Why Pavement Maintenance
and Preservation?
Sponsored by:
Minnesota T2 Center
Presented by:
Michael Marti, P.E.
SRF Consulting Group, Inc.
Dan Wegman, P.E.
SemMaterials
What Are We Talking About?
FHWA
Definition of Pavement Preservation
Pavement preservation is a strategically-planned,
engineering-based program to arrest light
deterioration, retard progressive failures, reduce the
need for routine maintenance and maintain safety on
the existing roadway system. It is a series of cost
effective maintenance strategies to delay the onset of
predicted distress. Pavement preservation does not
significantly improve the load carrying capacity of
pavements, shoulders, or structures, but extends the
useful life and improves the level of service.
FHWA
Practical Definition of
Pavement Preservation
The right treatment
At the right time
On the right project
Done right!
FHWA Maintenance: Needs vs Budget
Budget:
$27 billion
Needs:
Maintain: $50 billion
Eliminate backlog: $210 billion
Mn/DOT - Preventive Maintenance
Funding and Operational Issues
• In 1999, spent $30 million maintenance
• Estimated need is $118 million!
• Centralized recommendations based on
pavement management program
• Final decisions based on field review and local
issues/input
Types of Pavement Maintenance
• Corrective (reactive, rehabilitation)
– After deficiency occurs
– More expensive
• Preventive (proactive)
– Protective
– Retards deterioration
– Extends asset’s life
– Reduces need for corrective maintenance
Why Pavement Preservation?
Intuitive Argument
• Why do you change the oil in your car?
• Why do you paint the exterior of your house?
You do them to preserve your initial
investment and extend it’s life…
You don’t measure how long they last…
Pavement preservation is the same concept.
Pavement Lifecycle
Typical Maintenance & Rehabilitation Strategies
Routine Maintenance
Pavement Preservation
PSI
(Pavement Serviceability Index)
100
Defer Action
80
Rehabilitation
60
Reconstruction
40
20
0
Years
Pavement Preservation Strategy
Preventive Preservation Treatments
Conventional Overlay
Time or traffic
Pavement Structural Condition
Theory Behind Pavement
Preservation – Timing
Excellent
Good
40% drop
in quality
75% of life
Fair
$1 for PP here
40% drop
in quality
Poor
Would cost
$5 - $10 here
Very Poor
12% of life
Failed
5
10
15
Years
20
Where is the Proof?
Numerous studies/resources
•
•
•
•
•
FHWA
NCHRP
NHI
Foundation for Pavement Preservation
LRRB
Empirical facts
vs
Compelling data
Where is the Proof?
Current LRRB Study
(Inv 861 Wood and Lukanen)
1256 sections (constructed since 1985, bituminous over gravel base)
• 597 no preservation
 659 with preservation
No Maintenance
Seal Coated
Poly. (Seal Coated)
Poly. (No Maintenance)
4.0
3.5
Seal Coated Sections
y = 0.0005x 2 - 0.0419x + 4.0221
R2 = 0.8354
Average SR
3.0
2.5
2.0
1.5
No Maintenance
y = -0.0041x 2 - 0.0103x + 3.9607
R2 = 0.8967
1.0
0.5
0.0
0
2
4
6
8
10
12
Years since BAB Construction
14
16
18
20
Where is the Proof?
Current LRRB Study
(Inv 861 Wood and Lukanen)
1256 sections (constructed since 1985, bituminous over gravel base)
• 597 no preservation
 659 with preservation
No Maint.
Seal Coated
4.0
Average RQI
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
0
5
10
Time since BAB Construction, yrs.
15
Where is the Proof?
• Rougher roads have higher user costs
• Therefore, pavement preservation yields lower
user costs, but is it cost effective?
Where is the Proof?
TRB Report (Galehouse, Moulthrop, and Hicks)
• TR News
• Economic analysis (LCCA)
• Based on typical costs and expectations
Where is the Proof?
TRB Report (Galehouse, Moulthrop, and Hicks)
Where is the Proof?
TRB Report (Galehouse, Moulthrop, and Hicks)
• Data supports familiar graphs
Where is the Proof?
Typical costs in Minnesota
Typical Cost per Mile
New Construction
$436,868
Preservation Treatments
Chip Seal
$5,711
Crack Repair
$5,891
Crack Seal
$3,624
Crack Seal/Chip Seal
$9,792
Thin (1.5 -in.) Mill & Overlay
$62,791
Micro-Surfacing
$32,957
Thin (1.5 -in.) Overlay
$18,365
Rehabilitation
Medium (3 -in.) Overlay
$38,220
Medium Mill & Overlay
$83,654
Thick (5-in.) Overlay
$54,600
Thick Mill & Overlay
$104,963
Benefits of Pavement Preservation
Pavement Preservation…doing the right thing at the right time.
•
•
•
•
•
•
•
Preserving initial investment
Extended life or serviceability
Lower life-cycle costs
Lower user costs
Improved safety
Improved budget planning
Public support
Based on this, use your own data to determine if it’s
The RIGHT TIME to do the RIGHT THING?
Establishing a Preservation Program
• Number of Technical Components
• Two most important components are non-technical
• Agency Top Management Commitment
• Education/Outreach Program
What are some of the barriers?
Paradigm Shift
• Moving from “worst-first” process
Internal Issues
• Must be understood and accepted by all
• Must be committed to by top management
• Must have buy-in from work force
• Remove stigma that maintenance is less important or
“prestigious” than new construction
Marketplace Pressures
• Introducing new technologies
• Competition from industry (“rehab” and material suppliers)
Public Perception
• “Why are you fixing something that is not broken?”
Examples of Preventive
Maintenance Techniques
•
•
•
•
•
•
•
•
Crack sealing
Chip seals
Macro-surfacing
Slurry seals
Micro-surfacing
Ultra-thin bonded wearing coarse
Thin overlay
Mill and overlay