Relation between phase composition, over-all porosity and strength of hardened lime-pozzolana pastes

By means of X-ray analysis, differential and gravimetric thermal analysis, electron microscopy, and chemical analysis, the main hydration products of 22 pastes made from lime and various pozzolanic materials and hardened in water for 400 days were found to be calcium hydro-silicates of the tobermorite group (approximate formula C_0·8-1·1.S.H_0·9-1·5) and Strätling's compound, C₂ASH₁₁. A formula is developed giving the compressive strength of the pastes in terms of the volume of the hydration products produced.