the effect of chloride ions on the resistance of concretes containing aerogel under sodium sulfate attack

An experimental study was conducted to evaluate the damage progress of concretes containing aerogel powders subjected to sodium sulfate (na 2so 4) and combination of sodium sulfate and sodium chloride (nacl) attack under wetting–drying cycles. the amount of aerogel was considered at levels of 0.0, 1.75, 3.5, 5.25, and 7.0% of the concrete volume. the mechanical and physical properties of the concretes as well as the compressive strength and weight changes, and electrical resistivity were measured under the corrosive environments up to 12 months of exposure. results indicated that the use of 1.75% aerogel improves the mechanical and physical properties of the concrete. however, these properties declined by further increase of aerogel percentage. also, the aerogel usage up to 5.25% can increase the durability of concretes under sulfate attack. furthermore, the presence of chloride ions reduces the concrete deterioration under the sulfate attack, but it increases the probability of steel corrosion in the sulfate environment.