Removing sealers and coatings
There are two methods for removing sealers from concrete; mechanically grinding, blasting or sanding the coating off the surface, or chemically stripping the coating away.
While both work, the mechanical method often profiles or damages the surface and also creates noise and dust, which needs to be efficiently dealt with. The most common method for removing sealers, paints or coatings from concrete is therefore the use a chemical stripper.
A series of articles by Chris Sullivan covering this topic can be viewed at ConcreteNetwork