Utilization of Rice Husk Ash as partial replacement with Cement for production of Concrete Brick

Department of Silicate Materials, Faculty of Materials Technology, Ho Chi Minh city University of Technology, VNU-HCM

^* Corresponding author: letuanminhsx@gmail.com

Abstract

Rice husk ash (RHA) obtained from agricultural by-product could be a potential source for partial cement replacement to produce concrete brick. In this study, primary RHA and RHA heat-treated at 500oC were used to substitute cement in raw material mixtures. Preliminary analyses were conducted to evaluate some properties of RHA such as loss of ignition (LOI), morphology, chemical and phase compositions. X-ray Powder Diffraction (XRD) and X-Ray flourescence (XRF) results indicated that silica (SiO₂) is the major component of RHA. Transmission Electron Microscopy (TEM) images showed that RHA particles were in polygonal shapes with diameter approximately from 300 nm – 1 μm. Cement was replaced with RHA by weight at 10 %wt. The effects of RHA on the physical and mechanical properties of the aggregate cement bricks were investigated. Results demonstrated that the compressive strength of concrete bricks increased with age at curing and decreased as the percentage of RHA content increased. It is recommended that further studies should be carried out to achive optimum parameters for production of concrete brick in economic aspects.