Amorphous Silica in Siliceous Pozzolans: A Rapid Method for its Determination

摘要

Different non-aqueous solvents (NAS), such as ethylene glycol, 1,2-propylene glycol and glycerol, were tested in the study of the behavior of NAS/SiO_2-rich pozzolans (rice husk ash, RHA, and silica fume, SF). Dissolved SiO_2 in NAS/pozzolan mixtures was evaluated by several procedures: a) electrical conductivity measurements of the suspension; b) weighing of non-dissolved matter in reflux conditions; and c) titration using barium hydroxide solution. The obtained results were compared to those obtained by the reference method (solubility in boiling KOH solution). A good correlation between data obtained in NAS and the reference method was observed.