Partial replacement of fine aggregates with metakaolin

SUMMARY

The results indicate that partially replacing fine aggregates with metakaolin powder of grade 20 concrete is at its highest compressive strength at 20% replacement for 28 days and above, also 10% and 15% partial replacement percentages at 28 days and above seem to perform better than grade 20 conventional concrete. On the other hand, all other partial replacements for grade 30 and 40 seem to perform less than conventional concrete of grade 30 and 40.  For the other percentages though having significant increase, decrease and vice versa , the compressive strengths closest to the control are at 28 days, showing that a supplementary cementitious material such as metakaolin partially replacing fine aggregate at percentages higher than 20% may acquire an increase in compressive strength at days later than 28 days. It proves to be a suitable replacement for fine aggregate at 20% partial replacement for grade 20 concrete only. It is not suitable for grade 30 and 40 concrete.