Performance Guidelines for Selection of Hot-Poured

Bituminous Crack SealantNortheast Pavement Preservation Meeting Warwick, Rhode Island, 2007

Advanced Transportation Research and Engineering LaboratoryUniversity of Illinois at Urbana-Champaign Imad L. Al-QadiJ-F MassonS-H Sam YangEli Fini

Blends of bitumen andstyrene-butadiene copolymer (SB, SBS)recycled rubberadditives

inorganic fillerbonding agent

A

500 mμ

B

500 mμ

500 μm500 μ

H E

500 μm

A M H E

What is Crack Sealant?

Crack SealingCrack sealing/ filling is the most widely used maintenance activity of in-service pavements Inexpensive, quick, and a well-proven technique to delay pavement deterioration

Reduce water penetration Maintain pavement structural capacity Improves road rideabilityExtend pavement service life (3 to 5 years)

Installation related parameters (QC/QA, crack cleaning and preparation, etc.)

Sealant related parameters (viscosity, softness, bond strength, compatibility, etc.)

Field Performance of Crack Sealant

Sealant Failure ModesTracking: sealant is smeared on the pavement due to passing traffic

Adhesive failure: loss of bonding between sealant material and its substrate

Cohesive failure: failure within sealant material

Intrusive failure: foreign objectives intrude into sealants

Sealant Property Test Method ASTM Spec.

Application Characteristics Viscosity (binder) D4402

AdhesionBond Test

Asphalt CompatibilityD5329D5329

ExtensibilityElongation (rubber)

Ductility (binder)D412D113

Durability Track Abrasion (slurry) D3910

FlexibilityFlexibility

Cone PenetrationD5329D5329

TrackingFlow

Softening PointD5329D36

Available Specifications

Objective

Development of performance-based guidelines for the selection hot-poured crack sealant

Make use of SuperPave™ binder-testing equipment

Adapting spirit of the binder Performance Grade (PG) specifications

Viscosity Test (SC-2)

At Installation Temperature

Test DevelopmentInstrument and Testing Optimization

Rigid rodMelting time

20minSpindle size

SC-27Speed

60rpm Waiting time

30s

Test variableTemperature 0

3

6

9

0 30 60 90Time (s)

Visc

osity

(pa.

s)BB NN QQ

0

1

2

3

4

5

130 140 150 160 170 180 190 200Temperature (C)

Vis

cosi

ty (P

a.s)

VVADAEWW

Apparent Viscosity Threshold

00.5

11.5

22.5

33.5

44.5

5

BB PPWW UU EE AE AD MM VV QQ NN YY DD AB ZZ

Sealant

App

aren

t Vis

cosi

ty (P

a.s)

Vacuum Oven Aging (SC-3)

Simulate Crack Sealant Weathering in Kettle & Field

Test DevelopmentMicrowave agingSmall-kettle aging and pressure agingSmall-kettle aging, pressure aging and vacuum oven agingPressure aging Vacuum oven aging

Test Development

Method Output

GPC Separation of bitumen and polymer

FTIR Fingerprint of composition

TGA Weight loss upon heating

DSR Stiffness, relaxation

Test Procedure35g in each pan

Vacuum oven at 30″ Hg and 115°C for 16hr

Shelves spacing designed to allow uniform temperature profile

Test Verification

1.E+03

1.E+04

1.E+05

1.E+06

1.E+07

-40 -30 -20 -10 0 10 20 30 40Temperature, °C

Visc

osity

, Pa.

s

virgin 1 year 9 year 16h

24h 40h 64h

Dynamic Shear Rheometer Test (SC-4)

Intermediate Temperature for Tracking Resistance

Test Development

Taber Abraser to simulate field failure Correlate tracking flow as measured with DSRShear stress is applied for 2s then removed to allow recovery for 18s8 levels of stresses were applied

Year 1

Year 4

Time

Stra

in

Stress = 20Pa No stress: recovery

permanentdeformation

Test Parameter

Ostwald-DeWaelepower-law

γ&

10

100

1000

10000

0.0001 0.01 1Shear rate, 1/s

Stre

ss, P

a

46C52C58C64C70C76C82C

P)(C γ=σ & γ&

C: flow coefficient P: shear thinning exponent

Selection Criteria

10

100

1000

10000

100000

0.4 0.5 0.6 0.7 0.8 0.9 1Shear thinning exponent (P)

Flow

coe

ffici

ent (

C)/

Pa.

s

no tracking1 sample tracks2 samples track

A

B

C

E

D

100%97%

0

0

0

Bending Beam Rheometer (SC-5)

Low Temperature Flexural Properties

Test DevelopmentDeflection of the sealant bean is above the limit of the current BBR device

Doubling the beam thicknessModifying BBR device to support both binder and sealant beams

0

1

2

3

4

5

6

7

0 40 80 120 160 200 240

Time

Def

lect

ion

(mm

)

0

300

600

900

Load

(mN

)

DeflectionLoad

0

0.5

1

1.5

2

2.5

3

3.5

0 40 80 120 160 200 240Time (s)

Def

lect

ion

(mm

)

0

200

400

600

800

1000

1200

Load

(mN)

DeflectionLoad

Crack Sealant Specimen

Standard Binder Specimen 6.35mm

12.7mm

= 0.0966(t)0.3428

R2 = 0.9999

0.01

0.1

1

0.1 1 10 100 1000Time (sec)

Stra

in (%

)

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0 100 200 300 400 500 600 700Time (s)

Def

orm

atio

n (m

m)

0

200

400

600

800

1000

1200

Load

(N)

DeformationLoad

Test ParameterStiffness @ 240s

Average creep rate

CAt)t( =ε

)t(bh4PL)t(S 3δ

=

0

5

10

15

20

25

30

35

40

45

50Q

Q EE ZZ YY

AB

VV

UU

DD AE

MM

WW NN

AD PP BB

Sealant

Stiff

ness

(MPa

)

2°C -4°C -10°C -16°C -22°C -28°C -34°C -40°C

S(-10°C)=85MPa

0

0.1

0.2

0.3

0.4

0.5Q

Q EE ZZ YY AB VV UU

DD

AE

MM

WW NN

AD PP

BB

Sealant

Ave

rage

Rat

e of

Cre

ep

2°C -4°C -10°C -16°C -22°C -28°C -34°C -40°C

CSBBR Threshold

CSDTT Test (SC-5)

Low Temperature Extendibility

Crack movement in the field Simulates sealant extension in the fieldModification for existing testing

Extension of SuperPaveTM specimen: 33% 90+%Utilize FE tool to select appropriate specimen Dim.Select appropriate loading rate 6%/min

Test Development

0.6%0.120.6%0.26.0%1.26.0%260.0%1260.0%20

Strain Rate, mm/min

Disp. Rate, mm/min

Strain Rate, mm/min

Disp. Rate,mm/min

Type CType A and B

0.6%0.120.6%0.26.0%1.26.0%260.0%1260.0%20

Strain Rate, mm/min

Disp. Rate, mm/min

Strain Rate, mm/min

Disp. Rate,mm/min

Type CType A and B

A

B

C

N/AN/A716Masson & Lacasse, 1999N/AN/A6+90Cook et al., 1991

5x10-58x10-3N/A63Linde, 19882.5

Min Crack(%)

5x10-3

Fast Move.(mm/min)

2.77x10-418Smith & Romine, 1993

Slow Move.(mm/min)

Max Crack(%)

Studies

N/AN/A716Masson & Lacasse, 1999N/AN/A6+90Cook et al., 1991

5x10-58x10-3N/A63Linde, 19882.5

Min Crack(%)

5x10-3

Fast Move.(mm/min)

2.77x10-418Smith & Romine, 1993

Slow Move.(mm/min)

Max Crack(%)

Studies

Extendibility (l)Effective gauge length (Leff=20mm)

Test Parameters

effLLΔ

=λ

The extendibility criterion is suggested based on various climatic conditions

T (°C) -4 -10 -16 -22 -28 -34 -40λ (%) 10% 25% 40% 55% 70% 85% 85+

0

10

20

30

40

50

60

70

80

90

DD AE MM WW NN AD PP BBSealant

Exte

ndib

ility

(%)

-22 -28-34 -40

-10°C

-16°C Grade

-22°C Grade

-28°C Grade

-34°C Grade

-40°C Grade +

0

10

20

30

40

50

60

70

80

90

QQ EE ZZ YY AB VVSealant

Exte

ndib

ility

(%)

-4 -10

-16 -22

-10°C

-16°C

-22°C Grade

-28°C Grade

-34°C Grade

-40°C Grade +

CSDT Threshold

Adhesion Test (SC-7)

For Low Temperature Bonding

Surface Energy Method (Work of Adhesion)

A compatibility test for sealant producers

Direct Bond MethodA quality control test for DOT

Blister Test MethodFundamental test for advanced research

Test Development

Coefficient of Thermal ExpansionSurface EnergySurface Roughness

Limestone>Sandstone>Quartzite>Granite>Steel>Aluminum

Pore SizeSandstone>Quartzite>Aluminum

Substrate Selection

MaterialCoeff. of Thermal Exp.,

cm/cm/°C x 10–6Surface Energy,

mJ/m2

Aluminum oxide 23 70Soda Lime Glass 8 72Polycarbonate 22 46Stainless Steel 9.9–17.3 57Granite 7–9 425Limestone 6 111Quartzite 11–13 200Sandstone 11–12 105Basalt 6–8 74

MaterialCoeff. of Thermal Exp.,

cm/cm/°C x 10–6Surface Energy,

mJ/m2

Aluminum oxide 23 70Soda Lime Glass 8 72Polycarbonate 22 46Stainless Steel 9.9–17.3 57Granite 7–9 425Limestone 6 111Quartzite 11–13 200Sandstone 11–12 105Basalt 6–8 74

Aluminum was conservatively selected as substrate

0

20

40

60

80

100

UU BB AE PP AD WW MM

Wor

k of

Adh

esio

n (m

J/m

2 )

LimestoneQuartziteGraniteAluminum

)cos1( θγ += totalsaW

1st Level Adhesion Test: Work of Adhesion

Fixture designed to be used in the DT device

Two aluminum half-cylindersDiameter: 25mmSealant thickness: 10mm

Simulates sealant installationSimulates crack expansion

Displacement rate: 0.05mm/sSpecific failure location

2nd Level Adhesion Test:Direct Bond Test (CS-7)

Pmax

De-bond Energy

0

20

40

60

80

100

120

0 0.1 0.2 0.3 0.4 0.5 0.6Displacement (mm)

Load

(N)

PmaxEnergy

Test Parameter

0

40

80

120

160

Non-aged Oven-aged

Kettleaged

Less than3yr

More than3yr

Ener

gy (J

/m2 )

ABPPLL

0

50

100

150

200

Non-aged Oven-aged

Kettleaged

Less than3yr

More than3yr

P max

(N)

ABPPLL

Bonding Threshold

)t(d)t(PC)t(E =

3rd Level Adhesion Test: Blister Test

)()()( tE

tdtp∝)(tE

.iniIFE

.propIFE

CPdIFE .ini = )]t(IFE[AVG.IFEprop =

0

100

200

300

400

2 -4 -10 -16 -22

IFE

(J/m

2 )

EEDDUUABQQ

0

200

400

600

800

1000

1200

-22 -34 -40

IFE

(J/m

2 )

ADBBPPNNLLAEMM

Test Parameter

Temperature (°C)

Temperature (°C)

IFE

ini(J

/m2 )

IFE

ini(J

/m2 )

Crack SealantPerformance Grade

SG-46 SG-52 SG-58 SG-64 SG-70 SG-76 SG-82

-46-40-34-28-22-16-10-46-40-34-28-22-16-10-46-40-34-28-22-16-10-46-40-34-28-22-16-10-46-40-34-28-22-16-10-46-40-34-28-22-16-10-46-40-34-28-22-16-10

Apparent Viscosity, SC-2 Installation Temperature

Max. Viscosity (Pa.s) 3.5

Min. Viscosity (Pa.s) 1

Vacuum Oven Residue (SC-3)

Dynamic Shear, SC-4 46 52 58 64 70 76 82

Min. Flow Coefficient (kPa.s) 4

Min. Shear Thinning 0.7

Crack Sealant BBR, SC-5

-40-34-28-22-16-10 -4 -40-34-28-22-16-10 -4 -40-34-28-22-16-10 -4 -40-34-28-22-16-10 -4 -40-34-28-22-16-10 -4 -40-34-28-22-16-10 -4 -40-34-28-22-16-10 -4

Max. Stiffness (MPa) 25

Min. Avg. Creep Rate 0.31

Crack Sealant DTT, SC-6

-40-34-28-22-16-10 -4 -40-34-28-22-16-10 -4 -40-34-28-22-16-10 -4 -40-34-28-22-16-10 -4 -40-34-28-22-16-10 -4 -40-34-28-22-16-10 -4 -40-34-28-22-16-10 -4

Min. Extendibility (%)

>85>85>70>55>40>25>10>85>85>70>55>40>25>10>85>85>70>55>40>25>10>85>85>70>55>40>25>10>85>85>70>55>40>25>10>85>85>70>55>40>25>10>85>85>70>55>40>25>10

Crack Sealant DBT, SC-7

-40-34-28-22-16-10 -4 -40-34-28-22-16-10 -4 -40-34-28-22-16-10 -4 -40-34-28-22-16-10 -4 -40-34-28-22-16-10 -4 -40-34-28-22-16-10 -4 -40-34-28-22-16-10 -4

Min. Load (N) 50

Min. Energy (J/m2) 40

Comprehensive tests based on sealant rheological properties was developedSelection criteria is proposedA significant economic impact on the sealant industry and the pavement preservation program is expected

Outcome of the Study

Future PlanLaboratory validationField validation

Monitoring test section for four yearsFine tuning thresholdsQuantify cost effectiveness of crack sealant

AcknowledgementsFederal Highway Administration Pool-fund TPF5 (045) The US-Canadian Crack Sealant ConsortiumParticipating US states, Canadian provinces, airport and city agencies, and industry

A continuation of this pool-fund study has been decided in the last consortium meetingVirginia will be the lead statePlease contact:

Kevin McGhee of VTRC (Email:Kevin.McGhee@VirginiaDOT.org )Imad Al-Qadi (Email:alqadi@ad.uiuc.edu)Eli Fini and S-H Sam Yang