Effect of Age and Water-Cement Ratio on Size and Dispersion of Pores in Ordinary Portland Cement Paste

In this study, the effect of age and water-cement ratio (w/c) on size and dispersion of pores for ordinary portland cement (OPC) paste was determined through mercury intrusion porosimetry (MIP). The cement paste specimens were prepared from two different grades of OPC with a w/c of 0.2, 0.3, 0.4, 0.5, and 0.6, and were tested at different curing ages from 1 day to 150 days. The relationships involving w/c and age with a mean distribution radius (r^sub 0.5^) and coefficient d representing the dispersion of pore sizes are presented for both types of OPC pastes. Utility of the aforementioned relationship is demonstrated by relating the compressive strength of cement paste and the mean distribution radius estimated from mixture factors. The estimated pore size distribution (PSD) parameters are compared with the experimentally determined PSD parameters, and the observed variation between them is also discussed. [PUBLICATION ABSTRACT]