Z-Mon, the aluminum shed is supported at the edges. A wood frame shed of this type has a superstructure built on top of the floor. In essence, you build the floor first, and then build the walls on top. Removing the floor without removing the structure is not a trivial task.
BTW, I would be really hating life if I had to mix enough concrete to fill a 24x12 slab with depths reaching 10" or greater. I'm guestimating 4 yards of concrete for a 4" slab. Sackrete is in 1/3 CF bags, I think, so you'd need 300 bags??? 928's wife would need the biceps of Ah-nold.
