Assessment of mechanical properties of nano modified concrete

Abstract

Concrete is an adaptable material that is extensively used in the field of construction. To achieve higher strength and to increase the durability of concrete, mineral, and chemical admixtures were added to the concrete. In recent years Nanomaterials are used in concrete to study mechanical as well as durability properties. In this work, Nanosilica (NS) and Multi-Walled Carbon Nanotubes (CNT) were used in concrete. 1% of NS with 0.025%, 0.04%, and 0.055% CNT was furthermore added to the concrete. River sand was completely replaced with manufactured sand in the concrete. NS was hand mixed with the cement. CNT was dispersed with water using surfactant and an ultra-sonication process was carried out. The specimens were cast and tested after 28 days of curing. The mechanical properties of the nano modified concrete were assessed by conducting the compressive strength, flexural strength, and split tensile strength tests. The microstructure properties were analyzed by SEM analysis. The formation of calcium silicate hydrate and calcium hydroxide was observed using X-Ray Diffraction to show the hydration process. The mechanical properties of nano modified concrete were improved compared to the standard concrete. NS and CNT fill the micropores in the concrete which enhances the strength of nano modified concrete.