AASHTO 2002 Design Guide

AASHTO 2002 Design Guide
SEAUPG 2003 CONFERENCE
Planning for the
2002 Design Guide
Southeast Asphalt User/Producer Group Mtg.
Hilton Head Island, South Carolina
Harold L. Von Quintus, P.E.
Design Guide
November 20, 2003
Design Guide
The hierarchical
input procedure
allows a user to
use the Guide
• 2002 Design Guide
FAR EXCEEDS
the 1993 AASHTO
Design Guide in all
areas, but simplicity.
• The method is based on
tools that EQUAL OR
EXCEED state-of-theart!
with NO major
investment.
Design Guide
Point 4!
It’s a design-analysis
procedure with
Global:
• Correlations to
estimate selected
inputs.
• Default values.
• Calibration
factors – LTPP.
The accuracy or error of the new method
HAS BEEN quantified.
How accurate is our existing pavement
design procedure – the 1993 AASHTO
Design Guide?
1
Observed Values
Point 3!
Design Guide
1. Points to Remember
2. Questions/Products
3. Plan to Address Inputs
& Local Issues
Point 2!
Point 1!
Design Guide
Presentation Overview
0.8
0.6
0.4
0.2
0
Design Guide
0
0.2
0.4
0.6
0.8
Predicted Values
Hilton Head Isle, South Carolina - November 20, 2003
1
• BUT, can be used to determine/evaluate
other design features.
6” HMA
12” Crushed Stone
12” Aggr.
Aggr. Subbase
Flexible Pavements
•Asphalt binder grade
•HMA mix type
•Air Voids/Density
Design
Guide
•Drainage
A-5 Soil
120
100
80
Air Voids = 8%
60
Air Voids = 12%
40
Air Voids = 4%
20
0
0
5
10
15
Age, year
0.35
Rut Depth, inches
2002 Design Guide:
• A thickness design process.
0.3
0.25
Air Voids = 8%
0.2
Air Voids = 12%
0.15
Air Voids = 4%
0.1
0.05
0
140
IRI, inches/mile
Point 5!
Example:
Effect of
Air Voids
Fatigue Cracking, %
SEAUPG 2003 CONFERENCE
0
5
10
15
Age, year
120
100
Air Voids = 8%
80
Air Voids = 12%
60
Air Voids = 4%
40
20
0
Design Guide
Point 6!
0
5
10
15
Age, year
Questions & Products
It Ties Together:
•Structural Design
•Mixture Design
•Construction
Making sure that
the design criteria
have been meet
or exceeded.
Material and
Construction
Specifications
Design Guide
Type 1 Questions:
• What are the inputs?
• How do I determine
the inputs?
• How do I use the Type 2 Questions:
software?
• How applicable &
Design Guide
accurate are the
methods to my local
conditions/materials?
Questions & Products
Questions & Products
What do I need &
how do I use the
software?
How accurate are
the predictions to
my local conditions
& materials?
Design Guide
• Management video.
• Guide text &
appendices.
• User’s Manual in
support of software.
• Training course on
software execution.
Design Guide
• Expert input mode
• Local calibration
procedure
• Test procedures (lab &
field) to determine
inputs.
Hilton Head Isle, South Carolina - November 20, 2003
2
SEAUPG 2003 CONFERENCE
Inputs & Local Issues
1. Accumulate basic data
What can I
do to get
started?
2. Compare to traditional designs
3. Conduct sensitivity analysis
Design Guide
•
•
•
•
•
Design Criteria
Traffic
Materials/Soils
Climate
Rehab. – Pavement
Evaluation
Input Levels
1, 2, 3
Thermal conductivity,
Poisson’s ratio,
Creep compliance,
Dynamic modulus,
etc.
You want
me to
determine
WHAT????
WHAT????
Design Guide
S ection 182008
1996
200
1997
0
4
5
6
7
8
9
10
11
12
13
V e h icle Cla ss
IRI
20
Axle weight
distribution
Percent Axles
Surface
Initiated
Fatigue
Cracks
Build Truck Traffic
Library
Design Guide
1993
400
Rural Pavement Design Classes, Single Axles
Thermal
Cracking
Design
Guide
1. AVC Data
2. WIM Data
1992
600
15
VC 8
10
VC 9
VC 10
5
0
0
15000
30000
45000
Axle Load (lbf)
Total
Rutting &
HMA Rutting
Accumulate
Traffic Data:
• Truck volumes
• Axle weights
• Regional &
seasonal
effects
Truck Traffic
Projections
Design Guide
Average Daily Truck
Traffic
Bottom
Initiated
Fatigue
Cracks
Truck volume
distribution
ADTT
Truck Traffic
Design Criteria
800
3000
2000
1000
0
0
5
10
15
20
25
Age, years
Materials Testing:
HMA Characterization
• Dynamic modulus, master
curve
• IDT creep compliance
master curve
• IDT strength
• Density/Air voids
• Aggregation Gradation
• Asphalt binder PG properties
Design Guide
Hilton Head Isle, South Carolina - November 20, 2003
3
SEAUPG 2003 CONFERENCE
Materials Testing:
HMA Materials Library
Limited Testing of Mixes
•Dynamic Modulus
•Indirect Tensile Tests
Design Guide
Accumulate Construction Data
•Initial IRI
•Air Voids/Density
•Aggregate Gradation
•Asphalt Binder Type/Properties
Materials Testing:
Unbound Base & Soils
Materials Library
Accumulate
Construction Data:
Materials Testing:
Unbound Base/Soils
• Resilient modulus, or
• Strength Values
– CBR,
– R-Value, or
– Dynamic Cone Penetration
Design Guide
Damage in Existing Structure
Estimated from:
•Amount & Severity of Distress
•BackBack-Calculation of Layer Modulus
•Computation of Responses
• Density/Moisture
Content
• Gradation
• Atterberg Limits
Design Guide
Limited Resilient
Modulus Testing
Agency Implementation
& Local Issues
Adopting 2002 Design
Guide – ACCEPT AS IS?
Agencies with
Implementation
Design
Guide
Plans
Design Guide
2002 CalibrationValidation Process
• Used BEST Available Data.
• No Materials Testing – Relied on
existing databases for all inputs –
LTPP.
Can we
do better?
Design Guide
Input
Element
Material
Properties
Input Level
1
2
3
“Guessed
Lab
Equations
” Value
Testing
Hilton Head Isle, South Carolina - November 20, 2003
4
SEAUPG 2003 CONFERENCE
Implementation
Issue:
Too much error?
Applicability of error?
¾ Yes – Confirm
default values.
Implementation Issue
Are our design
standards &
materials similar to
LTPP sites?
•Pavement types
•Rehab strategies
•Materials/Mixtures
Remember point 1, no major investment
is needed for Level 3 inputs, BUT you
are going to get out of the program
based on what you put into it!
¾ No – Re-calibrate.
Design Guide
Design Guide
Implementation Issue
Implementation Plan
Remember Point 4:
All prediction models have errors;
BUT where does the error come from?
Procedures to determine inputs –
become equipped to do:
Observed Values
Observed = Pr edicted ± eTotal
1
0.8
• Repeated load/cyclic
testing; materials
characterization.
0.6
0.4
0.2
0
0
Design Guide
0.2
0.4
Predicted Values
Implementation Plan
Local confirmation of default
values & calibration factors:
• Build library of material
properties & traffic factors
(Confirm Level 2 inputs).
• Build library of default values
(Confirm Level 3 inputs).
• Use LTPP as a starting
point.
Design Guide
• Axle load spectra (TMG).
• Deflection testing & backcalculation of layer modulus.
0.6
0.8
Design Guide
Dual Purpose Plan
Local Calibration
Rut Depth
Fatigue
Cracking
Thermal
Cracking
Ride Quality
Confirmation of
Default Values
Number of Test
Sections
Required for
Calibration &
Determination
of Default
Values.
Traffic
Materials
Soils
Design Guide
Hilton Head Isle, South Carolina - November 20, 2003
5
SEAUPG 2003 CONFERENCE
Implementation Plan,
Other Issues & Topics:
1-37A
Design
Guide
Design Guide
• Comparison to conventional
designs
– Define the differences.
• Sensitivity of performance to
design features
– Identify the most
sensitive design features.
• Resources and time for
implementation
– 4 to 5 years.
Future Improvements –
NCHRP 9-30 Products
• M-E Database
• Experimental Plan
& Factorial for Mix
Characterization
Design Guide
Future Improvements
2002
Design
Guide
NCHRP 99-30
Experimental Plan
for Calibration &
Validation of HMA
Performance
Models for Mix &
Structural Design
Design Guide
NCHRP 11-42
TopTop-Down
Cracking of
HMA Layers
NCHRP 11-41
Selection of a Reflection
Cracking Model for HMA Layers
In Summary:
¾ You can use the 2002 Design Guide
using current practice.
¾ Will the errors or bias of the predictions
apply to your conditions & materials?
Design Guide
2002 Design Guide:
The future
of pavement
design.
Design Guide
Thank you for your attention!
Design Guide
Hilton Head Isle, South Carolina - November 20, 2003
6
SEAUPG 2003 CONFERENCE
Implementation
Plan
Implementation Plan Focus
• Use of the
software.
• Determination of
the inputs.
1. Training on design procedure.
2. Procedures to determine input
parameters.
3. Lab & field equipment.
4. Verification & confirmation of:
‰ Default values
‰ Calibration factors
0
0
A-5 Soil
Rut Depth, iinches
12” Aggr.
Aggr. Subbase
5
10
15
0.2
HMA = 6 inches
0.15
HMA = 8 inches
HMA = 10 inches
0.1
0.05
0
0
5
10
80
HMA = 6 inches
60
HMA = 8 inches
40
HMA = 10 inches
Effect of
Drainage
Layer
6” HMA
4” ATPB
8, 12” Crushed Stone
A-5 Soil
20
5
10
Age, year
0
5
Rut Detph, inches
10
15
Age, year
0.3
0.25
PG 70-28
0.2
PG 64-22
0.15
PG 58-16
0.1
0.05
0
5
10
15
Age, year
120
100
PG 70-22
80
PG 64-22
60
PG 58-16
40
20
0
Design Guide
5
10
15
Age, year
100
80
60
No Drainage
Layer
40
ATPB Layer
20
0
0
5
10
15
Age, year
0.25
No Drainage
Layer
0.2
0.15
ATPB Layer
0.1
0.05
0
12” Aggr.
Aggr. Subbase
15
Age, year
0
PG 58-16
20
0
0
Design Guide
PG 64-22
40
140
IRI, inches/mile
A-5 Soil
PG 70-28
60
0.3
0.25
100
12” Aggr.
Aggr. Subbase
80
0
Age, year
120
IRI, inches/mile
12” Crushed Stone
HMA = 10 inches
20
0.3
HMA
HMA = 8 inches
12” Crushed Stone
100
0
Rut Depth, inches
1
0
8
6
0
4
HMA = 6 inches
6” HMA
120
0.35
120
IRI, inches/mile
Effect of
HMA
Thickness
Fatigue Cracking, %
• LTPP database.
• NHI Course 131064 – Introduction to
Mechanistic-Empirical Design
Procedures.
• Agency test sections.
• APT and ALF sites.
• Test tracks – WesTrack, NCAT,
MnRoads, etc.
• NCHRP 9-30, Experimental Plan for
Validation of HMA Prediction Models.
Effect of
Asphalt
Binder
Type
Fatigue Cracking, %
Design Guide
Other Implementation
Products for Calibration
Design Guide
Material properties.
Recycling of materials.
Innovative materials.
Design features.
Traffic features.
Fatigue Cracking, %
Design Guide
• Applicability of the
methods & default
values to my local
conditions/materials.
0
5
10
15
Age, year
100
No Drainage
Layer
80
60
ATPB Layer
40
20
0
15
Design Guide
0
5
10
15
Age, year
Hilton Head Isle, South Carolina - November 20, 2003
7
SEAUPG 2003 CONFERENCE
Implementation Plan Focus
• Determination of
the inputs.
• Use of the
software.
• Applicability of the
methods & default
values to my local
conditions/materials.
Reduce uncertainty by using
level 1 inputs.
eLevel1 ≤ eLevel 2 ≤ eLevel 3
Input Level
Input
Element
In-place recycling.
New materials.
Design features.
Traffic features.
Design Guide
Components of the Error Term?
Distress Measurement
Struture Simulation
Traffic
30
Material
Properties
Design
Guide
Climate
HMA Properties
Sublayer Properties
0
Rutting
Fatigue
Cracking
Thermal
Cracking
Implementation Plan
Training & Communication are
essential!
Design Guide
3
Default; “Best
Lab
Regression
Guessed”
Testing equations
Value
1. Training on design procedure.
2. Procedures to determine input
parameters.
3. Obtain lab & field equipment.
4. Verification & confirmation
procedure.
– Default values
– Calibration factors
Summary: Road Map of
Implementation Plan Activities
Phase I Planning
¾Structural Design
¾Traffic
¾Construction
¾Materials Characterization
¾Pavement Monitoring
Design Guide
2
Implementation Plan Topics
Percent of 20
Total Error
10
Term
Design Guide
1
Phase II –
Initial Data
Collection & Analyses
Design Guide
Phase III –
Annual Data
Collection, Analyses,
& Confirmation
Hilton Head Isle, South Carolina - November 20, 2003
8
SEAUPG 2003 CONFERENCE
Road Map Activities
Phase I
1. Review Distress
Prediction Models.
2. Typical Design Features,
Materials, Construction
Procedures
Phase II
Phase III
5. Initial Data
Collection
& QC
6. Data Analysis
& Calibration
5. Periodic Data
Collection
3. Experimental Design
Factorial
4. Monitoring & Test
Plans
7. Data QC & Updates
to Confirm Calibration
Factors & Defaults
Design Guide
Hilton Head Isle, South Carolina - November 20, 2003
9
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