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RE: Steel column flange damage repair

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THE USE OF HEAT MAY EFFECT THE YIELD OF THE MATERIAL (MAX. ABOUT 10% REDUCTION LOCALLY); HOWEVER, UNLESS THE IRONWORKER IS TRAINED IN THE PROCESS THE RESULT WILL BE LESS THAN DESIRABLE.
HEAT STRAIGHTENING IS OFTEN USED IN THE FABRICATING SHOPS TO ADD CAMBER TO BEAMS OR TO REMOVE SWEEP FROM ROLLED SHAPES OR WELDED GIRDERS. IN THIS PROCESS THE HEAT IS APPLIED TO THE LIMITED PORTION OF THE FLANGE IN A CONTROLLED MANNER, HEATED TO CHERRY RED AND ALLOWED TO COOL. IN DOING SO THE HEATED AREA CONTRACTS IMPARTING CAMBER OR STRAIGHTENING THE MEMBER.
 
IN THE FIELD THE IRONWORKER NORMALLY HEATS THE AREA THEN TAKES A HYDRAULIC JACK OR A BEATER AND MOVES THE BENT FLANGE INTO ALIGNMENT. THIS PROCEDURE WILL ALLOW THE FLANGE TO BE  STRAIGHTEN BUT THE EDGE OF THE FLANGE WILL BE WAVY.
 
HEAT STRAIGHTENING IS AN ART. AND WITH THE PROPER TECHNIQUE THE REPAIR CAN BE INVISIBLE.
 
I WOULD RECOMMEND THAT THE FLANGE BE HEATED AND STRAIGHTENED WITH AN HYDRAULIC JACK, THEN REINFORCE WITH COVER PLATE ON THE OUTSIDE OF THE FLANGE ONLY.
 

David I. Ruby, S.E.
Chair, Coalition of American Structural Engineers
President, Ruby & Associates, P.C.
30445 Northwestern Hwy., Suite 310
Farmington Hills, MI 48334-3102

Phone:            (248) 865-8855
Fax:              (248) 865-9449
Cellular:         (248) 514-2677
E-mail:           druby(--nospam--at)rubyusa.com

-----Original Message-----
From: SDGSE(--nospam--at)aol.com [mailto:SDGSE(--nospam--at)aol.com]
Sent: Friday, December 08, 2000 2:28 PM
To: SEAint(--nospam--at)seaint.org
Subject: Steel column flange damage repair

I have a new moment frame column where the flange is bent locally inward on
one side for about 4 inch length. It appeared to have been caused during
shipping or fabrication. The fabricator erected the frame anyway and it was
not caught until I visited the site for structural observation. The damage is
located within the critical bending moment area.

I am proposing straightening the flange and adding plates on both sides of
the flange with weld all around. The fabricator suggested applying heat to
straighten the flange. The steel is ASTM A992.

Are there any concerns with the above procedure? are there other repair
schemes?

Thanks in advance.

Oshin Tosounian, S.E.
Los Angeles, CA