Method for producing geopolymer concrete from natural sand combined with red mud

A method for producing geopolymer concrete from natural sand (including desert sand, sea sand, river sand, and mined sand) and red mud, comprising the steps of:

• Preparing raw materials, including:
• Finely ground natural sand with a particle size of ≤200 microns, in an amount ranging from 50% to 95% by weight. Red mud, in an amount ranging from 5% to 50% by weight. Alkaline activator (NaOH, KOH, Na2SiO3, K2SiO3, Ca(OH)2, liquid glass, or their mixtures), added only if the alkalinity of red mud is insufficient to trigger geopolymerization, in an amount ranging from 0% to 20% by weight. Water, in an amount ranging from 5% to 30% by weight of the total mixture. Mixing the alkaline activator with water to form an activation solution (if needed), then thoroughly mixing with the sand and red mud to form geopolymer mortar. Shaping the geopolymer mortar by casting or pressing under pressure in molds to achieve the desired size and shape, wherein the shaping method may include hydraulic pressing, extrusion, rolling, centrifugal casting, vibration, or vibro-compaction. Hardening the material by drying at temperatures ranging from 60 °C to 250 °C to obtain geopolymer concrete.