I have compiled a step by step of a way to use round bars to represent rebar.
You will essentially have to create a new user_section for the size your company uses on a regular basis.
The step by step will show you how this is done. The changes will be reflected in your AstorProfile 2015.1 mdb databases, numbering, sections, as well as your BOMs.
Please see attached zip file.
Hope this helps.
Attachment: REBAR-HOW TO ADD TO EXT_AISC_Roundbar.zip