Larry Hernandez with Caltrans provides the department's perspective on in-place recycling in a presentation delivered during the CalAPA Spring Asphalt Pavement Conference March 7-8, 2024 in Ontario, Calif.

1. PAVEMENT RECYCLING
Presented by: Larry Hernandez
Recycling Branch, Office of Asphalt Pavements
Pavement Program
March 2024

2. TOPICS
Cold Recycling
in Caltrans
Pavement
Materials
Partnering
Committee Work
Senate Bill 1
2

3. WHY WE DO COLD RECYCLING
 Proven technology backed up by
research
 Uses all existing, paid for materials,
requiring limited new materials
 Minimizes trucking operations
 Shorter construction time, less traffic
disruption
3
 Removes distresses instead of covering
them
 Extended pavement life
 Specifications are in place
 Cost effective/ lower life-cycle cost

4. WHAT IS COLD RECYCLING IN
CALTRANS?

5. PARTIAL-DEPTH RECYCLING (PDR)
▪ Top-down distresses within the asphalt
layers
 Oxidized asphalt,
 Thermal cracks
 Top-down cracking
 Surface rutting
 Fatigue cracking (from debonding, not weak
structure)
▪ Recycle top 0.25 to 0.5 ft with 0.15 to 0.2 ft.
of HMA or RHMA-G overlay
 Milling teeth stay primarily in the AC layers
▪ 1 to 2 lane miles per day
▪ PDR-Emulsified Asphalt, PDR-Foamed
Asphalt
▪ New surfacing is required

6. ▪ Rehabilitation to address bottom-up distresses from the
underlying layers
 Bottom-up cracking (alligator A & B, block,
shrinkage, etc.)
 Base and/or subgrade rutting
 Thermal cracks
 Plus any top-down distresses usually addressed with
PDR
▪ Recycles top 0.7 to 1.0 ft.
 Milling teeth go through AC layers into underlying
base
▪ 1 to 2 lane miles per day depending on recycle train
▪ FDR-No Stabilizer, FDR-Foamed Asphalt, FDR-Cement
▪ New surfacing is required
FULL DEPTH RECYCLING (FDR)

7. COLD RECYCLING STRATEGIES

8. COLD RECYCLING
IN CALTRANS
First Caltrans FDR
completed (03-33900. Col-
20) was 2002; first PDR
completed (03-2M460, Col-
16) was 2007

9. COLD RECYCLING PROJECTS
9
PDR FDR CCPR
FY SHOPP MAINT SHOPP MAINT SHOPP MAINT TOTAL
18/19 4 4
19/20 4 5 9
20/21 5 5
21/22 4 4
22/23 1 3 2 1 2 9
23/24 5 1 6
24/25 1 1
25/26 4 4
26/27 3 4 7
27/28 4 1 5
Source of data: Contract Cost Data and Asset Management Tool

10. PAVEMENT
MATERIALS
PARTNERING
COMMITTEE
(PMPC)
 Provides a forum for Caltrans to work with the
Construction Industry to develop and improve
Caltrans specifications, test methods, and
construction procedures
 Improves construction contract standards by:
o Providing opportunity for Caltrans and
Industry to bring forward issues and/or
opportunities for improving current and
proposed construction contract standards.
o Exchanging information regarding new
technology, materials, and upcoming
initiatives.
o Providing transparency, stewardship,
efficiency, and sustainability.

11. PMPC TASK GROUPS
PMPC Task
Groups
Concrete
(CTG)
Asphalt (ATG)
Asphalt
Subtask Group
Preservation
Subtask Group
Recycling
Subtask Group
FDR-FA Working
Group
PDR Working
Group

12. CURRENT
COLD
RECYCLING
PMPC
WORK
FDR-C Specification Update
PDR Specification Update
FDR-FA Specification Update
CCPR Pilot Projects
PLC Pilot Projects

13. COLD RECYCLING
PILOT PROJECTS
 Provided additional funds
for cold recycling pilot
projects
13

14. SENATE BILL 1
Road Repair and Accountability Act
of 2017
“To the extent possible and cost effective,
and where feasible, the department and
cities and counties receiving funds under
the program shall use advanced
technologies and material recycling
techniques that reduce the cost of
maintaining and rehabilitating the streets
and highways, and that exhibit reduced
levels of greenhouse gas emissions through
material choice and construction method”
14

15. SENATE BILL 1
 As part of the SB-1, the department is
required to report efficiencies on an
annual basis.
 The definition of efficiencies, as
approved by the Caltrans Financial
Policy Board, is Caltrans will consider
efficiencies that result in cost
avoidance or a reduction in support or
capital costs.
 The Office of Asphalt Pavements
began reporting Cold Recycling
efficiency savings starting in FY 19/20
15

16. SB-1 REPORTED COLD RECYCLING
COST SAVINGS
FY 19/20 FY 20/21 FY 21/22 FY 22/23 FY 23/24
No. Projects 6 9 5 5 6
Lane Miles
of Paving
86 205 75 99 95
CR Paved
(tons)
130,000 235,000 111,000 140,000 230,000
Cost Savings $2 million $7 million $1.2 million $5.0 million $14.8

17. NEXT STEPS FOR COLD RECYCLING
 Continue monitoring pilot projects
 30-3 Full Depth Recycling – Foamed
Asphalt Updates
 30-4 Full Depth Recycling – Cement
 30-5 Partial Depth Recycling
 FY 23/24 SB-1 Efficiencies
 Providing support for CR projects
Thank You !

18. Link:
https://maintenance.onramp.dot.ca.gov/asphaltp
aves/asphalt-pavement-recycling-pr-branch
Cold Recycling Resources
•2022/2023 In-Place Recycling Webinar Series
• Part I: Project Selection & Development of the In-Place Recycling (IPR) Industry (October 2022)
• Part II: Partial Depth Recycling (March 2023)
• Part III: Full Depth Recycling (June 2023)
• Part IV: Cold Central Plant Recycling (September 2023)
•2020 Introduction to Cold Recycling Webinar
•Site Investigation Guide
•Highway Design Manual: Chapter 630 Flexible Pavement
•Caltrans PaveM Portal Website
•Caltrans Cold Recycling Manual
•DES Website
•Office of Asphalt Pavement
•Wirtgen Cold Recycling Technology Manual (external link)
•Basic Asphalt Recycling Manual (BARM) (upon request)
•Road Resource Website (external link)
•Portland Cement Association Manual (external link)
Available Specifications
•Standard Specifications
• Section 30-2 Full Depth Recycling - No Stabilizer
• Section 30-3 Full Depth Recycling - Foamed Asphalt
• Section 30-4 Full Depth Recycling - Cement (Upcoming 2024 Updates)
•Non-Standard Specifications
• NSSPs require pre-approval by HQ Pavement
• NSSP-30-5 Partial Depth Recycling (11.09.2022)
• NSSP-30-7 Cold Central Plant Recycling (04.05.2022)

19. RECYCLING BRANCH
• RESEARCHING NEW INNOVATIVE RECYCLING
TECHNIQUES,
• PROMOTING BEST PAVEMENT RECYCLING
PRACTICES, AND
• ASSISTING DISTRICTS WITH DESIGN.
Contact Information
Christina Pang
Christina.Pang@dot.ca.gov
(916) 531-5418
Saeed Pourtahmasb
Saeed.Pourtahmasb@dot.ca.gov
(916) 639-5646
Larry Hernandez
Larry.Hernandez@dot.ca.gov
(916) 879-6723
19