STUDY ON EFFECT OF SILICA FUME ON STRUCTURE AND PROPERTIES OF CEMENT MORTAR AND PROPERTIES OF CEMENT PASTE

The effect of the content of silica fume on the structure and property of the cement mortar and property of the cement paste were investigated.The results shows that the early stage rate of hydrated reaction is reduced to decrease the content of hydrated product and make the structure sparse,so that the early strength of cement mortar is reduced by adding silica fume to cement.The late stage rate of hydrated reaction is improved to increase the content of hydrated product and increase compactness of cement mortar,so that the late age strength of cement mortar is increased by adding proper content of silica fume to cement.The hydrated reaction can continue for long time,so that the long age strength of cement mortar is increased by adding proper content of silica fume to cement.The optimized content of silica fume is 8%.The flowability of cement paste is reduced and the setting time of cement is increased but the soundness is acceptable by adding silica fume to cement.