Effect of Nano-Silica on the Mechanical Properties and Durability of Concrete

Abstract

Nanotechnology offers a route to enhancing the performance of constructionmaterials, and the addition of nano-silica to concrete has attracted particularattention because of its high reactivity and fineness. This paper investigatesthe effect of nano-silica on the mechanical properties and durability ofconcrete. Concrete mixes were prepared with nano-silica partially replacingcement at several dosages, and the compressive strength was measured atearly and standard ages, while the durability was assessed through waterabsorption and resistance to chloride penetration. The results show that theaddition of nano-silica increased the compressive strength up to an optimumdosage, beyond which the strength declined owing to the agglomeration of the nanoparticles, and that at the optimum dosage the durability was markedly improved, with reduced water absorption and chloride penetration. The improvements are attributed to the filling of pores and the acceleration of cement hydration by the highly reactive nano-silica, which refine themicrostructure. The study demonstrates that an optimal dosage ofnano-silica enhances both the strength and durability of concrete, illustrating a beneficial engineering application of nanotechnology. KEYWORDS: Nanotechnology, Nano-Silica, Concrete, Compressive Strength, Durability, Cementitious Materials, Civil Engineering