Influence of silica fume on the microstructural development in cement mortars

Abstract Cement mortars containing 0, 10 and 30 percent silica fume were prepared at water/cement + silica fume ratios of 0.45 and 0.60. Compressive strength, Ca(OH) 2 and non-evaporable water contents and pore-size distribution were monitored up to 180 days. Silica fume reacts with most of the Ca(OH) 2 formed during hydration within 28 days and improves the compressive strength of the mortar. In addition it affects the pore-size distribution of mortars by reacting with Ca(OH) 2 formed around the sand grains and also with that dispersed throughout the cement paste.