Fw: [TowerTalk] Rebar

K7LXC@aol.com K7LXC@aol.com
Fri, 21 Jan 2000 17:02:37 EST


In a message dated 00-01-21 16:16:40 EST, thomas@cybrzn.com writes:

> I have a hard time believing that the steel in a concrete tower base is not
>  structural. Why do engineers specify lots of steel in foundation walls,
>  bridge piers, etc? They are also below grade. Controlling shrinkage in
>  concrete is done by controlling the amount of water in the mix-the higher
>  the slump, the more shrinkage you will get.

     Well, I'm not an engineer. Here's a comment from a real PE in regard to 
this:

>> It really depends on the shape of the foundation. If it is more like a
plate, i.e., larger in plan than in depth then the rebar is actually
structrual due the bending induced in the foundation by the soil pressure.
However if it is square or large indepth versus plan I can understand how
the reinforcing would be more likely to be for shrinkage and temperature
control than for bending or shear strength. >>

      So I guess it depends on several factors. In the case of my tower base, 
it was deeper than it was square so in this case the rebar function was 
primarily for shrinkage.

Cheers,   Steve     K7LXC
Tower Tech

--
FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm