Published Paper Details:

This study investigates the influence of metakaolin (MK) and colloidal silica (CS) as partial replacements for cement on the mechanical properties of M60 grade concrete. Four mix proportions with varying MK (10% to 30%) and CS (0% to 6%) were evaluated for compressive strength, split tensile strength, and flexural strength at curing periods of 7, 14, and 28 days. Results indicate that the mix containing 10% metakaolin and 2% colloidal silica (MD2) exhibited the highest compressive strength, achieving up to 37% greater strength than the conventional concrete at 28 days. Split tensile and flexural strength tests showed improved performance with lower percentages of colloidal silica, with the optimal tensile strength also observed in the MD2 mix. Higher replacement levels (20%-30% MK and 4%-6% CS) led to a decrease in tensile and flexural strengths and did not consistently improve compressive strength beyond early curing ages. The findings suggest that 10% metakaolin combined with 2% colloidal silica is the most effective replacement for enhancing the overall mechanical properties of M60 grade concrete.