What is the Superpave binder? and how it is superior over traditional Binder and limitation of traditional binder specification. And testing methods and consideration of Superpave Binder.

1. - Pravin Mali

2.  Limitations of Traditional Binder Specifications
 SuperPave
 SuperPave Asphalt Specifications
 Superpave Asphalt Binder Tests
2

3. Limitations of Traditional Binder
Specifications
3

4.  Results used to determine if the material meets specification criteria
 Results are related to pavement performance through experience
 Penetration & ductility tests are purely empirical
 Tests are conducted at one standard temp (i.e.. Pen @ 25°C ,Vis @ 60°C), despite
different climatic conditions
 Asphalt cements can have different temperature and performance characteristics
within same grade (Pen or Vis)
 Current empirical tests and specifications do not give information for the entire
range of typical pavement temperatures
4

5. Empirical Asphalt Specifications
can classify different asphalts with the same grading, in
fact these asphalts may have different temperature and
performance characteristics
because these asphalts are graded the same one might
erroneously expect the same characteristics during
construction and the same performance during hot and
cold weather conditions
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6. 6

7. New Superpave
Performance Graded
Specification
7

8. WHAT IS SUPERPAVE
• Final product of the 1987-1993 FHWA (Federal Highway
Administration) strategic highway research program
(SHRP) to investigate better pavement materials &
design methods.
• Superior Performing Asphalt Pavements = SUPERPAVE
• Produced new standards for aggregates and bituminous
binders used in paving as well as mix design changes.
• Asphalt cement specifications are referred to as binder
specifications, intended for both modified and unmodified
asphalt cements
8

9. Benefit of the PG Gradation (AASHTO M332)
 Fundamental properties related to pavement performance
 Environmental factors
 In-service & construction temperatures
 Short and long term aging
 New test procedures and new equipment
 Specified criteria remains constant but the temperature at which the criteria must be
achieved changes for various grades
 Tests measure physical properties that can be related directly to field performance by
engineering principles
 Tests are conducted at temperatures that are encountered by in-service pavements
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10.  High in-service temperature
 Desert climates
 Summer temperatures
 Sustained loads
 Slow moving trucks
 Intersections
Viscous Liquid
10

11.  Permanent deformation (rutting)
 Mixture is plastic
 Depends on asphalt source, additives, and aggregate properties
11

12. Function of warm weather and traffic
Courtesy of FHWA
12

13.  Low Temperature
 Cold climates
 Winter
 Rapid Loads
 Fast moving trucks
Elastic Solid
13

14.  Thermal cracks
 Stress generated by contraction due to drop in temperature
 Crack forms when thermal stresses exceed ability of material to relieve stress through
deformation
 Material is brittle
 Depends on source of asphalt and aggregate properties
14

15. Courtesy of FHWA 15

16. The grading system is based on Climate
PG 64 - 22
Performance
Grade
Average 7-day max
pavement temperature
Min pavement
temperature
SUPERPAVE ASPHALT BINDER SPECIFICATION
16

17. PG 46 PG 52 PG 58 PG 64 PG 70 PG 76 PG 82
(Rotational Viscosity) RV
90 90 100 100 100 (110) 100 (110) 110 (110)
(Flash Point) FP
46 52 58 64 70 76 82
46 52 58 64 70 76 82
(ROLLING THIN FILM OVEN) RTFO Mass Loss < 1.00 %
(Direct Tension) DT
(Bending Beam Rheometer) BBR Physical Hardening
28
-34 -40 -46 -10 -16 -22 -28 -34 -40 -46 -16 -22 -28 -34 -40 -10 -16 -22 -28 -34 -40 -10 -16 -22 -28 -34 -40 -10 -16 -22 -28 -34 -10 -16 -22
-28 -34
Avg 7-day Max, oC
1-day Min, oC
(PRESSURE AGING VESSEL) PAV
ORIGINAL
> 1.00 kPa
< 5000 kPa
> 2.20 kPa
S < 300 MPa m > 0.300
Report Value
> 1.00 %
20 Hours, 2.07 MPa
10 7 4 25 22 19 16 13 10 7 25 22 19 16 13 31 28 25 22 19 16 34 31 28 25 22 19 37 34 31 28 25 40 37 34 31
(Dynamic Shear Rheometer) DSR G* sin 
( Bending Beam Rheometer) BBR “S” Stiffness & “m”- value
-24 -30 -36 0 -6 -12 -18 -24 -30 -36 -6 -12 -18 -24 -30 0 -6 -12 -18 -24 -30 0 -6 -12 -18 -24 -30 0 -6 -12 -18 -24 0 -6 -12 -
18 -24
-24 -30 -36 0 -6 -12 -18 -24 -30 -36 -6 -12 -18 -24 -30 0 -6 -12 -18 -24 -30 0 -6 -12 -18 -24 -30 0 -6 -12 -18 -24 0 -6 -12
-18 -24
(Dynamic Shear Rheometer) DSR G*/sin 
(Dynamic Shear Rheometer) DSR G*/sin 
< 3 Pa.s @ 135 oC
> 230 oC
CEC
This is the binder specification - it is defined by AASHTO MP -1.

18. PG 46 PG 52 PG 58 PG 64 PG 70 PG 76 PG 82
(Rotational Viscosity) RV
90 90 100 100 100 (110) 100 (110) 110 (110)
(Flash Point) FP
46 52 58 64 70 76 82
46 52 58 64 70 76 82
(ROLLING THIN FILM OVEN) RTFO Mass Loss < 1.00 %
(Direct Tension) DT
(Bending Beam Rheometer) BBR Physical Hardening
28
-34 -40 -46 -10 -16 -22 -28 -34 -40 -46 -16 -22 -28 -34 -40 -10 -16 -22 -28 -34 -40 -10 -16 -22 -28 -34 -40 -10 -16 -22 -28 -34 -10 -16 -22
-28 -34
Avg 7-day Max, oC
1-day Min, oC
(PRESSURE AGING VESSEL) PAV
ORIGINAL
< 5000 kPa
> 2.20 kPa
S < 300 MPa m > 0.300
Report Value
> 1.00 %
20 Hours, 2.07 MPa
10 7 4 25 22 19 16 13 10 7 25 22 19 16 13 31 28 25 22 19 16 34 31 28 25 22 19 37 34 31 28 25 40 37 34 31
(Dynamic Shear Rheometer) DSR G* sin 
( Bending Beam Rheometer) BBR “S” Stiffness & “m”- value
-24 -30 -36 0 -6 -12 -18 -24 -30 -36 -6 -12 -18 -24 -30 0 -6 -12 -18 -24 -30 0 -6 -12 -18 -24 -30 0 -6 -12 -18 -24 0 -6 -12 -
18 -24
-24 -30 -36 0 -6 -12 -18 -24 -30 -36 -6 -12 -18 -24 -30 0 -6 -12 -18 -24 -30 0 -6 -12 -18 -24 -30 0 -6 -12 -18 -24 0 -6 -12
-18 -24
(Dynamic Shear Rheometer) DSR G*/sin 
(Dynamic Shear Rheometer) DSR G*/sin 
< 3 Pa.s @ 135 oC
> 230 oC
CEC
58 64
Test Temperature
Changes
Spec Requirement
Remains Constant
> 1.00 kPa

19.  The central theme of the Superpave Binder Specification is its
reliance on testing asphalt binders in conditions that simulate the
three critical stages during the binder’s life
 Tests performed on the original asphalt represent the first stage of transport,
storage and handling
 The second stage represents the asphalt during mix production and
construction and is simulated by aging the binder in a rolling thin film oven,
The thin film oven test exposes thin binder films to heat and air and
approximates the aging of asphalt during mixing and construction
 The third stage occurs as the binder ages over a long period of time as part of
the hot mix asphalt pavement layer. This stage is simulated for the specification
by the pressure aging vessel. The procedure exposes binder samples to heat and
pressure in order to simulate years of in-service aging in a pavement
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20. 20

21. 21

22.  Superpave Binder Aging Procedures
 Asphalt binder ages:
 volatilization of light oils present in the asphalt
 oxidation by reacting with oxygen in the environment
 Rolling Thin Film Oven Test (RTFOT)
 simulates both types of aging in the mixing and placement of asphalt mix because of the high
temperatures and air flow involved in the process
 Pressure Aging Vessel (PAV)
 simulates in service aging
22

23. 1. Binder Aging
2. RTFO
3. PAV
4. DSR
5. RV
6. BBR
7. DTT

24. RollingThinFilm
OvenTest(RTFOT)
• Simulates both types of aging in
the mixing and placement of
asphalt mix because of the high
temperatures and air flow involved
in the process
• Volatilization of light oils present in
the asphalt
• Oxidation by reacting with oxygen
in the environment
PressureAging
Vessel(PAV)
• Simulates in service aging
• Binder samples that have been
aged in the PAV have already been
aged in the RTFOT
• Consequently, the PAV residue
represents binder that has been
exposed to all of the environmental
conditions to which binders are
subjected to during production and
service
24

25. Rolling Thin Film Oven Test (RTFOT)
(AASHTO T240 ASTM D 2872)
provides aged asphalt binder that can be used for further
testing of physical properties
determines the mass quantity of volatile lost during the
process
 indication of the aging that may occur in the asphalt during
mixing and construction operations
 specified as 1% maximum
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26. 26

27.  Pressure Aging Vessel (PAV)
 AASHTO PP1
 simulates the effects of long term in-service aging of asphalt
 Uses binder that has previously been aged in the RTFOT since asphalt that is exposed to
long term aging has also been through the mixing and construction process
 exposes the binder to high pressure and temperature for 20 hours
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28. 28

29. 29

30. Dynamic Shear Rheometer (DSR) (AASHTO TP5)
Asphalt Behavior depends on both loading time and
temperature and this test evaluates both effects
measures rheological properties
 complex shear modulus
 phase angle
 intermediate to high temperatures
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31. Dynamic Shear Rheometer (DSR)
 used to characterize both elastic and viscous behavior
 G* (G star) complex shear modulus
 measures the total resistance of the asphalt to deformation
 elastic component (recoverable deformation)
 viscous component (non-recoverable deformation)
  (delta)
 indicates the relative amounts of recoverable and non-recoverable
deformation
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32. 32

33.  Values of G* and  for asphalts are highly dependant on temperature and
frequency of loading
 High temperatures
 behavior is viscous with no capacity for recovering or rebounding
  = 90°
 Low temperatures
 behavior is elastic witch rebounds from deformation
  = 0°
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34. 34

35. 35

36. 36

37. Dynamic Shear Rheometer (DSR)
Permanent Deformation
G*/sin  at test temperature > 1.00 kPa original binder
G*/sin  at test temperature > 2.20 kPa RTFOT binder
Fatigue Cracking
G* (sin ) at test temperature < 5000 kPa PAV binder
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38. Rotational Viscometer
(ASTM D4402)
 Used to determine the flow
characteristics of the asphalt
binder
 Ensure that the asphalt is
fluid enough to be pumped
and handled at the hot mix
facility
 Measured on the original
asphalt binder
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39. Bending Beam Rheometer (BBR) (AASHTO TP1)
Measures low temperature properties of asphalt that are
too stiff to be measured by the DSR
BBR (stiffness) used in conjunction with the Direct
Tension Test (strength and stretching ability before
breaking)
BBR measures deflection or creep under a constant load
and temperature
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40. Bending Beam Rheometer (BBR)
Test temperatures are related to a pavement’s lowest
service temperature when the asphalt binder acts more
like an elastic solid
PAV asphalt binder
Test measures the performance characteristics of binders
as if they had been exposed to hot mixing and some in-
service aging
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41. 41

42. Bending Beam Rheometer (BBR)
 Applying a constant load (980mN) to the center of the asphalt
beam and measuring the deflection during the 4 minute test creep
stiffness (S) and creep rate (m) can be calculated
 Creep load simulates thermal stresses that gradually build up in a
pavement when temperature drops
 Creep Stiffness (S) resistance of the binder to creep loading and
the m-value is the change in asphalt stiffness with time during
loading
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43. 43

44. 44

45. Bending Beam Rheometer (BBR)
Low temperature cracking
Creep Stiffness (S) @ 60s < = 300 Mpa
S is between 300 to 600 Mpa the Direct Tension
test may be used in lieu of the creep stiffness
requirement
m value (m) @ 60s > = 0.3
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46. Direct Tension Tester (AASHTO TP3)
strong relationship between stiffness of asphalt binders
and the amount of stretching they undergo before
breaking
asphalts that undergo considerable stretching before
failure are called “ductile”
those that break without much stretching are called
“brittle”
it is important that asphalts be capable of a minimal
amount of elongation
46

47. Direct Tension Tester
 typically stiffer asphalts are more brittle and softer asphalts more
ductile
 creep stiffness as measured by the BBR is not adequate enough to
completely characterize the capacity of asphalts to stretch before
breaking
 some asphalts exhibit high creep stiffness but can also stretch farther before
breaking
 therefore SHRP specifications recognize these stiff but ductile
binders
47

48. Direct Tension Tester
 these asphalts are allowed to have high creep stiffness (300 to 600
Mpa) if they can also display reasonable ductile behavior at low
temperatures
 if creep stiffness < 300 Mpa the direct tension test is not required
 PAV asphalt binder
 test measures the performance characteristics of binders as if they
had been exposed to hot mixing and some in-service aging
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49. 49

50. Fatigue
CrackingRutting
RTFO
Short Term AgingNo aging
Construction
[RV]
[DSR]
Low Temp
Cracking
[BBR]
[DTT]
PAV
Long Term Aging
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