steel concrete connections

[cvm2dm]

A structure with PT slabs supported on tubular steel columns and RC cores. The columns are too small to fill with concrete. How do I provide vertical ties and connect the columns to the slab other than by direct bearing?

 

[J1D]

PT means post-tensioning? Why not direct bearing? Is there a large space between top of column and the slab? What the vertical ties suppose to function?

 

[apsix]

If the column is not concrete filled I would use a cap plate (or possibly a shear head). It would then be simple enough to weld on studs or rebar 'tails' to provide some vertical and horizontal tie capacity.

With a small column, punching shear could well be a problem, has that been checked?