This presentation focuses on the decreasing quality and life of asphalt pavements in the United States, and what the asphalt industry can do to improve sustained age-resistance in our paving materials.

1. ReGen-erating Aged Binder
Virginia Pavement Research & Innovation Symposium
6-19-2019
R. Grover Allen, Ph.D., P.E.

2. 2
Recent Decline in Pavement Quality
Associated with RAP/RAS
Recycling Responsibility. Asphalt Institute, 9/17
During the last decade, the quality/life of asphalt pavements in
U.S. have DECREASED.
One state reported a DECREASE in pavement life of about 4 YEARS
Opinion: Issues with cracking stem from improper use of RAP/RAS

3. 3

4. 4
Asphalt Concrete Pavement Performance
2.25 million miles of asphalt-paved roads in the U.S.
alone.
➢ Average rating is D-
➢ 1/5 miles in Poor condition
➢ Annual backlog $80B

5. 5
Huber, AMAP 2019

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Starting with Aged (RAP) Binder (20% avg)
Multi-source RAP pile (RAP Best Practices. NCAT 2010.)
QIP-129 (NAPA 2015)

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Re-using Aged Asphalt
Assumed!
New
Mixture
Aged
Mixture
New
Mixture?

8. 8
Different approach to RAP:
Japan: US:
Binder quality: Waste/Very Poor Good enough to replace virgin binder
Binder upgrade: Mandatory (“rejuvenation”) None required/ “soften” virgin binder
Method: Mandatory E/R/Testing No RAP binder testing required
Winning Bid: Lowest Life-cycle Cost Lowest Initial cost
Warranty: Mandatory/Long-term Rare/Short (<2 yrs)/None
40 years ago…RAP becomes common in the US and Japan
NAPA. Info Series 139 (2015) - High RAP Asphalt Pavements.
Japan Practice – Lessons Learned.
Present Day:
Japan: US:
Avg RAP = 47% Avg RAP = 20%
97% roads in Good condition 30% roads in Good condition
20% roads in Poor condition
$80 billion annual backlog

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10. 10
RAP + ReGen®
(after heat)
RAP
(after heat)
Aged Asphalt Binder (from RAP)
Currently approved in most states to
replace up to 20% of required binder in mix.

11. 11
RAS +
Virgin
Aggregates
(after heat)
RAS + ReGen® +
Virgin
Aggregates
(after heat)
Aged Asphalt Binder (from RAS)
Currently approved in many states to
replace up to 20% of required binder in mix.

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Better Handling/Constructability

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Superior Mix Fatigue Resistance
(Fatigue-Resistant Bottom AC Layer)
25X

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Sustained Age-Resistance
30% RAP +
ReGen® >
PG 67-22
60% RAP +
ReGen ® >
30% RAP
“Bottom-grade”
with aging time
PG 67 “-22”

17. 17
ReGen Plant Mix Performance
• Volumetrics
• Asphalt %, RBR (AASHTO M323, FM 5-563)
• Bulk, Max SG (Gmb; Gmm), (FM 1-T 166; FM 1-T 209)
• AV (%), AASHTO T 289
• Mix Performance
• Rutting (Hamburg @ 50C, AASHTO T324)
• Cracking (Illinois Flexibility Test, I-FIT @ 25C)
• Durability (R30 LTOA + Cantabro Mass loss %, AASHTO TP 108)
• Conclusions
• 45% and 60% RAP + ReGen® mixtures:
✓ met all volumetric requirements
✓ matched mix performance of control
✓ Lower mix cost than control
45% RAP + ReGen
Customer impressed by “wet”
appearance compared to RAP
control mixture.
60% RAP +
ReGen®
45% RAP +
ReGen®

18. 18
High % RAP + ReGen®
Constructability
50% RAP + ReGen®

19. Thank You from
Blacklidge!
R. Grover Allen, Ph.D, P.E.
Technical Director
gallen@be-inc.com