Monday, 16 October 2017

Minnesota

Mn/DOT recently adopted a new RAS specification that now allows contractors to use tear-off shingles on a permissive basis (at the discretion of the contractor):

New, 2010 tear-off RAS specification: “Tear-Off Scrap Asphalt Shingles (02/22/2010)”:
http://www.dot.state.mn.us/materials/bituminousdocs/Specifications/2010/Shingle_TOSS_2010_02-22-2010.pdf

This tear-off specification complements the manufacturers’ scrap specification that was originally adopted by Mn/DOT in 1996. The current, 2010 version of the manufacturers’ specification was also recently revised by Mn/DOT:

Revised manufacturers’ RAS specification: “Scrap Asphalt Shingles from Manufacture Waste (02/22/2010)”:
http://www.dot.state.mn.us/materials/bituminousdocs/Specifications/2010/Shingle_MWSS_2010_02-22-2010.pdf

These two types of RAS specifications provide for the use in HMA pursuant to Mn/DOT’s 2010 bituminous specification 2360. The details of the blending ratios and the road level types is found in 2360 under: “Table 2360.3-B2a: Mixture Aggregate Requirements”:
http://www.dot.state.mn.us/materials/bituminousdocs/Special_Provisions/2009/Shingles/Table%202360.3-B2a_Agg_Req_2010.pdf

The footnotes provide important details for mix design and project planning:

1. When shingles are included as part of the allowable RAP percentage in Traffic Level 2, 3, 4, or 5 mixtures the ratio of added new asphalt binder to total asphalt binder shall be 70% or greater ((added binder/total binder) x 100 >= 70). A minimum of one spotcheck per day per mixture blend is required to determine new added binder.

2. MWSS is manufactured waste scrap shingle and TOSS is tear-off scrap shingle.

3. RAS may be included in the mixture to a maximum of 5 percent of the total weight of mixture as shown in Table 2360.3-B2a. Either manufactured waste scrap asphalt shingles (MWSS) or tear-off scrap asphalt shingles (TOSS) may be included in the mixture.”

 

To help Mn/DOT engineers better understand the theoretical and applied impacts of using tear-off shingles, Mn/DOT researchers recently completed a comprehensive lab and field study on the use of RAS in HMA as funded by MPCA:

“Incorporation of Recycled Asphalt Shingles in Hot Mixes Asphalt Pavement Mixtures: Final Report”.

The report is not yet posted on the Mn/DOT web page and therefore is attached as a separate document in PDF form:

For more information about Mn/DOT’s specifications or their shingle research program, see Mn/DOT Bituminous Office web site at: www.dot.state.mn.us/materials/bituminous.html, or contact:

Mark Watson, Mn/DOT Research Project Engineer
mark.watson@state.mn.us
651.366.5596

The Mn/DOT specification incorporates by reference the Minnesota Pollution Control Agency’ s (MPCA) shingle recycling QA/QC protocol:

“Guidelines for the 2009 Season of Supply and Processing of Recycled Asphalt Shingles (RAS) Derived from Tear-off Roofing Scrap” (May 6, 2009).

MPCA staff have stated that these 2009 guidelines will be in effect through 2010. Although MPCA and Mn/DOT have not yet published this report on their web pages, one of the leading shingle recyclers in Minnesota, Dem-Con, Inc., has:

http://www.dem-con.com/pdfs/sp-Final-MPCA-Issued-Guidelines-QA-QC-Protocol-2009.doc
along with the May 15, 2009 MPCA cover letter that released these guidelines:

http://www.dem-con.com/pdfs/sp-MPCA-Asphalt-Letter.pdf

Dem-Con has also published its own roofing scrap supplier specification:
“Dem-Con Shingle Processing, LLC Supplier Specifications 2009 Season”:

http://www.dem-con.com/pdfs/sp-Shingle-Supplier-Specifications-2009.pdf

For more information about Dem-Con’s current shingle recycling program, see their web page:

http://www.dem-con.com/shingleprocessing/ or contact:

Jason Haus, Vice-President
Dem-Con Shingle Processing, LLC
JasonHaus@dem-con.com
952-445-5755 (general)
952-224-7110 (direct)

Minnesota Shingle Recycling Operators  

Minnesota Draft Specification for Manufacturers' Recycled Asphalt Shingles

Minnesota Combined 2360/2350 (Gyratory/Marshall Design) Specification [See page 4, 2360.2 A2h and page 10, B2a: Mixture Aggregate Requirements, Note (3)]

Minnesota Current Research Projects

In April 2003 the Minnesota Department of Transportation sponsored the Second Recycling Asphalt Shingles Forum.  All presentations from the forum are available at:  Second Recycled Asphalt Shingles Forum - April 2003

Minnesota Shingle Recycling Fact Sheets


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Last Updated: ( Thursday, 27 May 2010 )