Title:
Study of Concrete Containing Silica Fume and Activated Amorphous Silica
Author(s):
H. Tanaka
Publication:
Symposium Paper
Volume:
145
Issue:
Appears on pages(s):
901-916
Keywords:
compressive strength; concretes; permeability; silica; silica fume; water; Materials Research
DOI:
10.14359/4419
Date:
5/1/1994
Abstract:
The physical properties of concrete with additions of silica fume and activated natural amorphous silica were investigated. Much research has been carried out to this point regarding the effects of silica fume on concrete, and it has been made clear that silica fume additions are effective in improving strength characteristics, resistance to water permeation, etc. In the present study, the effect of addition of a mix of silica fume and activated natural silica on the properties of concrete was investigated. The naturally occurring amorphous silica was activated by first treating it with alkali, after which it was neutralized by acid treatment. It was found that addition of this activated amorphous silica and silica fume is effective in reducing the water permeability of concrete to a significant extent. The amount of silica fume required in this case is less than a third of what is normally used in silica fume concrete. SEM observations suggest that the decrease in water permeability is due to a denser structure being obtained because of the uniform distribution of the activated amorphous silica and silica fume particles within the concrete and the effective filling up of the interparticle spaces by calcium silicate gel.