Effect of sodium silicate slurries on the properties of alkali-activated materials

Abstract

We have studied the effect of water glass prepared by a wet-chemical process on the principal properties of structural materials using alkali-activated mineral binders and determined the optimal hydrothermal leaching time for tripoli, corresponding to the maximum SiO₂ concentration in the water glass slurry. We have investigated the initial structure of the tripoli and the leaching-induced structural changes in its mineral component. The influence of three types of mixing agents has been analyzed in the context of the preparation of materials: water glass in the form of slurry, water glass slurry filtrate, and the filtered-off insoluble residue of the slurry in the form of thick mass. The strength of the obtained materials increases in the following order: insoluble residue < filtrate < slurry. The present results demonstrate that the materials have high strength characteristics and that water glass prepared by a wet-chemical process is potentially attractive for practical application.