HUSKY ASPHALT 1-2-3’s of PGAC Calgary Presentation August 14, 2006

HUSKY ASPHALT Properties 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 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

HUSKY ASPHALT Canadian Federal Specification Penetration at 25°C [dmm]

HUSKY ASPHALT Superpave PG Specification Superpave specification attempts to measure properties that are directly related to pavement field performance Handling Pump Permanent Deformation Fatigue Cracking Thermal Cracking Flow Rutting Structural Cracking Low Temp Cracking Rotational Viscometer Dynamic Shear Rheometer Bending Beam Rheometer Direct Tension Tester TEST EQUIPMENT PERFORMANCE PROPERTY

HUSKY ASPHALT Superpave Asphalt Binder Specification PG Performance Grade Average 7-day Max pavement temperature Min pavement temperature

HUSKY ASPHALT Performance Grade 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 (110) 100 (110) 110 (110) (Flash Point) FP (ROLLING THIN FILM OVEN) RTFO Mass Loss < 1.00 % (Direct Tension) DT (Bending Beam Rheometer) BBR Physical Hardening Avg 7-day Max, o C 1-day Min, o C (PRESSURE AGING VESSEL) PAV ORIGINAL < 5000 kPa > 2.20 kPa S < 300 MPam > Report Value > 1.00 % 20 Hours, 2.07 MPa (Dynamic Shear Rheometer) DSR G* sin  ( Bending Beam Rheometer) BBR “S” Stiffness & “m” - value How the PG Spec Works (Dynamic Shear Rheometer) DSR G*/sin  < 3 Pa. 135 o C > 230 o C CEC 5864 Test Temperature Changes Spec Requirement Remains Constant > 1.00 kPa

PG 46 PG 52 PG 58 PG 64 PG 70 PG 76 PG 82 (Rotational Viscosity) RV (110) 100 (110) 110 (110) (Flash Point) FP (ROLLING THIN FILM OVEN) RTFO Mass Loss < 1.00 % (Direct Tension) DT (Bending Beam Rheometer) BBR Physical Hardening Avg 7-day Max, o C 1-day Min, o C (PRESSURE AGING VESSEL) PAV ORIGINAL < 5000 kPa S < 300 MPam > Report Value > 1.00 % 20 Hours, 2.07 MPa (Dynamic Shear Rheometer) DSR G* sin  ( Bending Beam Rheometer) BBR “S” Stiffness & “m” - value Permanent Deformation (Dynamic Shear Rheometer) DSR G*/sin  < 3 Pa. 135 o C > 230 o C 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 (110) 100 (110) 110 (110) (Flash Point) FP (ROLLING THIN FILM OVEN) RTFO Mass Loss < 1.00 % (Direct Tension) DT (Bending Beam Rheometer) BBR Physical Hardening Avg 7-day Max, o C 1-day Min, o C (PRESSURE AGING VESSEL) PAV ORIGINAL > 1.00 kPa > 2.20 kPa S < 300 MPam > Report Value > 1.00 % 20 Hours, 2.07 MPa (Dynamic Shear Rheometer) DSR G* sin  ( Bending Beam Rheometer) BBR “S” Stiffness & “m” - value Fatigue Cracking (Dynamic Shear Rheometer) DSR G*/sin  < 3 Pa. 135 o C > 230 o C CEC < 5000 kPa PAV 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 (110) 100 (110) 110 (110) (Flash Point) FP (ROLLING THIN FILM OVEN) RTFO Mass Loss < 1.00 % (Direct Tension) DT (Bending Beam Rheometer) BBR Physical Hardening Avg 7-day Max, o C 1-day Min, o C (PRESSURE AGING VESSEL) PAV ORIGINAL > 1.00 kPa < 5000 kPa > 2.20 kPa 20 Hours, 2.07 MPa (Dynamic Shear Rheometer) DSR G* sin  ( Bending Beam Rheometer) BBR “S” Stiffness & “m” - value Low Temperature Cracking (Dynamic Shear Rheometer) DSR G*/sin  < 3 Pa. 135 o C > 230 o C CEC S < 300 MPam > Report Value > 1.00 % 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 (110) 100 (110) 110 (110) (Flash Point) FP (ROLLING THIN FILM OVEN) RTFO Mass Loss < 1.00 % (Direct Tension) DT (Bending Beam Rheometer) BBR Physical Hardening Avg 7-day Max, o C 1-day Min, o C (PRESSURE AGING VESSEL) PAV ORIGINAL > 1.00 kPa < 5000 kPa > 2.20 kPa S < 300 MPam > Report Value > 1.00 % 20 Hours, 2.07 MPa (Dynamic Shear Rheometer) DSR G* sin  ( Bending Beam Rheometer) BBR “S” Stiffness & “m” - value Miscellaneous Spec Requirements (Dynamic Shear Rheometer) DSR G*/sin  CEC < 3 Pa. 135 o C > 230 o C Flash Point Mass Loss

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Performance Grade Specifications Husky supports the use and the specification for Performance Graded Asphalt Cements (PGAC) as written in AASHTO M 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

HUSKY ASPHALT PGAC Selection Process

HUSKY ASPHALT Determining Pavement Design 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”

HUSKY ASPHALT Determining Pavement Design 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.

HUSKY ASPHALT Determining Pavement Design Temperatures

HUSKY ASPHALT Determining Pavement Design 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

HUSKY ASPHALT Determining Pavement Design Temperatures 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)

HUSKY ASPHALT Determining Pavement Design 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 Design 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 Design 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

HUSKY ASPHALT Determining PGAC Environmental Grade

HUSKY ASPHALT Determining Pavement Design Grade

HUSKY ASPHALT Determining Pavement Design 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 Environmental 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 (80/100A) PG (120/150A) PG (200/300A) PG (300/400A)

HUSKY ASPHALT Determining PGAC Environmental 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 Environmental 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

HUSKY ASPHALT Determining PGAC Environmental Grade

HUSKY ASPHALT PGAC Calgary, Alberta

HUSKY ASPHALT PGAC Calgary, Alberta

HUSKY ASPHALT PGAC Calgary, Alberta

HUSKY ASPHALT PGAC Calgary, Alberta

HUSKY ASPHALT PGAC Calgary, Alberta

HUSKY ASPHALT PGAC Calgary, Alberta

HUSKY ASPHALT PGAC Calgary, Alberta

HUSKY ASPHALT PGAC Calgary, Alberta

HUSKY ASPHALT PGAC Calgary, Alberta

HUSKY ASPHALT PGAC Calgary, Alberta

HUSKY ASPHALT PGAC Calgary, Alberta Environmental Grade PG 58-31

HUSKY ASPHALT PGAC Calgary, Alberta –Environmental Grade PG PG –Slow traffic where the average traffic speed is between 20 to 70 km/hr –Design ESAL’s over 0.3 million PG –Standing traffic where the average traffic speed is less than 20 km/hr –Design ESAL’s over 0.3 million

HUSKY ASPHALT Questions ?