Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: Question Regarding Wire Mesh for Column Stirrups

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Bill:

You are right on point, except I believe that you have a little typo in
that I believe that you wanted section 7.10.5.1 instead of 7.10.5.2 (I
shall await your errata <grin>).

You are also correct that section 7.10.5.3 will cause some grief if WWR is
used.  There would certainly be some situations where WWR could not be
used due to "crossing interferance".  A good example would be shown in
Figure R21.4.4 of ACI 318-02.  But you can still get some larger
rectangular columns with WWR, depending on how you configure the
reinforcement.  An example of one that could still be done with WWR that
would be larger than 16 inches on both sides is illustrated by Figure
R7.10.5 in ACI 318-02.  Note that the figures are the same in ACI 318-99.

Regards,

Scott
Adrian, MI


On Fri, 19 Nov 2004, Bill Polhemus wrote:

> refugio rochin wrote:
>
> >Dear Association,
> >
> >We are looking at a building here in Tortola, where the engineer of
> >record has decided to use wire mesh for column stirrups. ??
> >
> >As an independent check, we need to validate its use or choose otherwise.
> >
> >Anyone ever used wire mesh for column stirrups, and found it a valid choice??!
> >
> >
>
> FWIW, lateral reinforcement for columns are officially called "ties."
> "Stirrups" are for shear reinforcement in beams.
>
> I just reviewed the requirements of ACI 318-99 Section 7.10.5.
>
> 7.10.5.2 states "All nonprestressed bars shall be enclosed by lateral
> ties at least No. 3 in size for longitudinal bars No. 10 or smaller, and
> at least No. 4 in size for No. 11 [and greater]. .. DEFORMED WIRE OR
> WELDED WIRE FABRIC OF EQUIVALENT AREA SHALL BE PERMITTED."
>
> The problem I'd have is, if you've got a column of any appreciable size
> with multiple longitudinal bars across a face, how would you place
> "hairpin"-type reinforcing? It seems to me that as a practical matter,
> you would be limited in the size of a rectangular column for which you
> could practically use WWR as tie steel because of the requirements of
> 7.10.5.3.
>
> It seems to me that, practically speaking, you could use WWR as tie
> stell only for a rectangular column with a maximum dimension of any face
> ~16 inches. I suppose that any circular column could be used (or, come
> to think of it, any rectangular column with radially spaced
> reinforcement at a single radius).
>
> Irregularly-shaped columns (not rectilinear, at any rate) would be
> impractical.
>
> You could use a combination of WWR for "wrapping" the entire cage, and
> rebar for the "hairpins." Not sure if that would be of benefit or not.
>
> Sorry for the long-winded answer. I was trying to qualify my response
> without knowing specifically what your design considerations are.
>
> HTH.
>
> Bill Polhemus, P.E.
> Polhemus Engineering Company
> Katy, Texas USA
>
> ******* ****** ******* ******** ******* ******* ******* ***
> *   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
> *
> *   This email was sent to you via Structural Engineers
> *   Association of Southern California (SEAOSC) server. To
> *   subscribe (no fee) or UnSubscribe, please go to:
> *
> *   http://www.seaint.org/sealist1.asp
> *
> *   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you
> *   send to the list is public domain and may be re-posted
> *   without your permission. Make sure you visit our web
> *   site at: http://www.seaint.org
> ******* ****** ****** ****** ******* ****** ****** ********
>

******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
* 
*   This email was sent to you via Structural Engineers 
*   Association of Southern California (SEAOSC) server. To 
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you 
*   send to the list is public domain and may be re-posted 
*   without your permission. Make sure you visit our web 
*   site at: http://www.seaint.org 
******* ****** ****** ****** ******* ****** ****** ********