On Tue, 16 Feb 1999, Alan Hewat, ILL Grenoble wrote:
> >C4A3S is the 'precursor' for
> >ettringite formation and is added to Portland cement to produce shrink-
> >compensated, fast-setting concrete.
>
> Now that I have drawn the structure it looks interesting :-) 6-member
> rings of corner connected AlO4 tetrahedra with Ca in the center, and the
> rings connected to form large cavities containing the sulphate. Wulf Depmeier
> et al. had it cubic, while the recent x-ray Rietveld work of Colin Kennard
> et al has it othorhombic pseudo-cubic.
>
Y. G. Wang et al. did an electron diffraction study on it which revealed
superstructure reflections (J. Mater. Sci. Let. 9 (1990) 997).
Is the article of Kennard published already? I could not find it with
UnCover.
> It would perhaps be interesting to do some neutron work on this material
> to see if there is no hydration in all those cavities, n'est pas Colin ?
>
Maybe in the material found in cement, but most of the material for
studies is prepared from CaO and Al2O3 without any water or hydroxides
involved in the process.
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