Title:
Optimum Silica Fume Content and Its Mode of Action
on Concrete
Author(s):
Santanu Bhanja and Bratish Sengupta
Publication:
Materials Journal
Volume:
100
Issue:
5
Appears on pages(s):
407-412
Keywords:
compressive strength; concrete; pozzolan; silica fume.
DOI:
10.14359/12816
Date:
9/1/2003
Abstract:
The present paper is directed toward developing a better understanding of the isolated contribution of silica fume on concrete and determining its optimum content. Though the literature is rich in reporting on silica fume concrete, there still exists a basic disagreement among researchers regarding a number of key issues like the mode of action of silica fume on the mechanism of strength development and its optimum replacement percentage. Extensive experimentation was carried out over water-binder ratios (w/b) ranging from 0.26 to 0.42 and silica fume-binder ratios from 0.0 to 0.3. The results indicate that the optimum replacement percentage for 28-day strength is not a constant one but depends on the water-cementitious material ratio (w/cm) of the mixture and has been found to range from 15 to 25%. On quantifying the pozzolanic and physical effects of silica fume, it is observed that both the mechanisms significantly contribute to the concrete strength.