This stuff is easy to apply, water soluble. Looks like a clearcoat. It suppose to prevent moisture from rising through the concrete, if that is the issue. It seems to work but I don't know what it would be like without it. The bad part is, if gasoline is spilled on it, it will disolve it, but then it solidifies again, but I doubt if it is as effective then.
http://www.lmcc.com/products/dress_a..._seal_wb30.asp