Nitrate reducing CaCO₃ precipitating bacteria survive in mortar and inhibit steel corrosion

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• 作者：Yusuf Ç ; ağatay Erşan^a ; ^c ; Hilke Verbruggen^b ; Iris De Graeve^b ; Willy Verstraete^a ; ^d ; Nele De Belie^c ; Nico Boon^a ; ^{Nico.Boon@UGent.be" class="auth_mail" title="E-mail the corresponding author} ;
• 关键词：Aggressive environment ; Self-healing ; Nitrite ; Denitrification ; Protective carrier
• 刊名：Cement and Concrete Research
• 出版年：2016
• 出版时间：May 2016
• 年：2016
• 卷：83
• 期：Complete
• 页码：19-30
• 全文大小：1642 K

文摘

Microbial healing of concrete cracks is a relatively slow process, and meanwhile the steel rebar is exposed to corrosive substances. Nitrate reducing bacteria can inhibit corrosion and provide crack healing, by simultaneously producing NO₂⁻ and inducing CaCO₃ precipitation. In this study, the functionality of one non-axenic and two axenic NO₃⁻ reducing cultures for the development of corrosion resistant self-healing concrete was investigated. Both axenic cultures survived in mortar when incorporated in protective carriers and became active 3 days after the pH dropped below 10. The non-axenic culture named “activated compact denitrifying core” (ACDC) revealed comparable resuscitation performance without any additional protection. Moreover, ACDC induced passivation of the steel in corrosive electrolyte solution (0.05 M NaCl) by producing 57 mM NO₂⁻ in 1 week. The axenic cultures produced NO₂⁻ up to 26.8 mM, and passivation breakdown and pitting corrosion were observed. Overall, ACDC appears suitable for corrosion resistant microbial self-healing concrete.