Yes, I have done it before.

Here is the overview:
- Put builder felt (tar paper) over the concrete.
- Then you put pressure treated "sleepers" on hte floor and nail them into the concrete using a 22 caliber power hammer (or drill and masonry bolts)
- You can either put the barn wood over this, or but some plywood down, then the barn-wood.

If you ahve moisture problems with the floor, don't do anything until that is resolved.

RaceDeck now makes a plastic garage tile that looks like a wood floor. They designed it for shops where people restore vintage cars and want it to look more authentic.
I think it looks pretty good and will be very sturdy. If you really want true barnwood though, this may not work for you.
When you click the link see the video from My Classic Car TV show.
Good luck,
Annette

Here is a link that might be useful: racedeck floor