For scrubbing unfinished concrete or stripping jobs use a Grit brush.  Choose Extra Heavy Grit brush for stripping jobs depending on how aggressive the brush needs to be. The Medium Grit Brush is suitable for most stripping needs. Use a Lite Grit brush for general floor scrubbing on unfinished concrete and a Wire Scrub Brush for very aggressive stripping and scrubbing jobs on unfinished concrete.

Follow link for other Extra Heavy Grit Brushes.