Correlation between compressive strength and elastic modulus of light weight self-compacting concrete using coconut shell as coarse aggregate

Aggregates are the fundamental ingredient for making concrete. The incremental demand for aggregates in concrete is affecting the environment due to excessive exploitation of natural rocks. In an effort to conserve the natural resources and minimise the adverse impacts of industrial by-products in the environment, it is essential to explore the suitable alternate materials for construction. Under such circumstances, an attempt was made with coconut shell aggregate (CSA) as a substitute for conventional coarse aggregate (CA) in self-compacting concrete (SCC). In this investigation, binary and ternary blended SCC were developed using the mineral admixtures such as rice husk ash (RHA) and silica fume (SF). Two series of SCC were designed with the total powder content of 450 and 550 kg/m(3) , respectively, for investigation. The effects of CSA in SCC on fresh and hardened properties were studied and compared with the results obtained without CSA. The results revealed that use of 75% CSA in SCC reduced the density below the threshold level of structural lightweight concrete (1850 kg/m(3)) in dry state. The CSA-based lightweight self-compacting concrete (LWSCC) possesses good fluidity, deformability, passing ability and filling ability in its fresh state. The compressive strength and elastic modulus of LWSCC were determined and found that the results are decreased after the substitution of more than 75% of CSA. Further, the paper intended to predict an appropriate correlation between compressive strength and elastic modulus of CSA-based LWSCC.