Buzz Powell, technical director, Asphalt Pavement Alliance, examines various trends in the industry from a national perspective in a presentation delivered during the CalAPA Spring Asphalt Pavement Conference March 7-8, 2024 in Ontario, Calif.

1. NATIONAL PERSPECTVE:
Technical Trends and
How They May Impact California
Buzz Powell

2. Perspective

3. Asphalt Pavement Alliance
Seek first assistance, support from your SAPA, then APA…
Deploy effective resources directly to marketplace
Strengthen fact focused relationships between
decisionmakers, owners, agencies, and industry
3 pillars = innovation, collaboration, and education
Technical competence and trust with community
Support and promote quality asphalt pavement!

5. Performance
Related
Specifications

6. Increased RAP
Resilience

7. Warm mix
asphalt

8. Perpetual
pavement
Porous asphalt

9. Intelligent
construction

10. Surface friction
Quiet pavement
Ground tire
rubber

11. Performance
Sustainability
Resilience

13. Content
Mix/materials – meeting specific needs of each layer
Thickness design – preventing non-surface cracking
Preservation – safe, durable, renewable surface.

14. Specification Focus
Ensure performance for taxpayers (agencies)
Streamline the testing process (workforce)
Create opportunities for innovation (contractors).

15. Mix/Materials
Increasing RAP to offset the loss of virgin quarries
Practical aspects of EPD/LCA implementation
WMA for both energy reduction and compaction aid
Production BMD to index effective binder quality
Increasing binder content with polymer modification
High quality, lower carbon mix without a burner
Replace quarry limitations with specified friction.

16. Friction Mix Designs

17. Tools in the BMD Toolbox
Warm mix additives (some also antistrips)
Softer virgin binder grades (more tanks)
Long-term rejuvenation recycling agents
Short-term softener recycling agents
Onsite binder modification packages
High strength aramid fibers (options)
Recycled plastics (wet vs dry, caution advised)
Recycled ground tire rubber (wet vs dry).

18. Recycled Ground Tire Rubber
Finer grind in DGA, coarser grind in ARGG
As much as 20 percent of total binder weight (ARGG)
BMD testing challenge with simple methods
Extremely high fatigue life of ARGG mixes
Dry additive to protect reaction, tanks, plumbing
Warm mix additive to reduce temp, eliminate odor
EV tire wear rubber as greater particulate source.

19. Crack Prevention Interlayers

20. Thickness Design
“Perpetual Pavement”

21. Thickness Design
Designing pavements to survive rather than fail
Build a house on a rock then maintain the roof!
Perpetual thickness ranging from 5¾ to 14 inches
Change in philosophies with cement stabilization
Fatigue life impact of improving or eliminating tack
ThinLay surfaces on monolithic ThickLay buildups.

22. Preservation

23. Preservation

24. Innovative Screed Plates

25. Takeaways
Mix/materials – meeting specific needs of each layer
Thickness design – preventing non-surface cracking
Preservation – safe, durable, renewable surface.

26. Note Date Change !
Next Steps
Master plan complete before fall meeting
Workshops, training, demonstration projects
Identification of new projects for 2021 Track.
End-of-Cycle Conference for the
2021 NCAT Pavement Test Track and the
MnROAD Pavement Research Partnership
May 7-9, 2024
Auburn, AL

27. N C AT P a v e m e n t Te s t Tra c k
Performance Potential
of Quality Asphalt Thinlays

28. Questions?