High Alumina Cement

High alumina cement is a hydraulic binder based on calcium aluminates, rather than calcium silicates which are the basis of Portland cement. These high alumina cement provide specific properties which are ideally suited to certain applied building products. These include self-levelling, rapid hardening, fast  setting and high  strength mortars.
High Alumina Cement is used in applied products either as a hydraulic binder in its own right or as an accelerator of portland cement depending on the final performance required. Although the setting time is similar to that of portland cement, it offers rapid strength development.
Unlike portland cement, high alumina cement does not release free lime during hydration. In concretes with a low porosity, this property gives a good chemical resistance and eliminates the major cause of efflorescence.
High alumina cement may be used as a hydraulic cement on its own or in association with other mineral products such as Portland cement, calcium sulphates and filler or organics such as polymers in liquid or redispersible powder.
The main active constituent of calcium aluminate cements is monocalcium aluminate (CaAl2O4, CaO · Al2O3, or CA in the cement chemist notation). It usually contains other calcium aluminates as well as a number of less reactive phases deriving from impurities in the raw materials. Rather a wide range of compositions is encountered, depending on the application and the purity of aluminium source used.