The effects of nano-silica and nano-alumina on frost resistance of normal concrete

In this study frost resistance and mechanical properties of concrete containing nano-silica and nano-alumina are studied. Nano-particles were employed as a partial substitute of cement. The specimens were subjected to cycles of freezing and thawing in water according to ASTM C666A. The reduction in compressive strength, loss of mass, change in length and water absorption of specimens was measured after specified number of freeze and thaw cycles. Experimental results showed that the frost resistance of concrete containing nano-particles were considerably improved, as result of a more compacted microstructure. It was also concluded that the frost resistance of concrete containing nano-Al2O3 was better than that containing the same amount of nano-SiO2. Compressive strength of normal concrete containing nano-SiO2 was higher than that containing the same amount of nano-Al2O3.