Use of Condensed Silica Fume as Filler in Blended Cements


  • The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.

International Concrete Abstracts Portal


Title: Use of Condensed Silica Fume as Filler in Blended Cements

Author(s): M. Regourd, B. Mortureux, and H. Hornain

Publication: Special Publication

Volume: 79


Appears on pages(s): 847-866

Keywords: blended cements; bond (paste to aggregate); compressive strength; C-S-H; electron microscopes; fly ash; microstructure; mortars (material); pozzolans; silica; slags.

Date: 5/1/1983

At early ages, blended cement mortars with 30 % hydraulic slags or active pozzolans have lower mechanical strengths than mortars incorporating 100 % Portland cement. The action of 5 % condensed silica fume replacement for slag or pozzolan or material considered as inert has been studied from 7 days to 3 months by measuring the mechanical strengths of mortars made according to IS0 test method and by observing the microstructure of fractured samples. This action of the condensed silica fume is a function of the nature of the additive. With hydraulic slags, there is a competition between slag and silica fume for the available lime. With slightly or slowly reactive pozzolans (volcanic rock, fly ash) mechanical strengths and microporosity of mortars show improve-ment at 28 days. With inert materials (crystalline slag or quartz), the improvement is more marked. This is due to the formation of dense C-S-H, strong cement paste-aggregate bond and 20 % increase in mechanical strengths.