Scrubbing can be done on all types of hard floors. The scrubbing process is usually done on concrete, ceramic, porcelain, stone and some laminate floors. Due to the porousness of the various floors and the grout lines scrubbing your floors will give a deep clean needed to keep these floors bright and looking new. Scrubbing these floors can be especially important in high traffic locations such as restaurants (both kitchens and dinning rooms) as well as high traffic lobbies, store showrooms and especially restrooms.
We don't give much thought to concrete floors however like every other floor they do get dirty and depending on how they have been treated (i.e. sealed, stained, painted, epoxy or left natural) also depends on how much dirt they will hold and how easy it is to keep them clean.
The floor above shows the difference, on the left it has not been scrubbed and on the right it has been scrubbed rinsed and let dry.
Keep in mind that concrete is very porous, therefore if left untreated it will hold a lot of dirt and many times a concrete floor will also give off a concrete dust.
Cleaning ceramic tile can have simular problems as concrete depending on how it is made. Ceramic tile will have various degrees of porousness, too. Therefore the various brand or styles of tiles will collect and hold various amounts of dirt, which usually regular mopping will not remove all of this and a periodic scrubbing is recommended.
Cleaning Porcelain tile is a similar process as concrete and ceramic tile. Normally porcelain is less porous then the others but tiles normally all have grout. These grout lines will hold as much if not more dirt then the tiles themselves and you can see that by the discoloration of the grout itself.
Even though porcelain is shiny and less porous it is recommended that they be scrubbed to clean any stained spots and also to keep the grout lines clean which will hold odors especially in restrooms.
Below is the same floor after being scrubbed.