Optimizing the Durability and Functionality of PFC Surfaces
Don WatsonTest Track Sponsor MeetingMay 11, 2011
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Objective• Durability Issues–Raveling–Crack Resistance
• Functionality Issues–Permeability– Smoothness– Structural Value
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–Raveling–Crack Resistance
Durability Issues
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4
Raveling
Change in Texture with Traffic
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1.00
1.10
1.20
1.30
1.40
1.50
1.60
1.70
0.00 2.00 4.00 6.00 8.00 10.00
Text
ure
Dept
h (m
m)
ESALs (Million)
N1
N2
N13
S3
S4
S8
Crack Resistance
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PFC Surface Cracks (Tack Method)
• 2006 crack susceptible dense Superpave mix– Surface cracks after 1.9M ESALs (Rehab at 5.6M)
• 2009 PFC surface placed with conventional tack– Surface cracks after 2.2M (cracking/pumping at 8.2M)
• 2009 bonded PFC surface placed with spray paver– Surface cracks after 4.1M (looks good at 8.2M)
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OGFC Surface Cracks (Tack Method)
Conventional Tack
Bonded
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5/2/2011 Crack Maps (N2 / N1)
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–Permeability– Smoothness– Structural Value
Functionality Issues
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Permeability
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Same Mix Drains Better at 1¼”
N1 - ¾”Bonded
N2 - ¾”Tacked
S8 - 1¼”Tacked
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Smoothness
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Change in Smoothness with Traffic
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50.0
60.0
70.0
80.0
90.0
100.0
110.0
120.0
130.0
0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00
IRI (
in/m
i)
ESALs (Millions)
N1
N2
N13
S3
S4
S8
Structural Value
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Structural Contribution of OGFC
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Similar Rutting Performance
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Similar Strain Response
50% RAP
Virgin Mixes
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Questions??
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