Study on mechanical properties of ternary blended concrete containing two different sizes of nano-SiO2

Abstract

The aim of this study was to investigate the influences of combination of the two different SiO2 nanoparticles (15 nm and 80 nm) on compressive, flexural and tensile strength of ternary blended concrete. SiO2 nanoparticles with two different sizes of 15 and 80 nm have been used as a partial cement replacement by 0.5, 1.0, 1.5 and 2.0 wt.% in 16 different proportions of mixture followed by curing in lime solution for 7, 28 and 90 days. The results indicate that in all curing ages in lime solution specimens with 2.0% of 15 nm plus 1.5% of 80 nm cement replacement achieved higher mechanical properties. The continuous cement paste with the lowest delicate zones might be due to the fact of quick formation of C–S–H gel in the existence of ultra-high dynamic nanosized SiO2 in both average particle sizes together with their high filler effect. It was concluded that the use of novel ternary blended concrete provides significant improvement in the all mechanical properties of concrete. In other words, increasing in the strength could be due to this fact that the nucleus of strengthening gel might merely reach to the critical volume of nucleation.