fire rating for concrete filled hss columns

huangyhg

fire rating for concrete filled hss columns???
hi
i am looking for some published fire ratings for concrete filled hss columns.  my architect is pushing me for a ul assembly number, but since it is not a proprietary system, there is not one.  he is giving me grief as he thinks he needs a ul number.  does anyone know of any official body (code, institute, etc) which has published fire ratings for composite hss columns.  i need a 1 hour rating on an unprotected 8" hss column.
thanks in advance.
andrew
i know of no fire rating that you can achieve with bare steel (concrete filled or not).
i believe you have 4 options:
use lally column
well, i know that research done over the last decade or more has shown that filling a tube column with concrete can achieve up to at least a 3 hour rating.  and i know of several projects which have used unprotected filled columns where fire ratings are required.  what i can not find is any published ratings for these columns.  
think of metal deck.  if you put enough concrete over it, you can easily get a fire rating even if unprotected.
unfortunately, any kind of covering is not acceptable.  and intumescent paint may or may not be an option.
thanks.
you may wish to check out this article if you haven't already.