General characteristics of inorganic cements

Inorganic cements (inorganic binders) are powdered materials that, if allowed to react with a suitable liquid phase (usually water or a water solution of an appropriate reactant), undergo chemical reactions associated— at an appropriate liquid/solid ratio— with the formation of a firm solid stracture. 

In some cement pastes (that is, suspensions of a binder in a liquid phase) the hardening takes place only in air, and is associated with a loss of free water and/or with a reaction with the CO2 in the air. Such binders are called non-hydraulic binders, as opposed to hydraulic binders, in which the hardening may also take place imder water, and is associated with a hydration process. 

The chemical nature of inorganic cements may vary greatly. In some instances they are materials consisting of a single phase, but more often they contain several phases side by side. Some cements are even blends of two or more constituents, out of which some may be hydraulically active only in combination with others. 

Materials or constituents that react spontaneously with water, causing setting and hardening of the original mix, are considered to be hydraulicaUy reactive. They exhibit cementing or hydraulic properties. 

Latently hydraulic materials are also able to react hydraulically, but only in the 

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