Mechanical and microstructural properties of concrete with partial replacement of fine aggregate by steel slag and cement by GGBFS and Metakaolin

In recent decades the use of slag materials was increased in the preparation of building materials like Concrete, Bricks, Supplementary Cementous Materials (SCMs) to control the environmental problems in the view of sustainability and the safe management of waste materials. This research was conducted to study the Mechanical and Microstructural properties of concrete with partial replacement of Fine Aggregate by Steel Slag and Cement by GGBFS and Metakaolin. In this study, M40 grade concrete was considered as parametric study with partial replacement of fine Aggregates with Steel slag along with a constant amount 20% of Metakaolin by replacing cement with varying percentages of GGBFS. The study of mechanical properties was carried out and micro structural properties (SEM and FTIR analysis) was performed. The experimental works shows that the cement replaced with 40% of GGBFS, 20% Steel Slag and 20% of metakaolin had shown optimum results that is 53.7% raise in compressive strength, 28.19% increment in Flexural strength and 3.7% raise in Split tensile strength when compared to conventional concrete and further increase in quantity of GGBFS had shown decline phase. From the SEM and FTIR analysis shown that the formation of C–S–H gel was good at 40% GGBFS and beyond this, the formation C–S–H gel was not appropriate. Finally, this study was concluding that the use of slag materials in the concrete preparation will improves the properties of concrete at the amount of 40% GGBFS, and 20% of Steel Slag along with Metakaolin and also reduces environmental problems and make best from waste.