Development of a Polymer Wear Surface for a FRP Composite Bridge Deck

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Development of a Polymer Wear Surface for a FRP
Composite Bridge Deck

• D.C. Haeberle, L.A. Harris, J.J. Lesko,
• J.S. Riffle, and T.E. Cousins
• Materials Response Group
• Virginia Tech

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Acknowledgements

• Virginia Transportation Research Council
• Strongwell Corporation
• Landford Brothers Contractors
• Dow Plastics
• Reichhold Chemicals
• Materials Response Group
• Center for Adhesive and Sealant Science
• Adhesive and Sealant Council Education Foundation

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Strongwell Bridge Deck
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Field Application
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Presentation Overview

• Project Description
• Sample Preparation
• Tests Conducted
• Discussion of Results
• Conclusions

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Project Description

• Evaluation of the effects of sample variables on
  the properties of a polymer wear surface produced
  on a pultruded glass-reinforced isophthalic
  polyester surface for bridge deck applications.

Sample Variables
Properties
resin type aggregate size distribution surface
thickness treatments to the composite surface
temperature
strain-to-failure tensile rupture puncture
resistance durability
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Sample Parameters
Strain-to-failure Tensile Rupture Strength
Analysis

• Resins
• Derakane 411-350 Vinyl Ester
• Derakane 8084 Toughened Vinyl Ester
• Aquathane Polyurethane
• Thickness
• 1 Layer (about 1/16 in.)
• 2 Layers (about 3/16 in.)
• 3 Layers (about 5/16 in.)

• Aggregate
• VDOT Silica Sand
• Gap-Graded Quartz
• Fine Quartz
• Surface Treatment
• Acetone wash
• Grit-Blasted
• Temperature
• -40 oC
• 25 oC
• 60 oC

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Sample Components
Aggregate
Polymer Resin
FRP Plate
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Sample Preparation

• Step 1 Perform plate surface preparation
• Step 2 Apply thick coat of polymer resin
• Step 3 Pour aggregate over uncured resin
• Step 4 Allow resin to cure at room temperature
• Step 5 Brush off loose aggregate
• Step 6 Repeat steps 2-5 until for each
  additional layer
• Step 7 Apply a top coat of polymer resin

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Sample Properties
1/16 in.
Layers
3/16 in.
5/16 in.
Ewear surface 1.3 Msi Ecomposite 1.8
Msi Volresin 42
Volaggregate 58
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Percent Conversion of Vinyl Ester
Styrene CC
Methacrylate CC
Methacrylate 83 Conversion Styrene 75
Conversion
16 hr RT
FT-IR Scan Room Temperature, 6 hours
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Tensile Rupture Strength Test

• VTRC test method
• Modified improved for Instron Testing
• 200 psi strength desired

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Tensile Rupture Strength Results
Substrate Failures
Adhesive Failures
Cohesive Failures
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Failed Specimens

• Highly variable results due to brittle nature of
  the material
• Adhesive, Cohesive, and Substrate Failures

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Weigh Station Deck Model Vertical Deflection

• Edge loading
• With deck top plate
• With wearing surface
• L/414 for HS-20
• Max wearing surface strain gt 0.2

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Strain-to-Failure Test

• ASTM D-790 4-point bend test
• Wear surface on the tensile side
• Strain measured with an extensometer mounted to
  wear surface
• gt0.2 strain-to-failure desired

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Strain-to-Failure Results Resin Comparison
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Strain-to-Failure Results Surface Comparison
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Failed SpecimenAcetone Wash

• Crack causes immediate debond of wear surface
  from composite plate
• Brittle fracture behavior observed, cracks
  propagate through resin and aggregate (good
  particle adhesion)

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Failed SpecimenGrit-Blasted

• Crack causes no immediate debond of the wear
  surface from the composite plate
• Crack slowly propagates under the surface veil of
  the composite substrate

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Strain-to-Failure Results Temperature Comparison
Bottom Layer Gap-Graded Quartz Top Layer Fine
Quartz Resin Toughened Vinyl Ester
Standard Aggregate
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DMA Results

• Tg greater than 60 oC in all cases
• Failure Strain differences must be a result of
  stresses developed from CTE mismatch

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Conclusions

• Toughened vinyl ester provides 30 higher
  strain-to-failure but 90 less adhesion to the
  composite surface (acetone washed)
• Grit-blasting essential for required adhesion and
  prevention of catastrophic debonding upon surface
  fracture
• Smooth round aggregate provides higher
  strain-to-failure than the sharp quartz aggregate

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Troutville Weigh Station
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Preliminary Nanoindentation of a Composite Fiber
Indent 12 mN
10 mm

• Pultruded Vinyl Ester Matrix/Carbon Fiber/G
  Fiber Sizing
• Digital Instruments Nanoscope with Hysitron
  Indentor

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Load - Deflection Curve
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UV Testing Strategy

• Outdoor/Indoor Exposure of Low Cost Vinyl Ester
  Matrix Composites
• Determine if a Relationship between Indoor and
  Outdoor Exposure Exists and Develop that
  Relationship
• Determine the Effects of Exposure on Tensile
  Strength

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UV Exposure Equipment
Drum Diameter 16 inches Speed 3 RPM
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Sunlight Spectra
February 7, 2000
Integration time 10 msec
1030 am 1230 pm 230 pm
Intensity (counts)
Wavelength (nm)
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Current Work in the Development and
Implementation of Low Cost Composites for
Infrastructure Applications

• David Haeberle
• MRG Group Meeting
• February 17, 2000