Chloride ion penetration resistance of concrete containing fly ash and silica fume against combined freezing-thawing and chloride attack

Chloride ion penetration resistance (CPR) of concrete containing fly ash (FA)/silica fume (SF) against combined freezing-thawing and chloride attack was studied. The total charge passed, immersed in tap water and sodium chloride solution, subjected to 50 freezing-thawing cycles was evaluated. It was found that immersed in tap water, SF had more evident improvement on concrete's resistance to combined effects than FA. Sodium chloride solution immersion for 41d prior to test was more aggressive than tap water. After 50 freezing-thawing cycles, CPR of concrete with FA increased, while that with SF decreased. Interaction between freezing-thawing and chloride attack accelerated concrete deterioration.