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By: Jim McGraw, Dan Wegman, and Mihai Marasteanu. The Past 50 Years of Asphalt Liquid Asphalts. Simplified Asphalt Options. Naphtha or Kerosene. ASPHALT. Cutbacks. Straight Run Asphalt. Blown Asphalt. Asphalt blower. Hot Air. Emulsions. Water & Emulsifier. Asphalt Cement.
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By: Jim McGraw, Dan Wegman, and Mihai Marasteanu The Past 50 Years of AsphaltLiquid Asphalts
Simplified Asphalt Options Naphtha or Kerosene ASPHALT Cutbacks Straight Run Asphalt Blown Asphalt Asphalt blower Hot Air Emulsions Water & Emulsifier
Asphalt Cement • Asphalts originally “penetration graded” • Penetration at 25°C (77°F) “ambient temperature” • Softer (higher pen) - colder climates • Harder (lower pen) - hotter climates • 85/100, 120/150, 200/300 0 sec 5 sec penetration 100 g 100 g
Penetration Test • Stiffness @ 77 o F • Empirical • No information at high and low temperatures • Same Pen – Different Field Performance
SuperPave Binder Tests-1997 • PG Grading system based on: • Climate (Temperatures in ºC) • Engineering Properties • Traffic speed and load (Grade “Bumping”) • PG 70-28 (158-18°F) (high & low pavement temp)
Pre- SuperPave Testing Equipment Penetration Ductility Viscosity
SuperPave Binder Tests Climate Modulus Creep Stress Strain
Asphalt Certification • Test every load • 1995- Certified Sources-Comparison Testing • 1997-Tri-State • 1998-Combined State Binder Group • MN,WI,IA,MI,ND,SD and Neb
Liquid Asphalt Spec Timeline 1947 • AC-1 Paving • AC-2 Brick Filler • AC-3 Crack Filler • Penetration specified in plans • Penetration,Ductility,5 hour mass loss and spot test
Liquid Asphalt Specifications1947 • Rapid Cure Cutbacks-RC0-5 • MC Cutback • Road Tars
1959 • Emulsions-RS-1,RS-2, MS-2,SS-1 • Powdered Asphalt-crush/grind hard asphalt for surfacing
1964-1968 • 1964 -Cationic Emulsion-rapid set, high and low viscosity grades • 1968- AASHTO Penetration Grades 85/100, 120-150 & Cutback Grades RC-70, MC-250
1968- 1983 • 1968-Additional AE requirements for climate • 1968 eliminated Powdered AC • 1972 –Eliminated spot test • 1983-High Float Emulsions
1988--Present • 1988 eliminated Road Tars • 1997- SuperPave Binder Spec • Polymer Modified Asphalt Binder • 1st SuperPave project- Stearns Co