The top engineer leading pavement design initiatives will provide a perspective on the status of various specification changes, construction standards and pilot projects. Presenter: Tom Pyle, Chief, Caltrans Office of Asphalt Pavement. Presentation delivered Oct. 13, 2021 at the CalAPA Fall Asphalt Pavement Conference in Sacramento,

1. State Pavement Design
Perspective
Tom Pyle, P.E.
Chief, Office of Asphalt Pavement
October 13, 2021
Caltrans Pavement Program

2. EVERY PAVEMENT LASTS LONGER
2
Pavement Goal

3. • In Place Recycling (IPR)
• Asphalt Pavement Smoothness
• Decision Documents: Tack Coat, 2-yr JMF, TCE
• Balanced Mix Design (BMD)
• Statistical Pay Factor for Oil Content
• GHG Emissions Guidance and elCAP
• Pavement Preservation
• Pilot Projects
3
Outline

4. • Benefits
✓ Increase usage of recycling
strategies
✓ Decrease GHGs
✓ More competitive bidding process
In-Place Recycling (IPR)
Less Waste, More Recycling
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• New IPR terminology
✓ Partial Depth Recycling (PDR) instead of
Cold In-Place Recycling (CIR)
✓ Full Depth Recycling instead of Full
Depth Reclamation
• Updated the 10-year-old PDR nSSP
✓ Reflects recent technological
advancements in equipment and testing
✓ Streamlined specifications to decrease
cost and increase usage of PDR

5. • nSSP adopted in 2018
• 370 projects in progress
• 48 projects were completed
• 700 lane-miles analyzed
• nSSP updated in 2021
• Benefits
✓ Decrease GHGs
✓ Increase average MPG of every
vehicle on smooth road
✓ Incentivizes contractors to
pave smooth roads
✓ Decreases claims
Asphalt Pavement
Smoothness
Watch Out for Smoother Roads Ahead!
5

6. • Tack Coat: require tack coat in all
cases to increase design life
• 2-Yr JMF: extend JMF to 2 years
to reduce cost and improve
sustainability
• Trichloroethylene (TCE):
substitute chemical extraction
tests to improve health and
safety
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Decision Documents
Low Hanging Fruits
Credit: https://www.evolveyourweddingbusiness.com/wp-content/uploads/2013/05/Low-hanging-fruit.jpg

7. • 40% RAP in the HMA mix
• Superpave mix design method to establish an initial aggregate blend and
asphalt content
• HMA mix will be adjusted based on the test results
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Balanced Mix Design (BMD)

8. 8
Statistical Pay Factor
for Oil Content
From GOOD roads to GREAT roads
GOOD ROADS
Spec Upper Limit
90%
within Limit
Spec Lower Limit
GREAT ROADS
Spec Lower Limit Spec Upper Limit
99.5%
within Limit

9. • Guidelines being developed to help designers
quickly calculate GHG Emissions and savings
for projects
• Includes tables for various materials and
strategies with GHG numbers obtained from
UCPRC’s elCAP program
• Will help Caltrans designers get comfortable
thinking about GHGs and transition into
doing a full LCA for all projects using elCAP
• Pilot projects with GHG calculations and
savings on project title sheets
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GHG Emissions Guidance and elCAP
EFFICIENCY PARAMETERS
MATERIAL REUSED (TON)
GHG EMISSIONS SAVED THROUGH
MATERIAL, TRANSPORT, AND
CONSTRUCTION (KG CO2)
MATERIAL DIVERTED FROM
LANDFILL (TONS)
TRUCKS SAVED
COST SAVINGS ($)

10. • Some emulsions do not meet California’s air quality
standards, they are removed
• 400 projects in the last two years
• 1100 projects in construction or planned in the next two
years
• Clarify language for several pavement preservation methods
• Conduct online Pavement Preservation Training with the
Western Regional Association for Pavement Preservation
(WRAPP) for statewide Caltrans staff:
✓ Microsurfacing /Slurry Seals
✓ Chip Seals
✓ Emulsions Training completed July 22
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Pavement Preservation

11. 11
Pilot Projects
Since April 2021:
• 9 innovative ideas
• 17 projects
• $1.7 million committed
• 2 draft construction evaluation
reports

12. • Improve partial depth recycling
with foamed asphalt (PDR-FA)
construction and mix design
• Longer-lasting roadways at lower
costs
• Evaluate the effect of additional
fines or imported aggregates to
decrease the air voids and increase
the longevity of the pavement
12
PDR-FA with Additional Fines or Aggregates

13. Compare and evaluate the
performance of the recycling
agents:
• Emulsified Asphalt (EA)
vs.
• Foamed Asphalt (FA)
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PDR-EA vs. PDR-FA

14. Construct Test Sections
• Aggregate size from 0.75 inch to 1.25 inches
• Different air void percentages
• Use single and multi-unit recycling trains
Expected Outcomes
• Improve PDR construction and mix design specifications
• Better understand the maximum aggregate sizing impact on the performance
of the PDR-EA and PDR-FA
14
Effect of Aggregate Gradation on PDR-EA and PDR-FA
https://bluedotreadimix.wordpress.com/2016/04/26/ag
gregate-gradation-matters/

15. Pavement Preservation with Chip Seal
• Use of the Asphalt Rubber Binder (ARB) Type 3 in
chip seal projects in California’s northeast cold
region near the Oregon border
• Withstand snowplow damage better
• Seal pavement surface to minimize moisture
damage
• Can be installed in various climates
• Environmentally friendly
• Cost effective
SR 139
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16. • In Place Recycling (IPR)
• Asphalt Pavement Smoothness
• Decision Documents: Tack Coat, 2-yr JMF, TCE
• Balanced Mix Design (BMD)
• Statistical Pay Factor for Oil Content
• GHG Emissions Guidance and elCAP
• Pavement Preservation
• Pilot Projects
16
Summary

17. 17
Questions?
Tom Pyle, P.E.
tom.pyle@dot.ca.gov
916-704-9245