Early-age properties of silicomanganese fume and metakaolin-based cement mortar designed using RSM

Abstract. Contemporary and viable construction needs have shifted the interest of research towards utilizing unconventional materials sourced from industrial wastes or by-products. In this paper, two locally available waste materials, namely silicomanganese fume (SMF) and metakaolin (MK) were used as a partial replacement to the ordinary Portland cement (OPC) to optimize their impact on the flow and early-age compressive strength by varying their dosages and calcination temperature employing a Response Surface Methodology (RSM). A total of 29 mortar mixes suggested by RSM were prepared by varying SMF and MK content (0 to 30%), SMF and MK temperature (ambient to 700°C) at a constant sand to binder ratio of 2 and the water-to-cement ratio of 0.4. The experimental responses were used in the program to optimize the studied parameters, analyze the data statistically and develop prediction models. It was discovered that the flow is favored by the synergistic effect of high-volume SMF with low calcination temperature or MK with high calcination temperature. On the other hand, early strength development is favored by high-volume MK with high calcination temperature or moderate-volume SMF with moderate calcination temperature. This study will help promote valorization of solid waste materials, minimize energy consumption, preserve natural resources, lower carbon footprints in the concrete sector and possibly attain reasonable technical advantages.