The Effects of the Fineness Level of Rice Husk Ash as a Partial Cement Substitute in Self-Compacting Concrete (SCC)

Abstract

Rice husk ash (RHA) is recognised as a sustainable mineral additive derived from waste. The substitution of a portion of cement with RHA could improve the mechanical characteristics of concrete, leading to the increased adoption of Self-Compacting Concrete (SCC). The properties of rice husk ash need to satisfy specific criteria to ensure its reactive qualities are fully effective, including the fineness of the husk ash. The quality can be achieved using a filtering technique to obtain the RHA with a certain level of fineness, with division in several zones, 0,1,2,3 and 4. RHA from each zone partially replaces 10% cement in the SCC mixture. To obtain the physical characteristics of SCC, tests were carried out in the fresh phase, which includes slump flow, V-Vunnel, and L-box tests. Meanwhile, compressive strength, flexural strength, and modulus of elasticity tests were conducted to obtain the mechanical properties of the mixture. The results of the fresh concrete test showed that all mixtures are qualified as SCCs, and the results of the hardened concrete test suggested that the fineness of RHA enhances its mechanical properties.