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Guideline for the Implementation of the
Mechanistic Empirical Pavement Design
Guide (MEPDG) for the Concessionary
NovaDutra
7th Brazilian Congress on Highways and Concessions (CBR&C)
Maria Carolina Rodezno
Kamil E. Kaloush
October 26, 2011
Outline ASU – CCR NovaDutra collaborative study
MEPDG introduction and overview
Required input data
NovaDutra case studies
Summary and Recommendations
ASU – CCR NovaDutra Study Objective
Started early 2011
Framework for assessing MEPDG for NovaDutra
On-site staff collaboration
Collection of input data
Materials laboratory characterization
Pavement sections for initial assessment
MEPDG “The overall objective of the Guide for the
Mechanistic-Empirical Design for New and Rehabilitated Pavement Structures is to provide the highway community with a state-of-the-practice tool for the design and rehabilitated pavement structures, based on mechanistic-empirical principles.”
Flexible pavement: ASU
Rigid pavement: ARA
State-of-
Practice State-of-the-Art AASHTO 93
Pavement Design State of the Art
Empirical Mechanistic-
Empirical Mechanistic
MEPDG
2002 -2011
Statistical models from road tests
-Calculation of stresses / strains -Empirical pavement performance models
Mechanics-based pavement performance models
Benefits of M-E Design Approach
• Improve design reliability
• Improve rehabilitation design
• Includes method for local calibration
• Better evaluate impact of
– Traffic levels / seasonal / drainage effects / yearly changes in materials
An Analysis Method
An Iterative Design Method
Predict performance over time.
MEPDG Highlights
Relates pavement material characteristics with their
performance in the field
Calibrated based on LTPP data.
Capability to adapt to local conditions
New & rehabilitated pavement designs
Design Process
Climate Inputs
EICM
Material Properties
Transfer Functions
Predicted Performance Mechanistic Analysis
Traffic
Empirical Analysis
MEPDG Hierarchical Design Inputs
Level 1: Most reliable, data from laboratory testing
Level 2: Intermediate level of reliability. Inputs estimated through correlations
Level 3: Lowest level of reliability. Default values provided by the program
Input Level Selection
The importance of the project
Information available at the time of design
Resources & time available to the designer to obtain the inputs
Predicted Distresses
Design Procedure
Select an initial trial pavement structure
Identify pavement cross section
Specify layer material types & thickness
Is Seasonal Analysis required?
Two options
EICM (Enhanced Integrated Climatic Model)
Monthly Seasonal values
Main Inputs in the MEPDG
Climate
Traffic
Material Input/Pavement Structure
Climate in the MEPDG
Weather information HOURLY
air temperature
Precipitation
wind speed
percentage of sunshine
ambient relative humidity
Seasonal or constant water table depth
NovaDutra Climate Needs EICM in MEPDG only includes United States.
Climatic files can be created, but should be in the same format used in EICM.
National Institute of Meteorology (INMET) in Sao Paulo and Rio de Janeiro
hourly data was not available in continuous basis ( a minimum of 2 years data is required)
Hourly percentage of sunshine not available
Traffic Data in MEPDG
Number of axles by: Axle type
Truck type
Axle load interval
Number of axles within: Each year
Season within a year
Each hour
NovaDutra Traffic Needs
There are 4 WIM stations along Dutra Presidente Highway
an assessment of the data is required
However, ESAL approach can be used in the MEPDG until accurate WIM data can be implemented
Materials Input Asphalt Concrete Layer
a. Asphalt General – mix volumetrics
b. Asphalt Binder – consistency tests /
AC/PG grade
ASTM Ai-VTSi
c. Mix Stiffness – Dynamic Modulus E*
8628.4)sin
1(
10
*
G
Predictive Model OR
Binder PG Grading
PG grading that best match
the Ai and VTSi values
from standard binder tests.
Binder Type Ai VTSi
PG 58-22 AR 8.543 -2.781
PG 64-40 8.524 -2.798PG 64 -16 AR 8.048 -2.598
PG 70-40 8.129 -2.648
0
0.2
0.4
0.6
0.8
1
1.2
2.7 2.75 2.8 2.85 2.9 2.95
Log-Temperature (Rankine)
Log log-V
isco
sity
(cP
)
I-17 Project AR 58-22
I-17 Project AR PG 64-16
I-17 Project PG 58-22
I-17 Project PG 64-16
ADOT Virgin PG 76-16
NovaDutra Materials Lab
Materials Input
Unbound Materials (Base, Sub-base, Subgrade)
For Level 1 analysis, MEPDG requires resilient modulus data
Equipment acquired by ND capable of conducting resilient modulus testing
NovaDutra MEPDG Assessment Initial Efforts Preliminary study : Dutra Presidente Highway
between Sao Paulo -Rio de Janeiro
To provide good understanding of needs for future calibration.
The original highway built in 1960’s. (rehabilitation)
Historical construction records?
Seven pavement sections
Traffic (moderate -high)
Climatic zone (Sao Paulo- Rio de Janeiro)
Pavement design life.
Two typical HMA layers selected Climatic data challenges: 2 climatic location from Louisiana; each with
similar conditions to Sao Paulo and Rio de Janeiro
Traffic level: ESAL was used. MEPDG design life for all scenarios was 8 years. Actual pavement condition data collection is in
progress.
NovaDutra MEPDG Assessment Initial Efforts
Preliminary Case Studies
Section # Section IDRehabilitation
Records (year)
Traffic
Information
(AADT)
Heavy
Traffic
N
(USACE)
N
(AASHTO)
1North Bound
SP 63-01997, 2011 1.55E+04 8.08E+03 2.60E+08 7.81E+07
2North Bound
SP 107-1062003 1.97E+04 7.29E+03 2.35E+08 7.06E+07
3North Bound
SP 128-1182004, 2010 2.16E+04 5.84E+03 1.89E+08 5.66E+07
4South Bound
RJ 182-184
2000, 2006,
20102.45E+04 6.62E+03 2.13E+08 6.40E+07
5South Bound
SP 211-214 2002, 2007 1.10E+04 5.30E+03 1.71E+08 5.12E+07
6North Bound
RJ 218-2101999, 2008 1.07E+04 5.24E+03 1.69E+08 5.08E+07
7North Bound
RJ 309-3052007, 2010 1.33E+04 6.80E+03 2.19E+08 6.57E+07
NovaDutra Pavement Sections
HMA / Polymer modified
Old HMA
Granular Base
Subbase
Subgrade
4 – 12 cm
4 – 22 cm
15 – 65 cm
0 – 35 cm
Clay
Silty Clay
Silt
Silty Sandy Clay
Mix Properties Property CA Binder
Gmm 2.4 2
Gmb 2.305 2.368
Gsb 2.608 2.61
AC (%) 4.9 3.6
Va (%) 3-5( as built=7) 4-6% (as built=7)
Vbeff 8.95 5.54
Binder Type CAP 40~ AC-40 CAP30-45~Pen 40-50
r34 r38 r4 r200
% % % %
CA Mix 2 19 36 8
Binder Mix 26 45 60 6.8
Mix
Total AC Rutting Results
Longitudinal Cracking Results
Reflective Cracking Results
0
10
20
30
40
50
60
NB SP
63-0
NB SP
107-106
NB SP
128-118
SB SP
211-214
SB RJ
182-184
NB RJ
218-210
NB RJ
309-305
Pavement Section
Refl
ecti
ve C
ra
ck
ing
(%
)
Summary • Effort undertaken is a starting point for future
implementations of the guide.
• Need to verify measures of distress. The calibration and validation of the models will be necessary for NovaDutra conditions.
• Full implementation will require a good amount of time and resources. Effective use requires materials and traffic databases beyond Level 3 and MEPDG defaults information.
• Complete climatic information is also needed in order to create required climatic files.
Example 1: Fiber Reinforced Concrete
Pavement Rutting Evaluation
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0 1 2 3 4 5 6 7
Thickness (in)
To
tal R
utt
ing
(in
)
Control 1 lb/Ton
Example 2: Fatigue Cracking
Evaluation
0
1
2
3
4
5
6
7
0 1 2 3 4 5 6 7Thickness (in)
Fa
tig
ue
(%
)
Control 1 b/Ton
Example 3: HMA Rutting Generation-MEPDG
1440 HMA rutting predictions (20 locations x 2 Air Voids
x 4 gradations x 3 traffic levels x 3 thicknesses)
Variable Levels Description
AC thickness (in) 3 3, 6, 9
ESALs 3 2, 10 and 30x106
HMA variable thickness
Base Course-10"
MR=40,000 psi
Subgrade
MR=20,000 psi
Rutting Criterion Approach
y = 2.4341x-0.3118
R2 = 0.7014
y = 9.272x-0.3157
R2 = 0.739
y = 5.442x-0.3165
R2 = 0.69
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 5000 10000 15000 20000 25000 30000 35000 40000
Predicted Flow Number
ME
PD
G A
C R
utt
ing (
in)
2E+06 ESALs 10E+06 ESALs 30E+06 ESALs
AC Layer =3 in
432 kkk1 h*ESALs*FN*kRut
Recommendations • Continue Level 3 (best estimate, and default inputs); will
provide useful information on the general rationality of MEPDG output / comparative analysis.
• Start Phase II: data collection activities necessary for calibration and validation of MEPDG. – Detailed construction and traffic information.
– high priority efforts on testing to determine HMA dynamic modulus, binder testing and base materials moduli.
– Make use of quality deflection testing database (FWD)
– Collect distress and roughness information periodically.
• Establish test sections for future calibration and validation.
2011
Level 3 Level 2 Level 1
2012-13
2015?
CCR-NovaDutra Implementation Projection
Concluding Remarks
MEPDG is a major improvement for flexible
pavement design
Best approach for structural design
Provides link between -
Structural Design
Asphalt Mixture Design
Acknowledgment
• Agência Nacional de Transportes Terrestres (ANTT)
• CCR – NovaDutra