Lightweight Heat Resistant Geopolymer-based Materials Synthesized from Red Mud and Rice Husk Ash Using Sodium Silicate Solution as Alkaline Activator

¹ Faculty of Chemical Technology, Ho Chi Minh City University of Food Industry, 140 Le Trong Tan Str, Tan Phu Dist., Ho Chi Minh City, Viet Nam
² Faculty of Materials Engineering, Ho Chi Minh City University of Technology, 268 Ly Thuong Kiet Str, Dist. 10, Ho Chi Minh City, Viet Nam
³ Center of Excellence, Geopolymer & Green Technology (CeGeoGTech), School of Material Engineering, Universiti Malaysia Perlis (UniMAP), Perlis, Malaysia

^* Corresponding author: thangnh@cntp.edu.vn

Abstract

Geopolymer is an inorganic polymer composite with potentials to replace Ordinary Portland Cement (OPC)-based materials in the future because of its lower energy consumption, minimal CO₂ emissions and lower production cost as it utilizes industrial waste resources. Hence, geopolymerization and the process to produce geopolymers for various applications like building materials can be considered as green industry. Moreover, in our study, the raw materials we used are red mud and rice husk ash, which are are industrial and agricultural wastes that need to be managed to reduce their impact to the environment. The red mud and rice husk ash combined with sodium silicate (water glass) solution were mixed to form geopolymer materials. Moreover, the geopolymer specimens were also tested for heat resistance at a temperature of 1000°C for 2 hours. Results suggest high heat resistance with an increase of compressive strength after exposed at high temperature.