Performance of Nano-SiO2 and Nano-ZnO2 on Compressive Strength and Microstructure Characteristics of Cement Mortar

Abstract

Nanotechnology is the most active research areas in the field of Civil Engineering with both advance science and beneficial applications that has gradually established itself in the last two decades. This article reports an investigation on effects of nanozinc oxide (NZ) and nanosilica (NS) on the rate of hydration, characteristics of interfacial transition zone and compressive strength of plain cement mortar with single and combined nanoparticle. Two different nanoparticles of percentages 1, 3, and 5 by weight of cement were considered. Workability test was conducted to obtain rheological properties of cement mortar. Compressive strength results were calculated at 7 and 28 days. The results showed that 1, 3, and 5% by weight of cement provide the better compressive strength for NS when used on their own but there was a decrease in NZ with the same quantities. For all combinations, the strength was comparable with that of plain cement mortar. The rate of hydration was high for 1 and 3% of NS as it was low for other nanoparticles. Microstructure of the cement mortars at the interfacial transition zone (ITZ) was assessed by scanning electron microscopy (SEM). There was an increase in strength of specimens due to more packed pore structure of mortar containing NS and NZ when observed through the SEM images. 3NS was the optimum among all the varying percentages of nanoparticle.