Shingles Recycling: Quality Assurance / Quality Control

Shingles Recycling:Quality Assurance / Quality Control

A Presentation at theSacramento RMRC Workshop on

Tuesday, April 11, 2006

Presenter: Dan KrivitDan Krivit and Associates

Recycled MaterialsResource Center

www.rmrc.unh.edu

Presentation Outline

[Modified from presentation already in your big books!

Make sure to get all additional inserts:

• AASHTO spec

• Bibliography

• SWMCB packet

Material Introduction

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

Engineering Properties

Composition of Residential Asphalt Shingles

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)

Applications and Performance

Multiple Applications

• HMA• Aggregate (gravel)

• Dust control• Cold patch

• Ground cover• Fuel

• New shingles

[Most Proven]

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

Barriers to Shingle Recycling• Economic reasons• Policy and regulatory compliance• Environmental concerns• Technical reasons• Public sentiment-----------(Note: These barriers may be real or perceived!)

Engineering Performance Disadvantages

• Hotter mix requirements• Stiffer mix• Possible contamination

3-12

(Justus, September 2004)

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

• RecyclingCO$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 PerformancePerformance 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

Deleterious Material

• Nails• Wood• Plastic• Cellophane• Paper• Fiber Board

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

10.8 12.0

19.5

9.5

34.4 34.7

0

10

20

30

40

-10C -20C -30C

Stif

fnes

s @

100

sec

20% RAPPG 64-22

15% RAP5% shing.PG 64-22

MO: Mix Stiffness @ 100sec. (PG 64-22)

6.1

11.5

17.3

8.1

16.6

21.4

0

10

20

30

-10C -20C -30C

Stif

fnes

s @

100

sec

20% RAPPG 58-28

15% RAP5% shing.PG 58-28

MO: Mix Stiffness @ 100sec. (PG 58-28)

4.0

7.8

15.3

5.7

12.9

15.9

0

10

20

30

-10C -20C -30C

Stif

fnes

s @

500

sec

20% RAPPG 58-28

15% RAP5% sh ing.PG 58-28

MO: Mix Stiffness @ 500sec. (PG 58-28)

4.54.9

3.94.3 4.2

4.7

0

3

6

-10C -20C -30C

Te

nsile

Str

eng

th [

MP

a]

20% RAPPG 64-22

15% RAP5% shing.PG 64-22

MO: Tensile Strength (PG 64-22)

4.14.5 4.44.4 4.54.5

0

3

6

-10C -20C -30C

Te

nsile

Str

eng

th [

MP

a]

20% RAPPG 58-28

15% RAP5% shing.PG 58-28

MO: Tensile Strength (PG 58-28)

Mn/DOT lab data

• Jim McGraw, Director of Mn/DOT’s Chemical Lab, Maplewood, MN

• Preliminary lab data as of Thursday, April 6, 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 conduct

indirect tensile strength tests

Shingle Asphalt Content

0.0

10.0

20.0

30.0

40.0

50.0

1 2 3 4 5 6 7 8 9 10

Sample

%A

C

ManufactureWaste

Demcon Tear-Off

MN: Asphalt Content of RAS

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.

0.2

2.7

10.0

0.5

5.0

13.5

0.2

5.5

8.2

0

4

8

12

16

0 -10 -20

Temperature [oC]

Stif

fnes

s [G

Pa]

20% RAP15% RAP + 5% Tear-off15% RAP + 5% Manufactured

MN: Mix Stiffness [GPa] @ 500 sec.

0.11.1

5.6

0.2

2.3

8.7

0.1

2.7

5.3

0

4

8

12

16

0 -10 -20

Temperature [oC]

Stif

fnes

s [G

Pa]

20% RAP

15% RAP + 5% Tear-off

15% RAP + 5% Manufactured

MN: Tensile Strength [MPa]

3.2

4.64.8

3.2

4.5

5.1

2.9

4.5

5.3

0.0

2.0

4.0

6.0

0 -10 -20

Temperature [oC]

Tens

ile S

treng

th [M

Pa]

20% RAP

15% RAP + 5% Tear-off

15% RAP + 5% Manufactured

MN vs. MO: Mix Stiffness [GPa] @ 100 sec.

6.1

11.510.0

8.1

16.6

5.0

13.5

2.7

0

4

8

12

16

20

-10C -20C

Temperature [oC]

Stiff

ness

[GPa

]

20% RAP - MO

20% RAP - MN

15% RAP + 5% Tear-off - MO

15% RAP + 5% Tear-off - MN

MN vs. MO: Mix Stiffness [GPa] @ 500 sec.

4.0

7.8

5.65.7

12.9

2.3

8.7

1.1

0

4

8

12

16

20

-10C -20C

Temperature [oC]

Stiff

ness

[GPa

]

20% RAP - MO

20% RAP - MN

15% RAP + 5% Tear-off - MO

15% RAP + 5% Tear-off - MN

States Using RAS

(Justus, September 2004)

Western States

• California• Montana• Texas• Oregon

Other States’ Specifications[and Experiences]

– 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

• Minnesota

(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

7-2(Justus, September 2004)

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)

• 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.

Texas DOT - Conclusions

(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

Testing and Design Procedures

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

AASHTO:Subcommittee on Materials

THOMAS E. BAKER (360) 709-5401   Tumwater, Washington   bakert@wsdot.wa.gov

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

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)

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

Comprehensive Quality Control Plan

Quality control of supply

Worker safety and health protection

Final product quality, storage and handling

Shingle recycling system design

Final product sampling and lab testing

Mn/DOT Spec

• Maximum 5% manufacturers’ shingle scrap in HMA

• Considered a type of RAPExample:

5% shingles + 25% RAP = 30% max RAP

• QA/QC standards apply(blending charts)

Asbestos Risk

• Incidence of asbestos is extremely low

• Average content was only:

– 0.02% in 1963

– 0.00016% in 1973

Source: 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%

Source: Paul Ruesch, April 13, 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.)

Original source: Paul Ruesch, April 13, 2003.

DKA / AESFiber Tests

As part of the RMRC Project:Environmental Testing of Airborne Particles at

The Shingle Processing PlantApril 2003

Information Sources

Construction Materials Recycling Association

(CMRA)

EPA Project• CMRA web page

http://www.ShingleRecycling.orgWilliam Turley, Executive Director(630) 585-7530turley@cdrecycling.org

• Dan Krivit and Associates(651) 489 - 4990DKrivit@bitstream.net

Equipment Vendors

www.GreenGuardian.com/pdf/shingle_vendors.pdf

Summary

Current Trends and Future Growth

• Virgin asphalt is expensive, tipping fees are rising, improved economics

• Applications other than HMA are being developed

• Use of post consumer shingle waste is promising

National Asphalt Price Trend

Source: U.S. Dept. of Labor: Bureau of Labor Statistics

Shingles Recycling into HMA is a Proven Technology

• History of experience:

– Private operators

– State engineers

– Environmental regulators

• Substantial body of literature

• High quality HMA can be maintained

Quality Control = Savings

• QA/QC critical

• Use in HMA can be very cost effective:

– Cheaper alternative to landfilling

– $0.50 to $3.30 per ton of HMA

Quality Specs: Scrap Feedstock and

Final Products

• Free of debris / trash / foreign matter

• Tear-off scrap must be asphalt shingles only

• No nails!

Certification and Inspection of Shingle Supply

• Clear written spec for acceptable material• Certify suppliers• State licensed asbestos inspectors• Visual screening of all shingle scrap

– Types of shingles– I.d. non-shingle waste– I.d., layers, composites, thickness, etc.

Source: Paul Ruesch, April 13, 2003.

Model Sampling Protocol (if required)

• Specified sampling frequency of incoming loads

• Sampling of recycled asphalt shingles (ground / screened product)

• Willingness to certify quality of finished products

Source: Paul Ruesch, April 13, 2003.

Proposed Tear-Off Supplier Certification Form

“….. We …. certify that: – All tear-off shingle scrap came from

residential buildings having four or fewer dwelling units; and”

– These residential buildings are not “regulated facilities” according to state and federal rules; and”

– The material delivered consists of asphalt shingles only and contains no known hazardous material.”

Proposed Tear-Off Processor Certification Form

“….. We …. certify that: – All tear-off shingle scrap came from certified

suppliers only (see “Supplier Certification forms); and”

– The final product contains no known hazardous material.”

Key Conclusions

1. Proven and documented2. Quality control is essential3. Economics are driving the market4. Manufacturer shingle scrap recycling is

here today and commercialized5. Tear-off shingle scrap is

under development, but feasible

Recommendations

1. CONTINUE MARKET DEVELOPMENT:– Cities, counties and states should use

alternate bid language allowing shingles– EPA / CMRA project in progress:

• Asbestos statistics• Best practices guideline documents• Implementation / Outreach

Recommendations(Continued)

2. MANAGE the asbestos issue:– Restrict supply to private, residential homes

only (per NESHAP)– Tight supply specification– Certify suppliers (e.g., roofing companies)– Inspect each load (suggest becoming a

licensed inspector)

Recommendations(Continued)

3. PROTECT employee health and safety:– Develop dust management program– Develop employee hazard prevention– Shroud grinder– Water scrap shingles– Provide accurate information as part of a full

employee education program

Recommendations(Continued)

4. GUARANTEE YOUR PRODUCT QUALITY:– Asbestos free– No nails (use multiple magnets)– ½ - inch minus– Controlled mix ratios– Exceed State QA/QC procedures