Potential uses of silica fumes from Antalya Etibank elektrometalurji industry as admixtures in cement and concrete

This study has been aimed to investigate the effects of silica fumes collected to Antalya Etibank Elektrometalurji Industry plant on cement and concrete properties when used as admixtures. Accordingly, some properties of the cement, paste, mortar and concrete mixtures which were prepared by partial replacement of cement by silica fumes (Fesi and SiFeCr) at different levels, were studied and compared with properties of control mixtures containing no silica fume. According to the results, addition of silica fume improved the soundness of cements and prolonged the setting times. Normal consistency water requirements were increased in proportion with silica fume content. This necessitated the use of superplasticizing admixtures. Silica fume addition improved the compressive and flexural strengths and sulfate resistance of mortars. In silica concretes, abrasion loss, drying shrinkage and swelling were reduced while the compressive strength, freeze-thaw resistance and sulfate resistance were improved considerably as compared with control concrete mixtures. The positive effects of silica fume addition were more significant with FeSi fume. Optimum cement replacement level was found to be around 10%. The study also included x-ray diffraction, differential thermal analysis, thermogravimetric analysis studied on cement-silica fume mixtures and pastes.