Investigation on Mechanical Properties of Cementitious Composites Cured in Colloidal Nanosilica SiO2 Solution

الملخص

Nano technology is one of the most widely searched techniques in the world nowadays. Several studies reported with nanoparticles are based on the nano-silica (nano-SiO2) addition to the fresh mix to improve the performance of concrete. Nano-SiO2 is highly reactive with calcium hydroxide and is able to act not only as a filler, blocking the concrete pores, but also as an activator to promote pozzolanic reaction. In this paper, the effect of different concentration of nano silica solution on concrete compressive strength have been studied (when using it in curing instead of water). Samples were made by adding fly ash (FA/PC= 1.2 and 2.2) and some were immersed in water and others in a solution of water and Nano SiO2 with different concentrations (0.5, 1, 2 and 3) %. Then the samples have submitted to compression test after 3, 7 and 28 days to notice the impact of using Nano silica solution in curing stage. Fly ash has been used in this experiment for several reasons. 1. Development of the mechanical properties of the cement-bonded composites. 2. Reduces the percentage of cement use and therefore environment will keep clean because the cement reaction produces CO2 which cause pollution to the environment.