Multi-Stress Creep and Recovery Test Method A New Specification

Multi-Stress Creep and Recovery Test Method

A New Specification

John DJohn D’’AngeloAngelo

Federal Highway AdministrationFederal Highway Administration

Phone 202Phone 202--366366--0121 fax 2020121 fax 202--493493--20702070

John.DJohn.D’’[email protected]@dot.gov

Modified Binders Affect Modified Binders Affect PerformancePerformance

Study same mix different binders.Study same mix different binders.

PG 63-22 mod. no rutting PG 67-22 unmod. 15mm rutting

Multi Stress Creep and RecoveryMulti Stress Creep and Recovery

Test using the DSR

applying a 1 sec creep

stress followed by 9 sec recovery.

Multi Stress Creep and RecoveryMulti Stress Creep and Recovery

Sample prep is exactly the same as the existing Sample prep is exactly the same as the existing RTFOT DSR.RTFOT DSR.

Typical Plot of Creep and Typical Plot of Creep and Recovery dataRecovery data

500

600

700

800

900

1000

1100

1200

1300

1400

0 100 200 300 400 500 600 700 800 900 1000

% Strain

Time in S

Determination of Determination of JnrJnr

0

5

10

15

20

25

30

0 20 40 60 80 100

Time s

Nor

mal

ized

Stra

in %

γu = Avg. un-recovered q strain mm/mm

Jnr

= γu

/ τ

τ

= applied stress during creep kPa

Jnr

= non-recoverable compliance

0

1

2

3

4

5

6

7

0 2 4 6 8 10 12

time s

Stra

in %

γr = recovered strain

What is % Recovered StrainWhat is % Recovered Strain

γu = un-recovered strain

γp = Peak strain

% recovery= (γr /

γp)

X 100

Standard Test Procedure Standard Test Procedure developed for AASHTOdeveloped for AASHTO

MSCR and RuttingMSCR and Rutting

Any new specification must be blind to Any new specification must be blind to modification.modification.

A new specification must identify the rutting A new specification must identify the rutting potential of all binder types under multiple potential of all binder types under multiple conditions.conditions.

Miss I55 6yr rut Miss I55 6yr rut JnrJnr

3.2 3.2 kPakPa

y = 0.2907x + 0.1297R2 = 0.7499

00.5

11.5

22.5

33.5

4

0 2 4 6 8 10 12

6 yr Jnr 3.2 kPabinder mod true grade rut mm 70C

Ultrapave SBR 70-27 4.5 1.7Styrelf SB 77-29 2 0.44

GTR 80 75-29 1.5 1.21Sealoflex SBS 82-27 3 0.19

Multigrade 72-24 5 2.13Cryo Rubber 75-28 7 1.62

Control 70-24 11 3.5

Hamburg Rut testing MINN Road mixesHamburg Rut testing MINN Road mixes

Jnr 12.8kPa

y = 0.3976x - 0.2894R2 = 0.9646

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

0 5 10 15 20 25 30 35rut mm

Jnr

PG 58-28PG 58-34PG 58-40

-20

-15

-10

-5

0

RU

T D

EPT H

IN m

m

0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000RUT PASSES AT ~64° C & 158 LBS (703 N)

NuStar Analysis, E-10 Fine, 64-22S @ 64.4°C, 158# AVERAGE BOTH WHEELSBRRS-3, E-10 Fine, 64-22H (70-22) (Citgo) @ 64.2°C @ 158# AVERAGE BOTH WHEELSNuStar, E-10 Fine, 64-22V (76-22) @ 64.0°C 158# AVERAGE BOTH WHEELSNuStar Analysis, E-10 Fine- NuStar 82-22 (64-22V) @ 64.2°C 158# AVERAGE BOTH WHE

NUSTAR STUDY PG 64-22S, 64-22H, 64-22V BINDERS

TESTED IN HAMBURG

DRY AT ~ 64° C, 158# LOAD, E-10 FINE LIMESTONE BLEND

09/14/08 19:45:43 C:\DRIVE_E\PMW 2008\NUSTAR\NuStar Analysis, 64-22S, 64-22H, 64-22V @ ~64°C, 158#.spf

-20

-15

-10

-5

0

RU

T D

EPT H

IN m

m


NuStar Analysis, E-10 Fine, 64-22S @ 64.4°C, 158# AVERAGE BOTH WHEELSBRRS-3, E-10 Fine, 64-22H (70-22) (Citgo) @ 64.2°C @ 158# AVERAGE BOTH WHEELSNuStar, E-10 Fine, 64-22V (76-22) @ 64.0°C 158# AVERAGE BOTH WHEELSNuStar Analysis, E-10 Fine- NuStar 82-22 (64-22V) @ 64.2°C 158# AVERAGE BOTH WHEBRRS-3, E-10 Fine, 70-22 (Citgo) @ 70.0°C @ 158# AVERAGE BOTH WHEELS


TESTED IN HAMBURG


09/14/08 19:50:55 C:\DRIVE E\PMW 2008\NUSTAR\NuStar Analysis, 64-22S, 64-22H, 64-22V @ ~64°C, 158#

-20

-15

-10

-5

0

RU

T D

EPT H

IN m

m


NuStar Analysis, E-10 Fine, 64-22S @ 64.4°C, 158# AVERAGE BOTH WHEELSBRRS-3, E-10 Fine, 64-22H (70-22) (Citgo) @ 64.2°C @ 158# AVERAGE BOTH WHEELSNuStar, E-10 Fine, 64-22V (76-22) @ 64.0°C 158# AVERAGE BOTH WHEELSNuStar Analysis, E-10 Fine- NuStar 82-22 (64-22V) @ 64.2°C 158# AVERAGE BOTH WHEBRRS-3, E-10 Fine, 70-22 (Citgo) @ 70.0°C @ 158# AVERAGE BOTH WHEELSBRRS-3, E-10 Fine, 70-22 (Citgo) @ 74.7°C @ 158# AVERAGE BOTH WHEELS


TESTED IN HAMBURG


09/14/08 20:03:29 C:\DRIVE_E\PMW 2008\NUSTAR\NuStar Analysis, 64-22S, 64-22H, 64-22V @ ~64°C, 158#.spf

Rut test Rut test temptemp

PG PG GRADEGRADE

PG GRADE PG GRADE ((JnrJnr))

JnrJnr at Rut at Rut Test TempTest Temp

%RECO%RECO VERYVERY

MIN MIN %RECO%RECO VERYVERY

RUT RUT DEPTH DEPTH 10000 10000 PASSEPASSE SS

6464 7676--2222 6464--22V22V 0.240.24 55.855.8 50.650.6 1.681.68

6464 6464--2222 6464--22S22S 3.43.4 3.43.4 -------------------- 7.17.1

64.464.4 7070--2222 6464--22H22H 1.351.35 4.44.4 33.733.7 3.573.57

6464 8282--2222 6464--22E22E 0.0820.082 78.578.5 66.166.1 1.551.55

7070 7070--2222 7070--22S22S 2.922.92 1.51.5 -------------------- 5.15.1

74.774.7 7070--2222 7070--22<S22<S 5.745.74 0.50.5 ------------------ 13.213.2

NuStarNuStar

Rutting Study Dry Hamburg Rutting Study Dry Hamburg WI E10 fine mixWI E10 fine mix

NuStarNuStar

Rutting Study Dry Hamburg Rutting Study Dry Hamburg WI E10 fine mixWI E10 fine mix

y = 0.4848x - 0.3131R2 = 0.9586

0

1

2

3

4

5

6

7

0 2 4 6 8 10 12 14Rut mm

Jnr 3

.2 k

Pa-1

Affect of Affect of JnrJnr

on Ruttingon Rutting

Reducing Reducing JJnrnr

by half typically reduced rutting by by half typically reduced rutting by half.half.

This affect is seen on ALF sections and This affect is seen on ALF sections and Hamburg Rut TestingHamburg Rut Testing

But most importantly this is seen on the But most importantly this is seen on the Mississippi I 55 sections.Mississippi I 55 sections.

For all mix types and loadings For all mix types and loadings JnrJnr

less than 1 less than 1

had minimal rutting.had minimal rutting.

New high Temp SpecNew high Temp Spec

PG 64 (Standard, Heavy, Very heavy) based on PG 64 (Standard, Heavy, Very heavy) based on traffic.traffic.

PG 64SPG 64S--XX XX JJnrnr

=< 4.0=< 4.0

PG 64HPG 64H--XX XX JJnrnr

=< 2.0=< 2.0

PG 64VPG 64V--XX XX JJnrnr

=< 1.0=< 1.0

Special Cases Port Facilities, Quarry Entrances, Etc. a Special Cases Port Facilities, Quarry Entrances, Etc. a PG 64EPG 64E--XX XX JJnrnr

=< 0.5 can be considered.=< 0.5 can be considered.

Existing PG 76Existing PG 76--22 4% SBS tested @ 22 4% SBS tested @ 4 temperatures 82, 76, 70 & 644 temperatures 82, 76, 70 & 64

0

500

1000

1500

2000

2500

0 1 2 3 4 5 6 7 8 9 10 11

Strain

time S

Jnr 5.69 kPa‐1

% Recovery 20.5%

Jnr 2.35 kPa‐1

% Recovery 37.0%

Jnr 1.18 kPa‐1

% Recovery 40.3%

Jnr 0.47 kPa‐1

% Recovery 51.7%

76 S

70 H

64 E

SBS PG 70SBS PG 70--28 SBS28 SBS

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

10 100 1000 10000 100000Stress Pa

Jnr

58C64C70C76C72C calc

1

2

3

4

5

6

7

8

10Compliance values increase with temperature and stress. The rate of increase with stress increases with increased temperature.

OriginalOriginalDSR G*/sinDSR G*/sinδδ

Min 1.0Min 1.0

6464

RTFOTRTFOT64 Standard 64 Standard MSCR3.2 <4.0MSCR3.2 <4.0

6464

64 Heavy 64 Heavy MSCR 3.2<2.0MSCR 3.2<2.0

6464

64 Very heavy64 Very heavyMSCR3.2 <1.0MSCR3.2 <1.0

6464

PAVPAV

S grade S grade DSR G*sinDSR G*sinδδMax 5000Max 5000

2828 2525 2222 1919 1616

H & V grade H & V grade DSR G*sinDSR G*sinδδ

Max 6000Max 6000

2828 2525 2222 1919 1616

New MSCR Binder SpecNew MSCR Binder Spec AASHTO M320 Table 3AASHTO M320 Table 3

Low temp BBR and DTT remain unchanged

[(MSCR3.2 [(MSCR3.2 ––

MSCR 0.1)/ MSCR 0.1)/ MSCR 0.1] < .75MSCR 0.1] < .75

Experiment DesignExperiment Design Time Temperature studyTime Temperature study

Blending Time, hoursBlending Time, hours 2 h2 h 4 h4 h 6 h6 h 6 h + x6 h + x--linkinglinking

Blending Temperature, Blending Temperature, °°CC 188188 200200 188188 200200 188188 200200 188188 200200

M320 High Temp DSRM320 High Temp DSR XX XX XX XX XX XX XX XX

UDOT Elastic RecoveryUDOT Elastic Recovery XX XX XX XX XX XX XX XX

MSCR TestMSCR Test XX XX XX XX XX XX XX XX

UV MicroscopyUV Microscopy XX XX XX XX XX XX XX XX

Incompatible 67-22 base binder mixed with 4% linear SBS elemental sulfur as a cross linker.

76.0

82.0

88.018

8-2h

200-2

h

188-4

h

200-4

h

188-6

h

200-6

h

188-6

h+X

200-6

h+X

M32

0 H

igh

PG G

rade

Changes in M320 High Temp PG Changes in M320 High Temp PG with Processingwith Processing

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

118

8-2h

200-

2h

188-

4h

200-

4h

188-

6h

200-

6h

188-

6h+X

200-

6h+X

Jnr @

70C

Changes in Changes in JJ nrnr

with Processingwith Processing

PG 70E

PG 70V

Changes in UDOT Elastic Recovery Changes in UDOT Elastic Recovery with Processingwith Processing

60.0

65.0

70.0

75.0

80.0

85.0

90.0

95.0

188-2

h

200-2

h

188-4

h

200-4

h

188-6

h

200-6

h

188-6

h+X

200-6

h+X

UD

OT

Elas

tic R

ecov

ery,

%

AASHTO T301-modRTFO, 25°C, 20 cm pull and then cut

Changes in % Recovery MSCR test Changes in % Recovery MSCR test with Processingwith Processing

0

10

20

30

40

50

60

70

188-2h 200-2h 188-4h 200-4h 188-6h 200-6h 188-6h+X 200-6h+X

% R

ecov

ery

MSC

R Recommended Min % Recovery PGXX V

Recommended Min % Recovery PGXX H

Fluorescence MicroFluorescence Micro--graphs at 250 graphs at 250 magnificationmagnification

Table for MSCR % Recovery Table for MSCR % Recovery minimum valuesminimum values

Minimum % Recovery for Measured Jnr

values

Jnr

@ 3.2 kPa Minimum % Recovery

2.0 -

1.01 30%

1.0 -

0.51 35%

0.50 -

0.251 45%

0.25 -

0.125 50%

Conclusions and RecommendationsConclusions and Recommendations

Mixing Temperature and X-linking effect the properties of polymer modified binders.

The Elastic Recovery showed little difference between The Elastic Recovery showed little difference between the different processing methods. the different processing methods.

Both SHRP G*/sinBoth SHRP G*/sinδδ

and MSCR indicated the and MSCR indicated the differences between the different processing methods, differences between the different processing methods, but results are different for each.but results are different for each.

The MSCR both The MSCR both JJnrnr

and MSCR % Recovery indicated and MSCR % Recovery indicated larger differences than the SHRP and ER tests.larger differences than the SHRP and ER tests.

The Larger differences were verified by the Florescence The Larger differences were verified by the Florescence Microscopy.Microscopy.

ImplicationsImplications

MSCR test is more discriminating and a MSCR test is more discriminating and a fundamental property test fundamental property test

New practice for SBS blend optimization?New practice for SBS blend optimization?

For researchFor research

For spec.For spec.

ImplementationImplementation

MSCR can replace the ERMSCR can replace the ER

Single protocolSingle protocol

Quick and easyQuick and easy

Fundamental propertyFundamental property

New MSCR SpecificationNew MSCR Specification

MSCR test procedure TPMSCR test procedure TP--70 published Spring 70 published Spring 2008.2008.

New Table 3 accepted by AASHTO published New Table 3 accepted by AASHTO published Spring 2009.Spring 2009.

Thank YouThank You

Multi-Stress Creep and Recovery Test Method A New Specification

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