An admixture which, when added to concrete, mortar, or grout, increases the rate of
hydration of the hydraulic cement, shortens the time of set and increases the rate of hardening or
Air Entraining Agent
An addition for hydraulic cement, or an admixture for concrete or mortar which
entrains air in the form of minute bubbles in the concrete or mortar during mixing.
A composite material which consists essentially of a binding medium, within which are
embedded particles or fragments of a relative inert filler in portland cement concrete, the binder is a
mixture of portland cement, possibly additional cementitious materials such as fly ash and water; the
filler may be any of a wide variety of natural or artificial, fine and coarse aggregates; and in some
instances, an admixture.
(See air entrainment) Microscopic air bubbles intentionally incorporated in mortar or
concrete, to improve workability and durability (usually imparting a higher degree of resistance to
freezing and thawing).
A material that increases the workability or consistency of a concrete mixture, mortar or
(ASTM C 618) A siliceous, or siliceous and aluminous material, which in itself possesses
little or no cementitious value but will, in a finely divided form, such as a powder or liquid and in the
presence of moisture, chemically react with calcium hydroxide at ordinary temperatures to form
permanent, insoluble compounds possessing cementitious properties.
Delaying the hardening or strength gain of fresh concrete, mortar or grout.
An admixture which extends the setting time of cement paste, and therefore of mixtures such
as concrete, mortar, or grout.
A condition of freshly mixed concrete. mortar or cement -paste indicating that it is workable
and readily re-moldable, is cohesive, and has an ample content of fines and cement but is not over
Condition in which concrete, mortar, or cement paste will sustain deformation
continuously in any direction without rupture.
Property of freshly mixed concrete, cement paste or mortar which determines its ease of
molding or resistance to deformation.
Plastic – capable of being molded or modeled. Capable of adapting to varying conditions. Capable of
being deformed continuously and permanently in any direction without rupture. Applies to substances
soft enough to be molded yet capable of hardening into the desired fixed form
Cement - a substance used to adhere material together. In concrete, the dry powder that when
combined with the water chemically cements all the particles together.
Heat of Hydration – thermal energy given off by concrete or gypsum as it cures
Portland Cement – a combination of lime, iron, silica, and alumina. Lime comes from limestone,
marble, marl or seashells, Iron, silica, and alumina can be found in clay or shale
Type I - Normal, used most
Type IA- Normal, Air Entraining – contains ingredients that cause microscopic air bubbles