Optimum Mix Design of Rice Husk Ash-Based Geopolymer Concrete Based on Workability, Setting Time, and Compressive Strength Cured in Ambient Temperature Condition

Abstract

In this study, the Rice husk ash (RHA) was used to prepare geopolymer concrete. The effects of Rice Husk Ash (RHA) content, Sodium silicate to sodium hydroxide ratio (SSi/SHd), alkaline activator to binder content (RHA) ratio (Al’/Bd), sodium hydroxide concentration, superplasticizer content on the workability, setting time, and compressive strength of mixes were studied, to get better mix design with high strength and workability than standard concrete. The source material used was rice husk ash rich in silica, alkaline activator solution was the mixture of sodium silicate and sodium hydroxide, master glenium sky superplasticizer was used to improve workability. Based on workability, setting time and compressive strength test results, the most favourable mix design was found to have alkaline activator to RHA (binder) ratio of 0.4, sodium silicate to sodium hydroxide ratio of 2.0, binder content 500 kg/m3 and concentration of sodium hydroxide as 14 M. It was established that the properties of RHA based geopolymer concrete were better than standard conventional concrete.