husky asphalt 1-2-3’s of pgac calgary presentation august 14, 2006
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HUSKY ASPHALT
1-2-3’s of PGAC1-2-3’s of PGACCalgary PresentationCalgary Presentation
August 14, 2006August 14, 2006
HUSKY ASPHALT
Properties of AsphaltProperties of Asphalt
• Critical conditions during construction and service– Construction:
• mixing
• spreading appropriate viscosity
• compacting
– Service:
• plastic deformation (rutting)
• fatigue cracking
• thermal cracking
HUSKY ASPHALT
Specifications of Paving AsphaltsSpecifications of Paving Asphalts
• The role of specifications:– specify properties that directly reflect asphalt
behaviour– express these properties in physical units– provide information from which the service
performance can be predicted– establish limits for those properties to exclude
poor performing products
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Canadian Federal SpecificationCanadian Federal Specification
Penetration at 25°C [dmm]
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Superpave PG SpecificationSuperpave PG Specification
• Superpave specification attempts to measure properties that are directly related to pavement field performance
Handling Pump
Permanent Deformation
FatigueCracking
ThermalCracking
Flow
Rutting
Structural Cracking
Low Temp Cracking
Rotational Viscometer
Dynamic Shear Rheometer
Bending Beam RheometerDirect Tension Tester
TEST EQUIPMENTPERFORMANCE PROPERTY
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Superpave Asphalt Binder Superpave Asphalt Binder SpecificationSpecification
PG 58 - 31
Performance Grade
Average 7-day Max pavement temperature
Min pavement temperature
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Performance Grade Performance Grade Specifications Specifications
– PGAC specifications explicitly quantify the binder performance at actual in-service pavement temperatures
– PGAC specifications explicitly consider the in-service aging characteristics of the binder once it is placed on the road
– PGAC specifications contain formal protocols for addressing in-service traffic conditions
– PGAC specifications explicitly accommodate the concept of reliability
– PGAC specifications can be used to specify (high performance) modified binder systems
HUSKY ASPHALT
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) (ROLLING THIN FILM OVEN) RTFO RTFO Mass Loss Mass Loss << 1.00 %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) (PRESSURE AGING VESSEL) PAVPAV
ORIGINALORIGINAL
> 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
PPerformance erformance GGradesrades
(Dynamic Shear Rheometer) DSR G*/sin
(Dynamic Shear Rheometer) DSR G*/sin
< 3 Pa.s @ 135 oC
> 230 oC
CEC
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) (ROLLING THIN FILM OVEN) RTFO RTFO Mass Loss Mass Loss << 1.00 % 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) (PRESSURE AGING VESSEL) PAVPAV
ORIGINALORIGINAL
< 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
How the PG Spec WorksHow the PG Spec Works
(Dynamic Shear Rheometer) DSR G*/sin
(Dynamic Shear Rheometer) DSR G*/sin
< 3 Pa.s @ 135 oC
> 230 oC
CEC
58 64
Test TemperatureTest TemperatureChangesChanges
Spec RequirementSpec RequirementRemains ConstantRemains Constant
> 1.00 kPa
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) (ROLLING THIN FILM OVEN) RTFO RTFO Mass Loss Mass Loss << 1.00 % 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) (PRESSURE AGING VESSEL) PAVPAV
ORIGINALORIGINAL
< 5000 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
Permanent DeformationPermanent Deformation
(Dynamic Shear Rheometer) DSR G*/sin
(Dynamic Shear Rheometer) DSR G*/sin
< 3 Pa.s @ 135 oC
> 230 oC
CEC
> 1.00 kPa
> 2.20 kPa
•UnagedUnaged•RTFO AgedRTFO Aged
Permanent Deformation
Question: Why a minimum G*/sin to address rutting
Answer: We want a stiff, elastic binder to contribute to mix rutting resistance
How: By increasing G* or decreasing
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) (ROLLING THIN FILM OVEN) RTFO RTFO Mass Loss Mass Loss << 1.00 % 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) (PRESSURE AGING VESSEL) PAVPAV
ORIGINALORIGINAL
> 1.00 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
Fatigue Cracking
(Dynamic Shear Rheometer) DSR G*/sin
(Dynamic Shear Rheometer) DSR G*/sin
< 3 Pa.s @ 135 oC
> 230 oC
CEC
< 5000 kPa PAV AgedPAV Aged
Fatigue Cracking
Question: Why a maximum G* sin to address fatigue?
Answer: We want a soft elastic binder (to sustain many loads without cracking)
How: By decreasing G* or decreasing
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
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
Low Temperature Cracking
(Dynamic Shear Rheometer) DSR G*/sin
(Dynamic Shear Rheometer) DSR G*/sin
< 3 Pa.s @ 135 oC
> 230 oC
CEC
S < 300 MPa m > 0.300
Report Value
> 1.00 %
PAV Aged
PAV Aged
Low Temperature Cracking
Question: Why a maximum S value and
minimum m and ƒ values to address low temperature cracking?Answer: We want a soft, creep stiffness relaxing, ductile binder
How: By decreasing S or increasing the m and
ƒ values.
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
Miscellaneous Spec Requirements
(Dynamic Shear Rheometer) DSR G*/sin
(Dynamic Shear Rheometer) DSR G*/sin
CEC
< 3 Pa.s @ 135 oC
> 230 oC
FlashPoint
MassLoss
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Low Temperature Cracking M320M320--05 05 Table 2Table 2
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Performance Grade Performance Grade SpecificationsSpecifications
• Husky supports the use and the specification for Performance Graded Asphalt Cements (PGAC) as written in AASHTO M320-05 Table 1 (MP1) and Table 2 (MP1A).– No adjustment to spec limits (BBR S m DSR
G*/sin δ values) – No additional PG + Specifications– PGAC specifications are based on the science of
rheology, the study of stress and strain and not a consistency measurement such as penetration
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PGAC Selection ProcessPGAC Selection Process
Weather Database
PAVEMENT DESIGN TEMPERATURES -> (HT, LT)
Grade Selection Matrix
“ENVIRONMENTAL”GRADE -> PG HT-LT
Grade Bumping Protocol(HT Only)
“DESIGN”GRADE -> PG HT-LT
Practical Design Considerations
Special Design Considerations
1. Pavement Design Temperatures2. PGAC Environmental Grade3. PGAC “Design” Grade
PG HT-LT
< L
TP
PB
ind
v2
.1 >
< M
an
ual C
alc
ula
tio
ns >
Specify Site
Reliability, HT Reliability, LTDepth (mm)
Select Model
Pavement Temperature Models
Air Temperatures
•Availability•Storage & Handling•Cost vs, Reliability
1
2
3
A
B
STEP
STEP
STEP
Consid
erat
ion
Consid
eratio
n
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Determining Pavement Determining Pavement Design TemperaturesDesign Temperatures
• Starting with the Climatic Data
• It is important for practitioners to:• look at several sites near your design location, • understand the nature of the weather data for
each site, and • apply proper engineering judgment as to
which data set(s) are most applicable to your specific design situation.
“The best weather station may not necessarily be the closest weather station”
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Determining Pavement Determining Pavement Design TemperaturesDesign Temperatures
• For each weather station: – the hottest seven-day period was identified
and the average maximum air temperature (for this seven-day period) was computed and used to define the hot temperature design condition, and
– the one-day minimum air temperature was used to define the cold temperature design condition.
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Determining Pavement Determining Pavement Design TemperaturesDesign Temperatures
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Determining Pavement Determining Pavement Design TemperaturesDesign Temperatures
• Converting Climate Data into Pavement Temperatures– Most practioners in western Canada support the
use of the LTPP High Pavement Temperature Model coded into LTPPBind V2.1, July 1999
• More conservative than the SHRP High Pavement Temperature model
– Most practioners in western Canada support the use of the Revised Low Pavement Temperature Model in TAC Technical Brief #15, October 1998
• Superior correlation to observed field measurements at select Canadian sites
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Determining Pavement Design Determining Pavement Design TemperaturesTemperatures
• Converting Climate Data into Pavement Temperatures– LTPPBind 2.1 does not support the TAC
model – LTPPBind 2.1 has aggressive grade bumping
protocols (KMC,SHRP)
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Determining Pavement Determining Pavement Design TemperaturesDesign Temperatures
• Specifying Reliability– Explicitly Considering Risk– Reliability is defined as the percent probability,
in a single year, that the actual temperature (one-day low or seven-day average high) will not exceed the design temperature
“A higher level of reliability means a
lower level of risk”
HUSKY ASPHALT
Determining Pavement Determining Pavement Design TemperaturesDesign Temperatures
• Specifying Reliability – Explicitly Considering Risk– Level of reliability is a function of the
application• Is this a major highway or low volume road?• What is the implication of a failure?• Reliability must be consistent with Owner Agency
policy.– Reliability of the high temperature grade can
be different for the low temperature– Husky supports a high level of reliability (99%)
on the high temperature• Rutting leading to safety issues i.e. Hydroplaning• In addition to LTPP High Pvm’t Temperature model
HUSKY ASPHALT
Determining Pavement Determining Pavement Design TemperaturesDesign Temperatures
• Specifying Reliability – Explicitly Considering Risk– Husky supports a moderate level (90%) for low
pavement temperature • Failure modes like cracking are a performance cost/
issue and therefore must be set within the context of life cycle cost considerations.
– Consider using 99% reliability on the high temperature and 90% reliability for the low temperature
• Then adjust your reliability thresholds to be consistent with Owner/Agency policy and suit your site specific design requirements and project economics
• Provides reasonable environmental grades for most sites across western Canada
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Determining PGAC Determining PGAC Environmental GradeEnvironmental Grade
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Determining Pavement Determining Pavement Design GradeDesign Grade
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Determining Pavement Determining Pavement Design TemperaturesDesign Temperatures
Pavement PG design grade is determined by:
1) climatic statistics of the design site,
2) the pavement temperature model selected,
3) the design reliability,
4) high temperature grade bumping protocol,
HUSKY ASPHALT
Determining PGAC Determining PGAC Environmental GradeEnvironmental Grade
• Grade Selection Matrix-Customized for Western Canada– Husky supports the splitting of the low
temperature grade into 3 C intervals• The splitting of grades allow you to spec the actual
performance that has been provided by CGSB graded asphalts in western Canada (SGS and Cold Lake crudes)
• PG 64-25 (80/100A)• PG 58-31 (120/150A)• PG 52-34 (200/300A)• PG 46-37 (300/400A)
HUSKY ASPHALT
Determining PGAC Determining PGAC Environmental GradeEnvironmental Grade
• Grade Selection Matrix-Customized for Western Canada– Husky supports the splitting of the low
temperature grade into 3 C intervals• The slope of the straight run PG grading curve
indicates the high temperature grade increases 1.4 C for every 1 C decrease (worsening) in the low temperature grade
• Depending on the project site, modification in 3 C increments on the low temperature will save costs. May achieve the desired reliability at -37 C instead of -40 C.
HUSKY ASPHALT
Determining PGAC Determining PGAC Environmental GradeEnvironmental Grade
• Recommended Grade Selection Matrix-Customized for Western Canada– 16 potential grades for western Canada
• Production and inventory considerations• Some grades are redundant in that the lowest
quality straight run asphalt exceeds them• Some grades are too expensive to be practical• Some modified grades can be consolidated into
higher grades with similar cost structures– Maximize grade availability to maximize
design flexibility– Minimize grade availability to limit grade
proliferation
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Determining PGAC Determining PGAC Environmental GradeEnvironmental Grade
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PGAC Calgary, AlbertaPGAC Calgary, Alberta
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PGAC Calgary, AlbertaPGAC Calgary, Alberta
Weather Database
PAVEMENT DESIGN TEMPERATURES -> (HT, LT)
Grade Selection Matrix
“ENVIRONMENTAL”GRADE -> PG HT-LT
Grade Bumping Protocol(HT Only)
“DESIGN”GRADE -> PG HT-LT
Practical Design Considerations
Special Design Considerations
1. Pavement Design Temperatures2. PGAC Environmental Grade3. PGAC “Design” Grade
PG HT-LT
< L
TP
PB
ind
v2
.1 >
< M
an
ual C
alc
ula
tion
s >
Specify Site
Reliability, HT Reliability, LTDepth (mm)
Select Model
Pavement Temperature Models
Air Temperatures
•Availability•Storage & Handling•Cost vs, Reliability
1
2
3
A
B
STEP
STEP
STEP
HUSKY ASPHALT
PGAC Calgary, Alberta PGAC Calgary, Alberta
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PGAC Calgary, AlbertaPGAC Calgary, Alberta
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PGAC Calgary, AlbertaPGAC Calgary, Alberta
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PGAC Calgary, AlbertaPGAC Calgary, Alberta
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PGAC Calgary, AlbertaPGAC Calgary, Alberta
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PGAC Calgary, AlbertaPGAC Calgary, Alberta
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PGAC Calgary, AlbertaPGAC Calgary, Alberta
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PGAC Calgary, AlbertaPGAC Calgary, Alberta
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PGAC Calgary, AlbertaPGAC Calgary, Alberta
Environmental Grade PG 58-31
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PGAC Calgary, AlbertaPGAC Calgary, Alberta
– Environmental Grade PG 58-31• PG 64-31
– Slow traffic where the average traffic speed is between 20 to 70 km/hr
– Design ESAL’s over 0.3 million
• PG 70-31– Standing traffic where the average traffic speed is less
than 20 km/hr– Design ESAL’s over 0.3 million
HUSKY ASPHALT
Questions ?Questions ?