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RE: Archaic Concrete Expansion Anchors

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The M.B. is obviously a machine bolt or A307.  The anchor is a different
story.

Back in those days there were lag shells, loxins, caulk-ins, drop-ins, etc.
used to attach steel to hardened concrete.  They all used some sort of
deformable lead based metal that you could wedge into the hole that had a
hardened metal threaded sleeve that would expand when the bolt was inserted.
With the M.B. reference you can write off the lag shell.  With the "caulking
tool" reference it was some sort of caulk-in.  The wedging action was
achieved by deforming the shell around the bolt within the hole.

Unfortunately I can't find any of my old design information.  I would call
Rawl or Hilti and ask for the oldest guy there.  Another source would be old
ICBO Research Reports.  These old anchors were unreliable and very dependant
on the installer's skill.  

The dry pack would indicate the use of a non-shrink dry pack grout to anchor
the bolt.  This was another practice.  The aluminum shavings in the old dry
pack would expand the grout around the bolt within the hole.  

I would not bet the farm on these anchors.  They were O.K. in shear, but had
very poor tensile capacity.

Regards,
Harold Sprague
The Neenan Company
harold.sprague(--nospam--at)neenan.com


-----Original Message-----
From: Roche, Ann E. [mailto:ARoche(--nospam--at)ruthchek.com]
Sent: Wednesday, January 13, 1999 5:54 PM
To: 'seaint(--nospam--at)seaint.org'
Subject: Archaic Concrete Expansion Anchors


I am looking for information on concrete expansion anchors installed in
1961. The installation is a steel angle bolted to an existing concrete
wall.

The anchors are called out in the notes as DIAMOND RAM ANCHORS. The
detail calls out "7/8" dia. M.B." with "3 units of expansion anchor";
and the hole is noted as 1 1/2" dia. x 6" deep.

The placing procedure notes on the drawing state: "Set bolt and
expansion anchor (Diamond Ram Anchor). Ram hole with dry pack using
caulking tool or a piece of pipe."

Information on these anchors will be appreciated.