Author/Authors :
bagheria, a. k.n.toosi university of technology, تهران, ايران , parhizkarb, t. department of concrete technology, building and housing research center (bhrc), pas farhangian street, sheikh fazlollah express way, ايران , madani, h. graduate university of advanced technology, كرمان, ايران , raisghasemi, a. department of concrete technology, building and housing research center (bhrc), pas farhangian street, sheikh fazlollah express way, ايران
Abstract :
In this study, the pozzolanic activity of pyrogenic nanosilicas with different specific surface areas (90m2/g, 200m2/g and 300m2/g) and aggregation states in lime and cement pastes and their effects on cement hydration have been investigated and compared to the influences of silica fume. The results show very rapid pozzolanic activity for the pyrogenic nanosilicas compared to silica fume and the rate increases with increasing specific surface area of nanosilicas. The large differences in the initial aggregate sizes of nanosilicas appear not to influence their pozzolanic activity. Nanosilicas accelerate cement hydration at early ages, however; at later ages, progress in cement hydration is reduced.
Keywords :
Aggregation , Hydration , Pyrogenic nanosilica , Reaction , Stability , Surface area
