Microstructural Characterisation and Durability Enhancement of Concrete with Nano Silica

Abstract

Deterioration of concrete due to chemicals is aggravated by entry of harmful liquids and gases through its pores. The porosity and pore structure of the concrete play a vital role in transporting harmful substance, due to capillarity and permeability. Concrete's density, strength and its pore structure can be improved by using Nano Silica (NS). In this study NS was used as an addition and it was proved to improve the properties of concrete. The Scanning Electron Microscope (SEM) image of sample with NS shows that the concrete has denser, more compact and better gel formation with fewer pores than concrete without NS. NS particles fill the nano sized pores in the concrete and improve the pore structure of the concrete. The weight loss of concrete due to sulphuric acid and hydrochloric acid was 27.53% less and 32.34% less respectively, when NS was added.