2025, Volume 71(75), Issue 1 (January), pp. 23 - 35

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

LUCIAN PĂUNESCU, Daily Sourcing & Research SRL Bucharest, Romania, lucianpaunescu16@gmail.com
ENIKÖ VOLCEANOV, National University of Science and Technology “Politehnica”, Faculty of Engineering in Foreign Language, Bucharest, Romania; Metallurgical Research Institute SA Bucharest, Romania
BOGDAN VALENTIN PĂUNESCU, Consitrans SA Bucharest, Romania

pages 23 - 35   Download
DOI: 10.5281/zenodo.15062734

Abstract
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.
Keywords: fly ash, geopolymer foam, sodium perborate, silica fume, heat-insulating properties