Influence of Silica Fume on Durability of Cement-Based Materials Exposed to Chlorides

Abstract

The deterioration of cement-based materials used for the civil infrastructure has led to the realization that cement-based materials, such as concrete, must be improved in terms of their properties and durability. The use of admixtures, e.g. silica fume, is a relatively convenient way of improving cement-based materials. This paper is focused on the use of silica fume to improve durability of cement-based materials exposed to hydrochloric acid. 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 180 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. The highest concentrations of leached calcium (619.2 mg/L) and silicon (1581 mg/L) ions were observed for the sample without silica fume addition placed in the solution of hydrochloric acid.