An AFm phase is an "alumina, ferric oxide, monosubstituted" phase, or aluminate ferrite monosubstituted, or , mono, in

cement chemist notation Cement chemist notation (CCN) was developed to simplify the formulas cement chemists use on a daily basis. It is a shorthand way of writing the chemical formula of oxides of calcium, silicon, and various metals. Abbreviations of oxides The main o ...

. AFm phases are important hydration products in the

hydration Hydration may refer to: * Hydrate, a substance that contains water * Hydration enthalpy, energy released through hydrating a substance * Hydration reaction, a chemical addition reaction where a hydroxyl group and proton are added to a compound * ...

of hydraulic cements. They are crystalline hydrates with general, simplified formula where n may be comprised between 13 and 19 water molecules.
They form ''inter alia'' when

tricalcium aluminate Tricalcium aluminate Ca3Al2O6, often formulated as 3CaO·Al2O3 to highlight the proportions of the oxides from which it is made, is the most basic of the calcium aluminates. It does not occur in nature, but is an important mineral phase in Port ...

() reacts with dissolved

calcium sulfate Calcium sulfate (or calcium sulphate) is the inorganic compound with the formula CaSO4 and related hydrates. In the form of γ-anhydrite (the anhydrous form), it is used as a desiccant. One particular hydrate is better known as plaster of Pari ...

() or calcium carbonate (). As their sulfate form is the dominant one, they are often referred to as Aluminate Ferrite monosulfate or calcium aluminate monosulfate. However, carbonate-AFm phases also exist: monocarbonate and hemicarbonate.

See also

References

Further reading