Corrosion Resistance of 2205 Stainless Steel Bar in Modified Coral Concretes
The effect of different modification schemes for strengthening the coral coarse aggregate,namely direct incorporation of fly ash,cement slurry or cement-metakaolin composite slurry,on the corro-sion rate of 2205 stainless steel bars in the coral concretes was comparatively assessed so that to search insight the way to improve the durability of stainless steel reinforced coral concrete structure.The results show that the 2205 stainless steel bar always maintained a passivation state in the coral concrete.The incorporation of fly ash can reduce the corrosion rate of 2205 stainless steel bar,but the direct addi-tion of fly ash may significantly decrease the strength of coral concrete.With P.O 52.5 cement slurry or P.O 52.5 cement-metakaolin composite slurry as modifier can strengthen coral coarse aggregate,but the strength of coral concrete prepared with the modified crude aggregate has little difference with that of the control group,while the corrosion rate of 2205 stainless steel bar in the coral concrete strengthened with the coarse aggregate is significantly reduced.Among others,the corrosion rate of 2205 stainless steel bar is the lowest in the concrete of coarse aggregate reinforced with P.O 52.5 cement-metakaolin com-posite slurry In conclusion,using P.O 52.5 cement-metakaolin composite slurry to enhance coral coarse aggregate can effectively improve the durability of stainless steel reinforced coral concrete structures by providing high strength and greatly reducing the corrosion rate of 2205 stainless steel bar.