Quote:
Originally Posted by renormalised
How thick are the walls on that pipe, Al??
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I don't have my tables at home ATM but its about the 5 to 6mm mark. However, the wall thickness is of little concern as the section modulus is proportional to the diameter to 4th power, so there's little difference between two pipes of of different wall thickness but the same outside diameter.
Obviously you don't want a paper thin pipe that has the section modulus but not enough local robustness to stop you poking holes in it with your fingers!
If I was making a concrete pier I'd make it at least 200mm diameter, simply because you want about 30 to 50, of cover over your reo to prevent it rusting, so that only gives about 100 to 140mm between reo bars. Anything smaller than that in concrete is getting impractical IMHO. A steel pier of equivalent stiffness is about 133mm diameter according to my quick calcs... (I hope I haven't made a silly mistake
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Al.