Ambient Termal stresses in Circular Prestressed Concrete water Tank

[itzka]

I need a detailed updated book or article describing the following :
When a temperature on the exterior of a water concrete tank differs from that on the interior, a temperature gradient will exist in the wall.
The temperature gradient in the wall will produce hoop forces, and circumferential Moments.
I need a complete analysis of that fenomena, including detailed examples

 

[jrmack]

I do not recall any hoop stresses caused by a temperature differential. For the bending moment it is (differential strain caused by temperature/2)*(modulus of elasticity of the concrete)*(section modulus of the concrete). This would be in both directions (horizontal and vertical). This would have to be a substantial temperature difference to really cause a problem, above 20 degrees celcius.

 

[kocos]

Look into the Circular Storage Tanks and Silos by Ghali. It has the answer in details for your question.

 

[tincan]

The Portland Cement Association (PCA) has a good publication "Circular Concrete Tanks w/o Prestressing". There is an example of hoot sterss and circumferential bending moment due to a temperature gradient in the tank wall. You can normally compensate for the normal temperture ranges by increasing the hoop steel 5-10% depencing upon the tank diameter (the bigger the dia the more steel. Ul\nless you have a hot liquid or extreme temperature variations, the additional stresses are not that high.

Best of luck, Tincan