Effect of using nano-silicates in concrete strength properties (A laboratory study)

The presented study attempted to investigate mechanical properties of concrete containing nanosilicates based on experimental uniaxial compressive strength test (UCS). For this purpose, different nanosilica dosages including 0%, 2%, 4% and 6% with considering the cement/water ratio are used to preparing the totally 10 mixing scheme and 30 concrete laboratory samples (10×10×10 cm cubic specimens) which is tested under 7, 28 and 90 days age. According to the experimental results by increasing the amount of nanosilica in the samples, UCS is increased and mechanical properties of concrete improved under loading. But in 6% nanosilica specimens incremental slope is get smooth then 4% nanosilica specimens. This was also observed for the 28-day and 90-day samples. In the meantime, some samples containing 6% nanosilica under uniaxial pressure experienced a resistance drop in strength features, indicating a decreasing trend of durability improvement at values above 6% nanosilica.