Recycling shingles since 1996 Presentation at the March 4, 2004 MAPA Contractors’ Workshop By Dusty Ordorff Bituminous Roadways, Inc.

Bituminous Roadways, Inc Asphalt paving contractor Founded in 1946 Three permanent asphalt plants Serve the Minneapolis/St. Paul metro area

Eight Years of Shingle Recycling Experience 800,000 tons of finished hot-mix asphalt produced with shingles added About $500,000 in savings due to avoided raw material costs

History of BRI’s shingle recycling 1996 MNDOT specs first allow 5% ground shingles (manufacturer’s scrap), with project engineer’s approval First contract with CertainTeed Corp. of Shakopee Maxigrind and Finlay screen used for processing First use of ground shingles in hot mix

1997 First OEA market development grant Shredder, hammermill, and Powerscreen used for processing Maxigrind burns up

1998 Two Maxigrinds and Finlay screen used for processing

2000 Two Maxigrinds and trommel screen used for processing A series of cold-mixed field tests for lightweight pavement: –100% ground shingles –Ground shingles + crushed concrete mix –Ground shingles + RAP mix

2001 Second OEA market development grant ‘The Beast’ grinder made by Bandit Industries and trommel screen used for processing Field demonstration at SKB’s Rosemount landfill as dust control: –Ground shingle + RAP mix –Ground shingle + crushed concrete mix

2002 Positive news media coverage for projects in Hennepin and Scott Counties Air testing performed to evaluate potential risk of asbestos. No risks detected due to dust or fiber

2003 MNDOT changes the wording in their scrap shingle specification to be less restrictive (allow HMA producers discretion to use shingles)

2003: “Tear-Off” demonstration In City of St. Paul 50 tons of ground, tear-off shingles in HMA Certified sourcing of residential roofing scrap from: –Sela Roofing (roofing contractor) –Armor Waste (hauling, sorting and transfer) Nails removed by magnet on “The Beast”

2003: “Tear-Off” demonstration (cont’d) Side-by-side installation: –5% tear-off vs. –5% manufactured shingle scrap No performance difference Tear-offs seem easier to grind, but requires additional effort to remove nails and staples

Current Mn/DOT Specification Shingles used must be scrap from shingle manufacturers only  No tear-offs (yet). Sources must be certified Gradation of ground shingle scrap: –100% passing the ¾” sieve, and –At least 95% passing the #4 sieve Maximum of 5% by weight allowed

Processing and Handling Grinding has very high wear on equipment Low production at about 20 tons per hour Extended storage of ground shingles results in re-agglomeration (chunking) Grind during the paving season (just-in-time for HMA production)

Processing and Handling Shingle scrap must be free from other debris to protect grinder We grind to ½-inch minus gradation Water helps with cooling and controlling dust Shrouding equipment further helps with controlling dust Feed ground shingles into our asphalt plants through standard recycle bins

Economics Goal: The cost of processing = The disposal (tipping) fee Offer a savings to our mix production

Experience With Use of Ground Shingles Less than 50% of the asphalt in the shingles is effective in the mix Use of ground shingles has not been detrimental to quality  Cannot yet prove that ground shingles offers improved quality to our mix

Specific Projects France Avenue – Hennepin County County Road 42/83 – Scott County 19 th Avenue No. – City of South St. Paul Highway 13 – Mn/DOT Various residential street reconstruction projects – City of St. Paul

The Future Consider blending ground shingles with sand or RAP for storage New wording in state specifications should allow for more use – set record in 2003 Tear-offs Other applications (dust control, additive to aggregate base)

For more information, contact: Dusty Ordorff, Bituminous Roadways (612) Dan Krivit (

Summary of Past Research Mn/DOT & RMRC April 10, 2003 Forum: