“understanding the performance of modifiers in asphalt …spave/old/technical info/meetings... ·...

“Understanding the “Understanding the Performance of Modifiers in Performance of Modifiers in

Asphalt Mixtures” Asphalt Mixtures” ––6767--80 Binder Study80 Binder Study

Materials & Construction TeamMaterials & Construction Team

Federal Highway AdministrationFederal Highway Administrationwww.TFHRC.govwww.TFHRC.gov

The SuperpaveThe Superpave®® SystemSystem

•• Performance Grade (PG) Binder SpecificationPerformance Grade (PG) Binder Specification–– Safety / Constructability Safety / Constructability (Pump(Pump--ability)ability)–– AgingAging–– Permanent Deformation Permanent Deformation (Rutting)(Rutting)–– Fatigue CrackingFatigue Cracking–– LowLow--Temperature CrackingTemperature Cracking

•• Volumetrically Based Mixture Design SystemVolumetrically Based Mixture Design System–– Gyratory Compaction (Gyratory Compaction (VVaa, VMA, VFA), VMA, VFA)–– SuperpaveSuperpave®® Performance Test(s) (|E*|, FT, FN)Performance Test(s) (|E*|, FT, FN)

Superpave PG Binder Superpave PG Binder “Purchase” Specification“Purchase” Specification

•• In Situ Permanent DeformationIn Situ Permanent Deformation–– Cumulative Plastic DeformationCumulative Plastic Deformation

•• PG Binder CharacterizationPG Binder Characterization–– Dynamic Shear RheometerDynamic Shear Rheometer–– ViscoVisco--Elastic Response (G*, Elastic Response (G*, δδ))

•• The Goal of the PG system was/is NOT to The Goal of the PG system was/is NOT to predict performance, but rather to assure good predict performance, but rather to assure good performanceperformance

FHWA Modified Binder FHWA Modified Binder Research ProgramResearch Program

Output – Validation/Calibration Data, Specification Recommendations

TRB Superpave Committee-Binder ETG-Mix/Aggregate ETG

TPF 5(019) / SPR 2(174)Technical Working GroupTWG

LaboratoryStudy 90-07Study 67-80

ALF LoadingResponse Data

CollaborativeResearchers

IndustrySupport

Technical Working Group (TWG) Meeting December 5-6, 2002(17 States, 29 Industry Partners/Collaborative Researchers)

Not YetTPF-5(019)SPR-2(174)

2001 ALF PF2001 ALF PF

1993 SHRP Validation1999 NCHRP 90-07 / 2001 ALF PF

2003 PG 67-80 Study

ConstructionConstruction RuttingRutting FatigueFatigueCrackingCracking

LowLow--TempTempCrackingCracking

MM--E ModelingE Modeling

FWD / Geogauge|E*| Study ALF / Lab ALF / Lab Lab Only

Final Test Matrix… Final Test Matrix…

AZCRM----70-22

1

PG70-22Control

2

AirBlown

3

SBS

4

TXTBCR

5

T-P

6

PG70-22

+Fibers

7

PG70-22

8

SBS64-40

9

AirBlown

10

SBS

11

T-P

12

Rutting StudyRutting Study

RealWorld

ALF –Sections

Lab –Mixture Testing

Lab –Binder Testing

ImplicitAssumption

Step 1:Binder - Mix

Step 3:Binder - ALF

Step 2:Mix - ALF

6767--80 Binder Study80 Binder StudyOutlineOutline

•• Research ApproachResearch Approach•• 6767--80 Binders80 Binders•• Mixture CharacterizationMixture Characterization•• Proposed Binder ParametersProposed Binder Parameters•• Assessment of Current ApproachAssessment of Current Approach•• Preliminary Evaluation of Proposed Preliminary Evaluation of Proposed

Parameters (PParameters (P--PG’s)PG’s)

Research ApproachResearch Approach

•• HHoo ––

The HT cThe HT c--PG PG defines the defines the temperature where temperature where mixtures yield the mixtures yield the same HT same HT performance

0

200

400

600

800

1000

1200

64 70 76 82 88

HT c-PG, (°C)C

ycle

s to

2%

Str

ain

performance


•• Perfect ParameterPerfect Parameter–– Y = m X + bY = m X + b–– m = zerom = zero–– b = mix constantb = mix constant–– RR22 = n/a= n/a

(Y = b) 0

200

400

600

800

1000

1200

64 70 76 82 88

HT c-PG, (°C)C

ycle

s to

2%

Str

ain

(Y = b)


•• AnalysisAnalysis–– YYAVEAVE = Sum [ Y= Sum [ Yii ] / n] / n

–– ∆∆ Y = [(Y = [(YYAVEAVE -- YYii ]]22]]½½ / n / n

–– % % ∆∆ cPGcPG = 100 = 100 ∆∆ Y/Y/YYAVEAVE

•• Normal Distribution Normal Distribution

0

200

400

600

800

1000

1200

1400

64 70 76 82 88

HT c-PG, (°C)C

ycle

s to

2%

Stra

in


•• Ex. AnalysisEx. Analysis–– YYAVEAVE = 1000= 1000

–– ∆∆ Y = [300Y = [300] / 3 ] / 3

–– %%∆∆ cc--PG = 100 / 1000PG = 100 / 1000= 10 %= 10 %

0

200

400

600

800

1000

1200

1400

64 70 76 82 88

HT c-PG, (°C)C

ycle

s to

2%

Stra

in

900 1150 950

2001 ALF PF2001 ALF PFTarget Grade, AB cTarget Grade, AB c--PG 74PG 74--2828

Binder IDBinder ID cc--PG HTPG HT cc--PG LTPG LT UTIUTI

1: AZ CR1: AZ CR2/8: Control2/8: Control3/10: Air3/10: Air--blownblown4/11: SBS4/11: SBS--lglg5: TBCR5: TBCR6/12: Terpolymer6/12: Terpolymer9: SBS 649: SBS 64--4040

n/an/a727274747474797974747171

n/an/a--2323--2828--2828--2828--3131--3838

n/an/a9595102102102102103103105105109109

UTI – Useful Temperature Index

In situ ALF BindersIn situ ALF Binders

-40

-34

-28

-2258 64 70 76 82

Continous High Temperature Grade, (c-HT) °C

c-LT

, °C

ControlAirblownSBS-lgTBCRTerpolySBS

ETG Concern

6767--80 Binders80 Binderscc--PG based on G*/sin PG based on G*/sin δδ Original/RTFOOriginal/RTFO

Binder IDBinder ID CodeCode cc--PG HTPG HT cc--PG LTPG LT

1: 1: EnviroEnviro. Friendly. Friendly2: EF + SBS2: EF + SBS3: Terpolymer3: Terpolymer4: Terpolymer4: Terpolymer5: Terpolymer5: Terpolymer6: Terpolymer6: Terpolymer

B6308B6308B6309B6309B6310B6310B6311B6311B6312B6312B6316B6316

777780805959686872728282

--2525--2424--3030--2828--3131--2424

6767--80 Binders80 Binderscc--PG based on G*/sin PG based on G*/sin δδ Original/RTFOOriginal/RTFO

Binder IDBinder ID CodeCode cc--PG HTPG HT cc--PG LTPG LT

7: TBCR7: TBCR8: TBCR8: TBCR9: TBCR9: TBCR

10: SBS LG10: SBS LG11: SBS LG11: SBS LG12: SBS LG12: SBS LG

B6313B6313B6314B6314B6315B6315B6324B6324B6325B6325B6326B6326

707076768282686877778484

--2525--2525--2323--2626--2323--2222

6767--80 Binders80 Binders

-40

-34

-28

-2258 64 70 76 82 88

Continous High Temperature Grade, (c-HT) °C

c-LT

, °C

EFEF + SBSTerpolyTBCRSBS lg

58 64 70 76 82 88

Mix DesignMix Design

FHWA 0.45 Power Chart12.5 mm Nominal Maximum Size

0.075 0.3 1.18 4.75 9.5 12.5 25192.36

0

10

20

30

40

50

60

70

80

90

100

Sieve Size, mm

Perc

ent P

assi

ng

SuperpaveSuperpave

12.5mm NMS12.5mm NMSCoarse GradedCoarse GradedPPbb = 5.3 %= 5.3 %cc--PG 74PG 74--2828NNdesigndesign = 75= 75

Mixture Test at HT cMixture Test at HT c--PGPG

• Superpave Shear Tester (SST)– Repeated Shear at Constant Height (RSCH)

• Cycles to 2% Strain Failure• Strain at 5,000 cycles• Strain at 1,000 cycles

Mixture CharacterizationMixture CharacterizationRSCH Test Results

Cycles to 2% Strain Table 1aRep. 1 Rep. 2 Rep. 3 Rep. 4

604

503

536

352

5: Terpolymer 1411 1321 2141 765 862 1300 547 42.1

1344

1784

Average STD

1: EF 331 387 575

Rep. 5

480

593

624

773

648

475 117 24.7

2: EF+SBS 1129 600 519 669 261 39.0

3: Terpolymer 499 770 1049 696 223 32.1

4: Terpolymer 501 299 712 528 211 40.0

2023

5: Terpolymer 1966 1242 936 1227 495 40.3

6: Terpolymer 2475 2201 2121 291 13.7

CV,%Binder ID

Mixture CharacterizationMixture CharacterizationRSCH Test Results

Cycles to 2% Strain Table 1aRep. 1 Rep. 2 Rep. 3 Rep. 4

447

8: TB CR 2666 464 1449 2004 267 1370 1015 74.1

613

602

369

531

427

Average STD

7: TB CR 280 796 896

Rep. 5

815

610

1001

184

433

647 268 41.4

626

8: TB CR 1873 1199 714 1002 544 54.3

9: TB CR 500 875 1194 834 285 34.1

10: SBS LG 194 344 450 308 115 37.4

11: SBS LG 707 737 944 670 198 29.6

12: SBS LG 403 827 432 543 182 33.6

CV,%Binder ID

Cycles to 2% StrainCycles to 2% StrainAverage of 5 ReplicatesAverage of 5 Replicates

0 500 1,000 1,500 2,000 2,500

SBS 84

SBS 77

SBS 68

TB 82

TB 76

TB 70

TP 82

TP 72

TP 68

TP 59

EF+80

EF 77

Superpave Shear Tester, RSCH

Ave 5Ave 5

Cycles to 2% StrainCycles to 2% StrainCoefficient of Variation (CV)Coefficient of Variation (CV)

0 20 40 60 80 100

SBS 84

SBS 77

SBS 68

TB 82

TB 76

TB 70

TP 82

TP 72

TP 68

TP 59

EF+80

EF 77

Superpave Shear Tester, RSCH

5 Rep5 Rep

Summary of Mixture TestingSummary of Mixture TestingMin & Max CV for 5 ReplicatesMin & Max CV for 5 Replicates

MixMixCycles to 2% Strain

Strain at

5000 cycles

Strain at

1000 cycles

Min CVMin CV 13.713.7 6.56.5 2.92.9

Max CVMax CV 54.354.3 40.940.9 25.725.7

The higher testing variability (CV >20%) is common at higher temperatures

SST at HT cSST at HT c--PGPGAve s = 266cAve s = 266c

0

500

1000

1500

2000

2500

52 58 64 70 76 82 88

Superpave HT c-PG Temperature, °C

SS

T C

ycle

s to

2%

Stra

in

EFEF+TPTBCRSBS

YYAVEAVE = 810 c= 810 c∆∆ Y = 324 cY = 324 c%%∆∆ cc--PG = 40 % PG = 40 % RR22 = 0.10= 0.10

Normal Distribution of SST DataNormal Distribution of SST Data

0.000

0.004

-1000 0 1000 2000 3000 4000Cycles to 2% Strain, RSCH

Dis

tribu

tion

EF77 EF+80 TP59 TP68 TP72 TP82 TBCR70 TBCR76TBCT82 SBS68 SBS77 SBS84 Filter

Filtered w/oTP 72 (67 %)TP 82 (100 %)TBCR 76 (49 %)

Filter + 2s

SST at HT cSST at HT c--PGPGAve s = 91x10 Ave s = 91x10 --4 4

0

100

200

300

400

500

600

700

52 58 64 70 76 82 88


SST

Stra

in a

t 500

0c x

10 4

EFEF+TPTBCRSBS

YYAVEAVE = 439= 439∆∆ Y = 70.2Y = 70.2%%∆∆ cc--PG = 16 % PG = 16 % RR22 = 0.11= 0.11

SST at HT cSST at HT c--PGPGAve s = 32x10 Ave s = 32x10 --4 4

0

50

100

150

200

250

300

350

52 58 64 70 76 82 88


SST

Stra

in a

t 100

0c x

10 4

EFEF+TPTBCRSBS

YYAVEAVE = 238= 238∆∆ Y = 30.1Y = 30.1%%∆∆ cc--PG = 13 % PG = 13 % RR22 = 0.11= 0.11

High Spec. Temperature, THigh Spec. Temperature, THSHS

•• |G*|/sin |G*|/sin δ = 2200 Paδ = 2200 Pa at 10 rads/sat 10 rads/s (Superpave)(Superpave)

•• |G*|/(1|G*|/(1--(1/tan(1/tanδδ sinsinδ)) = 50 Paδ)) = 50 Pa at 0.25 rads/sat 0.25 rads/sCriterion 1 Criterion 1 (FHWA)(FHWA)

•• TTE E /(1/(1--(1/tan(1/tanδδ sinsinδ)) where Tδ)) where TEE is when |G*|= 50 is when |G*|= 50 PaPa at 0.25 rads/sat 0.25 rads/sCriterion 2 Criterion 2 (FHWA)(FHWA)

High Spec. Temperature, THigh Spec. Temperature, THSHS

•• η’ = 220 Paη’ = 220 Pa--ss, LSV , LSV at 0.01 rads/sat 0.01 rads/s (Binder ETG)(Binder ETG)

•• ηη00 = 250 Pa= 250 Pa--ss, ZSV , ZSV at 0 rads/sat 0 rads/s (Binder ETG)(Binder ETG)

•• MVR MVR = 50 cc/10min= 50 cc/10min at 1.225 kg loadat 1.225 kg load (FHWA)(FHWA)

High Temperature ParametersHigh Temperature Parameters

•• % γ% γaccacc Repeated Creep Repeated Creep @@300 Pa 300 Pa (NCHRP 9(NCHRP 9--10)10)

•• % γ% γaccacc Repeated Creep Repeated Creep @@25 Pa 25 Pa (NCHRP 9(NCHRP 9--10)10)

High Temperature ParametersHigh Temperature Parameters

•• NonNon--recovered Compliance after 50 cyclesrecovered Compliance after 50 cyclesRepeated Creep Repeated Creep @ @ 50Pa, 100Pa, 500Pa, 1000Pa, 50Pa, 100Pa, 500Pa, 1000Pa, 1600Pa, 3200Pa 1600Pa, 3200Pa (Binder ETG)(Binder ETG)

•• NonNon--recovered Compliance Multirecovered Compliance Multi--stress after 10 stress after 10 cyclescycles Repeated Creep Repeated Creep @ @ 25Pa, 50Pa, 100Pa, 25Pa, 50Pa, 100Pa, 200Pa, 400Pa, 800Pa, 1600Pa, 3200Pa 200Pa, 400Pa, 800Pa, 1600Pa, 3200Pa

(Binder ETG)(Binder ETG)

Binder CharacterizationBinder CharacterizationSuperpaveSuperpave®®, , |G*|/sin |G*|/sin δδ

|G*|/sinδ = 2200 Pa Table 2Rep. 1 Rep. 2 Rep. 3 Average STD

1: EF 79 80 80 80 0.136 0.17

2: EF+SBS 81 82 81 81 0.106 0.13

3: Terpolymer 60 61 61 61 0.675 1.11

4: Terpolymer 71 71 70 71 0.564 0.79

5: Terpolymer 72 72 74 73 1.058 1.45

6: Terpolymer 81 80 82 81 1.276 1.58

CV,%Binder ID

Binder CharacterizationBinder CharacterizationSuperpaveSuperpave®®, , |G*|/sin |G*|/sin δ δ

|G*|/sinδ = 2200 Pa Table 2Rep. 1 Rep. 2 Rep. 3 Average STD

7: TB CR 71 71 71 71 0.207 0.29

8: TB CR 75 77 77 77 1.077 1.41

9: TB CR 83 83 83 83 0.200 0.24

10: SBS LG 71 71 71 71 0.142 0.20

11: SBS LG 80 80 80 80 0.199 0.25

12: SBS LG 83 83 84 83 0.480 0.58

CV,%Binder ID

Summary of Binder TestingSummary of Binder TestingMin & Max CV for 3 ReplicatesMin & Max CV for 3 Replicates

BinderBinder G*/sin δSuperpaveSuperpave

f(G*,δ)CriterionCriterion 11

FHWAFHWA

f(G*,δ)CriterionCriterion 22

FHWAFHWA

LSV LSV BinderETGBinderETG

ZSV ZSV BinderETGBinderETG

MVRMVRFHWAFHWA

Min CVMin CV 0.130.13 0.070.07 0.050.05 0.200.20 0.080.08 0.000.00

Max CVMax CV 1.581.58 1.361.36 1.811.81 1.181.18 2.392.39 0.000.00


BinderBinder%%γγaccacc

99--10 10 300Pa300Pa

%%γγaccacc99--10 10 25Pa25Pa

Min CVMin CV 0.740.74 0.550.55

Max CVMax CV 4.504.50 8.408.40


BinderBinderNC

BinderETGBinderETG

50Pa50Pa

NCBinderETGBinderETG

100Pa100Pa


500Pa500Pa


1000Pa1000Pa


1600Pa1600Pa


3200Pa3200Pa

Min CVMin CV 0.440.44 0.540.54 1.301.30 0.400.40

5.715.71

1.211.21 1.081.08

Max CVMax CV 7.767.76 9.039.03 6.856.85 5.885.88 3.083.08


BinderBinderNCMSBinderETGBinderETG

25Pa25Pa

NCMSBinderETGBinderETG

50Pa50Pa


100Pa100Pa


200Pa200Pa


400Pa400Pa

Min CVMin CV 0.630.63 0.240.24 0.160.16 0.230.23 0.310.31

Max CVMax CV 5.665.66 4.794.79 5.285.28 5.575.57 5.915.91


BinderBinderNCMSBinderETGBinderETG

800Pa800Pa


1600Pa1600Pa


3200Pa3200Pa


2525--3200Pa3200Pa

Min CVMin CV 0.290.29 0.430.43 0.630.63 0.300.30

Max CVMax CV 5.555.55 5.715.71 5.635.63 5.245.24

Summary of BinderSummary of BinderCoefficient of Variation (CV) 3 ReplicatesCoefficient of Variation (CV) 3 Replicates

0 5 10 15 20 25 30 35 40

NCMS

NC

9-10 25Pa

9-10 300Pa

MVR

ZSV

LSV

FHWA Crit 2

FHWA Crit 1

Superpave

Range of CV for 12 Binders

HighLow

ObservationsObservations

•• The 10 Binder HT Parameter tests are The 10 Binder HT Parameter tests are repeatable for the 12 binders:repeatable for the 12 binders:–– CV for 3 replicates < 10 %CV for 3 replicates < 10 %

•• Current Superpave HT Parameter does not Current Superpave HT Parameter does not appear to fully capture rutting potential appear to fully capture rutting potential based upon SST mixture responsebased upon SST mixture response

AcknowledgementsAcknowledgements

Thanks toThanks to•• Mr. Scott Parobeck for making samples for SSTMr. Scott Parobeck for making samples for SST•• Mr. Frank Davis for generating SST dataMr. Frank Davis for generating SST data•• Ms. Susan Needham for generating DSR dataMs. Susan Needham for generating DSR data•• Dr. Ghazi AlDr. Ghazi Al--Khateeb for analyzing SST dataKhateeb for analyzing SST data•• Dr. Aroon Shenoy for summarizing the dataDr. Aroon Shenoy for summarizing the data

Next StepsNext Steps

•• What next?What next?

Next StepsNext Steps

•• Expand SST test of each Expand SST test of each binder over the predicted binder over the predicted range of crange of c--PPG’sPPG’s

•• Expand Mix testing to Expand Mix testing to include Hamburg (W/D), include Hamburg (W/D), Pine RWT ?Pine RWT ?

•• Compare proposed Compare proposed parameters

0

200

400

600

800

1000

1200

1400

64 70 76 82 88

HT c-PG, (°C)C

ycle

s to

2%

Stra

in

parameters

“understanding the performance of modifiers in asphalt …spave/old/technical info/meetings... ·...

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