Controlling amount of free chloride ion for prevention chloride-induced corrosion of reinforcement bars by chloride ion-absorbent

It is of great importance for controlling content of free chloride ion in concrete to improve durability of reinforced concrete structure exposure to chloride ambient condition. A chloride ion-absorbent is developed to reduce free chloride ion in concrete in this paper. Experiments are carried out to investigate the effects of absorbent, GGBS and FA on amount of free chloride ion in concrete. And the effect of absorbent on ingress depth of chloride ion into concrete is also discussed. Further, the corresponding mechanism is presented. Results indicate that the capability of paste binding chloride ion can be enhanced greatly by addition of chloride ion-absorbent. Compared with FA and GGBS particles, absorbent is much more effective in reducing free chloride ion of paste. Coupling with GGBS and absorbent, free chloride ion of sample can be further reduced. The ingress depth of chloride ion in sample with absorbent greatly decreases, which results in remarkable extending service life of concrete structures and decrease the risk of chloride ion-induced reinforcement corrosion within designed service life.