Effects of metakaolin and treated rice husk ash on the compressive strength of concrete

Cement industry being source of emission of carbon dioxide (CO₂) causing global warming; it is necessary to source for alternative binder in concrete. The problem of longer age strength attainment by pozzolanic blended concrete calls for introduction of treated pozzolans. This paper investigates the influence of co-addition Metakaolin (MK) and Treated Rice Husk Ash (TRHA) in the production of concrete. The kaolin was calcined at a temperature of 650°C for 2 hours and thereafter, characterized. Furthermore, the rice husk (RH) was roasted to temperature of 700°C and thereafter, treated with H₂SO₄. MK was replaced in varying percentages of 0%, 5%, and 10%. Thereafter, TRHA was added by weight of the cement in varying percentages of 1%, 2%, and 3% to the optimum MK replacement (5%). From the results, it was found that concrete with 5% MK and 2% TRHA had enhanced compressive strength as against the control. Hence, it can be inferred that 5% MK and 2% TRHA concrete could be used in the construction industry. The increase in the strength properties of the concrete could be as a result of additional binding tendency exhibited by MK and TRHA.