Influence of nano-silica on strength and gas permeability of concrete

The study presented herein was carried out to investigate the Influence of Nano-Silica (nS) on Strength and Gas Permeability of Concrete. Three different series of concrete mixtures were designed with various water/binder (w/b) material ratios of 0.33, 0.45, and 0.55. The nS was used 0%, 1%, 3%, and 5% of the binder by weight in the mixes. Superplasticizer was used in varying amounts to adjust the workability. All groups of mixtures was incorporated binary cementitious blends of 0%, 1%, 3%, and 5% nS with each ratio of 0.33, 0.45 and 0.55 of w/b. Totally, twelve concrete mixtures were cast and tested for mechanical and durability related properties such as compressive strength, water sorptivity, and gas permeability. The tests were conducted at 28 days after casting. Test results demonstrated that using the nS improved the strength and gas permeability properties of nS concretes. It was seen that the addition of nS enhanced the mechanical and durability properties of concrete depending on mainly nS content. The highest compressive strength observed at 3% of nS content as 66.7, 58.2 MPa with and without nS were obtained at first group, respectively.