Here's a few tips for making your coating last longer....
First- your concrete slab must be absolutely dried and fully cured. That means no moisture in the concrete or coming through the slab from underneath.
If you are pouring a new slab, use 10 mil (NOT 6 Mil) polyethylene and overlap the joints 12" and then tape the joints. When laying down the reinf. mesh, be sure not to ********* the poly. Pour your concrete and WET CURE the top of the concrete. Don't use a curing compound to retain the moisture. Mist the slab with a little water and cover with wet burlap or poly. Wait 2-3 days before you remove the burlap and make sure it stays damp the whole time. It doesn't hurt to spray it a few times after you remove the burlap. The longer it takes to cure, the stronger the slab.
BTW- if you have the choice, use 3000-3500 psi concrete and have them add an "air-entraining add mixture". It makes the concrete stronger and more resistant to freeze thaw action by adding microscopic air bubbles in the concrete. Works great on sidewalks as well.
Wait several months. To see if your slab is fully cured- take a 12" square piece of aluminum foil, place it on the slab and duct tape the edges to the slab, making it air tight. Wait 24 hours. Remove. See moisture or condensation on the side facing the slab? Your slab is not cured yet or your old slab is allowing moisture from underneath it in. If there is moisture on the top of the foil-the atmospheric conditions are allowing ground condensation-wait until this goes away.
If you have an old slab and there is moisture on the foil facing the slab, then you don't have too many good options. However, you might find surface water running against your garage or you need to add gutters and downspouts. Alternatively, a clay tile floor that is thinset might be a good choice.
If you have a slab that was cured with curing compound, your best bet is to shot blast the surface ($) or attempt to acid etch it. After etching, you should neutralize it and then wash it off with water. Let it dry (foil test) and then apply your product.
By far, most the failures I see with flooring or paint is from the surface not being prepped properly or moisture (vapor pressure) "blowing" the material off from underneath. A little moisture can easily turn to "steam" in the sun or from a hot engine and peel the paint right off.<FONT face="Tahoma">Type your text here</FONT f>