Effect of nanosilica and microsilica on bond and flexural behaviour of reinforced concrete

Abstract

Nanosilica is a recent addition to the group of pozzolanic admixtures in concrete, which is recognized as efficient in improving strength and durability of concrete. This paper presents a comparative evaluation of some structural properties, namely bond and flexural behaviour, of nanosilica added high-performance concrete, microsilica added high-performance concrete and a reference concrete. The experimental results show the beneficial effects of nanosilica addition on the structural properties of reinforced concrete. The nanosilica added high-performance concrete showed better concrete–rebar interface, higher bond stress, a fewer number of cracks with lesser crack width, higher ultimate load carrying capacity and an improvement in the ductile nature of concrete, compared to the other two concretes. The study concludes that nanosilica can be a promising pozzolanic admixture for structural concrete applications.