Methods of Fire-Proofing Steel 1

[asixth]

Hi guys

This is probably a question that I can post in the Steel or Structures Other Topics forum but I have been getting such a great response in this forum I will try here first, particularly now that the Australian participants on this site are increasing.

How do I go about achieving fire-rating for bare steel and will bare steel (SHS/HSS column) be able to achieve any fire-resistance on it's own?

I have read many methods to fire-proof steel include encase 50mm of concrete to each side, drywall boxing the section with a fire-rated product, coating the section with intumescent paint, coating or spraying the section with fire-proofing material and boxing the section out with unrated drywall.

How much fire-resistance is achievable with each method and what codes/reference material should I be looking at to find out this information?

Can I also be directed to some good manufacture's of any fire-rating materials that anyone should know of.

Any help will be appreciated.

 

[OzEng80]

asixth

Fire rating for bare steel is determined in accordance with AS4100 ch12. My experience is that you get very little fire resistance out of untreated steel. I have always achieved fire rating by boxing out with Fyrchek - CSR product. Download the CSR 'red book' - has plenty of info. If your columns are large enough concrete filling may also be an option.

Cheers

 

[apsix]

The BCA has deemed to comply tables showing required thickness for various rating periods, for concrete, masonry and gypsum plasters.

For less generic advice refer to the manufacturer.

Intumescent paint should be an option, but last time I tried in Melbourne it was knocked back by the building surveyor. This was 6 or 7 years ago, acceptability has probably improved by now.

 

[csd72]

Intumescant coating is normally only capable of 2 hours or less. specify the required FRL and the manufacturer will give the coating thickness.

 

[bernoullies123]

You can also refer to the American Standard as a reference ANSI/AISC 360-05 Specification for Structural Steel Buildings APPENDIX 4. STRUCTURAL DESIGN FOR FIRE CONDITIONS.
This can be downloaded from the web here:

http://www.aisc.org/WorkArea/linkit.aspx?LinkIdentifier=id&ItemID=17640)

 

[asixth]

Thanks for the help everyone. I looked through the relevant section in AS4100. Following the equations you really need to provide a low exposed surface area (m^2/tonne) to get any substantial FRL for unprotected steel.

 

[rowingengineer]

Asixth,
They ASI gives this out for free, thought you may be intrested in reading it.

Arguing with an engineer is like wrestling with a pig in mud. After a while you realize that they like it