In today’s world, industries and agriculture produce a lot of waste materials like slag, fly ash, rice husk ash (RHA), and red mud. These wastes create serious environmental problems when dumped. A new method called geopolymerization can help use these waste materials in a useful way by turning them into strong building materials using sodium hydroxide (NaOH).

In this study, four waste materials slag, fly ash, RHA, and red mud were mixed with different amounts of NaOH (5%, 10%, and 15%). Tests were done to find out how much water and how tightly these mixtures can be packed. Then, cylindrical samples were made and kept at room temperature for 0, 7, and 28 days. Their strength was checked using a compressive strength test, and the chemical changes were studied using an X-ray test (XRD).

Results showed that slag and fly ash became much stronger when mixed with NaOH especially slag with 10% NaOH, which reached around 27 MPa strength in just 7 days. Fly ash also showed good strength after 28 days. RHA had lower strength at first, but improved after 28 days. Red mud gave better results only at 5% NaOH; higher NaOH made it weaker. The X-ray test confirmed that a special bonding material was formed, which helped improve the strength. This study shows that using waste materials with NaOH can create eco-friendly and low-cost construction materials, helping reduce pollution and save natural resources.