structural steelconcrete column

huangyhg

structural steel/concrete column
i did a design and spec'd a square hss 10" column.  anyway, the architect doesn't want such a large column since they still have to fire treat it.
their request was to design a column of steel encased in concrete.  
i've done columns of just steel and columns of steel hollow sections filled with concrete but not like this.
is there anything i should keep in mind? should i change the hollow section to a w shape?
any advice would be appreciated.
aisc 13th edition has tables for composite steel-concrete columns - you could start there.

the steel encased with concrete would be larger by a long mile.
why cant they coat it in intumescant paint - this can give up to 2 hours fire rating in the thickness of a few coats of paint.

what is the controlling factor on the 10" hss column? is it filled or hollow?  
i agree, encasing a steel column in concrete is probably going to make your column the same if not bigger than the 10x10 tube.
the problem of fire-treatment and column size after the design was put out seems like a break-down in coordination by the arch.
can you make a thicker 8x8 work?
thanks everyone for your help
the project requirements have changed and they are now specifying concrete posts and lintels.
so back to the drawing board
concrete column would be much larger than 10" hss. but better in fire rating i guess.
check the minimum column dimensions for the fire rating in the code, check that the concrete can take the axial load as if it was  a plain section - thn there is your initial concrete column size for the architect to compare.