What is the degradation of structural steel after a fire? 2

[henrisan]

I have to determine the structural integraty of one of our buildings that sustained a fire last week. What is the reduction for allowable stress, if any, after the material has been subjected to a fire?

Henri St. Denis
Project Engineering
Solutia Chemical

 

[youngstructural]

This is too broad a question to give you a meaningful answer;

What code do you want to check this against?

How long was the fire?

Of what intensity?

What protection was present to reduce the possible effects on the steel?

What are: The building layout, the length of the columns, the type of floor system, the actual sizes and connections of members (used to determine energy conducted to adjacent section)? The list, honestly, goes on...

I only know a little about Fire Engineering, but I know enough to realise that your situation is not one that I would try and handle on my own.

I think, to be frank, you need to talk to a Fire Engineer. Specifically, this would depend on where you are and just how big a building you are talking about. There are a good deal of very competent specialists about. Two (off the top of my head) would be Dr. George Hadjisophocleous, the National Fire Engineering Research Chair in Canada and Dr. Roger Plank from the University of Sheffield in Great Briton. Both are very good at what they do, and short of a great deal of study, I don't think you can do it on your own. Sorry, just an honest opinion...

Hope that helps, not hinders,

YS

B.Eng (Carleton)
Working in New Zealand, thinking of my snow covered home...

 

[UcfSE]

You should hire someone experienced for this. There is a lot of liability involved in ssaying a structure is acceptable.

 

[unclesyd]

Here is a generalization of the assessment of steel for reuse.
This is for British Steel but is applicable to the US variety.
The article is form a book from Corous Publications, which might be a good investment.

http://www.azobuild.com/details.asp?ArticleID=3621

Watch out for experts in this field. Make sure they have track record as the two I've met didn't know anything about fire damage and recovery. After one said that 4 large I beams form a furnace/HRSG were dead as they couldn't be straightened I had the audacity to invite him back after they had been straighten. The beams had a 2-3 foot bow the hard way with almost a full twist.