The Indiana Department of Transportation (INDOT) has announced new paving specifications that allow for additional use of recycled materials. By increasing the amount of reclaimed asphalt pavement and recycled roofing shingles within asphalt mixes, INDOT anticipates it can save $10 to $15 million on annual paving expenses.
INDOT previously allowed a limited amount of reclaimed asphalt pavement and new roofing shingles discarded at the factory to be included in hot mix asphalt. Starting in April, INDOT contractors can use an increased amount of these materials, as well as post-consumer shingles torn off existing roofs.
Recycled materials are tested to make sure the overall asphalt mix meets or exceeds standards for safety, durability and longevity set by the American Society of Testing Materials and the American Association of State Highway and Transportation Officials. The INDOT also notes that because liquid asphalt is a petroleum-based product, the change also reduces Indiana's dependency upon imported crude oil.
"Indiana is one of the leading states in the country in using recycled materials in its highways," says Ron Walker, manager of INDOT's Office of Materials Management. "Recycling existing concrete and asphalt pavement makes use of a valuable resource previously financed by Indiana's taxpayers."
As research in this field continues, INDOT hopes to make increasing use of recycled paving materials in the future.