Incorporation of metakaolin and nanosilica in blended cement mortar and concrete- A review

The construction industries are focusing on the use of innovative, cost efficient and ecofriendly materials in infrastructural development. In view of this, there is need to search for alternative construction materials that can be used in place of the conventional normal concrete. There have been numerous materials that could be used as supplementary cementitious materials in concrete thereby making it sustainable and durable. Some of these materials are naturally occurring or byproducts of agro-based or manufacturing industries, and as well as agricultural wastes. Metakaolin being obtained from naturally occurring kaolin clay had been extensively used in place of cement in mortar/concrete making but much attentions have not been given towards considering the effect of the source of the clay on its reactivity properties as well as effect of factory blending approach of MK and clinker. Also, the delay in strength attainment of pozzolan blended concrete calls for incorporation of innovative materials that will enhance the development of strength at early stages. Nanoparticles are innovative construction materials obtained from green plants or chemical and have been shown to enhance the development of mechanical properties of mortar and concrete at low age of curing with enhancement in microstructural arrangement. There is need to explore more of the green method of synthesis as recent researches are tailored towards the reduction/eradication of greenhouse gases that could deplete the ozone layer. This article focuses on previous researches that have been carried out to investigate the effect of MK and nanosilica on the properties of mortar and concrete.