Asphalt-Rubber Systems

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Asphalt-Rubber Systems
Types and Uses
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Types
SAM Stress Absorbing Membrane SAMI Stress
Absorbing Membrane Interlayer ARC - DG Asphalt
Rubber Concrete Dense Graded ARC - GG Asphalt
Rubber Concrete Gap Graded ARC - OG Asphalt
Rubber Concrete Open Graded
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SAM - Stress Absorbing Membrane
Pre-existing Pavement
Aka. Chip seal or seal coat
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SAMI - Stress Absorbing Membrane Interlayer
Pre-existing Pavement
AC or ARC Overlay
Also known as a Two Layer System, or an
under-layer.
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SAMI in a three layer system
AC or ARC Overlay
SAMI
Leveling Course
Pre-existing Pavement
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Aggregate Gradation Comparison
Open Graded Gap Graded Dense Graded
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SAM - Where To Use

• Fatigue Cracking
• Little or no cracking
• Satisfactory Ride

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Fatigue Cracking - Townsend Divide
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SAM - Where To Use

• Block Cracking
• generally lt 5 spacing
• seal and fill cracks
• satisfactory ride

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Block Cracking - Ravendale
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SAMI - Where To Use

• Fatigue Cracking
• Ride Improvement Required
• Structural Improvement Required
• Moderate Severity Rutting
• (unless overlay is thick)

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SAMI - Where to Use

• Stabilized Bases
• Improved Ride vs. SAM
• Additional Structural Support
• Swelling Soils
• Reduce Moisture Variation
• Entire Width of Roadbed

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Sami in Northern, AZ
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Block Cracking
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OVERLAY .5 ACFC
1.5 AC MEMBRANE
2.75 AC AZ-MO
LEVELING
ASPHALT RUBBER MEMBRANE
CUT SECTION
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OVERLAY .5 ACFC 1.5 AC
MEMBRANE
2.75 AC AZ-MO
LEVELING
ASPHALT RUBBER MEMBRANE
FILL SECTION
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(No Transcript)
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3 Layer System

• Rough or Faulted Pavements
• Reflective Cracking Stresses are High
• Very Effective on PCC Pavement

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Water Pumping Through Cracks I-40
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Open Graded ARC

• Top Course
• Rehabilitation or New Construction
• Improve Friction (Especially in Wet
• Weather)
• 2 or 3 Layer Systems
• 1 to 1-1/2 Over PCCP
• Flushed or Bleeding Pavement with
• Low Rutting

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I-19 OG Overlay Placed 1988 Valencia Rd Exit
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I-19 OG Overlay Placed 1988 Valencia Rd
Exit Photo taken 03/00
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I-40 Cracked PCCP Flagstaff, AZ 1989
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I-40, 1998 4 Conventional AC (left) 2 AR OGFC
over 2 ARC GG (right) after 8 years service
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AR-OGFC on PCCP, I-17 Phx, AZ Aug 2000
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AR-OGFC on PCCP, I-17 Phx, AZ Aug 2000
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Gap Graded ARC

• Almost Any Cracked Pavement
• Additional Structure is Required
• Top Lift in 2 or 3 Layer Systems
• Bottom Lift in 3 Layer Systems

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Gap Graded Overlay
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Gap Graded Overlay
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Open Graded 1 and 1.5 Gap Graded Overlay US 70
Tennessee
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I40 Open Graded 0.75 over PCCP Cores
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Dense Graded ARC

• New Construction
• Thick Overlay for Structure is Required

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Possum Modified AC