海洋微生物对C40混凝土耐腐蚀性能的影响

Influence of marine microorganisms on the corrosion resistance of C40 concrete

将C40混凝土分别置于灭菌海水、富集硫酸盐还原菌(SRB)海水和富集铁细菌(IOB)海水中干湿循环2400 h,通过化学滴定法和交流阻抗谱(EIS)研究了SRB菌和IOB菌对混凝土耐腐蚀性能(氯离子扩散规律)的影响。结果表明:SRB和IOB微生物膜层均呈龟裂状态,无法有效阻隔海水侵蚀;SRB和IOB降低了混凝土内部的pH值;经SRB和IOB腐蚀后混凝土的氯离子扩散系数分别为4.65×10^(-10)m^(2)/s和4.20×10^(-10)m^(2)/s,比灭菌海水环境下分别提高了63.16%和47.37%。

C40 concrete was exposed to sterile seawater,rich SRB seawater and rich IOB seawater for 2400 h respectively for dry wet cycle corrosion.The influence of SRB bacteria and IOB bacteria on the corrosion resistance of concrete(chloride ion diffusion law)was studied by chemical titration and electrochemical impedance spectroscopy(EIS).The results show that both SRB and IOB microbial membranes are in a cracked state,which cannot effectively block seawater corrosion.SRB and IOB reduce the pH value inside the concrete.The chloride ion diffusion coefficients of concrete corroded by SRB and IOB are 4.65×10^(-10)m^(2)/s and 4.20×10^(-10)m^(2)/s,respectively,which are 63.16%and 47.37%higher than that of concrete in sterilized seawater.