Rice Husk Ash as Fine Aggregate Sustainable Material for Strength Enhancement of Conventional and Self Compacting Concrete

Rice husk ash (RHA) is a by-product of the rice milling industry. Near about 20 million tonnes of RHA is produced annually which creates environmental pollution. Utilization of RHA as a supplementary cementitious material adds sustainability to concrete by reducing CO2 emission of cement production. But, the percentage of utilization of RHA is very less. This paper presents the results of an experimental investigation to study the effects of partial replacement of fine aggregate with RHA on mechanical properties of conventional and self-compacting concrete (SCC). The fine aggregate is replaced by RHA in conventional concrete (CC) with six different percentage by weight such as 0%, 10%, 20%, 30%, 40% and 50% having w/c ratio 0.375 with variation of super plasticiser dose, whereas in SCC the replacement of fine aggregate by RHA is 0%, 10%, 20%, 30%, 40%. The design mix for CC is targeted for M30 grade concrete. The fresh concrete test of SCC is conducted by using slump flow, T500, J-ring, L-box, U-box and V-funnel to know the filling ability, flow ability and passing ability of SCC. As fresh concrete property concerned, the result indicates that the slump flow value satisfied the EFNARC 2005 guidelines upto 30% replacement of fine aggregate with RHA whereas 40% replacement did not satisfy the guideline. As hardened concrete property concerned, the compressive strength, split-tensile strength and flexural strength of CC and SCC are determined at 7, 28 and 90 days. The test result indicates that upto 30% replacement of fine aggregate with RHA enhances the strength in CC whereas the strength enhancement in SCC upto 20% replacement.