Influence of Nanosilica and Microsilica on Mechanical and Microstructural Properties of Self-cured Fibre-Blended Concrete

The most significant engineering material is concrete. Concrete has a significant environmental impact since it contains cement, whose manufacture generates a lot of CO2. Partial replacement of cement by pozzolanic materials will alter the mechanical properties of concrete. In this research, we studied about the effect of cementitious materials like nanosilica and microsilica for the replacement of cement in a self-cured fibre-blended concrete on mechanical and microstructural properties. A 2%, 4%, 6%, and 8% dosage of microsilica partially replaced and 0.5%, 1%, 1.5% and 2% dosage of nanosilica partially replaced with cement and addition of constant dosage of 0.2% of polypropylene fibre concrete mixtures were prepared and cured internally with a constant dosage of 1% of polyethylene glycol-200. The outcomes showed that 0.5% of nanosilica replacement gives 23.3% and 17.5% strength increment in compression at 7 and 28 days, respectively. Also 8.0% of micro silica replacement gives 14% strength increment at 28 days. The addition of fibre improved the flexural and tensile strength of concrete compared to nominal mix concrete. From the microstructural studies, these supplementary cementitious materials reduce the voids in concrete, which leads to dense the concrete.