NCAT Pavement Test Track
3/5/2018
Combining RAP, RAS, and WMA at Your Plant Session Code T33 Buzz Powell
NCAT Pavement Test Track
Combining RAP, RAS, and WMA at Your Plant
1
3/5/2018
Content • • • • • • APAI – 12/2/08
Milling RAP RAS WMA Combinations Experience 4
Milling → RAP • • • • • •
Milling to remove distresses in aged layer(s) Restore cross slopes & improve smoothness Maintain geometry (curbs, inlets, bridges) Reclaim/reuse valuable raw materials Reduce the cost of new surface mix(es) Burden of RAP mountains in urban markets.
APAI – 12/2/08
5
Improved Mill/RAP Practices
2
3/5/2018
RAP Mix Design • Tier 1: Up to 15% RAP – use specified binder grade • Tier 2: 15%-25% RAP – One full binder grade lower (e.g., PG64-22→PG58-28) • Tier 3: Over 25% RAP – Extract, recover, and grade RAP binder (assumptions) – use blending charts to determine required grade • We should expect RAP to change with each reuse.
NCAT Pavement Test Track
High RAP Mixes and Virgin AC Grade
45% RAP PG58-28
20% RAP PG67-22
45% RAP PG67-22
20% RAP PG76-22
45% RAP PG76-22
3
3/5/2018
RAS Mix Design Shingle binders are stiffer than paving grade binders Post consumer shingles (PC-RAS) are also rooftop aged Shingles must be processed for use in HMA plants “Deleterious materials” must be removed from PC-RAS Mixing must occur at or above extracted binder grade Volumetrics may not be representative of mix quality Caution of volumetric changes with storage time Practical limits on aged binder content from RAS Need for a dedicated feed system for very low rates.
• • • • • • • • •
RAS Mix Design
Why Warm Mix ? • • • • • •
Less energy needed for mix production Fewer emissions from asphalt plants Less fumes & odors for paving crew, neighbors Workability/compaction at lower, equal temps Longer hauls, extended paving season Improved smoothness on crack sealing.
APAI – 12/2/08
12
4
3/5/2018
Warm Mix Options • Organic Additives • Chemical Additives • Asphalt Foaming Technologies – Foaming additives – Water Injection Systems
• Combinations of above.
APAI – 12/2/08
13
Warm Mix Concerns • • • • • • •
Burner efficiency, recalibration Adequate drying of the virgin aggregates Condensation in the baghouse Increased/over amperage of plant motors Starting hot and reducing temperatures When/how to dose with additives Institutional commitment to utilization.
APAI – 12/2/08
14
Warm Mix Energy Savings 40 39 38 37
Burner Setting (%)
36 35 34 33
8%
6%
32 31 30 29 28 27 26 25 10:33 AM
10:48 AM
11:02 AM
11:16 AM
11:31 AM
11:45 AM
12:00 PM
12:14 PM
12:28 PM
12:43 PM
12:57 PM
Time of Production on 7/3/09
APAI – 12/2/08
15
5
3/5/2018
Warm Mix Emissions Reductions
8% fuel→10% CO2
APAI – 12/2/08
16
WMA Mix Design • Drop in additive technologies – Mixing/compaction temps via technology provider
• Lab foamers are recommended, but… – No way to replicate proprietary technologies
• NCHRP 9-43 “Volumetrics Plus” approach – Compactability (N92comp-30F / N92comp ≤ 1.25) – T283 (≥ 80 percent) and coating test for moisture – FN with criteria as function of traffic – Mix above PG grade of recycled materials. APAI – 12/2/08
17
Combining RAP and Warm Mix • Superheating reduces baghouse concerns – Improved flights and variable speed drives
• Superheating improves virgin aggregate drying – Ideal to stay below the liquid asphalt flash point
• Superheating makes cold starts easier • RAP improves WMA moisture damage susceptibility • Greatest economic & environmental benefit. APAI – 12/2/08
18
6
3/5/2018
2009 GE+ Fatigue Expectations Actual
10 million ESAL strain cycles
19
High RAP Mixes and WMA
Virgin HMA
50% RAP HMA
Virgin WMA-F
50% RAP WMA-F
Virgin WMA-A
Strategic Use of RAP, RAS, GTR, & WMA Purpose of Each Layer
N5 Control
S5 Higher RAP
S6 RAP+RAS
Durable, Rut 20% RAP20 25% RAP11 5% RAS21 Resistant Surface 67-22/82-16 DG 67-22/76-22 SMA 67-22/88-16 SMA
S13 Recyc Tires VIRGIN 82-2212 SMA
Stiff, Strain 35% RAP39 Reducing Middle 67-22/88-10 DG
50% RAP41 67-22/82-16 DG
50% AGED26-24 67-22/94-10 DG
35% RAP37 82-2212 DG
Fatigue Resistant 35% RAP39 Base Layer 67-22/88-10 DG
35% RAP34 94-28/94-10 DG
25% RAP24 +76-22/88-16 DG
VIRGIN 88-2220 AZ
Green = Evotherm Q1 Additive, Blue = Astec Green Foamer
7
3/5/2018
Targeted Use of RAP, RAS, and GTR Control
GTR RAP+RAS
RAPDebonded
RAPRebuilt
Lee Road 159 Low Traffic Preservation
Benefit of Preservation (PG)
MAP-21 Banded Pretreatment Condition Green = “Good” (< 5% of lane cracked) Yellow = “Fair” (5% ≤ 20% of lane cracked) Red = “Poor” (> 20% of total lane area cracked)
8
3/5/2018
Benefit of Preservation (PG)
PG Thinlay Cracking Performance
US-280 High Traffic Preservation
9
3/5/2018
Mix Design • • • • • • • •
Cost of liquid asphalt Total vs aged vs virgin binder content Voids in mineral aggregate Blended bulk specific gravity Design compactive effort Shape of gradation curve Nominal maximum aggregate size Rutting vs cracking/durability.
Mix Design
RAP11+RAS3 Thinlays20 on Cold Recycle CCPR Foam
No Rutting
Emulsion
No Cracking CIR
10
3/5/2018
Cold Climate Sections
Minnesota Preservation Sections (PG)
710 ADT with 8% Heavy Commercial
16,500 ADT with 3% Heavy Commercial
20% Aged Binder Thinlay on US-169
11
3/5/2018
Cracking Group (CG) Experiment
Southern Cracking Group (CG)
Summary • • • • • • • •
100% use of all RAP in the most cost effective way Cold recycle & hot and/or warm mix asphalt Careful use of sustainable clean, processed PC-RAS Strategic selection of warm mix technologies Aged agency verification of balanced mix designs Production testing using same-day practices Emerging rejuvenator & equipment technologies Optimize both sustainability and life cycle cost.
12
3/5/2018
High Friction Surface Treatments
37
http://www.omnicrete.com.au/road-safety-surfacing/
Thank You
Session Evaluations/PDH’s
See you again at:
• Professional Development Hours logged in session feedback.
• World of Asphalt 2019
• Complete session feedback in mobile app.
• February 12-14, 2019 • Indianapolis, IN
• CONEXPO – CON/AGG 2020 • March 10-14, 2020 • Las Vegas, NV • 140+ education sessions
• Answer “Yes” to last questions for PDH’s
#WorldofAsphalt
13
Combining RAP, RAS, and WMA at Your Plant Session Code T33 Buzz Powell
NCAT Pavement Test Track
Combining RAP, RAS, and WMA at Your Plant
1
3/5/2018
Content • • • • • • APAI – 12/2/08
Milling RAP RAS WMA Combinations Experience 4
Milling → RAP • • • • • •
Milling to remove distresses in aged layer(s) Restore cross slopes & improve smoothness Maintain geometry (curbs, inlets, bridges) Reclaim/reuse valuable raw materials Reduce the cost of new surface mix(es) Burden of RAP mountains in urban markets.
APAI – 12/2/08
5
Improved Mill/RAP Practices
2
3/5/2018
RAP Mix Design • Tier 1: Up to 15% RAP – use specified binder grade • Tier 2: 15%-25% RAP – One full binder grade lower (e.g., PG64-22→PG58-28) • Tier 3: Over 25% RAP – Extract, recover, and grade RAP binder (assumptions) – use blending charts to determine required grade • We should expect RAP to change with each reuse.
NCAT Pavement Test Track
High RAP Mixes and Virgin AC Grade
45% RAP PG58-28
20% RAP PG67-22
45% RAP PG67-22
20% RAP PG76-22
45% RAP PG76-22
3
3/5/2018
RAS Mix Design Shingle binders are stiffer than paving grade binders Post consumer shingles (PC-RAS) are also rooftop aged Shingles must be processed for use in HMA plants “Deleterious materials” must be removed from PC-RAS Mixing must occur at or above extracted binder grade Volumetrics may not be representative of mix quality Caution of volumetric changes with storage time Practical limits on aged binder content from RAS Need for a dedicated feed system for very low rates.
• • • • • • • • •
RAS Mix Design
Why Warm Mix ? • • • • • •
Less energy needed for mix production Fewer emissions from asphalt plants Less fumes & odors for paving crew, neighbors Workability/compaction at lower, equal temps Longer hauls, extended paving season Improved smoothness on crack sealing.
APAI – 12/2/08
12
4
3/5/2018
Warm Mix Options • Organic Additives • Chemical Additives • Asphalt Foaming Technologies – Foaming additives – Water Injection Systems
• Combinations of above.
APAI – 12/2/08
13
Warm Mix Concerns • • • • • • •
Burner efficiency, recalibration Adequate drying of the virgin aggregates Condensation in the baghouse Increased/over amperage of plant motors Starting hot and reducing temperatures When/how to dose with additives Institutional commitment to utilization.
APAI – 12/2/08
14
Warm Mix Energy Savings 40 39 38 37
Burner Setting (%)
36 35 34 33
8%
6%
32 31 30 29 28 27 26 25 10:33 AM
10:48 AM
11:02 AM
11:16 AM
11:31 AM
11:45 AM
12:00 PM
12:14 PM
12:28 PM
12:43 PM
12:57 PM
Time of Production on 7/3/09
APAI – 12/2/08
15
5
3/5/2018
Warm Mix Emissions Reductions
8% fuel→10% CO2
APAI – 12/2/08
16
WMA Mix Design • Drop in additive technologies – Mixing/compaction temps via technology provider
• Lab foamers are recommended, but… – No way to replicate proprietary technologies
• NCHRP 9-43 “Volumetrics Plus” approach – Compactability (N92comp-30F / N92comp ≤ 1.25) – T283 (≥ 80 percent) and coating test for moisture – FN with criteria as function of traffic – Mix above PG grade of recycled materials. APAI – 12/2/08
17
Combining RAP and Warm Mix • Superheating reduces baghouse concerns – Improved flights and variable speed drives
• Superheating improves virgin aggregate drying – Ideal to stay below the liquid asphalt flash point
• Superheating makes cold starts easier • RAP improves WMA moisture damage susceptibility • Greatest economic & environmental benefit. APAI – 12/2/08
18
6
3/5/2018
2009 GE+ Fatigue Expectations Actual
10 million ESAL strain cycles
19
High RAP Mixes and WMA
Virgin HMA
50% RAP HMA
Virgin WMA-F
50% RAP WMA-F
Virgin WMA-A
Strategic Use of RAP, RAS, GTR, & WMA Purpose of Each Layer
N5 Control
S5 Higher RAP
S6 RAP+RAS
Durable, Rut 20% RAP20 25% RAP11 5% RAS21 Resistant Surface 67-22/82-16 DG 67-22/76-22 SMA 67-22/88-16 SMA
S13 Recyc Tires VIRGIN 82-2212 SMA
Stiff, Strain 35% RAP39 Reducing Middle 67-22/88-10 DG
50% RAP41 67-22/82-16 DG
50% AGED26-24 67-22/94-10 DG
35% RAP37 82-2212 DG
Fatigue Resistant 35% RAP39 Base Layer 67-22/88-10 DG
35% RAP34 94-28/94-10 DG
25% RAP24 +76-22/88-16 DG
VIRGIN 88-2220 AZ
Green = Evotherm Q1 Additive, Blue = Astec Green Foamer
7
3/5/2018
Targeted Use of RAP, RAS, and GTR Control
GTR RAP+RAS
RAPDebonded
RAPRebuilt
Lee Road 159 Low Traffic Preservation
Benefit of Preservation (PG)
MAP-21 Banded Pretreatment Condition Green = “Good” (< 5% of lane cracked) Yellow = “Fair” (5% ≤ 20% of lane cracked) Red = “Poor” (> 20% of total lane area cracked)
8
3/5/2018
Benefit of Preservation (PG)
PG Thinlay Cracking Performance
US-280 High Traffic Preservation
9
3/5/2018
Mix Design • • • • • • • •
Cost of liquid asphalt Total vs aged vs virgin binder content Voids in mineral aggregate Blended bulk specific gravity Design compactive effort Shape of gradation curve Nominal maximum aggregate size Rutting vs cracking/durability.
Mix Design
RAP11+RAS3 Thinlays20 on Cold Recycle CCPR Foam
No Rutting
Emulsion
No Cracking CIR
10
3/5/2018
Cold Climate Sections
Minnesota Preservation Sections (PG)
710 ADT with 8% Heavy Commercial
16,500 ADT with 3% Heavy Commercial
20% Aged Binder Thinlay on US-169
11
3/5/2018
Cracking Group (CG) Experiment
Southern Cracking Group (CG)
Summary • • • • • • • •
100% use of all RAP in the most cost effective way Cold recycle & hot and/or warm mix asphalt Careful use of sustainable clean, processed PC-RAS Strategic selection of warm mix technologies Aged agency verification of balanced mix designs Production testing using same-day practices Emerging rejuvenator & equipment technologies Optimize both sustainability and life cycle cost.
12
3/5/2018
High Friction Surface Treatments
37
http://www.omnicrete.com.au/road-safety-surfacing/
Thank You
Session Evaluations/PDH’s
See you again at:
• Professional Development Hours logged in session feedback.
• World of Asphalt 2019
• Complete session feedback in mobile app.
• February 12-14, 2019 • Indianapolis, IN
• CONEXPO – CON/AGG 2020 • March 10-14, 2020 • Las Vegas, NV • 140+ education sessions
• Answer “Yes” to last questions for PDH’s
#WorldofAsphalt
13
