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RE: Unreinforced Masonry Building

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David,

I have done this myself on rehabilitation jobs.  Don't have them "point" the
top.  That infers mortar.  

Have them cut out the face shells, install the rebar, and as they mortar in
the face shells have them add grout tubes.  You can then just pump the grout
in at the base and wait till it comes out the top.  Cementitous grouts are
commonly available.

I would also consider epoxy grouting the dowels into the foundation as
opposed to the bottom bond beam.  And you might want to take a hard look at
the top to see how you resist wind uplift.  How does your load path continue
from your roof structure to the wall?  A #4 straight bar requires about 12"
to be developed.

You could consider drilling down through the top of the wall, but then you
will be getting into all the roofing, flashing, etc.  That could be more
expensive.

Regards,
Harold Sprague

> -----Original Message-----
> From:	David Hall [SMTP:Dahl(--nospam--at)deainc.com]
> Sent:	Friday, February 11, 2000 11:42 AM
> To:	RickLennen(--nospam--at)AOL.COM; seaint(--nospam--at)seaint.org
> Subject:	Unreinforced Masonry Building
> 
> A few weeks back I sent out a request asking if anyone knew how to conduct
> non-destructive testing to determine if reinforcing and grout was placed
> in the voids of an existing masonry building.  I appreciate the responses
> that I received from many of you.
> 
> Well guess what.  There was only grout and reinforcing in the horizontal
> bond beams which were placed at 4 foot centers horizontal, in the lintels,
> and vertically at each side of the expansion joints and openings.
> 
> Now heres another one for you, there are 15 of these building designed by
> our office and from what I recently heard 12 more that were designed by
> another.  
> 
> These buildings are telecommunication building in Texas which is in
> seismic zone 0 with a 80 mph wind speed.  I haven't checked yet but I
> believe that #4's at 4 feet on center will work vertically.  
> 
> Now to retrofit this building I am considering having them saw cut and
> remove the inner shell of the block from the inside, embed #4 bars into
> the upper and lower bond beams with epoxy grout ,lapping the bars 30
> inches, then gluing the shell back up to the course just below upper bond
> beam, then filling the void with grout continuing up carefully and adding
> the last shell and pointing the remainder.
> 
> What a mess, If anyone has a better idea I would sure like to hear it.
> Adding shotcrete with a grid of steel to the interior is not an
> alternative.
> 
> I would appreciate your suggestions.
> 
> 
> David A. Hall, S.E., P.E.
> Senior Structural Engineer
> David Evans and Associates, Inc.
> 2828 SW Corbett Ave
> Portland, OR 97201
> 503-499-0280
> Fax 503-223-2701
> E-Mail dahl(--nospam--at)deainc.com
> 
>