Impact of Unique Mixing Methodology on Macro and Microstructural Characteristics of Concrete Containing Slag and Fly-Ash (2023-01)¶

The main aim of the study is to determine the effect of dissolving slag in water. Two mixing procedures were studied. Initially, a standard mixing procedure was adopted in which slag is mixed directly with the other concrete constituents. Secondly, a unique mixing process was adopted wherein slag is dissolved in water for a fixed period of time in prior to its addition with the other concrete constituents. The study was carried out using five percentages of slag—0%, 2.5%, 5%, 10%, 20%. Unique mixing process has shown a better performance as compared to the standard mixing method. Highest compressive strength of concrete was obtained at 2.5% slag replacement with 1 h immersion period. The optimum percentage of 2.5% slag replacement was fixed using unique mixing method and further substitution of cement was carried out using fly ash by adding directly. Fly ash percentages of 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40% were used in the study. The final optimum mix which was obtained was compared with the control mix and the mix corresponding to the standard mixing mode of slag and fly ash. Unique mixing procedure has been studied to reduce the problem of carbonation which is due to increased slag content in concrete. Till date, standard mixing procedure has been adopted and is implemented in the field. The change in the mixing methodology was adopted to be beneficial in places where slag is available. Hence, the effect of unique mixing methodology has been studied on ternary blended concrete to reduce carbonation depth, carbon foot print and to maximize the mechanical strength of concrete with reduced slag content.