PolymerPolymer--Modified Asphalts Modified Asphalts ––Enhancing HMA PerformanceEnhancing HMA Performance

WilkesWilkes--Barre, PA.Barre, PA.October 23, 2003 October 23, 2003

Harold L. Von QuintusHarold L. Von Quintus

Study Sponsors:Study Sponsors:

Industry AssociationsIndustry AssociationsThe Asphalt The Asphalt InstituteInstituteThe Association of The Association of Modified Asphalt Modified Asphalt ProducersProducers

Federal Highway Federal Highway AdministrationAdministration

Corporate SponsorsCorporate SponsorsArrArr--Maz ProductsMaz ProductsATOFINA ATOFINA Petrochemicals, Inc.Petrochemicals, Inc.DexcoDexco Polymers LPPolymers LPDynasolDynasol LLCLLCGoodyear ChemicalGoodyear ChemicalKRATON PolymersKRATON PolymersPolimeriPolimeri EuropasEuropasAmericasAmericasUltrapaveUltrapave

Presentation OverviewPresentation Overview

1.1. Study Objectives & StatusStudy Objectives & Status2.2. Overview of Overview of Users OpinionsUsers Opinions3.3. Performance ComparisonsPerformance Comparisons4.4. Summary of Initial FindingsSummary of Initial Findings

Study ObjectivesStudy Objectives

1.1. Quantify the effect of using PMA Quantify the effect of using PMA as compared to conventionalas compared to conventional--unmodified HMA mixtures.unmodified HMA mixtures.

2.2. Identify conditions that maximize Identify conditions that maximize effect of PMA to increase HMA effect of PMA to increase HMA pavement & overlay life. pavement & overlay life.

Phase I Tasks:Phase I Tasks:1.1. Update literature review.Update literature review.2.2. Update contacts with Update contacts with

selected agencies.selected agencies.3.3. Review test sections with PMA mixes.Review test sections with PMA mixes.4.4. Select companion PMA & Select companion PMA &

unmodified HMA test unmodified HMA test sections.sections.

CompletedCompleted

Phase II Tasks:Phase II Tasks:

5.5. Predict performance of test sections.Predict performance of test sections.6.6. Compare performance Compare performance

characteristics of PMA & unmodified characteristics of PMA & unmodified HMA pavements.HMA pavements.

7.7. Prepare study documents.Prepare study documents.

90% Complete90% Complete

Reason for Using PMA?Reason for Using PMA?

0

20

40

60

80

100

R T F M D R T

Response, %

R = RuttingT = Thermal CrackingF = Fatigue CrackingM = Moisture Damage

or strippingD = DurabilityR = RavelingT = Tenderness

Is There a Benefit Using Is There a Benefit Using PMA?PMA?

01020304050607080

Yes Unsure NoOpinion

Response, %

Yes, BUTBUT:Insufficient data to quantify that benefit.

Concern: Concern: ShortShort--Term versus LongTerm versus Long--Term Term

Benefit?Benefit?

0

20

40

60

80

100

120

0 2 5 10 15 20

Time, years

Perf

orm

ance

Mea

sure

Conv.

Data needed to quantify long-term benefit.

PMA?

Finding & ConclusionFinding & Conclusion

PMA mixtures do extend the service PMA mixtures do extend the service life of HMA pavements & overlays.life of HMA pavements & overlays.

The real issue is:The real issue is:QUANTIFICATION OF THE QUANTIFICATION OF THE

INCREASE IN SERVICE LIFE.INCREASE IN SERVICE LIFE.

Selected Pavement Locations for Selected Pavement Locations for Detailed Analyses in Phase IIDetailed Analyses in Phase II

Not all LTPP sites located on map.

Test Sections Test Sections -- Experiments Experiments

LTPP: Core & Supplemental SectionsLTPP: Core & Supplemental SectionsSPSSPS--1; SPS1; SPS--5; SPS5; SPS--6; SPS6; SPS--99GPSGPS--1; GPS1; GPS--2; GPS2; GPS--6; GPS6; GPS--77

MTO Modifier StudyMTO Modifier StudyAccelerated Pavement Tests, examplesAccelerated Pavement Tests, examples

FHWA ALF, Turner FairbanksFHWA ALF, Turner FairbanksNCAT Test RoadNCAT Test RoadCalifornia HVS StudiesCalifornia HVS Studies

Individual State Agency Test SectionsIndividual State Agency Test Sections

Experimental FactorialExperimental Factorial

25261716Total No. PMA Sections4434PCC6633HMAHMA

Overlays

2210Coarse-Grained2210Fine-Grained

Full-Depth

2322Coarse-Grained3222Fine-Grained

Thick HMA

3333Coarse-Grained3422Fine-Grained

Thin HMA

DryWetDryWetNon-FreezeFreeze

ClimateFoundation

Pavement Cross Section

Types of Analyses:Types of Analyses:PMA Versus Unmodified MixesPMA Versus Unmodified MixesComparison of actual distress Comparison of actual distress observations; companion sectionsobservations; companion sectionsMechanisticMechanistic--empirical analysis of empirical analysis of performance history:performance history:

Fracture, Load RelatedFracture, Load RelatedDistortion, Load RelatedDistortion, Load Related

Performance Performance EvaluationsEvaluations

Load Related CrackingLoad Related CrackingRuttingRuttingThermal CrackingThermal CrackingIRI, SmoothnessIRI, SmoothnessOther Surface DistressOther Surface Distress

Unmodified MixesUnmodified MixesVersusVersus

PMA MixesPMA Mixes

Load Related Load Related Cracking AnalysisCracking Analysis

Load Related Cracking:Load Related Cracking:PMA Versus Unmodified Mixes PMA Versus Unmodified Mixes

02468

10121416

0 10 20 30 40 50

Fatigue Cracking - Conventional HMA Mixes, %

Fatig

ue C

rack

ing

- PM

A M

ixes

, %Series1

Line ofEquality

One data point represents aPMA & Companion Unmodified Section

Fatigue Cracking AnalysisFatigue Cracking Analysis

( )

−

−= −

33

621

10854.0

10291.3947.15

HMAf

tfff

ELog

LogNLog

β

εββ

PDMAP Fatigue Curve initially used in fatigue analysis.

ββff = 1.0 for initial damage analyses= 1.0 for initial damage analyses

Importance Importance of Local of Local

CalibrationCalibration0

10

20

30

40

50

60

0 0.5 1 1.5 2 2.5

Fracture Damage Index

Fatig

ue C

rack

ing,

%

0102030405060

0 0.5 1 1.5 2 2.5

Adjusted Damage Index

Fatig

ue C

rack

ing,

%

Fatigue Cracking Fatigue Cracking EvaluationsEvaluations

Local = CellLocal = Cell

Cracking versus Damage Cracking versus Damage IndexIndex

0102030405060

0 1 2 3

Adjusted Damage Index

Fatig

ue C

rack

ing,

%

f

actual

NnxDamageInde =

Line represents Unmodified Mixes

Rutting AnalysisRutting Analysis

Unmodified MixesUnmodified MixesVersusVersus

PMA MixesPMA Mixes

Rutting:Rutting:PMA Versus Unmodified MixesPMA Versus Unmodified Mixes

0

0.2

0.4

0.6

0.8

0 0.1 0.2 0.3 0.4

Rutting - PMA Mixes,in.

Rut

ting

- C

onve

ntio

nal M

ixes

, in

.Series1

LineOfEquality

One data point represents aPMA & Companion Unmodified Section

Rutting EvaluationRutting EvaluationPermanent-resilient strain ratio used in initial analysis.

ββRR = 1.0 for initial distortion damage analyses= 1.0 for initial distortion damage analyses

( ) ( )( )TLog

LogNLog

R

d

r

pR

RR

3

2

1

491.34471.0

587.4

ββεε

ββ

−

+=

Importance Importance of Local of Local

CalibrationCalibration0

0.10.20.30.40.50.60.70.8

0 1 2 3 4

Distortion Damage Index

Rut

Dep

th, i

nche

s

00.10.20.30.40.50.60.70.8

0 1 2 3 4

Adjusted Distortion Damage Index

Rut

Dep

th, i

nche

s

Rutting Rutting EvaluationsEvaluationsLocal = CellLocal = Cell

Rutting versus Rutting versus Damage IndexDamage Index

00.10.20.30.40.50.60.70.8

0 1 2 3 4

Adjusted Distortion Damage Index

Rut

Dep

th, i

nche

s

Line represents Unmodified Mixes

FindingsFindingsField & laboratory investigations of Field & laboratory investigations of

PMA mixes suggest:PMA mixes suggest:Enhanced PerformanceEnhanced Performance

25 to 100 % increase in service life25 to 100 % increase in service life3 to 10 years increase in service life3 to 10 years increase in service life

Reduced Maintenance ActivitiesReduced Maintenance ActivitiesCrew SafetyCrew SafetyTraffic DelayTraffic Delay

Estimate of Enhanced Estimate of Enhanced Performance Based on Performance Based on

Damage AnalysisDamage Analysis

00.5

11.5

22.5

0 10 20 30 40 50

Age, years

Dam

age

Inde

x

Conventional HMA Mixtures PMA Mixtures

FindingFindingMechanisticMechanistic--empirical analysis empirical analysis confirms need for confirms need for different different calibration factorscalibration factors for for predicting performance of PMA predicting performance of PMA mixes.mixes.

0102030405060

0 1 2 3 4

Damage Index

Area

Fat

igue

Cra

ckin

g,

%PMA Sections

ObservationObservation

Longitudinal cracking in wheel path is much lower in PMA mixes, as compared to conventional-unmodified mixes.

Products from StudyProducts from Study1.1. Detailed Study ReportDetailed Study Report2.2. Executive Summary of FindingsExecutive Summary of Findings3.3. Guidelines for Application & UseGuidelines for Application & Use

PavementPavementStructuralStructural

DesignDesign

Life CycleLife CycleCostCost

AnalysisAnalysis

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Thank you for your attention Thank you for your attention --Any questions?Any questions?

Contact Information:Contact Information:Mark Mark BuncherBuncherAsphalt InstituteAsphalt InstituteTim Tim GlanzemanGlanzemanEE--mail: mail: Phone: (832) 204Phone: (832) 204--54615461Cell: (832) 860Cell: (832) 860--10601060