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RE: Basic CMU design (was Fireproof partitions)

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AFAIK,  (minimum reinforcement for masonry):

As=0.0007bt either vertical or horizontal and

As=0.002bt total horizontal and vertical.

For a 8" wall, either #4 verticals at 24" or #5s at 32" and (2)-#4
horizontals at 48" satisfies this requirement.

Maybe this is just a high seismic region requirement, but I don't know
any better.

I don't have the code reference handy, s/b in any version of the UBC
though.

Regards,

T. William (Bill) Allen, S.E. (CA #2607)
V/F (949) 248-8588
San Juan Capistrano, CA


:-----Original Message-----
:From: ESuk(--nospam--at)technip-coflexip.Com [mailto:ESuk(--nospam--at)technip-coflexip.Com] 
:Sent: Wednesday, May 28, 2003 7:33 AM
:To: seaint(--nospam--at)seaint.org
:Subject: Re: Basic CMU design (was Fireproof partitions)
:
:
:
:I figured there was an ACI spec on masonry.  Hmm, I doubt 
:anybody in the office will have a copy though.  As you may be 
:able to tell, we don't design in CMU on a regular basis.  
:Thanks for the help though.  I appreciate it.
:
:-Eugene
:
:
:
:|---------+--------------------------->
:|         |           "Jordan         |
:|         |           Truesdell, P.E."|
:|         |           <jordan@truesdel|
:|         |           l.org>          |
:|         |                           |
:|         |           05/28/2003 06:02|
:|         |           AM              |
:|         |           Please respond  |
:|         |           to seaint       |
:|         |                           |
:|---------+--------------------------->
:  
:>--------------------------------------------------------------
:--------------------------------------------------|
:  |                                                            
:                                                    |
:  |        To:      <seaint(--nospam--at)seaint.org>                        
:                                                    |
:  |        cc:                                                 
:                                                    |
:  |        Subject: Re: Basic CMU design (was Fireproof 
:partitions)                                                |
:  
:>--------------------------------------------------------------
:--------------------------------------------------|
:
:
:
:
:Check ACI 530 for minimum reinforcement - I believe minimums 
:are predicated
:
:upon seismic zone. Have you considered epoxying the vertical 
:bars into the slab-footing as the masons begin work? Take a 
:look at Hilti HY-150; Ultimate bond strength exceeds #5 60ksi 
:yield at about 7-1/2" embed. You might want to check your 
:concrete allowable on a conical shear surface to make sure the 
:concrete won't fail. Jordan
:
:
:At 02:35 PM 5/27/2003 -0700, you wrote:
:
:>OK, so we convinced the client to go with a CMU free standing 
:>(nonbearing) wall.  One of them is 50' long by 12' high.  Since I 
:>really haven't designed in masonry before, I have a number of general 
:>questions.  If any body out there can bear with me, I'll express my 
:>concerns.  Furthermore, I am sure there are some 
:considerations that I 
:>am neglecting, so any additional info would be greatly appreciated.
:>
:>First off, I am pretty sure that I can get away with 8" CMU, 
:reinforced 
:>with #5 bars  at either 16" or 24" oc (much less will do, but my boss
:would
:>like this as a minimum).  It is designed to take only flexure, and 
:>besides wind pressure, are there any other loads I should 
:consider (I'm 
:>also considering the self weight at the base of the wall, but it is
:negligible).
:>
:>I cannot seem to find a minimum steel ratio in the UBC, only maximums 
:>and maximum allowable stresses.  Is there one?
:>
:>Anchorage is another concern I have.  We are using an exiting slab on 
:>the site which is between 24" and 30" thick.  Because of erection 
:>concerns and the construction schedule, we can't have the 
:reinforcement 
:>sticking out of the ground before hand and can't cut the slab 
:when the 
:>wall will be installed.  Therefore, we are going to try to embed some 
:>hooks and tie
:into
:>the longitudinal slab reinforcement early, and have a coupler at the 
:>top
:of
:>the slab.  Then when the contractor gets around to installing 
:the wall, 
:>we can tie the wall reinforcement directly into the couplers. 
: How does 
:>that sound?  As it is, I am trying to use a single bar in the 
:center of 
:>the block(s).  But when anchoring, do I need two bars (one up against 
:>each interior wall) to transfer the moment at the footing, or can I 
:>keep the single bar as long as the CMU can take the compression
:>
:>What kind of requirement, if any, is there for grouting beneath the 
:>wall? Am I required to have a pilaster for this type of wall? 
: Or can I 
:>design
:it
:>as a pure flexural member.  Is there a shear requirement along the 
:>length?
:>
:>I suppose that covers the majority of my questions.  Any help is 
:>appreciated.
:>
:>
:>Regards,
:>Eugene
:>
:>
:>
:>|---------+--------------------------->
:>|         |           "Stuart,        |
:>|         |           Matthew"        |
:>|         |           <mStuart@schoord|
:>|         |           epalma.com>     |
:>|         |                           |
:>|         |           05/14/2003 01:48|
:>|         |           PM              |
:>|         |           Please respond  |
:>|         |           to seaint       |
:>|         |                           |
:>|---------+--------------------------->
:>
:>  >
:---------------------------------------------------------------
:-------------------------------------------------|
:
:>   |
:>                                           |
:>   |        To:      "'seaint(--nospam--at)seaint.org'"
:> <seaint(--nospam--at)seaint.org>
:|
:>   |        cc:
:>                                           |
:>   |        Subject: RE: Fireproof
:> partitions
:> |
:>
:>  >
:---------------------------------------------------------------
:-------------------------------------------------|
:
:>
:>
:>
:>
:>How about CMU?
:>
:>
:>
:>
:>
:>-----Original Message-----
:>From: ESuk(--nospam--at)technip-coflexip.Com [mailto:ESuk(--nospam--at)technip-coflexip.Com]
:>Sent: Wednesday, May 14, 2003 4:48 PM
:>To: seaint(--nospam--at)seaint.org
:>Subject: Fireproof partitions
:>
:>
:>I need some guidance into a suitable system for a project I 
:am working 
:>on.
:>
:>
:>I need a "fire-wall".  I work in the petrochemical industry and 
:>basically
:I
:>
:>need a partition which has been already been sized (say 22' x 
:12' high)
:and
:>
:>located.  In the past, we have used Durock cement board (wonderboard).
:The
:>
:>problem with using that now, however, is that the current 
:partition is 
:>fully exposed to the elements (unless we enclose/waterproof it).
:>
:>
:>Are there any proprietary products anybody has heard of or has used 
:>that might work in this situation?
:>
:>
:>
:>
:>
:>
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