STRESSSTRAIN REALATIONSHIP OF STEEL REBARS

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STRESS-STRAIN REALATIONSHIP OF STEEL REBARS

• YEUK-HIN CHAN
• Emre Gelgin
• Undergraduate Student of Civil Engineering
• University of Southern California, Los Angeles CA

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Introduction

• Why we use rebars in concrete structures?
• Low tensile strength of unreinforced
  concrete (results in limited structural
• applications)
• Bebars high strength, ductility, and
  stiffness impact strength and toughness
• to concrete.

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Objective of the experiment

• To determine the material properties of
  reinforcing steel bars
• e.g. Elastic Modulus, Yield Strength and
  Ultimate Strengths

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Experimental program

• Specimens
• - Three No.5 bars and two No. 2.9 Spirals
• Testing Method
• - A uniaxial tension test
• - using an Universal Testing Machine.
• - EA-06-250BG-120 Strain gauges

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Specimens
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Universal Testing Machine
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One of the specimens just broken
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Stress-Strain relationship
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Experimental Results
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Results compare to ASTM Standard

• The average value of the modulus of elasticity of
  the tested steel is 33,216Ksi. (29,000ksi)
• About 15 error
• All specimens met the Yield Strength requirement
  of ASTM standard.

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Suggestions

• Stopping using the Degreaser Solvent, which
  contains chemicals caused damages of OUR OZONE
  LAYER
• , to clean the surface of the steel bars