Fly Ash-Geopolymer Foam Activated in Alkaline Environment Based on Potassium

Fly ash-geopolymer foam was made under the conditions of choosing an alkaline activator solution composed of potassium hydroxide and potassium silicate compared to the sodium-based ones usually used. The adopted expanding agent was sodium perborate substituting the known hydrogen peroxide (H2O2), silica fume was chosen due to its ability for increasing the foam strength, and olive oil was the agreed surfactant replacing more effective but more expensive materials. The results showed porous products with excellent heat-insulating properties and simultaneously satisfactory compression and flexural resistance obtained at an early age (7 days) the quality level being almost similar to that of the best products worldwide.