An admixture is defined as a material other than water, aggregates, hydraulic cementitious material or fiber reinforcement that is used as an ingredient of a cementitious mixture to modify its freshly mixed, setting or hardened properties and that is added to the batch before or during mixing.
Achemical admixture is usually defined as a nonpozzolanic (does not require calcium hydroxide to react) admixture in the form of a liquid, suspension or water-soluble solid. An admixture is a material other than water, aggregates, hydraulic cementitious material or fiber reinforcement that is used as an ingredient of a cementitious mixture to modify its freshly mixed, setting or hardened properties and that is added to the batch before or during mixing.
We will look at specialty admixtures such as corrosion inhibiting, shrinkage reducing and alkali-silica reaction reducing admixtures. There are other admixtures on the market, and new ones are being developed every day. However, for the scope of this article we will focus on those most commonly used.