Maximum Load on a Plastic Sheet

In summary, the conversation is about using a sheet of HDPE as a slide bearing between a concrete footing and a column to allow for thermal expansion. The question is how to determine if the HDPE will be crushed by the weight of the column and if it is not strong enough, what alternative material could be used. The discussion also mentions the possibility of using Teflon or UHMW Polyethylene, with a lower coefficient of friction, and the compressive strength of UHMW being 3000 psi. The question remains if the pressure from a load is comparable to compressive stress.
  • #1
jamesm
9
0
I am going to attempt to use a sheet of HDPE betwen 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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  • #2
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?
 
  • #3
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.
 

1. What is the maximum load that a plastic sheet can bear?

The maximum load that a plastic sheet can bear varies depending on the type of plastic, its thickness, and the conditions under which it is loaded. It is important to consult with the manufacturer or conduct tests to determine the specific maximum load for a particular plastic sheet.

2. How is the maximum load on a plastic sheet determined?

The maximum load on a plastic sheet is determined through testing and analysis. Standardized tests, such as ASTM D638, are used to measure the tensile strength and yield point of the plastic. These values are then used to calculate the maximum load that the sheet can bear without breaking or deforming.

3. What factors can affect the maximum load on a plastic sheet?

The maximum load on a plastic sheet can be affected by various factors including temperature, humidity, and exposure to chemicals. The type of loading, whether it is tension, compression, or bending, can also impact the maximum load. Additionally, the manufacturing process and quality of the plastic sheet can play a role in its maximum load capacity.

4. Can the maximum load on a plastic sheet be increased?

Yes, the maximum load on a plastic sheet can be increased by using a thicker sheet or a different type of plastic with higher strength properties. Reinforcements such as fibers or fillers can also increase the load-bearing capacity of a plastic sheet. Additionally, proper design and support can help distribute the load and prevent failure of the sheet.

5. What are the safety considerations when determining the maximum load on a plastic sheet?

When determining the maximum load on a plastic sheet, it is important to consider safety factors such as the intended use of the sheet, the expected load during use, and potential hazards that could cause the sheet to fail. It is important to always stay within the recommended maximum load and to regularly inspect the sheet for any signs of damage or wear that could compromise its load-bearing capacity.

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