Title: Effect of Silica Fume on Alkali-Silica Expansion in Mortars

Author(s): Mitsunori Kawamura, Kunio Takemoto, and Shigemasa Hasaba

Publication: Symposium Paper

Volume: 91

Issue:

Appears on pages(s): 999-1013

Keywords: alkali content; expansion; microhardness; mortars (material); opal; silica; silica gel; x-ray analysis.

DOI: 10.14359/10109

Date: 2/1/1986

Abstract:
The expansion of mortars containing up to at least 10% silica fume by weight of cement were about three times as great as that of the additive-free mortar. Concentrations of calcium and alkalies within opal grains in the silica fume mortars were determined by energy dispersive x-ray analysis(EDXA). The intrusion of smaller amounts of calcium into opal grains in the mortars at early ages seems to show that the conversion of alkali-silica gels into sols was delayed by the presence of silica fume. The delay of this conversion was also confirmed by microhardness measurements.