Helium flow and density measurement of the hydrated tricalcium silicate-water system

Measurementswere made on samples initially conditioned at 11% R. H. and dried in stages to the d-dry condition. Helium flow measurements, although less quantitatively, are qualitatively similar to those found for hydrated portland cement. It was con concluded that the narrow spaces into which helium flowed are interlayer spaces, not fixed-dimension narrow-necked pores. In the measurement of density it was shown that if aqueous solution is used on d-dried samples, account will have to be made for the fact that re-entrance of interlayer water occurs. However, if the material is dried only to 11% R. H. density can be measured by helium, methanol or aqueous Ca(OH)2 solution. The value varies only from 2.35 to 2.37 gm/cc for the hydrated C3S.