Properties of sustainable self-compacting concrete made with rice husk ash

Abstract

Rice husk ash (RHA) is an agricultural by-product obtained from incineration of abundantly available rice husk (RH) which can be used as a substitute for cement. In this study, RHA up to 30% has been utilized as partial replacement of cement by weight along with fly ash as one of the components in self-compacting concrete (SCC). Experimental programs were conducted to evaluate the fresh properties of SCC. Strength properties i.e. compressive strength, splitting tensile strength, and durability properties such as sorptivity, water absorption & porosity, rapid chloride permeability test (RCPT), sulphate resistance were also evaluated up to the age of 365 days. It was found that the inclusion of RHA up to 15% had a positive effect on strength properties while durability properties improved significantly at all replacement levels of RHA. The compressive strength results were verified with microstructure analysis using scanning electron microscope (SEM). Moreover, it was observed that material cost savings of up to 18% can be achieved by using up to 30% of RHA along with reduction in the carbon footprint and embodied energy. Multi linear regression models were established to predict the strength and durability properties at different curing ages and replacement levels of RHA.