Painting any kind of floor can be a real challenge. There are a large number of details and factors that can go in to a floor treatment failing or suceeding. It may not appear that ther is any type of coating or finish on the floor but often times different plastic polymers are mixed into concrete to help it cure or to change it's strengh/flexibility. The most common way to overcome issues like this is through proper preperation of the floor. Beyond a siple sweep and mop or
power wash, Surface prep is the number on reason that painted concrete floor finishes fail. What is really necessary is a cleaning with muriatic acid. There are several brands available at hardware stores and home centers. Muriatic acid essentially etches the top layer of concrete roughing it up so that the binding agents of a paint have something to grab on to. I can't stres enough how important it is to read understand and follow the manufacturers directions. Muriatic acid is extremely dangerous, toxic and icky.
Second most common reason for floor paints to fail: Moisture. Bet you thought that concrete floor was solid as a rock didn't you ? Well it is... sort of, it's as solid as a very porous rock. water can go right through it. and under certain conditions water can even be drawn trough it by the act of improperly sealing the top surface. I suggest a really good masonry sealer, ther are several on the market.
Third biggest reason fo failure:
point loads. Let's
face it no matter what you put down it going to be layer on top of an extremely hard surface if you use small areas to carrry the load of a set peice or tool or peice of equipment the material is going to flake, chip, or scuff off. So choose your materials carefully.
There are a ton of floor paints available but if you really don't want to have any issues with your floor I would suggest stripping it with acid then laying down an expoxy floor treatment like that which is used in garages. It's expensive, but there really is no substitute for a good
base layer. You can paint on top of it if necessary and most paints stick to it rather well.