Effect of α: Phase Nano Al2O3 and Rice Husk Ash in Cement Mortar

Abstract

The study focused on the investigation of the influence of α-phase nano Al2O3 (NA) and M-sand as a fine aggregate on the partial replacement of cement by micro rice husk ash (MRHA) to enhance the mechanical properties and durability of mortar and achieve an environmentally sustainable material. MRHA was added to the M-sand cement mortar (by partial replacement of cement) at varying concentrations of 0%, 5%, 10%, 15%, and 20% by weight of cement; and NA was added at the rate of 0%, 0.5%, 1%, 1.5%, and 2% by weight of cement. The results showed that the partial replacement of cement by MRHA (10%) improves the comprehensive and tensile strength by 7% and 6.9%, respectively, compared to the control. Moreover, the incorporation of NA in cement increased the comprehensive and tensile strengths by 15.5% and 41%, respectively. The optimal increment in the combination of MRHA and NA (MN) in the partial replacement of cement resulted in a 26.4% comprehensive strength and a 48.72% tensile strength compared to the control. The flowability of M-sand mortar containing MRHA and NA was observed to vary depending on the degree of dosage and the admixture. Our study concludes that the partial replacement of cement by the admixtures MRHA (10%) and NA (1%) in combination improved the strength and reduced water absorption when compared to the individual effects and control, suggesting the application of MRHA and NA in concrete technology.