Bill Sherman
CH2M HILL / DEN
720-286-2792
> -----Original Message-----
> From: Gil Brock [mailto:gil@raptsoftware.com]
> Sent: Friday, September 04, 2009 2:54 PM
> To: seaint@seaint.org
> Subject: re: bar spacing in a wall
>
> Andrew,
>
> You cannot achieve reasonable crack control with bar spacings
> greater than 18" according to ACI. Other codes have since
> reduced this to 12"
> (Eurocode and AS3600). Wider than that and the crack width
> between the bars is not controlled by the bar. BS8110
> theoretically allows 750mm (30") as an absolute maximum but
> not if you want good crack control for which they give
> reduced values depending on certain factors I cannot remember
> (code is at work). So, yes, it has to do with the Z factor
> and its replacement method.
>
> It has nothing to do with warm and fuzzies and little to do
> with strength, except that for a cantilever wall for strength
> I would not think you would want a spacing greater than the
> wall height, but probably significantly less than that, say
> about half wall height.
>
>
> At 01:43 AM 5/09/2009, you wrote:
> >I should not post twice on the same subject, but I will be that guy
> >because it is Friday and I am feeling chippy, hombre.
> >
> >Riddle me this batman, why in one situation could I go with
> 8" CMU with
> >#4@48" o.c. in solid grouted cells but ACI would require me
> to go 18"
> >o.c. max for that same wall if it is 6" solid poured? I have
> done more
> >than my fair share of CMU calcs so I understand the
> intricacies, I want
> >a common sense type answer. Don't blind me with your
> science. I think
> >the answer is somewhere between a longstanding ACI minimum
> that gives
> >people warm and fuzzies, and something to do with bond stress or the
> >old Z factor or something? I don't have my ACI around and I
> don't have
> >it memorized like Scott, but I bet he knows the answer.
> >
> >But Jeff says the IRC table says 48" o.c. for 30 psf, which
> makes sense
> >from a CMU perspective, and we all know about CMU being of much less
> >compressive strength than solid concrete. I have also heard
> people in
> >the ICF business throw 48" o.c. out there also.
> >There has to be some science or testing behind this, but it from a
> >residential wall standpoint it would seem about right. (I
> still would
> >pay the extra for my house from a crack control perspective).
> >
> >I digress. Rebar, we talkin about rebar? REBAR? REBAR?
> (Allen Iverson
> >talkin about practice). How much more, anyone anyone anyone,
> can this
> >860sf addition cost either way for say about 20-30 more
> bars? Have the
> >GC tell you, then bill him for your extra time on this list
> and doing
> >research and call it even. Add in our time as "consulting and
> >research".
> >
> >Its 100am where Conrad in Adelaide is, means we can all have
> a beer now right?
> >
> >
> >Andrew Kester, PE
> >Orlando, FL
> >
> >
>
> Regards Gil Brock
> Prestressed Concrete Design Consultants Pty. Ltd. (ABN 84 003 163 586)
> 5 Cameron Street Beenleigh Qld 4207 Australia
> Ph +61 7 3807 8022 Fax +61 7 3807 8422
> email: gil@raptsoftware.com
> email: sales@raptsoftware.com
> email: support@raptsoftware.com
> webpage: http://www.raptsoftware.com
>
>
> ******* ****** ******* ******** ******* ******* ******* ***
> * 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@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@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
******* ****** ****** ****** ******* ****** ****** ********