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Shingles Recycling : Experiences in Other States. Western Central Wisconsin Recyclers’ Special Shingle Recycling Workshop September 12, 2006 By Dan Krivit. Definitions. Manufacturers’ Asphalt Shingle Scrap Tear-Off Asphalt Shingle Scrap Recycled Asphalt Shingles (RAS) (Crushed & screened).
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Shingles Recycling:Experiences in Other States Western Central Wisconsin Recyclers’ Special Shingle Recycling Workshop September 12, 2006 By Dan Krivit
Definitions • Manufacturers’ Asphalt Shingle Scrap • Tear-Off Asphalt Shingle Scrap • Recycled Asphalt Shingles (RAS)(Crushed & screened)
History • 15 years + • Multiple research studies in lab and field • Manufacturer shingle scrap in hot-mix asphalt best known, most accepted practice • Still relatively new application
Recent Composition Weight Ranges of Typical Asphalt Shingles • 32 to 42% Coating filler (limestone or fly ash) • 28 to 42% Granules (painted rocks & coal slag) • 16 to 25% Asphalt • 3 to 6% Back dust (limestone or silica sand) • 2 to 15% Mat (fiberglass, paper, cotton rags) • 0.2 to 2% Adhesives (modified asphalt based)
Multiple Applications [Most Proven] • HMA • Aggregate (gravel) • Dust control • Cold patch • Ground cover • Fuel • New shingles
Factors Affecting HMA Performance • Aggregate gradation of RAS • Properties of final blended binder content within the HMA as affected by: • RAS asphalt binder • Virgin binder
Factors AffectingHMA Performance(continued) • Location RAS is incorporated into HMA • Temperature • Moisture content of RAS and other aggregates • Retention time in HMA drum
Engineering Performance Advantages • Reduce need for virgin binder • Add fibrous reinforcement • Modify PG grade binder High temp performance • Reduce landfill needs 3-11
Potential Benefits *(* Manufacturers’ RAS) • Cracking resistance • Rutting resistance • Conservation of landfill space Source: Paul Lum, Lafarge Construction Materials Ltd., April 13, 2003.
Challenges • Need for improved grinding and handling • Blending and storage • Continued research into engineering effects of RAP and RAS on AC binder content • Quality control and quality assurance
Engineering Performance Disadvantages • Hotter mix requirements • Stiffer mix • Possible contamination (Justus, September 2004) 3-12
Asphalt Shingles in HMAMissouri DOT Experience Joe Schroer, PE Construction and Materials Division March 30, 2005
In The Beginning • Approached by Pace Construction and Peerless Landfill • MoDOT Not Using RAP in Mixtures • Deleterious Material • Stiffness of Asphalt in Shingles
Why Should We Pursue Shingles? • High Asphalt Content • Granules Are Hard and Durable • Recycling CO$T
Concerns • How Will Deleterious Material Affect the Mixture • Can the Low Temperature Grading be Maintained at Various Blending Ratios
Asphalt After Blending with Shingle Asphalt • Resist Rutting • Resist Fatigue Cracking • Resist Cold-Weather Cracking
Asphalt Grades • High Temperature for Rut Resistance • Low Temperature for Fatigue and Cold Weather Performance Performance Graded = PG PG 64-22 (PG Sixty-four Minus Twenty-two) High Temp 64°C (147°F) Low Temp –22°C (-8°F)
Asphalt Modifications Require PG 64-22 • Stiffer at High Temperature – OK • Stiffer at Low Temperature • Use Lower Percentage of Shingles • Use Softer Roadway Asphalt
Deleterious Evaluation • Specification for Aggregate • 0.5% “Other Foreign Material” • Sticks, mud balls, deer fur, etc. • Shingle “OFM” • Approximately 3% Total
Nails Wood Plastic Cellophane Paper Fiber Board Deleterious Material
No Difference • Visually • Standard Mixture Tests • Placement
Can Tear-Off Shingles be Used? • Allowance in OFM Due to Small Percentage of Shingles and Trial Mixture • Start with Softer Roadway Asphalt
Where Are We?The “Ex” Factor 2 • Extrinsic Material Allowance Raised • 3.0% Total • 1.5% Wood • Expect PG 64-22 met w/ PG 58-28 • Extra grades optional w/ testing • Examining various proportions and asphalts • Exuberant Contractors
U of M Lab Data:Missouri Samples • Prof. Mihai Marasteanu,U of M Dept. of Civil Engineering • Preliminary results as of 4-6-2006 • Report with Mn/DOT lab data to be released soon
Mn/DOT lab data • Jim McGraw, Director of Mn/DOT’s Chemical Lab, Maplewood, MN • Lab data as presentedJuly 12, 2006 • Report with U of M lab data, including Mo/DOT samples, to be released soon
New Minnesota Lab Study • Funded by OEA • Co-sponsored by Mn/DOT • Comparing manufacturer RAS to Tear-Off RAS • Mn/DOT to conduct PG extractions • U of M Civil Engineering to conductindirect tensile strength tests
U of M Lab Data:Minnesota Samples • Prof. Mihai Marasteanu,U of M Dept. of Civil Engineering • Preliminary results as of Thursday, April 6, 2006 • Report with Mn/DOT lab data to be released soon
MN: Mix Stiffness [GPa] @ 100 sec. 16 13.5 20% RAP 15% RAP + 5% Tear-off 12 15% RAP + 5% Manufactured 10.0 8.2 8 Stiffness [GPa] 5.5 5.0 4 2.7 0.5 0.2 0.2 0 0 -10 -20 o Temperature [ C]
Georgia • - Manufacturing and Post Consumer Shingle • - Mixing Permitted • -100% passing the ½ inch Sieve • - Maximum 5.0% RAS permitted • - Gradation - meet requirements of Mix Design • - No foreign material ( paper, roofing nails, wood, and metal flashing) • - Free of Asbestos when tested with Polarized • Light Microscopy. Test every 1000 Tons (Justus, September 2004)
Minnesota • Manufacturing Shingle Waste Only • 100% passing the ½ inch Sieve • Maximum of 5.0% RAS permitted • Gradation meet the requirements of the mix design • Performance grade of virgin asphalt binder based on the properties of the shingle asphalt binder • No limits on deleterious materials or asbestos (Justus, September 2004)
New Jersey • Manufacturing Shingle Waste Only • 100% passing the ¾ inch Sieve • Maximum of 5.0% RAS permitted • Gradation meet the requirements of the mix design • No limitations on deleterious materials or asbestos (Justus, September 2004)
North Carolina • Manufacturing Shingle Waste Only • 100% Passing the ½ inch Sieve • Maximum of 6.0% RAS permitted • Gradation meet the requirements of the mix design • No Limitations on the presence of deleterious materials or asbestos (Justus, September 2004)
Texas DOT • Texas DOT- State Highway 31 Corsicana, Navarro County – 1997 - 2 x 1,000 foot sections post consumer RAS - 2 x 1,000 foot sections manufacturing RAS - 2 x 4,000 foot sections Control Mixture • The Mix Design required 5% Post Consumer RAS and 5% Manufacturing RAS • All three Mixes required 5% Stripping Agent (Justus, September 2004) 7-2
Texas DOT- Conclusions • Shingle binder content does not relate to reduced quantity of virgin binder • Felt appeared to migrate to the surface • Processed shingles (RAS) did not clump • Post consumer shingle more difficult to handle (Justus, September 2004)
Texas DOT - Conclusions • Smoothness, stability, moisture susceptibility, creep indicated similar characteristics among the three mixes. • 1999 Falling Weight Deflectometer testing showed performance agreement among the three mixes. • Visual evaluation shows no apparent distress in any of the mixes. (Justus, September 2004)
Texas (old proposed specification): • Both Manufacturing and Tear-Off Shingle Waste permitted • 100% passing the ½ inch Sieve • Gradation meet the requirements of the mix design • No Contamination - dirt or other objectionable materials • No harmful quantities of asbestos when tested according to EPA guidelines
New TCEQ Memo • March 20, 2006 • Manufacturers’ RAS in HMA approved * • Tear-offs not approved depending on stack testing results and subsequent review of impacts • * Must follow same procedures as RAP into HMA
American Association of State and Highway Transportation Officials (AASHT0) Recycled asphalt shingles specification and practice was approved by the Subcommittee on Materials (SOM) August 2005
Review of AASHTO Specification Subcommittee on Materials (SOM) • Both manufacturers and tear-offs allowed • 100% passing the ½ inch Sieve • Maximum addition rate contractor option • Gradation and volumetrics must meet the requirements of the mix design
AASHTO Specification (continued) • Addition rates (Section 7): “If RAS binder if greater than 0.75 percent, the virgin asphalt binder and RAS binder combination shall be further evaluated to ensure PG requirements”
AASHTO Specification (continued) • Tear-off material composition (Section 5.2): May only include: asphalt roll roofing, cap sheets, and shingles (including underlayment). May not include other roofing debris such as: coal tar epoxy, rubber, or other undesirables [metal, plastic, wood, glass]
List of Roofing Waste Items Included for Recycling“YES” (Include these items): • Asphalt shingles • Felt attached to shingles
List of Roofing Waste Items Excluded for Recycling “NO” (Do NOT include): • Wood • Metal flashings, gutters, etc • Nails (best effort) • Plastic wrap, buckets • Paper waste • No other garbage or trash
Lista de material para techos basura artículo para reciclar: