Investigate and comparison effect add amorphous and crystalline-nano SiO2 on properties of concrete

الملخص EN

In this paper, the study included the comparison between amorphous silica and crystalline silica (quartz), and with nano scale size, two types of silica were added to concrete by ratios (5 %, 10 %, 15 %, and 20 %) as a replacement by the weight of cement.

Destructive and non-destructive tests were conducted on the specimens, the results show in destructive test the compressive and tensile strength increase in 15 % wt addition ratio in both types of silica, but in amorphous silica was high than in quartz.

The results of non-destructive tests show in (Schmidt Hammer) the 15% ratio in both kinds of silica show high hardness than other ratios.

Ultra sonic (pules velocity) test, noted the better quality was in 15 % ratio in amorphous silica and also show fastest pules velocity.