Effect of nanoparticles on the hydration of NaOH‐activated GGBFS

The effect of nanoparticles and nucleation seeds on the hydration kinetics of alkali-activated materials is not well understood. Implications of nano-TiO2 (nTiO2) and C–S–H nucleation seeds (XSeed) on the early-age hydration and later-age properties of sodium hydroxide-activated ground granulated blast furnace slag were investigated. The effect of NaOH concentration (0.5, 1, 2, and 4 M) in the activator solution was reported. Results indicated the acceleration of early hydration kinetics with mixes of XSeed and nTiO2 when the concentration of the activator solution was 0.5/1 M. No considerable effects were noted with XSeed addition for 2/4 M, whereas there was an acceleration with the addition of nTiO2. These differences were attributed to the lack of dispersion of XSeed at higher activator concentrations. Hydrate phase assemblage did not change with the addition of nanoparticles by 28 days of hydration. Increase in strength, along with pore refinement, was observed with the incorporation of nanoparticles.