Wrong. You use a "shell" of not less than 1/2 of the Ag, and then use 1% of
that area as your area of reinforcement.
I have come across this misconception many times among structural engineers,
that the code(s) allow you to "skimp" on the minimum column reinforcement.
This flies in the face of logic since why even mention the 1% of Ag, when
you're going to allow 0.5% for all cases?
"Not less than half of Ag" is appropriate for the "massive pedestal"
situation, but he will have to use 1% of the resulting area, not 0.5%.
> -----Original Message-----
> From: Ed.Haninger(--nospam--at)fluordaniel.com [mailto:Ed.Haninger(--nospam--at)fluordaniel.com]
> Sent: Wednesday, May 26, 1999 11:38 AM
> To: seaint(--nospam--at)seaint.org; Vyacheslav Gordin
> Subject: Re: Reinforcement of massive pedestals
> What I would propose, is that you look at a "shell" of
> concrete that
> will take all the design loads. Maybe the outer 6" would do it.
> Consider this your structural section and use the 0.005
> ratio of steel
> in this area. Leave the remainder of the concrete in
> the middle as
> plain concrete. It is just a filler.
> We have been using much less than the 0.005 ratio for
> years on our
> massive pedestals, with no structural problems or
> building official
> questions that I know of.
That's because you work for Fluor. I used to work for B&R, and that's where
I ran into this mistaken assumption again and again.
That the building official doesn't question it is irrelevant. It is