TITLE:
Geopolymer Foamed Mortars Based on Pozzolan: Structure, Physical and Mechanical Behavior as Function of Metakaolin Addition
AUTHORS:
Gustave Tchanang, Mamadou Yaya Baldé, Jean Marie Kepdieu, Ansoumane Keita, Berthelot Sop Tamo, Franc-Zobel Kouakep, Cyprien Joel Ekani, Chantale Njiomou Djangang, Phillipe Blanchart
KEYWORDS:
Pozzolan, Metakaolin, Foam, Geopolymer Mortar, Properties
JOURNAL NAME:
World Journal of Engineering and Technology,
Vol.14 No.2,
March
20,
2026
ABSTRACT: To obtain porous mortars, sand and a foaming agent were added to geopolymer pastes. The latter were made by mixing an activating solution made of sodium silicate and sodium hydroxide with an aluminosilicate powder, primarily composed of pozzolan which was gradually replaced with metakaolin at 20%, 30%, and 40% by weight. Metakaolin was added as an accelerator to promote a higher compressive strength. The microstructures of the mortars were changed by the addition of a foaming agent, resulting in increased porosity as confirmed by the values of the open porosity and water absorption, attaining 27.6% - 73.3% and 14.9% - 40.2%, respectively. These materials are referred as porous and lightweight mortars due to their relatively low density between 1.51 - 1.7 g/cm3. The mechanical strength is in the range of 12.4 - 16.1 MPa, which is consistent with that of some structural materials. The obtained materials may be of potential interest in civil engineering, trapping, storage, as well as in thermal and acoustic insulation.