Influences of Mineral Admixture and Corrosion Solution on Corrosion Behavior of Steel Bar in Concrete

The corrosion behavior of reinforced bar in concrete with mineral admixture including fly ash and ground granulated blastfurnace slag (GGBS) was studied by electrochemical impedance spectroscopy(EIS). And the influence of corrosion solutions including seawater, sodium chloride and composite solutions on EIS of steel bar was also researched. The experimental results indicated that the compressive strength of C30 concrete mixed with 30% fly ash and 30% (mass ratio to concrete) GGBS decreased by 45% and 35%, respectively. And the loss of compressive strength of concrete increased with increasing replacement rate of mineral admixture. And the corrosion rate of steel bar in solutions decreased in the following order, composite solution> sea wate> chloride solution. The corrosion resistance capacity of concrete was the best when 15%-20% GGBS, or 15% fly ash was used to replace the cement. And then the resistance capacity of concrete decreased with increasing replacement rate of mineral admixture.