As widely known, concrete in its meaning is considered to be the most widely used construction material due to the availability of its ingredients with economical value compared to other building materials. Cement is the most and expensive material in concrete and its manufacture involves use of raw materials and energy. Thus, replacement of cement with less expensive materials would partially reduce the cost of construction and simultaneously conserve energy and resources. Replacement is especially effective when the materials substituting for cement happen to be waste materials or by product of another industry. The granulated blast-furnace slag and silica fume are by-product materials. Slag resultingin the blast-furnaces during extraction processes of the cast iron from iron ore. Silica fume resulting from the processes of production of silicon and ferro-silicon alldys and it is collected from the gases escaping from the electric furnaces.
This paper studies the usage of granulated blast-furnace slag as a ground material ( % passing from size # 45 urn = 0.85 %, i.e. specific surface area = 2500 cm2 I gram ) with combination of silica fume in concrete mix as a partial replacement of cement. This study shows that the best combination of (cement , GGBF slag and silica fume) with ratios gives the highest concrete strengths compared to control mix (100 % cement ) specially after 91 days is the mix that contains 60% cement, 33% GGBF slag and 7% silica fume at WIC = 0.46.
* Prof. Dr., Head of civil Enginzering Technology department in B. H. I. T., Benha, Egypt. ** Lecturer, Civil Eng. Dept, Faculty of Engineering, Minia University, Minia, Egypt. *** Assistant Prof, Civil Eng. Dept, in B. H. I. T., Benha Egypt. **** Civil Eng., Egypt. |
