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RE: Crooked Anchor Bolts

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A449 is a quenched and tempered material.  Heating to 1200 degrees will alter the mechanical properties.  Quenched and tempered steels can be heated and even welded, but the material must be retreated which means heating the material and fast cooling rates (about 6 degrees per second to 900 degrees).  The concrete will act as a heat sink and make controlled heating cooling almost impossible plus the concrete may be damaged by the heat.

Call a metallurgist for proper procedures.

If you do not need the A449 strength go ahead and use minimum heat and straighten the bolts.  If strength must be maintained, I think you'll have to chip them out and patch them in again.

20/20 hind site.  Require sheet metal templates and run nuts on the template to hold the anchor bolts plumb on the template.  It won't cure bad construction, but it takes one potential oops out of the process.

Harold Sprague
Krawinkler, Luth & Assoc.

-----Original Message-----
From:	Brent Koch [SMTP:brentk(--nospam--at)tdl.com]
Sent:	Monday, May 11, 1998 10:06 AM
To:	seaoc(--nospam--at)seaoc.org
Subject:	Crooked Anchor Bolts

I have this current condition at a jobsite:
We are using 1-3/8" diameter A449 anchor bolts to connect several precast mansard to a parking garage. A bolted connection is used along six ramp bays where our panels are bolted down directly to the tops of the columns at constant elevation. (The roof slab is continually changing elevation along these bays.) Here, pairs of anchor bolts extend vertically about 3 ft out of the column and will pass through (2)3-1/4" dia. sleeves in the precast. The sleeve is eventually grouted and mechanical anchorage is provide by a plate and nut at the end of the rod.
The general contractor has not placed the rods plumb coming out of the columns. We need the rods plumb to facilitate installation and to permit proper alignment of the panel once the panel is landed.
Is it possible to heat this type steel, not in excess of 1200 deg F, to straighten the rods?
Comments and references appreciated. Thanks in advance.
Regards,
Brent Koch, P.E.


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