Bush hammering is the process of making cavities in the concrete and peeling off its top layer.
The grained surface reduces slipperiness and increases the adhesion of concrete to thick layers of resin.
Bush hammering becomes more and more popular in giving the concrete floor a decorative look.
Bush hammering  is also widely-used for removing a very thin layer of paint, as well as for lowering the level of the concrete floor or screeds.