Porous materials are formed in nature and by man by many different processes. The nature of the pore space, which is usually the space left over as the solid backbone forms, is often controlled by the morphology of the solid backbone. In particular, sometimes the backbone is made from the random deposition of elongated crystals, which makes analytical techniques particularly difficult to apply....

Hydraulic cements develop mechanical strength and low permeability as a result of hydration, which involves chemical reactions between water and the anhydrous compounds present in the cement. Solid hydration products form both at the surfaces of the cement particles and in the pore space by nucleation and aggregation. As a result, the solid phase becomes highly connected and the material transf...