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RE: Reinforced Concrete Blockwork Construction

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It won't really cause a problem with the fire rating of the wall.  Its
not like they use a lot of this.  A favorite is flattened out wax paper
cups.  Although, I'm sure the fire Marshall would have some serious
questions.  These "plugs" would not normally be exposed to flame during
a fire as they are inside the wall and protected by the face shell.  But
like I previously mentioned, the best method would be the installation
of the light gage metal "core plugs".

-----Original Message-----
From: Todd.Hill(--nospam--at)theaustin.com [mailto:Todd.Hill(--nospam--at)theaustin.com]
Sent: Tuesday, July 27, 1999 9:46 AM
To: seaint(--nospam--at)seaint.org
Subject: RE: Reinforced Concrete Blockwork Construction



Would stuffing masonry cells with "paper/trash" decrease the fire
stopping
capability of the wall?




jbseegert(--nospam--at)matrixti.com on 07/27/99 05:19:04 AM

Please respond to seaint(--nospam--at)seaint.org

To:   seaint(--nospam--at)seaint.org
cc:    (bcc: Todd Hill/we/Austin)
Subject:  RE: Reinforced Concrete Blockwork Construction




In reply to Harold Sprague:

Having been involved with material testing and design of hundreds of
projects around the United States and Canada, I can say that he
predominant block used for installing horizontal reinforcement on the
entire east coast/west coast is bond beam block.  This consists of a
typical 8 x 8 x 16 with a U-shaped profile to place the horizontal steel
in with the normal vertical cells installed to allow reinforcement to be
installed.

The installation of fabric or mesh is not considered to be good masonry
practice.  First of all this costs additional money and is never
installed correctly.  This results in an unsatisfactory bonding of the
mortar to the block. Another reason is that it readily allows water to
filter through, thus reducing the volume of the grout which results in
voids.  Typically, the contractor will stuff the cell with paper/trash
which is readily available on a job site. this tends to be satisfactory
enough to prevent any significant leakage.  The best option is to
install the very thin (36 gage) 6 x 6 aluminum cell closures.  These are
sized small enough not to inhibit proper mortar placement.

Masonry U-shaped lintel block and bond beam block are the same thing.
There also exists a U-shaped precast lintel beam that has become very
popular in the masonry world as it does not require any extended shoring
during the grout curing period (solid bottom; no cell openings).  It is
constructed so as to have vertical openings ( typical cell) on each end
to allow the installation of the jamb reinforcement on each end of the
opening.

-----Original Message-----
From: Harold Sprague [mailto:harold.sprague(--nospam--at)neenan.com]
Sent: Monday, July 26, 1999 6:13 PM
To: 'seaint(--nospam--at)seaint.org'
Subject: RE: Reinforced Concrete Blockwork Construction


Jeffery Seegert wrote:
"In many areas of the country horizontal reinforcement is installed in
U-shaped bond beam blocks as opposed to concrete tie beams."

In partially reinforced masonry walls few masons will install a bond
beam
unless it is a "knock out" bond beam unit.  The "knock out" bond beams
are
installed over fabric or lath grout barriers to keep the grout from
flowing
into the vertical cells below.  The "U" shaped bond beams are reserved
for
lintels.  That way you don't have to knock holes into the bottom a "U"
shaped bond beam to run the vertical rebar through.

This detail is shown in the US Army Corps of Engineers "Masonry
Details",
Sept 1997, detail 3.1.  I could not find it on their web site.  Although
they do have a detail of the "knock out" bond beam.

Regards,
Harold Sprague
The Neenan Company


http://cadlib.wes.army.mil/cgi-shl/dbml.exe?action=Query&template=secure

Regards,
Harold Sprague