Red Mud-Based Geopolymeric Clay Brick

Abstract

In earlier works, the successful fabrication of clay bricks using geopolymeric constitutes was done. In the present study, considering the increasing demand for sustainable and environmentally friendly construction materials, the red mud-based geopolymeric clay bricks were cast by utilizing the red mud as fresh caustic, since red mud has bound caustic which participates in the reaction and is used in bulk quantity. The objective of the present study is to utilize Bayer’s processed red mud from the alumina manufacturing process in clay bricks using geopolymeric approach. The production of geopolymeric bricks is considered to be one of the solutions to the ever-increasing red mud disposal problems. The geopolymeric bricks with alkali liquid to binder ratio 0.4 and sodium silicate to sodium hydroxide ratio 2.5 were studied. These bricks were optimized by varying the molarity of NaOH, along with the replacement of clay in clay bricks with varying percentages of fly ash, red mud, and curing conditions. The casted bricks were characterized by X-ray diffraction (XRD). The compressive strengths and water absorption of optimized red mud-based geopolymeric bricks were compared with conventional brunt clay bricks. The compressive strength of casted bricks was comparable to conventional clay bricks were as water absorption was less than 1.70%.