Dem-Con Recovery & Recycling, a subsidiary of Dem-Con Companies, Shakopee, Minn., is ready to recycle tear-off asphalt shingles and is awaiting for the proper materials specification to be developed by the Minnesota Department of Transportation (McDOT) in order to meet market demand.

CMRA member Dem-Con is a mixed C&D recycling company that has recently invested in the equipment and systems needed to turn tear-off shingles into a valuable recycled product.  Once residential asphalt shingles has been sorted and cleaned to remove contaminants and then ground, the product can be introduced into the mix at hot mix asphalt (HMA) plants.  HMA plants manufacture asphalt mix that paving companies use for making flexible bituminous pavement for roads, parking lots, driveways.

Commercial Asphalt Co., a nearby HMA producer, has successfully tested the use of asphalt shingles (RAS) material produced by Dem-Con. Commercial Asphalt, a subsidiary of Tiller Corp., manufactures high-quality asphalt.  Commercial has been making and using recycled asphalt pavement (RAP) from old bituminous roads for more than 20 years.  Commercial has extensive experience with the quality control procedures needed to produce high quality products.  They believe the time has come for tear-off shingles to be a part of a viable HMA product.

“Recycling of tear-off shingles will be a significant new step forward in abating the need for land filling shingles,” said Jason Haus, vice president, Dem-Con. “Our landfill along receives about 50,000 tons per year of roofing waste.”

Dem-Con is serious about is commitment to produce the highest quality tear-off RAS product. “Based on other demonstrations in Minnesota and in other states, we not only invested in a new shingle grinder, but also a sorting and cleaning system to assure we can meet any material specification our customer’s needs,” said Haus.  “The quality and cleanliness of the RAS will differentiate companies that are looking to enter this market.  We have received samples of very high quality and low quality RAS and the main difference is the effort put forth to ensure the cleanliness of the product.  The cleaning and sorting process to eliminate foreign debris is critical in producing a high quality RAS.

“The next neede step for large scale recovery of tear-off shingles if a permissive MnDOT specification similar to the specification granted for manufactured scrap shingles,” said Haus.

“Once the permissive specification is determined and assuming virgin asphalt prices remain high, the land disposal of shingle material will become rare.  Our industry is prepared to provide his material to HMA producers on a large scale.  Without the MnDOT space, we will have to continue land filling valuable tear-off shingles.  We have a great opportunity to reduce materials being land filled while providing a substitute for virgin asphalt at a lower price.  Recycling and positive economics have always been a large debate within the solid waste field and with recycled asphalt shingles, there is very little debate, it just makes sense.”

“We have the capacity to do this,” said Robert Keuhborn, manager of product design/quality control, Commercial Asphalt. “Recycling tear-off shingles is now a well proven, feasible technology.  When we bring this new technology up to full scale, it will help us conserve asphalt cement and save money.  Part of this savings can be passed along to the driving public.  The time has come for tear-off asphalt shingles to be accepted as another standard recycled material into hot mix asphalt.  Tear-off shingles should be part of permissive materials specification similar to the way RAP and manufacturers’ asphalt shingle scrap are considered by MnDOT today.  In order to consume any meaningful quantity of tear-off shingles, the HMA industry needs a permissive specification because we want to produce MnDOT certified mixes on a standard, full scale basis.”

One recent study indicated that on a statewide basis, tear-off shingles recovery could reach at least 156,000 tons per year by 2012.  Given the oil content within tear-off shingles (at least 20%). About 32.000 tons per year of binder (i.e., virgin liquid asphalt oil) would be conserved by recycling shingles into HMA pavement.  Using a conservative price estimate of $400/ton of liquid virgin binder, this savings has an equivalent of about $12.5 million.

Source: C&D World: Industry News – January/February 2009