DBPapers
DOI: 10.5593/SGEM2014/B51/S20.004

APPLICATION OF SILICA FUME AS WASTE MATERIAL IN CEMENT COMPOSITES EXPOSED TO HYDROCHLORIC ACID

A. Estokova, M. Kovalcikova
Wednesday 1 October 2014 by Libadmin2014

References: 14th International Multidisciplinary Scientific GeoConference SGEM 2014, www.sgem.org, SGEM2014 Conference Proceedings, ISBN 978-619-7105-17-9 / ISSN 1314-2704, June 19-25, 2014, Book 5, Vol. 1, 23-30 pp

ABSTRACT
The use supplementary cementing composite materials have been reported to increase the resistance of concrete to deterioration by aggressive chemicals such as chlorides. Silica fume, a very fine solid material generated during silicon metal production, has historically been considered a waste product and due to its high pozzolanicity and its extreme fineness, is considered to produce low permeability concrete and extends construction life, resulting in resource savings. The use of silica fume converts a waste product into a useful, marketable product. The paper is aimed at comparative study of resistance of Portland cement composites with addition of silica fume as durability increasing factor in various environments (hydrochloric acid with pH 5.06, rain water with pH 6.65 and distilled water as reference medium). Effect of hydrochloric acid attack on the silica fume based cement composites and cement composites of ordinary CEM I Portland cement without any additives was investigated during 90 days under model laboratory conditions. The calcium and silicon contents in leachates were evaluated during the experiments using X – ray fluorescence method (XRF). Silica fume based concrete samples were found to have better performance in terms of calcium and silicon ions leaching for all environments except for distilled water environment.

Keywords: silica fume, chloride attack, concrete, leaching.