Transcript Document

Shingles Recycling:
CMRA’s Best Practices Guide
A presentation at the
CMRA Annual Meeting
On Sunday, January 14, 2007
January 14 – 16, 2007 ● San Antonio, Texas
Definitions
• Manufacturers’ Asphalt Shingle Scrap
• Tear-Off Asphalt Shingle Scrap
• Recycled Asphalt Shingles (RAS)
(Crushed & screened)
Comprehensive
Quality Control Plan
 Quality control of supply
(Must comply with NESHAP*)
 Worker safety and health protection
 Final product quality, storage and handling
 Shingle recycling system design
 Final product sampling and lab testing
“Best Practices Guide”
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Markets first (especially HMA)
RAS product specifications
Processing guidelines
Worker health and safety
Sourcing *
Overall system design
Key Barriers
• Lack of clear industry standards and
specifications
• Inconsistent state regulations
• Lack of adequate information /
technology transfer
• Lack of national leadership by private
industry and government
Acknowledgments
• Sean Anestis, Roof Top Recycling
• Ken Snow, Recycle America Enterprises
• John Adelman, Commercial Paving &
Recycling Systems
• Ron Sines, PJ Keating
Acknowledgements
(continued in the midwest)
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Dusty Ordorff, Bituminous Roadways
Jim Omann, Omann Brothers
Roger Brown, Pace Construction
Joe Schroer, MoDOT
Mn/DOT
NAPA
CMRA’s Web Site
$400
New Jersey DOT Asphalt Cement Price Index
$350
$ per ton (English)
$300
$250
$200
$150
$100
$50
$0
J-90
J-91
J-92
J-93
J-94
J-95
J-96
J-97
J-98
J-99
J-00
Month (as of June 1 each year)
J-01
J-02
J-03
J-04
J-05
J-06
Multiple Applications
• Hot mix asphalt (HMA)
• Aggregate / gravel
• Dust control
• Cold patch
• Ground cover
• Fuel (e.g., cement kilns)
• 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 Affecting
HMA Performance (continued)
• Location RAS is incorporated
into HMA drum
• Temperature
• Moisture content of RAS and
other aggregates
• Retention time in HMA drum
Potential Benefits
• Rutting resistance (especially at warmer
temperatures)
• Conservation of landfill space
• Economic savings to HMA producer due
to reduced need for virgin asphalt binder
(add oil)
Potential Disadvantages
• Contamination (tear-offs)
• Added costs of processing and use in
HMA
• Increased low-temperature / fatigue
cracking
Mitigating Low Temperature
Impacts of RAS
• Use less RAS instead of 5%
(e.g., use 2% to 3%)
• Adjust the virgin binder PG to one grade
softer (e.g., PG 52-34)
• Assure minimum amount of virgin binder
(regardless of PG)
Engineering Design Philosophy
• Manufacturing a high quality product
• Not just recycling a waste material
• Long-term sustainability
Deleterious Material
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Nails
Other metal
Wood
Cellophane
Other plastic
Paper
Fiber board
Two Sourcing Alternatives
• Source separation
(at the job site)
• Central processing
(at the shingle recycling facility)
Pre-Sorting
• Inspections prior to any grinding
• Manual removal of any large items
• Elevated sorting platform
Require Certification
• Require written “chain-of-custody”
certifications
• Develop pre-approved customer list of
certified suppliers
• Maintain permanent file of all supply
certifications
Grinding Equipment Vendors
• Examine designs dedicated to shingles
• Get customer references and then ask the
questions about actual operating
performance
• Plan for adequate maintenance
Ayres, April 2004
Dust Control
• Comprehensive plan
• Spray with optimum amounts of water at
critical grinding stages
• Shrouds
• Negative air (i.e., suction) systems to
remove ambient dust and light debris
• Standard employee health and safety
protection equipment and procedures
Removal of
Nails and Other Ferrous
• Assure an even layer of material on conveyor
belts equipped with magnets
• Multiple magnets (minimum of three or four)
• Use combination of pulley belt and overhead
magnets
• Combine metal detection device with manual
hand sorting for final quality control process
Final Product Quality
• Conduct adequate testing
• Provide quality guarantees
• Keep covered to reduce unwanted
moisture
• Metered pre-blending with bituminous
aggregate or RAP to reduce
reagglomeration
Final Product Preparation
• If stockpiled, pulverization of final
product may be necessary immediately
prior to use in HMA plant
• Alternatively, use RAS “fresh” about one
week after production to avoid extended
stockpiling
RAS Tests
• Gradation
• Asphalt content
• Asphalt cement (AC) performance grade
(PG)
• Debris
• Moisture
Quality Specs:
Scrap Feedstock and
Final Products
• Free of debris / trash / foreign matter
• Tear-off scrap must be asphalt shingles
only
• No nails!
Economics
• Tipping fees
• Value of final product
Business Models
• Mobile and stationary
• Multiple products
• Integrate with existing RAP and
aggregate production infrastructures
Multiple Products
(Beyond RAS)
• Clean wood for mulch
• Clean wood and other organic wastes for
biomass fuel
• Gypsum (sheetrock) for land application
• Metals for recycling
Regulatory Compliance
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Pro-active, assertive planning
Anticipate requirements
Use precedents to your advantage
Document adequate market demand to
avoid “speculative stockpiling”
Siting
• Optimize location of tear-off shingles
processing facility
• Consider location of competing landfills
and transfer stations
• Consider location of HMA plants
Additional National
Developments
• New AASHTO specification
• EPA / CMRA study
• www.ShingleRecycling.org
• Asbestos data base
AASHTO Specification (continued)
• Deleterious material maximum limits (Section 8):
(material retained on the No. 4 sieve)
– Heavy fraction = 0.50%
– Lightweight fraction = 0.05%
Missouri Shingle Spec
• Extrinsic Material Allowance Raised
– 3.0% Total
– 1.5% Wood
AASHTO Specification (continued)
Asbestos levels:
“…shall be certified to be asbestos free.”
(Section 5.2)
“(Tear-off shingles are) construction debris
and various state and local regulations may
be applicable to its use. The user of this
specification is advised to contact state and
local transportation departments and
environmental agencies to determine what
additional requirements may be necessary.”
(Note 2)
Asbestos Risk
• Incidence of asbestos is extremely low
• Average content was only:
– 0.02% in 1963
– 0.00016% in 1973
NAHB, 1999
ASRAS Data
• Iowa (1,791 samples), no hits
• Maine (118 samples), no hits
• Mass:
– (2,288 composite samples) 11 hits < 1%
– (69 tarpaper samples) 2 < 5%
– (109 ground RAS samples) 2 < 1%
• Florida (287 samples), 2 hits > 1%
Ruesch, April 2003.
ASRAS Data
(continued)
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Missouri (6 samples), no hits
Hawaii (100 samples), 1 hit > 1%
Minnesota (156 samples), no hits
Minnesota (50 tarpaper), 1 hit @ 2% - 5%
We still want more data!
(for EPA / CMRA project.)
Ruesch, April 2003.
DKA / AES
Airborne Fiber Tests
As part of the RMRC Project:
Environmental Testing of Airborne Particles at
The Shingle Processing Plant
Krivit, April 2003.
Summary Highlights
• Risk from asbestos is negligible to nonexistent
• Two rounds of sampling for total:
– Dust (1999)
– Fibers (2002)
• Common sense and best management
practices can help prevent employee
exposure
Krivit, April 2003.
Asbestos Testing
• Explore exemption alternative, but if not,
then …..
• ….develop product sampling plan
• ….develop supply sampling plan on
whole shingles / mixed roofing scrap
• Recognize that more initial testing may
be needed to gather adequate baseline
data
Additional
Environmental Risks
• Air emissions impacts from tear-off RAS
in HMA plants
• PAH and other particulates
• Run-off from whole shingles and RAS
stockpiles
• Run-off from RAS use as ground cover or
dust control (in 100% form)
Recommendations
1. Continue MARKET DEVELOPMENT
(a)
2. MANAGE the asbestos issue (b)
3. PROTECT employee health and safety (c)
4. GUARANTEE your product quality (d)
CMRA’s Web Site
Dan Krivit and Associates
651-489-4990
[email protected]
January 14 – 16, 2007 ● San Antonio, Texas