shingles recycling

Shingles RecyclingA presentation by Dan Krivit at the

49th Annual WisconsinAsphalt Paving Conference

In Waukesha, Wisconsin

Wednesday, November 15, 2006

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

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

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)

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)

Multiple Applications• Hot mix asphalt (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 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

Performance Grading (PG)

Asphalt Grades• PG 64-22

(“PG sixty-four minus twenty-two”)

• High temperature for rut resistance 64°C (147°F)

• Low temperature for fatigue and cold weather performance(e.g., cracking) -22°C (-8°F)

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)

Deleterious Material• Nails

• Other metal

• Wood

• Cellophane

• Other plastic

• Paper

• Fiber board

U of MN Research

• Professor Mihai MarasteanuDept. of Civil EngineeringAsphalt Lab

• Adam ZofkaGraduate Student

Missouri HMA Samples

• Two recycled sources:– Tear-off shingles (5%)– Recycled asphalt pavement (20%)

• Two virgin binders performance grades:– PG 64-22– PG 58-28

Marasteanu, July 2006

Creep Stiffness (MO: PG 64-22)

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

Marasteanu, July 2006

Creep Stiffness (MO: PG 64-22)

Marasteanu, July 2006

7.48.9

16.4

5.9

27.530.3

0

10

20

30

40

-10C -20C -30C

Stif

fnes

s @

500

sec

20% RAPPG 64-22

15% RAP5% shing.PG 64-22

Marasteanu, July 2006

Creep Stiffness (MO: PG 58-28)

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

Marasteanu, July 2006

Creep Stiffness (MO: 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% shing.PG 58-28

Marasteanu, July 2006

Strength (MO: PG 64-22)

Marasteanu, July 2006

4.54.9

3.94.3 4.2

4.7

0

3

6

-10C -20C -30C

Ten

sile

Str

engt

h [M

Pa]

20% RAPPG 64-22

15% RAP5% shing.PG 64-22

Marasteanu, July 2006

Strength (MO: PG 58-28)

4.1

4.5 4.44.4 4.54.5

0

3

6

-10C -20C -30C

Ten

sile

Str

engt

h [M

Pa]

20% RAPPG 58-28

15% RAP5% shing.PG 58-28

Marasteanu, July 2006

Conclusions: Stiffness (MO: At temperatures below -10°C)

• PG -22 mixture: addition of shingles increases the mixture stiffness considerably (a)

• PG -28 mixture: stiffness difference lessened (b)

Marasteanu, July 2006

Conclusions: Strength (MO: At temperatures below -10°C)

No significant affects due to shingles for either PG -22 or PG -28 mixtures

Marasteanu, July 2006

Minnesota HMA Samples

• Three types of recycled materials

– 20% reclaimed asphalt pavement (RAP),

– 15% RAP + 5% Tear-off recycled asphalt shingles (RAS),

– 15% RAP + 5% Manufactured RAS.

• Only one virgin asphalt binder: PG 58-28

Marasteanu, July 2006

Creep Stiffness (MN: PG 58-28) (@ 100 seconds)

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% RAP

15% RAP + 5% Tear-off

15% RAP + 5% Manufactured

Marasteanu, July 2006

Creep Stiffness (MN: PG 58-28) (@ 500 seconds)

0.1

1.1

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

Marasteanu, July 2006

Strength (MN: PG 58-28)

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]

Ten

sile

Str

engt

h [M

Pa]

20% RAP

15% RAP + 5% Tear-off

15% RAP + 5% Manufactured

Marasteanu, July 2006

Creep Stiffness (MO vs. MN)(@ 100 seconds)

6.1

11.5

10.0

8.1

16.6

5.0

13.5

2.7

0

4

8

12

16

20

-10C -20C

Temperature [oC]

Sti

ffn

ess

[GP

a]

20% RAP - MO

20% RAP - MN

15% RAP + 5% Tear-off - MO

15% RAP + 5% Tear-off - MN

Marasteanu, July 2006

Creep Stiffness (MO vs. MN) (@ 500 seconds)

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]

Sti

ffn

ess

[GP

a]

20% RAP - MO

20% RAP - MN

15% RAP + 5% Tear-off - MO

15% RAP + 5% Tear-off - MN

Marasteanu, July 2006

Conclusions: Stiffness (MN)

• Adding tear-offs significantly increases stiffness of the mixtures at all test temperatures (a)

• Adding manufactured increases stiffness only at 0°C and -10°C (b)

Marasteanu, July 2006

Conclusions: Strength (MN)

No significant affects due to either tear-off or manufacturers’ shingles scrap

Marasteanu, July 2006

Conclusions: Stiffness(MO vs. MN)

• Lower stiffness values for the Minnesota RAP mixtures compared to Missouri mixtures

• Lower stiffness values for the MN combinations of RAP + RAS compared to MO mixtures (a)

Marasteanu, July 2006

Minnesota Extracted Binder Samples

Marasteanu, July 2006

• Bending Beam Rheometer (BBR) (a)

• Direct Tension Tests (DTT) (b)

BBR (MN)

Marasteanu, July 2006

BBR Conclusions (continued)

Marasteanu, July 2006

• Addition of shingles changes the properties (a)

• The two types of shingles perform differently– The manufactured material seems to be

beneficial (b)

– The tear-off material affects properties in a negative way (although it also decreases BBR stiffness) (c)

BBR Conclusions (continued)

• m-value not fully understood (a)

• The limited data also shows that binder and mixture results do not always agree (b)

• Need further research (c)

Marasteanu, July 2006

Mn/DOT Research

• Jim McGraw,DirectorMn/DOT Chemistry Lab

Shingle Asphalt Content

0.05.0

10.015.020.0

25.030.035.0

40.045.0

1 2 3 4 5 6 7 8 9 10

Sample

%A

C

Manufacture Waste

Demcon Tear-Off

RAP

McGraw, July 2006

AC Impact in Final Mix(at 5% RAS)

• RAS binder addition:

–Manufacturers’ adds 1.0% binder

–Tear-offs adds 1.8%

McGraw, July 2006

Shingles Low PG Temp

-15.0

-10.0

-5.0

0.0

5.0

10.0

15.0

1 2 3 4 5 6 7 8 9 10

Sample

PG

Tem

p

MW- TTS TO-TTSMcGraw, July 2006

Final Hot Mix Low Temperature PG (a)

• Tear-off -28.8 (b)

• Manufacturers’ -26.2 (c)

• RAP -29.2 (d)

McGraw, July 2006

Conclusions• More mixture testing (a)

• Experimental design needs true control

• Shingle only study (b)

• Field reviews of past projects (c)

• Re-evaluate current Mn/DOT spec (d)

McGraw, July 2006

Additional National Developments

• New AASHTO specification

• EPA / CMRA study

• www.ShingleRecycling.org

• Asbestos data base

States Using RAS(in 1999)

Justus, September 2004

Ayres, April 2004

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.

La Cross County, WIShingles Recycling Demonstration

• Marty Cieslik (Foth & Van Dyke) and Brian Tippetts (La Crosse County Solid Waste Director)

• Dr. Ervin Dukatz (VP-Materials and Research - Mathy Construction Company - Onalaska).

Use of Shingles on Dairy FarmsWest Central, WI

• Bernie Wenzel (Resource Recovery Team - Stratford, WI) and Deb Pingel (DNR-West Central Region).

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.

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:

Si (Incluya) No / Ningun (No incluya)

• Repias • Madera

• Papel del fietro • Metal: flashings, canales

• Clavos

• Plastico

• Basura de papel

• La otra basura

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

Quality Specs: Scrap Feedstock and

Final Products

• Free of debris / trash / foreign matter

• Tear-off scrap must be asphalt shingles only

• No nails!

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)

NCAUPG

• Conference in Minneapolis, MNJanuary 10-11, 2007Contact:

Lynn Warble at (765) 463-2317 or warble@purdue.edu

• http://cobweb.ecn.purdue.edu/~spave/NCAUPG/Index.html

NCAUPG January 2007 Conference

• Hot Mix Asphalt Technical Conference Session II Wednesday, January 10, 2007, 1:00 – 5:00 p.m. Moderators: Mike Kvach and Will Stalcup, NCAUPG Co-Chairmen – HMA Economics 101

• 1:00 – 2:00 RAP and Recycling of Asphalt Shingles:– Roger Brown, Pace Construction

– Joe Schroer, Missouri DOT

– Dusty Ordorff, Bituminous Roadways

– Dan Gallagher, Gallagher Asphalt

NCAUPG January 2007 Conference

• Hot Mix Asphalt Technical Conference Session III Thursday, January 11, 2007, 7:30 – 11:45 a.m.

• Moderators: Mike Kvach and Will Stalcup, NCAUPG Co-Chairmen – 9:30 – 10:00 Low Temperature Cracking:

Mihai Marasteanu, University of Minnesota

C&D Recycling World Exposition and Show

• Conference in San Antonio, TexasJanuary 14 - 16, 2007Contact:Lola Perez or Maria Miller at 800.456.0707 or lperez@giemedia.com or mmiller@giemedia.com

• http://www.cdworldshow.com/

Dan Krivit and Associates

651-489-4990

DKrivit@bitstream.net