No, it is not at all impossible, but very easy.
Anyone claiming a diamond blade dulls quickly on concrete is just lying.
I have had the same masonry blade for over a decade, and it has easily cut through 4" thick concrete, totally over hundreds of linear feet by now. All you have to do is keep it cool by spraying it with a little water.
But that is NOT how you cut through these steel columns that are only filled with concrete.
With those columns, all you have to do is cut the surface steel with a sawsall blade. Then you whack the section with a sledge hammer, the remaining steel bend and peels, while the concrete shatters and turns to gravel.
A disc cutter will also cut through the steel, as long as you have the right blade.
This would do nicely for the steel.
I would need at least 1 extra battery though.