Study the Influences of Nano-Silica on Electrical Resistivity of Cement Paste

This paper presents the influences of adding nano-silica on electrical resistivity of cement paste, because the electrical resistivity test is one of the non-destructive test in durability issues that can help us to assess the resistance of cement is facing by ion attacks. Furthermore, because the transition area in concrete is one the weak parts of concrete. It is tried to improve the durability properties of transition area that is mainly filled by cement and water. So, this research focuses on assessing the electrical resistivity of cement paste when it is integrated with pozzolan material in nano and micro scale. In to end, the cement paste without any additive is compared with cement paste integrated with nano-silica and micro silica. The amounts of additive materials are limited to 2.5%, 5%, 7.5% and 10% of cement weight. The two types of nano-silica have been used in this research that are liquid suspended nano-silica and solid nano-silica particle. So, the 3 different pozzolan materials were used that include two different nano silica (liquid and solid) and micros silica. Then all the results have been compared with results of ordinary cement paste as reference point. Then the samples were tested at age of 3, 28 and 90 days. The results show that before age of 3 days, adding nano silica or micro silica led to decline the electrical resistivity because the pozzolanic reaction is not started, but at age of 28 days the top achieved electrical resistivity belong to the samples which has nano-silica in its mixture. However, after age of 28 days, just the samples with micro-silica have electrical resistivity growth. The results of the samples that contain the both of nano-silica and micro-silica are between the results of samples that contain micro-silica and the samples which integrated by nano-silica. Keywords: