Shot Blasting
Shot blasting is primarily known as an all-purpose, one-step cleaning and profiling method for concrete floors. It can efficiently clean materials such as dirt, grime, old coatings, and embedded chemical contaminants. The shot-blasted surface is uniformly clean and profiled, and it readily accepts all coatings applied to it. In effect, a thin layer of the surface is blasted away to increase the overall porosity of the concrete surface, so that there is better penetration and adherence of primers and coatings.
Abrasive Blasting
Conventional abrasive blasting is an effective method of removing paint, rust, salts, and foreign contaminants from metal or concrete surfaces. It is very effective in creating a well-profiled, uniform, and clean surface to which protective coatings can bond. Where there are environmental restrictions or sensitive equipment, wet abrasive blasting may be used to suppress dust. Abrasive blasting can be used to lightly abrade the surface, or it can remove the top surface of the concrete altogether.
Scarifying/Grinding/Sanding
Scarifying machines scratch the surface of concrete to remove dirt, coatings, grease, and sealers. Scarification is accomplished by a rotating drum, which has hardened cutters that scratch or abrade the concrete until all surface contamination is removed and sound concrete is exposed. Scarifying can achieve a profile ranging from 60 grain sandpaper to 1/8-inch grooves.
Grinding and sanding are other methods of mechanical surface preparation. Grinding is the rotation of one or more abrading stones or discs applied under pressure at right angles to the surface. Sanding is accomplished through using different grits of sandpaper attached to sanding pads. Sandpaper ranges from 20 to 250 grit, depending upon the outcome desired.
Pressure Washing
Pressure washing is one method of mechanically cleaning concrete floor and wall surfaces. It uses a relatively low amount of water at high pressure, usually in the range of 1,500 - 4,000 psi, to give the water more cleaning power. Typically, commercial detergents and degreasers are immersed in cold or heated water to boost the cleaning power delivered. High pressure water blasting will remove dirt, grime, oil and grease, chalking or peeling paint, mold and mildew, and pollutants from most surfaces.
Chemical Cleaning
 Chemical cleaning is the use of detergents, solvents, acidic and alkaline materials, in combination with high-pressure, cold or heated water, to clean concrete surfaces of dirt, oil and grease, and other foreign contaminants, prior to applying a coating system. Existing surface contaminants can prevent a coating system from bonding satisfactorily to the substrate. Some coating systems require that the concrete be acid-etched in order to ensure proper adhesion of a coating system to the concrete surface.
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