Identification of the cementing material in a light‐weight sand‐lime block

The cementing material of a commercial light‐weight sand‐lime block has been shown by analytical and X‐ray investigations to be calcium silicate hydrate (I) (for nomenclature see Taylor, 1950), of approximate composition 1.28CaO, SiO2, 2.05H2O. The X‐ray powder data are in close agreement with those of laboratory preparations. This result shows that calcium silicate hydrate (I) is capable of being formed under the conditions appertaining in a paste. It therefore appears possible that the cementing agents of sand‐lime bricks in general, and also of hydrated Portland cement, are composed of the same, or a very similar compound.