Temperature Susceptibility

Performance Grade (PG) binder selection, aging protocols, and climate-based grading per AASHTO M332 / R29

🌡️

PG Binder Grading System

High/low temperature performance grades with traffic and climate adjustment

PG 58-22

High: 58°C / Low: -22°C

Climate: Standard / Mild
Traffic: < 10M ESALs
Region: Northern US, Canada
Rutting: G*/sinδ ≥ 1.0 kPa

PG 64-22

High: 64°C / Low: -22°C

Climate: Warm
Traffic: 10-30M ESALs
Region: Central US, Europe
Rutting: G*/sinδ ≥ 1.0 kPa

PG 70-22

High: 70°C / Low: -22°C

Climate: Hot
Traffic: > 30M ESALs
Region: Southern US, Desert
Rutting: G*/sinδ ≥ 1.0 kPa

PG 76-22

High: 76°C / Low: -22°C

Climate: Extreme Heat
Traffic: Very Heavy + Slow
Region: Phoenix, Middle East
Rutting: G*/sinδ ≥ 2.2 kPa

PG 58-28

High: 58°C / Low: -28°C

Climate: Cold Standard
Traffic: < 10M ESALs
Region: Northern Tier, Alaska
Cracking: S × m ≤ 180

PG 64-28

High: 64°C / Low: -28°C

Climate: Cold Warm
Traffic: 10-30M ESALs
Region: Upper Midwest, Canada
Cracking: S × m ≤ 180

Original Binder (Tank)

G*/sinδ @ 10 rad/s: ≥ 1.0 kPa (rutting)
Test Temp: PG High Grade
Flash Point: ≥ 230°C
Viscosity @ 135°C: ≤ 3 Pa·s (pumping)

RTFO Aged (Construction)

Mass Loss: ≤ 1.00%
G*/sinδ @ 10 rad/s: ≥ 2.2 kPa (rutting)
Test Temp: PG High Grade
Simulates: Mixing/Construction

PAV Aged (In-Service)

G*×sinδ @ 10 rad/s: ≤ 5000 kPa (fatigue)
Stiffness @ 60s: ≤ 300 MPa (creep)
m-value @ 60s: ≥ 0.300 (relaxation)
Test Temp: PG Intermediate

Climate-Based PG Selection (LTPPBind)

Seattle, WA / Vancouver, BC

PG 58-22

Marine, mild temps

Denver, CO / Salt Lake City, UT

PG 64-28

High altitude, wide range

Atlanta, GA / Dallas, TX

PG 64-22

Humid subtropical

Phoenix, AZ / Las Vegas, NV

PG 70-22 / 76-22

Desert extreme heat

Minneapolis, MN / Winnipeg, MB

PG 58-34 / 58-40

Severe cold

Miami, FL / Houston, TX

PG 67-22

Hot humid, no freeze

PG Grade Adjustment Rules

Traffic speed: Slow/standing → bump high grade +1 (e.g., 64→70)
Traffic volume: >30M ESALs → bump high grade +1
Traffic volume: >10M ESALs → bump high grade +1 (if slow)
Climate reliability: 98% reliability standard (vs 50% for old AC grading)
Polymer-modified binders: Use PG Plus grades (e.g., PG 76-22 PM)
MSCR (AASHTO T350): J_nr at 3.2 kPa for rutting verification
ΔTc (AASHTO T313): Cracking susceptibility check for modified binders
R-value correlation: PG grade correlates with Marshall R-value for mix design

← Back to Asphalt & Marshall