Effect of nano-silica on mechanical, microstructural and durability properties of cement-based materials: A review

Abstract

Nanotechnology is a cutting-edge technology that has proven beneficial in various engineering aspects. The use of nanomaterials in civil engineering has been a modern wonder. As recognised by researchers, the best utilization of nanomaterials in civil engineering is the use of nanomaterials to obtain sustainable and more durable concrete. Although significant research has been carried out in this field, variations in research outcomes have challenged scientists to comprehend nanoparticles before employing them. Different nanomaterials like carbon nanotubes, nano-silica, nano-alumina, nano-TiO2, and others have been used. Nano-silica (nS) has been extensively used as a partial replacement for cement or as a durability enhancer in concrete. This paper reviews the effectiveness of nano-silica as SCM in developing a sustainable cement-based material (CBM). Various properties of nano-modified CBM, such as fresh and hardened state (including mechanical and durability) properties, physical properties, and microstructural properties of CBM, are rigorously reviewed in this paper. This review also looks at different ways to disperse nS particles to stop them from agglomerating together, as well as how nS particle agglomeration changes the properties of nano-modified concrete. nS is a sustainable material that reduces greenhouse gas emissions. Synergistic effect of nS and other SCM, especially agricultural waste, which can reduce carbon footprints, is also considered in this review.