Abstract
The usage of nanomaterials in the construction industry is becoming more and more popular. Among the several types of nanomaterials, nano silica (NS) has drawn interest due to its high specific surface area and strong pozzolanic reactivity. By enhancing concrete’s performance, NS allows for the achievement of greater compressive strength and durability with less cement which lowers the carbon footprint associated with the cement production. Because they are substantially smaller than conventional supplementary cementitious materials (SCMs), NS particles are better able to fill the micropores in the cement matrix. This work provides a comprehensive analysis of earlier studies on the influence of NS addition on concrete properties. It investigates the impact of NS on the workability and setting time of fresh concrete. The study also explores how NS affects concrete mechanical characteristics, such as its modulus of elasticity, flexural strength, and compressive strength, with an emphasis on the underlying mechanisms driving these improvements. It is shown that NS apart from its filling ability, accelerates hydration process by acting as nucleation sites for hydration products to form through seeding effect. The microstructure becomes dense and pore size refinement occur. However, an ineffective NS dispersion serve as a barrier to add a larger percentage of NS to the cement paste. Overall, this research study offers insightful information about the potential of NS as an additive to improve concrete’s sustainability and performance.