The Effect of Nano-SiO2 on Cement Hydration

Abstract

The nanoparticles of SiO2 with a size range of 5–20 nm were synthesized in acidic and basic medium from tetraethoxysilane (TEOS) using sol–gel method. The effect of agglomerated nanoparticles on the hydration of portland cement systems was analyzed by X-Ray Diffraction technique. Experimental results demonstrate that developed nano-SiO2 produced in acidic medium accelerate the hydration by creating nuclei sites for the formation of C-S-H, whereas the nano-SiO2 produced in basic medium reacted like a pozolanic material. Most of the portlandite was consumed and transformed into C-S-H due to a pozolanic reaction producing a dense microstructure characteristic for composites with both types of nanoparticles.