MEPDG Development in Colorado - · PDF fileS1SP ARA0127-1 MEPDG Development in Colorado Rocky Mountain Asphalt Conference & Equipment Show Session: Making Our Pavements Last February

S1SP ARA0127-1

MEPDG Development in Colorado

Rocky Mountain Asphalt Conference & Equipment ShowSession: Making Our Pavements Last

February 19, 2009Harold L. Von Quintus, P.E.

Expanding the Realm of Possibility2

Outline1. Past-Present-Future2. Colorado’s MEPDG—The Plan3. Examples—LTPP Sites4. Designing & Building

Pavements that Last Longer5. Summary


The Past: 2001; Developed first road map for

implementing MEPDG in Colorado; CAPA-DOT effort.

2006, Updated Road Map.

The Present: 2008; Issued RFP to Execute the Road Map.

The Future 2009-2011; Execution of Road Map;

3-year implementation effort.


Implementation Programs Around the Country

√

√

√

√

√

√

√

√

√ √√


Colorado’s MEPDG:The Plan/Road Map


Colorado’s MEPDG—The Plan 2009 to 2010; Data collection & input

determination, 80+ test sections Materials Testing and Characterization Traffic Analyses Performance Analyses

2010 to 2011; Data analysis & calibration/validation Create Input libraries Determine local calibration values

2011; Documentation & Design Manual Continuous Training


Colorado’s MEPDG—The PlanExperimental Factors: Type of Structure1. Conventional Flexible Pavements2. Depth Strength Flexible Pavements3. Full-Depth HMA Pavements4. HMA Overlay of Flexible Pavements5. HMA Overlay of Intact PCC Pavements6. HMA Overlay of Fractured PCC Pavements

LTPP test sections & other roadway segments; pavement management sections.


Colorado’s MEPDG—The PlanExperimental Factors: Rehabilitation Strategies

of Flexible Pavements1. Simple overlay with & without milling2. Chip coat prior to overlay3. Hot in place recycling4. Cold in place recycling

Experimental Factors: Climate Elevation/temperature

Secondary Factors:Neat, PMA, & SMA mixes; with & w/o RAP; stabilized

soils; etc.


Colorado’s MEPDG—The Plan2. AASHTO; MEPDG

Calibration Guide

Document has been submitted to NCHRP with demonstrations & examples.

1. AASHTO; MEPDG Manual of Practice

Two primary documents used in validation-

calibration of MEPDG.


Colorado’s MEPDG:Examples


LTPP Test Section Locations

18 Test Sections


Examples—LTPP Test SectionsInput

ParameterConvent.

HMAConvent.

HMA

ATB, Deep-

Strength

SPS-5; RAP & Virgin

RoadwayCraig, Rte. 40

Montrose, Rte. 50

La Junta, Rte. 50

Limon, IH-70

Climate North West

West Central

South East

East Central

Traffic, AADTT 176 1012 680 1860

HMA, in. 4.1 4.6 10.72.0

(Overlay)Soil A-4 A-6 A-7-6 A-7-6


Examples—Rut Depth

00.10.20.30.40.50.60.70.8

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0

Age, years

Rut

Dep

th, i

nche

s

08-1029, Craig

08-1029, Craig,Predicted08-1053, Montrose,Predicted08-2008, La Junta,Predicted08-1053, Montrose

08-2008, La Junta

00.05

0.10.15

0.20.25

0.30.35

0 2 4 6 8 10

Age, years

Rut

Dep

th, i

nche

s

08-0506, Virgin,Predicted08-0502, RAP,Predicted08-0506, Virgin

08-0502, RAP

MEPDG Version 1.0 – Globally Calibrated

What is the accuracy of current design method?

0

0.1

0.2

0.3

0.4

0.5

0.6

0 0.2 0.4 0.6 0.8

Measured Rut Depth, inchesPr

edic

ted

Rut D

epth

, inc

hes

08-1029, Craig Line of Equality 08-1053, Montrose08-2008, La Junta 08-0502, RAP 08-0506, Virgin


Examples—Fatigue Cracking

0

10

20

30

40

50

0 5 10 15 20 25 30 35

Age, years

Fatig

ue C

rack

ing,

per

cent

of

tota

l lan

e ar

ea

08-1029, Craig, Predicted

08-1029, Craig

08-1053, Montrose,Predicted08-2008, La Junta,Predicted08-1053, Montrose

08-2008, La Junta


0

10

20

30

40

50

60

0.00 10.00 20.00 30.00 40.00 50.00 60.00

Measured Fatigue Cracking, % Lane AreaPr

edic

ted

Fatig

ue C

rack

ing,

% L

ane

Area

08-1029, Craig Line of Equality 08-1053, Montrose08-2008, La Junta. 08-0502, RAP 08-0506, Virgin


0

10

20

30

40

50

60

0 2 4 6 8 10

Age, years

Fatig

ue C

rack

ing,

% T

otal

Lan

eA

rea

08-0502, RAP, Predicted08-0506, Virgin, Predicted08-0502, RAP08-0506, Virgin


Examples—Transverse Cracking

0

500

1000

1500

2000

2500

3000

3500

4000

0 1000 2000 3000 4000 5000

Measured Transverse Cracking, ft./mi.Pr

edic

ted

Tran

sver

se C

rack

ing,

ft./m

i.

Line of Equality 08-1029, Craig 08-1053, Montrose08-2008, La Junta. 08-0502, RAP 08-0506, Virgin

0200400600

800100012001400

0 2 4 6 8 10

Age, years

Tran

sver

se C

rack

ing,

ft./m

i.


08-0502, RAP


0.0500.0

1000.01500.02000.02500.03000.03500.04000.04500.0

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0

Age, years

Tran

sver

se C

rack

ing,

ft./m

i. 08-1029, Craig

08-1029, Craig,Predicted08-1053, Montrose,Predicted08-2008, La Junta,Predicted08-1053, Montrose

08-2008, La Junta



Examples—Smoothness

0.0020.0040.0060.0080.00

100.00120.00140.00160.00180.00

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0

Age, years

IRI,

inch

es/m

ile

08-1029, Craig

08-1029, Craig,Predicted08-1053, Montrose,Predicted08-2008, La Junta,Predicted08-2008, La Junta

08-1053, Montrose

020406080

100120140160

0 2 4 6 8 10

Age, years

IRI,

in./m

i.


08-0502, RAP


0

20

40

60

80

100

120

140

160

180

0 50 100 150 200

Measured IRI, in./mi.

Pred

icte

d IR

I, in

./mi.

Line of Equality 08-1029, Craig 08-1053, Montrose

08-2008, La Junta 08-0502, RAP 08-0506, Virgin



Examples—Summary of Results; NCHRP Projects, Rutting

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6Total Predicted Rut Depth,

inches

Mea

sure

d R

ut D

epth

, inc

hes

Kansas; SPS-1 Mid-West

Kansas; SPS-5 Mid-West

Montana, NewConstructionMontana, Overlays

SPS-1, General

SPS-5, General

MnRoads

Test Tracks

APT, Simulated Loads

Line of Equality

Kansas PM, NewConstructionKansas PM, Overlays

NCHRP Project 1-40B

Material & Mix

Specific Calibration

Factors


Examples—Summary of Results; NCHRP Projects, Fatigue Cracking

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

0 20 40 60 80 100

Total Predicted Fatigue Cracking, %

Mea

sure

d Fa

tigue

Cra

ckin

g, %

Kansas; SPS-1, Mid-West

Kansas; SPS-5, Mid-West

Montana, New Construction

Montana, HMA Overlays

MT, New Construction

MT, HMA Overlays

Test Tracks

SPS-1, General

Line of Equality

Kansas PM, New Construction

Kansas PM, Overlays

NCHRP Project 1-40B

Material & Mix


Factors


Examples—Summary of Results; NCHRP Projects, Transverse Cracking

0500

10001500

20002500

30003500

40004500

5000

0 1000 2000 3000 4000 5000Predicted Thermal Cracking,

ft./mi.

Mea

sure

d Tr

ansv

erse

Cra

ckin

g, ft

./mi. Kansas; Mid-West Sites,

New Construction

Kansas; Mid-West Sites,HMA Overlays

Montana, New Construction


Kansas PM, NewConstruction

Kansas PM, HMA Overlays

Line of Equality

NCHRP Project 1-40B

Material & Mix


Factors


Examples—Summary of Results; NCHRP Projects, Roughness (IRI)

40.0

60.0

80.0

100.0

120.0

140.0

160.0

180.0

200.0

40 60 80 100 120 140 160 180 200

Predicted IRI, in./mi.

Mea

sure

d IR

I, in

./mi.

Kansas; Mid-West Sites,New Construction

Kansas; Mid-West Sites,HMA Overlays

Montana, NewConstruction


Kansas, PM; NewConstruction

Kansas, PM; HMAOverlays

Line of Equality

NCHRP Project 1-40B

Material & Mix


Factors


Colorado’s MEPDG:Designing-Building Pavement’s

that Last Longer

Life Cycle Cost Considerations


Design Features & LCCFactors 1993 AASHTO MEPDG

Simple/Less Costly

Diversity of Conditions

Colorado Calibration; Roadway Segments

Accuracy of Method

Climatic Effects

Material Properties - Site

Time Effects on Properties


Design Features & LCC

0

0.2

0.4

0.6

0.8

1

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

Measured Rut Depth - Companion Sections, Neat Mixtures, inches

Mea

sure

d R

ut D

epth

- PM

A Se

ctio

ns, i

nche

s

0

20

40

60

80

0 10 20 30 40 50 60 70 80

Measured Fatigue Cracking - Companion Sections, Neat Mixtures, %

Mea

sure

d Fa

tigue

Cr

acki

ng -

PMA

Sect

ions

, %

Pavements with PMA mixtures

have less distress than those with

neat HMA mixtures.

Asphalt Institute Report; Calibration

Factors for PMA Mixes.

2007 Colorado Study found similar

results.



010203040506070

6 7 8 9 10 11 12

Effective Asphalt Content by Volume, %

Pred

icte

d Fa

tigue

Cra

ckin

g,

%

12.5 mm Mix

010203040506070

6 7 8 9 10 11 12


Pred

icte

d Fa

tigue

Cra

ckin

g,

%

37.5 mm Mix

0

0.2

0.4

0.6

0.8

1

6 7 8 9 10 11 12


Pred

icte

d H

MA

Rut

Dep

ths,

in.

37.5 mm Mix

0

0.2

0.4

0.6

0.8

1

6 7 8 9 10 11 12


Pred

icte

d H

MA

Rut

Dep

ths,

in.

12.5 mm Mix

Mixture Design & Distress Predictions

Integration of Structural & Mixture Design!



01020304050607080

0 5 10 15 20 25 30 35 40

Age, months

Pred

icte

d Fa

tigue

Cra

cks,

%To

tal L

ane

Are

aDesign Voids; B-Fine Graded Limestone High Voids Low Voids

0

0.2

0.4

0.6

0.8

1

0 5 10 15 20 25 30 35 40

Age, monthsPr

edic

ted

Rut

Dep

th, i

nche

s

Design Voids, B-Fine Graded Limestone High Voids Low Voids

Construction Properties

(Air Voids) & Distress

Predictions



Limitations (factors not considered by the MEPDG):

DurabilityWorkability Etc.


Colorado’s MEPDG:Summary


Overall, global calibration factors are in the ball park for Colorado roadways (predicted vs. measured distress)!

Comprehensive tool for pavement design & analyses.

Excellent forensic tool! Optimize on design features – not just

increase pavement thickness! Accuracy can be quantified.

Summary: Colorado’s MEPDG


Summary: Colorado’s MEPDGCritical Step—Determining appropriate input

values, especially for rehab.

Input libraries will be important for implementation.


QUESTIONS?



Colorado’s MEPDG—The PlanExperimental Factors: Pavement Layers &

Materials HMA thickness; <4, 4 to 8, >8 Binder; conventional & modified HMA; dense bituminous plant mix, Superpave, SMA Aggregate base materials; class 6 & 7 Coarse-grained; non-expansive fine-grained, &

expansive fine-grained soils Stabilized subgrade soils


Colorado’s MEPDG—The PlanExperimental Factors: Secondary Factors HMA aggregate type HMA with and without RAP


Colorado’s MEPDG—The PlanMaterials Testing & Characterization HMA—Input Level 2 Unbound Materials—Input Level 2, R-value; confirm R-

value versus MR relationship Existing Pavements for Rehabilitation—Backcalculate

modulus values from FWD deflection basins

Truck Traffic Characterization Normalized Truck Volume & Axle Weight Distributions—

Input Level 2, Regional values & virtual distributions.


2. Inputs:•Procedures•Testing•Equipment•Policy Items

1. Experimental Plan & Database:

• Section Layout• LTPP sections• Other sections (newer, research)

3. Validation:•Distress• IRI•Sensitivity of design features

4. Calibration:•Establish new coefficients of models, if needed

•Sensitivity

5. Application:•Training & user’s manual•Concurrent designs•Default input libraries (materials, performance, traffic, etc.)

•Continuing validation of models•Catalogs of designs

MEPDG Implementation Activities

Colorado’s MEPDG—The Plan


SummaryUse of PMA mixes extended the overlay service life over neat HMA mixes by:3 years – 75 percentile value6 years – 50 percentile value


MEPDG & Data Integration: Effective use of available, but limited local resources.

MEPDGDatabase

M-E Based Mix Design


Climate Sites AvailableStation Elevation Station ElevationAkron 4664 Grand Junction 4826Alamosa 7536 La Junta 4193Aspen 7725 Lamar 3675Burlington 4198 Leadville 9938Colorado Springs 6183 Limon 5350Cortez 5899 Meeker 6333Craig 6192 Montrose 5753Denver, DIA 5382 Pueblo 4655Denver, Cent. 5827 Rifle 5506Durango 6677 Trinidad 5749

20 Weather Stations in MEPDG!


N u m b e r o n M a p

E x p e r i m e n t N u m b e r

L T P P I D . N u m b e r

C o m m e n t

1 S P S - 3 0 8 A 3 0 0 2 G P S - 1 0 8 1 0 5 3 S e a s o n a l S i t e 3 S P S - 3 0 8 B 3 0 0 O u t o f S t u d y 4 G P S - 2 0 8 2 0 0 8 O u t o f S t u d y 5 S P S - 5 0 8 0 5 0 0 6 S P S - 8 0 8 0 8 0 0 7 G P S - 1 0 8 1 0 2 9 8 G P S - 1 0 8 1 0 5 7 O u t o f S t u d y 9 G P S - 1 & 6 B 0 8 1 0 4 7 O u t o f S t u d y

1 0 G P S - 6 A & 6 C 0 8 6 0 0 2 1 1 G P S - 6 A 0 8 6 0 1 3 1 2 G P S - 7 A & 7 S 0 8 7 0 3 5 1 3 G P S - 7 A 0 8 7 0 3 6 O u t o f S t u d y 1 4 G P S - 6 A 0 8 7 7 8 0 1 5 G P S - 2 & 6 B 0 8 7 7 8 1 1 6 G P S - 6 A 0 8 7 7 8 3

1 ,2

8

1 6

7

9

1 4

1 2

61 1

1 3

5

1 01 5

3 ,4


Data Collection – Forensic Investigations

1. Establish test segments.

2. Recover materials for testing.

3. Cores & trenches for crack propagation & layer rutting.



Documents

MEPDG Development in Colorado - · PDF fileS1SP ARA0127-1 MEPDG Development in Colorado Rocky Mountain Asphalt Conference & Equipment Show Session: Making Our Pavements Last February