january 14 – 16, 2007 ● san antonio, texas shingles recycling: cmra’s best practices guide a...
TRANSCRIPT
January 14 – 16, 2007 ● San Antonio, Texas
Shingles Recycling:CMRA’s Best Practices Guide
A presentation at theCMRA Annual Meeting
On Sunday, January 14, 2007
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”
• 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)
• Dusty Ordorff, Bituminous Roadways
• Jim Omann, Omann Brothers
• Roger Brown, Pace Construction
• Joe Schroer, MoDOT
• Mn/DOT
• NAPA
CMRA’s Web Site
New Jersey DOT Asphalt Cement Price Index
$0
$50
$100
$150
$200
$250
$300
$350
$400
J-90 J-91 J-92 J-93 J-94 J-95 J-96 J-97 J-98 J-99 J-00 J-01 J-02 J-03 J-04 J-05 J-06
Month (as of June 1 each year)
$ p
er t
on (
En
glis
h)
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 AffectingHMA 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• 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
• 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)
• 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 / AESAirborne Fiber Tests
As part of the RMRC Project:
Environmental Testing of Airborne Particles atThe Shingle Processing Plant
Krivit, April 2003.
Summary Highlights
• Risk from asbestos is negligible to non-existent
• 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
January 14 – 16, 2007 ● San Antonio, Texas
651-489-4990
Dan Krivit and Associates