AFm phase

An AFm phase is an 'alumina, ferric oxide, monosulfate' phase, or aluminate ferrite monosulfate, or Al2O3, Fe2O3 mono, in cement chemist notation. AFm phases are important in the hydration of hydraulic cements. An AFm phase is an 'alumina, ferric oxide, monosulfate' phase, or aluminate ferrite monosulfate, or Al2O3, Fe2O3 mono, in cement chemist notation. AFm phases are important in the hydration of hydraulic cements. They are crystalline hydrates with general, simplified formula 3 CaO·(Al,Fe)2O3·CaSO4·nH2O. They form inter alia when tricalcium aluminate reacts with dissolved calcium sulfate.