Size and volume relationship of pore for construction materials

A general relationship between cumulative pore volume and pore sizes as measured through mercury intrusion porosimetry (MIP) and BSE image analysis technique is presented in this paper. From the results of the MIP study conducted on hardened cement paste, cement silica fume paste, cement silica fume sand mortar, brick, soil cement, and concrete, it is observed that a general relationship exists between applied pressure and intruded volume of mercury. This relationship closely follows the MMF (Morgan, Mercer and Flodin) model. The general relationship between pore sizes and intrusion volume in MIP is then derived from this relationship using Washburn's equation. A similar model is also observed to describe the relationship between cumulative volume and pore sizes obtained through BSE image analysis. The variations of the parameters namely median pore radius and dispersion coefficient (a measure of the spread of pore sizes), with silica fume content, ratio of water-to cementitious material and age are then discussed to demonstrate the utility of the model.