HMA Bond Research

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HMA Bond Research

• Update of Field Sampling/Testing
• tack versus no-tack on milled surfaces
• Laboratory test of tacking materials
• Most common tack materials
• Average recommended application rate
• Planned activities

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Test Methods
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Shear (Milled Surfaces)
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Tension (Milled Surfaces)
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Tack Material Lab Comparison

• 3 most commonly used tack materials
• Prepare original surface specimen in SGC and
  age with sandblasting
• Condition original surface (50-deg C)
• Apply Tack at 0.075 gal/sy (2.75 gm/4-inch
  specimen)
• Apply new overlay in SGC
• Cure overnight room temp
• Test for shear and tensile strength
• 5 shear/5 tension per material

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Relative Material Strength
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Planned Activity

• Bond for milled surfaces
• Final report March 2009
• Common tacking materials (laboratory)
• Low limit application (.05 gal/sy undiluted)
• High limit application (.15 gal/sy undiluted)
• Field Performance Test
• Torque shear device development

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Low-Noise Pavement

• Rte 234 Manassas
• Superior Pavt Corp.
• 9.5 mm PFC 1-in. thickness
• Ride Testing (Prel.)
• 41 in/mi IRI (47.5 avg. improvement)
• Noise Testing ? early November