Effect of Silica Nanoparticles on Improvement in Compressive Strength of Aerated Lightweight Concrete

In this research¡ reinforced and unreinforced aerated concretes using a slush mixture of cement¡ sand¡ lime and Al powder in water and SiO2 reinforcement addition (0¡ 1 and 2 wt.%) were prepared and the effect of SiO2 nanoparticles on microstructure and compressive strength of the concretes were investigated. The results showed the homogenous pore size of microstructure and significant strength increases of 20 and 27% with the addition of 1 and 2 weight percentage SiO2 compared to unreinforced concrete after 28 days curing. The increase of compressive strength with addition of SiO2 is attributed to decrease in Ca(OH)2 content¡ homogenous pore size distribution and rapid formation of a continuous calcium silicate hydrate phase (C-S-H).