© 2015 Cargill, Incorporated. All rights reserved.AnovaTM Asphalt Solutions
Anova Asphalt Solutions
• Rejuvenators
• Warm Mix Asphalt
• Cold Mix Solutions– with or without RAP
– produced with 100% RAP
• Emulsifiers
• Anti-strip
• Modifiers
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Hassan A. Tabatabaee, Ph.D.Cargill Industrial Specialties
© 2015 Cargill, Incorporated. All rights reserved.AnovaTM Asphalt Solutions
What is rejuvenation?• “Rejuvenation” is an inaccurate, but popular term.
• Rejuvenators do not undo oxidative aging!!!
• A good rejuvenator reverses the impact of aging on asphalt, reactivating the bitumen, to restore performance, and durability.
• Reduce modulus/viscosity
• Restore balance of asphalt fractions • Restore phase/colloidal stability• Reduce brittleness / improve damage resistance• Restore “healing” ability• Equal (or better) aging behavior than original binder!
Softening
Reju
venatin
g
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© 2015 Cargill, Incorporated. All rights reserved.AnovaTM Asphalt Solutions
0%
5%
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20%
25%
30%
35%
40%
45%
SAR
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ions
40hr PAV 40hr PAV + Anova™
Re-Balancing Asphalt Fractions• Decreasing asphaltenes content and association through balanced
addition of bio-based “aromatic” and “resin” functionality.
Thin Layer Chromatography (TLC) using an Iatroscan
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0%
5%
10%
15%
20%
25%
30%
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40%
45%
SAR
A F
ract
ions
Unaged 40hr PAV
Aging Rejuvenation
Rejuvenator
© 2015 Cargill, Incorporated. All rights reserved.AnovaTM Asphalt Solutions
Material Considered in this PresentationThe Rejuvenator: An Engineered Solution
The Asphalt Binders Considered:• RAP contents ranging from 30 to 85% by weight of mixture.• Base binders ranging from XX-34 to PG64-22, as well as
pen grades 40/50, 50/70, and 70/100.• All are dense graded surface and base course mixes.• All DCT tests done at climatic PG+10 temperature.• All IFIT and Overlay tests done at 25C.
Description Flash Point Viscosity at 60°C
Engineered Bio-based Rejuvenator (AnovaTM)
>290°C 28.5 mPa.s
TFO Mass loss TFO Visc Ratio
<1% 1.1
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© 2015 Cargill, Incorporated. All rights reserved.AnovaTM Asphalt Solutions
The Potential of High RAP Rejuvenation…
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31% RAP 40% RAP 45% RAP
50% RAP 67% RAP 100% RAP
© 2015 Cargill, Incorporated. All rights reserved.AnovaTM Asphalt Solutions
Performance-based DesignA common sense concept:
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Cracking
Resistance
Rutting
Resistance
Design Property
Acceptable Range
Can be: • Asphalt content • RAP Content• Rejuvenator dosage• Bitumen Rheology
© 2015 Cargill, Incorporated. All rights reserved.AnovaTM Asphalt Solutions
Adjusting Performance using Rejuvenator Dosage
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Rejuvenator Dosage (%)
Fracture Energy of 61% Recycled HMA using Anova™ Rejuvenator
PGXX-34 (No Rej.)
PG58-28 + Rejuvenator
• Normal paving grade asphalt + Anova can perform better than soft asphalt / flux.
© 2015 Cargill, Incorporated. All rights reserved.AnovaTM Asphalt Solutions
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3.8
1.7
2.8
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1.0
2.0
3.0
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5.0
6.0
7.0
APA Rut Depth (mm) Field Cores
Example 1:
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22% RAP45% RAP + 5%
RAS + Rejuvenator
45% RAP 45% RAP + Anova Rej
45% RAP + 5%RAS
45% RAP + 5%RAS + Anova Rej
• Rejuvenation resulted in a high improvement in durability, with minimal impact on rutting.
45% RAP 45% RAP + Anova Rej
45% RAP + 5%RAS
45% RAP + 5%RAS + Anova Rej
© 2015 Cargill, Incorporated. All rights reserved.AnovaTM Asphalt Solutions9
Fracture Energy
Example #2: 100% RAP HMA
Rejuvenated 100% RAP
Permanent Deformation
• HMA solely consisted of RAP and Rejuvenator
• Rejuvenator sufficiently activated RAP to achieve +500 J/m2 fracture energy.
• No rutting issues observed.
© 2015 Cargill, Incorporated. All rights reserved.AnovaTM Asphalt Solutions
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125 150 175 200 225 250 275 300 325
Air
Void
s (%
)
Compaction Temperature (°F)[Plant Produced 9.5mm Surface Course]
50% RAP + Anova™
30% RAP
Improved Compaction with Proper Rejuvenation
• Use of the rejuvenator significantly improved the Compactability, even after a 20% increase in RAP content.– A 25°C improvement in compaction temperatures achieved– No over-compaction at hot mix temperatures.
205°F45°F
250°F
© 2015 Cargill, Incorporated. All rights reserved.AnovaTM Asphalt Solutions
Plant Incorporation Process
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Many options for dosing:
• In virgin asphalt using additive / antistrip pump • Pre-blended into virgin asphalt• Pre-treatment of RAP• Injection into pugmill
© 2015 Cargill, Incorporated. All rights reserved.AnovaTM Asphalt Solutions
Closing Thoughts• Proper rejuvenation can improve workability and durability of
high-recycled HMA.
• The rejuvenator dosage and AC type can be used as the design property in Performance-based design methodology.
• Proper rejuvenation can “tune” the cracking performance to target values with proper balance of dosage, AC type, and AC content.
• Rutting is usually not a controlling factor in properly rejuvenated hi-recycled mixes. “Durability/Cracking Resistance” is the controlling property.
• Aging must be a consideration in performance-based designs, especially with use of additives and rejuvenators.
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