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Courtesy TxDot,

AUSTIN – With an agency goal of improving air quality and a desire to reduce waste, cut costs and improve efficiency, the Texas Department of Transportation (TxDOT) and their contractors have to get creative. The use of recycled or reclaimed materials, such as asphalt shingles or rubber tire scrap, in road building is one way to accomplish that goal.

Approximately 11 million tons of asphalt roofing shingle scrap is generated each year in the United States. TxDOT, contractors, manufacturers, roofers and builders collaborated in blending recycled asphalt shingles into asphalt pavement because of the large quantity of scrap material, rising petroleum prices and increased disposal costs.

“Using recycled asphalt shingles in hot mix asphalt has created a win-win solution between the asphalt paving industry, TxDOT and the environment,” said Robert Lee, pavement construction engineer. “Not only are we saving money and stretching taxpayer dollars, using recycled asphalt shingles reduces carbon emissions, decreases the energy it takes to produce hot mix asphalt and saves landfill space.”

Cost savings for materials are also realized through the use of these recycled products. Five percent of recycled shingles added to hot mix asphalt results in a 20 percent cut back on liquid asphalt purchases.

The savings can really add up. Not just fiscally, but also in the consumption of landfill space. Placing a two-inch hot mix overlay with five percent recycled shingles on one mile of a two-lane road uses 80 tons of shingles and saves 40 cubic yards of landfill space. That’s as many shingles as roofers would remove from 40 2000-square foot homes.

In the last 18 months, TxDOT has prequalified two dozen shingle processing operations to supply TxDOT projects.

“It’s taken a lot of hard work from multiple agencies, the recycling industry and the paving industry to get the process off the ground,” Lee said. “We’re finally starting to see the benefits of all our efforts.”

TxDOT is committed to improving the environment, and in 2009, the department was honored by the Texas Commission on Environmental Quality with an Environmental Excellence Award for TxDOT’s commitment to a cleaner future for Texas.
In fiscal year 2009, TxDOT used more than 2.8 million tons of reclaimed asphalt and the equivalent of about 780,000 tires of scrap rubber in highway projects throughout Texas.
Since FY 2006, TxDOT has reclaimed and reused about 15 million tons of roadway material, saving space in landfills and reducing the environmental impact of new roadway material production and transport.
Using alternative fuels, TxDOT has saved over 52 million gallons of gas since 1993.    The use of low emission diesel reduced emissions of nitrogen oxide by approximately 52 tons Sept. 2003 – March 2005. 

For more information on asphalt roofing shingles and the application process, please visit http://www.txdot.gov/business/contractors_consultants/recycling/asphalt_shingles.htm.