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Re: Steel Building Evaluation

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Here is the text from the Sept. 1992 issue of MSC:

What procedures should be followed when assessing steel that has been
exposed to a fire? 

The following is taken from "Technical Committee No. 8: Fire and Blast,
Discussion No. 4, Repair of Steel Structures after Fire" presented at the
International Conference on Planning and Design of Tall Buildings: 
The post-fire repair of a steel-framed structure is a situation that many
designers have not been faced with. The following brief discussion of the
subject provides some general recommendations, as well as an appraisal of
the conditions under which structural damage can be expected. 
Fires are unique; their effect on a building and the extent of required
repairs is a special situation that has to be considered and handled for
each particular circumstance. The following checklist outlines several, but
not necessarily all, of the parameters that should be investigated by any
1. An appraisal should be made of those members that have been subjected to
potential damage. For convenience, this appraisal should be conducted on
members grouped as to their importance: 
a. Columns. 
b. Primary Horizontal Members, such as girders and trusses. 
c. Secondary Floor Members, such as beams, fillers and floor deck. 
2. After identifying those members of potential damage, each structural
member in a fire damaged area should be evaluated for individual damage.
This evaluation should also include connections. 
3. On the basis of the damage evaluation, an economic evaluation of repair
or replacement of the structure should be considered. 
4. If it is decided to repair the structure, damaged members should be
divided into three categories: 
a. Members having nominal damage and adequate structural capacity for
continued service without further repair. 
b. Members having light damage and repairable in place. 
c. Members with severe damage that should be replaced. 
5. Throughout all of these steps, the designer must recognize that
expediency will often dictate the approach. Fires usually mean a temporary
loss of business and rental income; owners and occupants will insist on a
very rapid restoration of building service and availability, a situation
that may lead to costly, but quick, solutions. Fortunately, steel is a
material with a very high tolerance for fire. All of the processes of its
manufacture, from smelting the ore to rolling the structural shape, are
done at temperatures above those that are likely to occur in an accidental
building fire. 
At this point, the designer needs only some guidance on evaluating the
degree of structural damage. Fortunately in steel, the rule is very simple:

Any steel member which has been distorted by fire so that it has a
permanent deflection, crippled web or flange area, or damaged end
connections should be considered for either in-place repair or replacement.

In practice, it may be easier to apply the corollary: 
Any structural steel member remaining in place, with negligible or minor
distortions to the web, flanges or end connections shall usually be
considered satisfactory for further service. 
There are only two exceptions which should be considered by the designer.
Quenched and tempered structural steels, of which relatively small tonnages
have been used, may undergo a change in properties during the heating and
cooling cycle of a fire. A second area of possible departure from the above
rule pertains to high strength fasteners.. Under certain conditions it is
possible that their properties may be altered by prolonged fire exposure.
But should there be any question, it is relatively easy to remove
individual fasteners for test purposes and, should replacement be
necessary, to replace those that are suspected of damage. 

The answer above appeared in Steel Interchange. All questions and answers
from the entire history of Steel Interchange are available at the Modern
Steel Construction website ( You can also register for
a free subscription at the site.

Scott Melnick
Editor & Publisher
Modern Steel Construction

> From: Harold Sprague <harold.sprague(--nospam--at)>
> To: 'seaint(--nospam--at)'
> Subject: RE: Steel Building Evaluation
> Date: Sunday, August 22, 1999 6:52 PM
> There was a very interesting response to a similar question by R. H.
> of Bethlehem Steel Corp.  The response was in the September 1992 issue of
> Modern Steel Construction p. 9.  
> Also check out
> Regards,
> Harold Sprague
> The Neenan Company
> -----Original Message-----
> From: jojosee(--nospam--at) [mailto:jojosee(--nospam--at)]
> Sent: Sunday, August 22, 1999 5:14 PM
> To: seaint(--nospam--at)
> Cc: ncma(--nospam--at)
> Subject: Steel Building Evaluation
> Hello there!
> I'm looking for code,publication and other related documents
> for steel bldg. who was damaged by fire with or without the possibility
> repair.
> jojo see
> Get your freemail at
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