Pore size distribution modification of OPC paste through inclusion of fly ash and sand

摘要

This paper presents a study into the modification of pore size distribution of ordinary Portland cement (OPC) paste due to inclusion of fly ash (FA) and sand as determined through mercury intrusion porosimetry. Cement-sand mortar specimens were prepared from two different grades of OPC with water to cement (w/c) ratios of 0-2, 0-3, 0-4, 0-5 and 0-6 and tested at different curing ages from 1 day to 90 days. Cement-FA paste and mortar specimens were also prepared by incorporating FA at four levels of FA to cement (f/c) ratio (0-1, 0-2, 0-3, 0-4) and a control mix along with four w/(c + f) ratios (0-25, 0-35, 0-45 and 0-55). These specimens were tested at 7, 28 and 90 days. The relationships involving w/c ratio and age with mean distribution radius (r_(0.5)) and coefficient (d) representing dispersion of pore sizes are presented for both types of OPC-sand mortar. The relationships involving w/(c + f) ratio, f/c ratio and age with r_(0.5) and d are also presented separately for cement-FA paste and mortar.