Published online by Cambridge University Press: 15 February 2011
Up to 8 per cent of SO3 may be incorporated into the crystalline lattice of C2S if burned in the presence of CaSO4. C3S may be formed only in the presence of F-. Under these conditions up to 5 per cent of SO3 may be incorporated. In the presence of CaSO4 and CaF2 in the raw meal portland clinkers may be formed that contain simultaneously the phases C3S and C4A3S. Clinkers of this kind yield cements with favorable strength properties at “optimum gypsum” additions.