Modification of Cement Matrix Using Carbon Nanotube Dispersions and Nanosilica

Abstract

Complex nanodispersed systems with multi-walled carbon nanotubes and nanodispersed silica have a significant impact on the processes of hydration, setting and hardening of construction composites with Portland cement binder predetermining their durability. The main effect of the modification of cement matrix in the case of adding complex nanodisperse systems is provided by the directed influence on the processes of hydration and subsequent crystallization of new products in hardened cement paste. The effect of the addition of the carbon nanotubes is analyzed and quantified by inspecting in each case one sample with nanotubes and one without by the help of a nanoindenter and another scanning electron microscope. Carbon nanotube dispersion and nanosized silica being added, the binding matrix is forming a perfect dense shell from crystalline hydrates on the surface of solid phase that provides strong binding matrix in cement concrete.