Grout is a construction material used to embed rebars in masonry walls, connect sections of pre-cast concrete, fill voids, and seal joints (like those between tiles). Grout is generally composed of a mixture of water, cement, sand and sometimes fine gravel (if it is being used to fill the cores of cement blocks). Sometimes color tint is applied as a thick liquid and hardens over time, much like mortar.
It is also a component of mosaics. Although ungrouted mosaics do exist, most have grout between the tesserae. Main varieties include: tiling grout (either urethane, cement-based or epoxy), flooring grout, resin grout, non-shrink grout and thixotropic grout.
There are a few tools associated with applying and removal of grout such as:
- grout saw or grout scraper; a manual tool for removal of old and discolored grout. The blade is usually composed of tungsten carbide.
- grout float; A blade-like tool for smoothing the surface of a grout line
- grout sealer is a water-based sealant applied over dried grout that resists water, oil and acid-based contaminants.
- dremel grout attachment; an attachment guide placed over a Dremel rotary tool for faster removal of old grout than a standard grout saw.
Source: Wikipedia