Application of High Performance Materials to Bridges

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Application of High Performance Materials to
Bridges

• Strength Evaluation of MMFX
• By Judd Galloway
• Advisor Professor Michael J Chajes
• Chair of the CE Dept.
• University of Delaware
• Funded by NSF - REU

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Outline

• Introduction
• Test Methods
• Results
• Conclusions
• Recommendations for Future Research

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Introduction Development of MMFX

• A new microcomposite steel reinforcement
• Corrosion Resistant (75 yr)
• Stronger (110ksi)
• Ductile Failure mode

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Introduction to MMFX
Corroded rebar in Bridge Decks
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Introduction Research FocusStrength Evaluation
Composite Behavior

• From Bridge Decks to Floor Beams and Girders

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Test Methods Strength Testing

• Tensile Test
• Generate a stress vs. strain diagram
• Flexure Test
• Reinforced Concrete Beams
• MMFX, Clad, Normal (A615)

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Test Methods Beam Design
Resulted in 4 in. x 6in. x 60 in (5ft) beams
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Test Methods Beam Design

• Beam reinforcement
• 1 6 stainless steel clad rebar
• 1 6 normal A615 steel rebar
• 1 6 MMFX rebar
• 3 4 MMFX rebar
• 1 4 A615 rebar

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Test Methods 3 point bending
All specimens were monotically loaded to failure
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Test Methods Tensile Test
MMFX
A615
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Test Methods Concrete Strength

• Compression testing

average fc 6000 psi
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Results Tensile Test
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Results Tensile Test
MMFX
fy 153.5 ksi
Stress (ksi)
fy 61.2 ksi
A615
Strain ()
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Graph of the Load vs. Strain generated from 3
point bending tests of reinforced concrete beams
MMFX design yield line strain 3800
MMFX experimental yield line strain 3100
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Results 3 point bending
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Conclusions

• More evaluation of test data needs to be
  conducted
• MMFX is stronger in tension and in flexure than
  A615
• Direct substitutions of MMFX for A615 is not
  recommended
• The yield stress and ultimate stress in concrete
  beams reinforced with MMFX might be significantly
  different.

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Future Research

• More Tensile and Strength Testing
• Investigate the magnetism as a means of
  non-destructive evaluation

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Acknowledgements

• Thanks to Gary Wenczel and Danny Richardson
• Thanks to Dr. Chajes
• The End