A

abrasion resistance – How well a concrete surface or decorative coating resists being worn away by friction or rubbing.

abrasive blasting – Propelling an abrasive medium (such as sand or steel shot) at high velocity against concrete to roughen, clean, or profile the surface in preparation for decorative coatings or overlays. Methods include sandblasting, shotblasting, bead blasting, and sand brushing.

accelerator – An admixture used to shorten the set time of concrete and/or speed strength development. Accelerators are also used to the speed the chemical reaction and shorten the curing time of resin-based coatings.

acetone – Common solvent. Often used as a carrier for solvent based sealers. Considered an exempt solvent from VOC regulations.

acid etching – Application of muriatic or phosphoric acid to clean or profile a concrete surface. Used as an alternative to abrasive blasting for surface preparation. (Also see neutralize.)

acid stain – (or chemical stain) A stain containing inorganic salts dissolved in an acidic, water-based solution that reacts chemically with the minerals in hardened concrete to produce permanent, transparent color that will not peel or flake. Gives concrete an attractive variegated or marbleized appearance. Colors tend to be earth tones, such as tans, browns, reddish browns, and greens. (Also see polymer stain).

adhesive stencils – Adhesive-backed masking patterns made of vinyl or plastic used for creating stenciled concrete effects. The adhesive keeps the patterns firmly in place on the concrete surface while the decorative treatment of choice is applied, such as acid stains, dyes, spray-down systems, etching gels, or sandblasting. (Also see sandblast stenciling.)

admixture – An ingredient in concreteother than water, portland cement, and aggregate used to modify the properties of concrete in its freshly mixed, setting, or hardened states. May be added to concrete at the batch plant or on the job site. Prepackaged admixtures are available for convenient job site addition, giving contractors the ability to modify the concrete they receive when necessary, such as extending the amount of time available for decorative stamping.

aggregate – A granular material such as sand, rock, crushed stone, gravel, or other particles added to concrete to improve its structural performance. (Also see decorative aggregate.)

air content – The amount of entrained or entrapped air in concrete, usually expressed as a percentage of total volume.

air entrainment – Adding an air-entraining admixture to fresh concrete to cause the development of microscopic air bubbles. Helps to improve the freeze-thaw resistance and durability of hardened concrete.

alligatoring – Surface imperfections in a coating resulting in a wrinkled appearance. Usually caused by incompatibility of a newly applied coating with an existing surface coating orsealer. Also know as orange peel or fish eyeing.

antiquing – A color layering technique for giving decorative concrete surfaces an aged or mottled appearance.

B

bleed through – Color change caused by the diffusion of color from an underlying surface.

bleed water (bleeding) – Water that rises to the surface of freshly placed concrete due to segregation. Bleeding may interfere with finishingoperations. If a dry-shake color hardener is being applied to the concrete surface, some bleed water is needed to wet out the hardener sufficiently so it can be floated into the surface.

blistering – The formation of blisters in toppings or coatings and the loss of adhesion with the underlying substrate. On concrete surfaces, this is often caused by moisture or moisture vapor transmission