Maximum Load on a Plastic Sheet

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SUMMARY

The discussion focuses on the use of HDPE (High-Density Polyethylene) as a bearing material between a concrete footing and a column to accommodate thermal expansion. The column exerts a pressure of approximately 140 psi, while HDPE has a tensile strength of 4,000 psi and a Rockwell hardness of Shore D60-68. Concerns were raised about whether HDPE would be crushed under this load, leading to the consideration of alternatives such as Teflon or UHMW (Ultra-High-Molecular-Weight) Polyethylene, which has a compressive strength of 3,000 psi and is expected to handle the 150 psi exerted by the column.

PREREQUISITES
  • Understanding of material properties, specifically tensile and compressive strength.
  • Knowledge of thermal expansion in structural engineering.
  • Familiarity with bearing materials and their applications in construction.
  • Basic principles of load distribution and pressure calculations.
NEXT STEPS
  • Research the mechanical properties of Teflon as a bearing material.
  • Investigate the long-term performance of UHMW Polyethylene under compressive loads.
  • Learn about the effects of thermal expansion on structural integrity.
  • Explore alternative bearing materials suitable for high-load applications.
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Structural engineers, materials scientists, and construction professionals involved in designing load-bearing structures and selecting appropriate materials for thermal expansion management.

jamesm
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I am going to attempt to use a sheet of HDPE between a concrete footing and the base of a column to allow the column to move with thermal expansion in the structure it is supporting. My question is how can I determine if the HDPE will be crushed by the weight of the column and no longer act as a "bearing". The pressure from the column will be ~140 psi, and the tensile strength of HDPE is 4,000 psi with a Rockwell hardness of [Shore D60-68]. If this material is not strong enough what would be a suitable alternative?
 
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I'm sorry you are not generating any responses at the moment. Is there any additional information you can share with us? Any new findings?
 
If I decide to stick with the slide bearing idea I will probably use Teflon or UHMW Polyethylene since it has a lower coefficient of friction. I did find that the UHMW has a compressive strength of 3000 psi. The pressure that the column exerts on the UHMW will be ~150 psi so I'm thinking it will be fine, but I'm not 100% sure if pressure from a load is comparable to comp stress.

Thanks for following up.
 

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