Mechanical Properties of Bamboo

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Mechanical Properties of Bamboo

• By Andrea Carrasco, John Fronda, and Brian
  MacRae.
• Undergraduate Civil Engineering Student Research
  University of Southern California
• Los Angeles, CA 90089-2531

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Discussion Topics

• Background on bamboo
• Preparation and Testing Methods
• Data Analysis
• Discussion of Results
• Conclusion
• Questions and Answers

3
Background on bamboo

• Consists of two parts culms (stem) and the
  rhizome
• Very flexible plant, and rarely snaps in the
  wind.
• Its properties of resilience, shape, and strength
  make it an ideal material for construction.

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Drawbacks of bamboo

• It is not durable against wood degrading
  organisms
• Large percentage of bamboo used for structural
  purposes deteriorate in a couple of years.
• Increased demands of repair and maintenance.

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Preparation and Testing Methods

• Preparation
• Cut specimen to appropriate length
• Apply generous amount of epoxy and attach steel
  plates
• Affix strain gauges to specimens

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Preparation and Testing Methods

• Testing
• Secure each specimen in SATEC machine
• Connect wires to strain gauge boxes
• Apply loads
• Obtain data

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Data Analysis

• Results from wide bamboo with steel plates
  (sample 6) and with two strain gauges
• Outside Tensile Strength15103 psi
• Outside E1.96106 psi

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Data Analysis

• Inside Tensile Strength14811 psi
• Inside E3.17106 psi

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Data Analysis

• Results from narrow bamboo with steel plates
  (sample 10) and one strain gauge
• Outside Tensile Strength11461 psi
• Outside E1.74106 psi

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Data Analysis

• Results from wide bamboo without steel plates
  (sample 5) and one strain gauge
• Outside Tensile Strength1017 psi
• Outside E6.81106 psi

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Discussion of Results

• The data for specimens without steel plates are
  inaccurate and not useful
• Clean breaks and accurate data came from
  specimens with steel plates

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Discussion of Results

• Outside strain is larger than inside
• Inside modulus (E) 1.7 times higher than outside
  (E)
• Ave. inside (E) 2.86106 psi
• Ave. outside (E) 1.68106 psi
• Total Ave. (E) 2.27106 psi
• Ave. tensile strength for narrow samples is 11232
  psi

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Discussion of Results

• Ave. tensile strength for wide samples is 14196
  psi
• (Note Ave. tensile strength values exclude the
  samples with no steel that cracked early and have
  poor results)

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Conclusion

• Accurate data can be obtained by attaching steel
  plates to the specimens or pre-cracking the ends
• 50 of specimens were successful
• The tensile strength and modulus of elasticity is
  much lower than that of steel

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THANK YOU!!!

• QUESTIONS AND ANSWERS