warm mix, we can use less energy to produce high-quality pavements, and RAP and RAS allow us reuse liquid asphalt, saving costs and preserving natural resources," said John Keating, NAPA 2013 Chairman and President and COO East of Oldcastle Materials Inc.
According to the survey, about 66.7 million tons of reclaimed asphalt pavement (RAP) and 1.2 million tons of reclaimed asphalt shingles (RAS) were collected in the U.S. during 2011 for use in new pavements. Also, about 19 percent of all asphalt produced in the country that year was made using warm-mix asphalt (WMA) technologies.
The use of RAP and RAS during the 2011 paving season translates to a saving of 21.2 million barrels of liquid asphalt binder, saving taxpayers some $2.2 billion. When reclaimed asphalt pavement and shingles are processed into new pavement mixtures, the liquid asphalt binder in the recycled material is reactivated, reducing the need for virgin asphalt binder.
Using reclaimed materials also reduces demands on aggregate resources. With RAP, old roads can be effectively mined for the raw materials needed to create their replacements. Warm-mix asphalt technologies allow asphalt pavements to be produced at lower temperatures, which means reduced energy demands, as well as lower levels of emissions during production and paving.
"The way old asphalt pavements can be used to build new ones cannot be matched by any other paving material," said Mike Kvach , Executive Director of the Asphalt Pavement Alliance. "Cities, states, and private companies should embrace the use of recycled materials and warm-mix asphalt to ensure that they get high-quality, sustainable roads and save taxpayers billions of dollars in the process."
Compared to a previous survey of the 2009 and 2010 construction seasons, the use of these sustainable practices has continued to increase.
In 2011, RAP usage reached 66.7 million tons, a 7 percent increase from 2010 and a 19 percent increase from 2009. More than 99 percent of reclaimed asphalt pavement went back into new construction, pavement preservation, rehabilitation, and other paving projects.
RAS usage also continued to climb, increasing to 1.2 million tons in 2011 — an 8 percent increase over 2010, and a 52.5 percent increase since 2009. Since 2009, RAS usage has been reported in 36 states. RAS includes both manufacturers' scrap shingles and post-consumer roofing shingles.
In 2011, total WMA tonnage in the U.S. was estimated at about 69 million tons, a 67 percent increase from 2010 and a nearly 309 percent increase since 2009.
The survey was conducted in mid-2012. Results from 203 companies with 1,091 plants in 49 states and Puerto Rico, along with data from 32 state asphalt pavement associations, were used to calculate industry estimates for total tonnage. A slight variation from the previously reported 2010 results is due to changes in survey design to ensure greater accuracy.
A copy of the full survey, including a state-by-state breakdown of the data, is available at www.asphaltpavement.org.
Original source: www.asphaltmagazine.com.