In terms of the length of time it has been produced, the volume produced and the breadth of applications, calcium aluminate cements are by far the most important class of non-Portland cements. Calcium aluminate cements are a relatively large family with a range of compositions which varies much more widely than Portland cement. Today the two major markets for calcium aluminate cement are in castable refractories and in dry mix mortars for special construction applications, which together account for around 80% of consumption. The use in technical concretes, for example, sewer linings, rapid repair, etc. is rather small. Calcium aluminate cements are known for their rapid strength gain, especially at low temperatures, superior durability across several categories and high temperature resistance. Their ability to consume water rapidly during hydration makes them a preferred component in building chemistry applications as this contributes to construction expediency. CACs are highly versatile materials that can be used as the full binding material, or as is more common, a component of a blended system where the contribution is based on the final desired properties.

2 – Calcium aluminate cements

Hydration states of AFm cement phases

Hydration of Portland cement with additions of calcium sulfoaluminates

Formulating a low-alkalinity, high-resistance and low-heat concrete for radioactive waste repositories

Strätlingite formation in high alumina cement - silica fume systems: Significance of sodium ions

Reaction mechanisms of strtitlingite formation in high-alumina cement (HAC)—zeolite systems were studied. A component separation method that made it possible to study individual reactions involving hydrated HAC and zeolite was employed. Different sodium salts, e.g. sodium silicate, sodium carbonate, sodium sulphate and sodium nitrate, were used to promote statlingite formation in the HAC paste. Strtitlingite forms preferentially to the cubic hydrogarnet phase in hydrated HAC systems in the presence of zeolite. A sufficiently high silicate concentration, arising from the dissolution of silicabearing materials such as zeolite, is required. A high pH environment is also conducive to stratlingite formation. The thermochemical stability of CAH10, the normal precursor to hydrogarnet formation, is apparently increased under the condition of high microsilica content.

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J. Ding

Papers

Strätlingite formation in high-alumina cement — zeolite systems