fire resistancecomposite sections

huangyhg

fire resistance:composite sections
i have a concrete filled hollow steel section incorporating an i section inside it.
now, i want to determine the temperature distribution throughout the section when the column is heated on all 4 sides for a rating r60 (6o minutes duration of fire)
i do not want to take up fe thermal analysis at the moment.
anyone can anyone provide some reference/publication/tips here?

for a possible quick solution. if you lost all strength in the outside tube, would the column still have enough strength to support the dead load above?
if the answer is no, then the fire resistance of the tube dictates the section, and i doubt it would be much better than a standard hollow tube. you would then need to coat the tube to achieve the rating.aisc design guide 19 would then be appropriate.
your description seems to describe the composition of prefab-fire proof columns: structural section inside + non-structural steel shell with concrete fill.  you may want to see websites for dean lally,l.p, or blackrock columns to see if these assemblies would help you.  these assemblies have published u.l. fire resistance ratings (u.l. x101, 104, and 106).