A la altura de las circunstancias

28 de noviembre de 2015


El permiso otorgado por el Departamento de Transporte de Tennessee para reciclar tejas de asfalto en las mezclas para capas de rodadura le a dado un impulso al reciclado en todo el estado.

By Vaugn Cassidy
Construction & Demolition Recycling, cdrecycler.com
Noviembre de 2015

Recycled road material is nothing new. In Tennessee, the Tennessee Department of Transportation (TDOT) has implemented a number of processes that utilize recycled materials such as glass and crumb rubber. These measures reduce costs, conserve natural materials, and as demonstrated the material that follows, spur local business.

Beginning February 2014, TDOT officially authorized the use of asphalt roofing shingles as a supplemental material for recycled asphalt road mixes. Brian Egan, then the director of the department's construction division, sent out the provided the approval to allow roofing shingles in recycled asphalt pavement mixes.

Asphalt shingle recycling reduces quarrying, mining and oil consumption while keeping 75 million tons of material out of landfills each year. Recycling asphalt also dramatically reduces the consumption of resources such as fuel, machinery, transportation and labor.

This change in the TDOT rules offered a tremendous opportunity for several entrepreneurs in the recycling business, as well as creating a few challenges. The first challenge was identifying shingles to recycle. Keith Street, Putnam County solid waste director, decided to work with any and all area recyclers to ensure a steady supply of feedstock. County officials decided Putnam County would become the first county in the state to divert all asphalt roofing shingles from the landfill to a beneficial end-use. "With our construction and demolition landfill getting more full all the time, we were tickled to death to save all that space," says Street.

Seizing the opportunity

Ground Up Recycling, a start-up company in Cookeville, Tennessee, was the first recycler in Putnam County to take advantage of the opportunity. The company, owned by Matt Allen and Lincoln Young [Ground Up Recycling], took full advantage of the opportunity and soon faced the second challenge: how to make the shingles “road-ready” in an economic and efficient way. Luckily, Allen already had extensive experience in the industry as a result of working in road construction most of his life.

The answer to the second challenge was a custom modified Peterson 4710 grinder, which is portable and crushes and screens the shingle material into a uniform size usable in almost any asphalt manufacturing plant.

Allen and Young also were faced with the third challenge: understanding the complexity of the regulatory environment for a new industry. "This was our biggest hurdle," Allen says, "since we were a new type of business. We soon became the first shingle recovery company to be in full compliance with all of the Tennessee Department of Environment and Conservation and the Tennessee Department of Transportation regulations."

Currently, only 5 percent of any recycled asphalt mixture is allowed to be from shingle material, but that is still a 5 percent savings of material costs. For some asphalt producers in other states this has equated to just over $15 per ton or nearly $500,000 annually, according to a recycled-content analysis from Asphalt Shingle Recycling Systems partner Alan Clarke.

Recovery and reuse of asphalt shingles extends the life of any landfill and lowers costs for roads by not using virgin materials. State Rep. Ryan Williams, R, Cookeville, says, "Tennessee needs our good roads, so we need to save money for those roads any way we can."

Seeing the benefits and the emerging industry, Mac Nolen, solid waste director for Rutherford County, soon followed suit and Rutherford County became the second county in Tennessee to have 100-percent diversion of asphalt shingles from the landfill. State Rep. Mike Sparks, R, Smyrna, who represents part of Rutherford County, says, "I was on the county commission for eight years, so I know a bit about landfill issues. This is a smart option for Rutherford County and for Tennessee."

Making a difference

The public-private partnership has made a difference in the amount of shingles recycled, but Ground Up Recycling also has established a business connection, which has made a significant impact. Owens Corning Roofing and Asphalt LLC, Toledo, Ohio, was the first roofing manufacturer to create a process that increases shingle recycling and material reuse across the U.S. It is continually connecting roofing contractors with shingle recycling facilities throughout the country. Contractors can even take the Shingle Recycling Pledge to be marketed as an Owens Corning Preferred Contractor.

The amount of asphalt shingles that impact Tennessee's landscape is quite staggering. Asphalt Shingle Recycling Systems, another innovative business seeking to use asphalt shingles as primary feedstock, was instrumental in removing nearly 30,000 tons of shingles from two illegal dump sites in Knoxville, Tennessee. The magnitude and innovation of the project caught the attention of Mark Braswell, regional director for external affairs for the Tennessee Department of Environment and Conservation (TDEC) in the Johnson City environmental field office.

"It's refreshing to see traditional waste products recognized as valuable resources when they are recycled and beneficially reused," says Braswell. "Asphalt Shingle Recycling Systems demonstrated superior work in the materials management category and should be recognized as true stewards for the environment."

Currently, only 5 percent of any recycled asphalt mixture is allowed to be from shingle material, but that is still a 5 percent savings of material costs. For some asphalt producers in other states this has equated to just over $15 per ton or nearly $500,000 annually, according to a recycled-content analysis from Asphalt Shingle Recycling Systems partner Alan Clarke.

In addition to the cost savings, finding a beneficial use for a waste product saves resources. For example, a typical residential roof provides enough recycled asphalt to pave a 200-foot section of one lane of highway. That one household of shingles takes four barrels of unrefined oil to produce. Landfills nationwide receive enough shingles in a year to amount to 14 million barrels of oil.

According to Larry Christley of Solid Waste Management Division for the TDEC, several studies were conducted by Middle Tennessee State University and Tennessee State University in 2007 and 2008. The studies estimated that approximately 12 percent of Tennessee’s construction & demolition (C&D) waste stream is asphalt roofing, equating to 171,000 tons. About 65,500 tons are disposed of in Class I landfills while the remaining 105,500 tons go to Class III landfills. Because Class III landfills usually have lower tipping fees than Class I and often charge per cubic yard rather than ton, Class III landfills are the preferred option for disposers of shingles due to the high density of the shingles.

The number of shingles that are being landfilled is decreasing, thanks to the new TDOT regulations. TDOT and TDEC are working in tandem with permitted asphalt recyclers in Tennessee to develop new and improved source collections sites, partnerships with local municipalities, landfills and community leadership to encourage responsible recycling.

http://www.cdrecycler.com/article/cdr1115-recycled-asphalt-shingles-tennessee/