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