Production of silica fume-based geopolymeric foam

Shakouri, Sahra
This study investigates the activation of silica fume powder with sodium hydroxide solutions, to produce foamy geopolymeric material. The powder was mixed with NaOH solutions of different concentration, at different solution-to-powder ratios and cured at 100 °C for different length of time. Upon to heating to 200-500 °C, a volume expansion up to 10 times of the initial paste volume took palace, and a porous structure resulted. Ground perlite, expanded perlite and basalt fibers were tested as additives to the initial mixtures. The main goal of this study was to reach a uniform foamy structure with as low density as possible. The final density of materials decreased to as low as ~50 kg/m3. The morphological characteristics of samples were investigated by SEM analyses performed on heat treated products. Compressive strength of expanded materials ranges between 50 kPa and 1 MPa. Also the structural evolution of pastes was determined using FTIR spectroscopy and 29Si MAS NMR measurements. Pore size distribution and pore volumes measured by nitrogen adsorption and x-ray microcomputed tomography.
Citation Formats
S. Shakouri, “Production of silica fume-based geopolymeric foam,” M.S. - Master of Science, Middle East Technical University, 2017.