Greensite Recycling is a new asphalt shingle recycling venture in Winnipeg, Manitoba, Canada. As a family owned and operated business that has been in existence since April 2009, Greensite is a drop off and recycling depot that collects tear off shingles from roofing companies in the greater Winnipeg area and now serves more than 30 different roofing contractors. The shingles are processed into a valuable recycled asphalt shingle (RAS) product, which is then hauled to local hot-mix asphalt (HMA) producers to be used in asphalt paving mix.
Lead by John Krueger, the family has been in the roofing industry for more than 30 years and continues to run a roofing company based in Winnipeg. This new shingles recycling program is based on the concept of receiving clean, separated loads of shingles in order to minimize the sorting at the processing site before grinding. As a spin-off of a local roofing company, Greensite's philosophy is that quality control for the recycling of shingles begins on the roof.
Because Greensite Recycling was founded by and for roofing contractors, key elements of its strategy for success have included: convenient location relative to local landfills; responsive hours of operation; discounted tipping fees for clean loads; and relatively easy sorting instructions for the roofers. "We also strive for quick unloading and turn around times once they arrive at our facility," said Krueger. "The roofers want to get in and out as quickly as possible."
Previously, the roofing contractors were forced to haul their roofing materials to one of two landfills in the Winnipeg region, both of which are over 15 miles from downtown. The established tipping fee is about C$35/ton of waste for landfill disposal. Thus, over C$700.000 a year is spent on landfill tipping fees for shingles that could be diverted for recycling.
"Greensite's goal is to produce an engineered RAS product at a profit that can sustain our growth," said Krueger. "We have acceptance standards at each step in the process starting at the roofing job site and then all the way through the point of sale and beyond to the use by our HMA producer customers." The supply and processing quality control steps are shown in Figure 1.
Greensite purchased a Rotochopper RG1 shingle grinding machine as its first major capital investment. Additional handling and sorting equipment has also been purchased such as front-end-loaders, a grapple crane, and an at-grade truck scale. These capital investments, including buildings and site development (including some additional, new asphalt paving), were originally estimated at more than $1 million.
Greensite also made other substantial investments in the "soft" costs of promotions to help attract a sufficient quantity of shingles. A brochure was produced that includes sorting instructions and addresses the benefits to roofing contractors by recycling their shingles at Greensite rather than disposal at a local landfill (See Figures 2 and 3).
Greensite initially considered accepting commingled roofing materials but quickly decided that it would be better to provide an economic incentive to the roofing contractors to "source separate" their loads. "Our program is based on providing ample incentives for the roofing contractors to supply clean loads only. We believe strongly that in our situation "source separation" by the roofers is the best approach rather than trying to sort out commingled loads ourselves," said Krueger.
"We started out this new shingle recycling business as roofers our selves," said Jeremy Kosman, Greensite Recycling general manager. "With 25 years of experience, we knew that source separation at the job site would not be a problem. It's just a matter of changing our habits from dumping all materials mixed in the trailer to a new way of first loading shingles only. We simply contain the other trash and debris separately in a bag outside of the trailer."
Greensite went even further and provided plastic bags, or Rhino bags, to their roofing contractor customers supplying shingles. If the plastic stretch wrap and shingle bundle plastic wrappers are contained in plastic bags, they can be easily removed when the load is tipped.
If the other roofing debris is kept separate from the job site, it is a very easy process to place it in the correct pile or bin at Greensite Recycling. The wood and metal Items are also recycled using separate containers hi their facility.
Greensite has invested in multiple site improvements, including attractive signage, to help make it as easy as possible for the roofing contractors to find and then tip their loads of shingles.
The big incentive is that roofers can cut their disposal costs in half. "Now that most of our suppliers are trained and accustomed to our standards, it is rare that we get contaminated loads," said Kosman. "But, on occasion, we still need to reject loads that are too contaminated." Once tipped and inspected, Greensite staff do a final, quick sort of any remaining contaminants before pushing the load into a pile of only clean, whole shingles.
The Greensite processing system includes a Rotochopper RGI grinder fed by a track-mounted, grapple crane. The grapple is stationed on the pad above the grade of the RGI grinder and feed hopper and is equipped with a clamshell bucket to provide more precise control of sorting. Grapple loading from the elevated platform down into the Rotochopper hopper helps with final visual inspection of feedstock as it is fed into the RGI.
Greensite's early experience with producing a top-quality RAS product helped them get through a very rapid learning curve. During the grinding operations, dust and temperature is controlled using the watering nozzles that are standard with the Rotochopper RGI. The grinding chamber grate is a 3/4-inch nominal size that allows Greensite to produce RAS at up to 60 tons per hour. While this results in a very clean, nominal l/2-inch minus RAS product, Greensite has elected to "double grind'" the material to reduce the RAS to 3/8-inch minus. This finer particle size from the double grind has been more attractive during initial RAS sales efforts and paving demonstrations. "While the RGI produces a very nice product in one pass, we run the material through a second time to further reduce the particle size and give the material a second pass under the RGl's overhead belt magnet to take out any remaining nails or other ferrous metal," said Kosman. Whether or not Greensite continues to use a double grind process will depend on the comparative value of the product compared to the added operating costs.
The end result is a super fine product that is contaminant free. Figure 11 shows the two stockpiles; one for the single pass RAS and the other for the double pass RAS.
The RAS products are stored on a well drained asphalt pad. "We are working closely with our end markets to schedule trucking off site to their HMA plants. There has been very strong interest from several HMA producers to purchase our RAS," said
Krueger. "Our HMA producer customers have been very pleased with the quality of the RAS product and are stating they can use all that we can produce."
Greensite retained the independent lab services of Thunder Bay Testing (TBT) Engineering, The first season of lab data indicates a very high asphalt content of Greensite’s RAS at about 34% due to the predominance of organic (or paper-backed) shingles in Manitoba. Additional lab tests on the final HMA product indicate that nearly all of the paper lhat was in the RAS is no longer in the finished asphalt mix as this organic content is burnt off in the drum at the asphalt plant.
Greensite Recycling paid for its own mix design work to be conducted by TBT Engineering. "We targeted the same quality of pavement that the City of Winnipeg specifies for its roads," said Hermie Manalo, laboratory manager, TBT Engineering. "This same mix design was then specified by Greensite when we paved their yard within the new Greensite Recycling facility. We used 3% RAS for the top course and 4% RAS for the bottom course, in part because of the high asphalt content of their RAS product."
"Maple Leaf Construction was our asphalt partner for the paving demonstration at our site on October 14, 2009," said Krueger.
"We were very pleased with the material," said Barry Brown, president and owner, Maple Leaf Construction Ltd., in Winnipeg. "No recycled asphalt pavement (RAP) was utilized for this demonstration. While we may combine these two recycled products (RAS RAP) in future mixes, we decided to keep it simple for this initial paving demonstration to show the quality of the RAS (only) derived asphalt pavement."
TBT Engineering tests indicated that 18% of the total binder in the Maple Leaf test mix was from the RAS asphalt content. The balance of the asphalt, about 82%, came from the virgin binder add oil. "While we recognize this is a very conservative ratio of RAS binder, this mix design leaves room when RAP is added in next year," said Manalo. "This mix design also helps assure excellent pavement performance at this critical R&D and demonstration phase of Greensite's market development efforts."
Benefits of using RAS in HMA pavements include: Partial virgin binder replacement, partial aggregate replacement, improved rut resistance, and landfilling diversion of a valuable resource.
"Our next steps include: Highway pavement demonstrations in 2010 under the sponsorship of Manitoba Infrastructure & Transportation and the City of Winnipeg; developing draft agency Specifications; and increasing our tonnage," said Krueger. "We hope to grow our business to over 20,000 tons per year in the next year or two. We are already considering adding additional drop-off sites to increase the convenience to the roofing contractor customers,"
"We've had initial great success so far," said Kosman. "We even had some excellent news coverage by a local TV news station."
"We have several key partners in our success to date including Maple Leaf as the HMA producer and paving company that conducted our asphalt paving at our site and TBT," said Krucger. "We are also happy to have Dan Krivit from Foth Infrastructure & Environment, LLC, on our team to help with strategic and technical consulting during our start-up phase."