| Related citation: | Jie Yuan,Xin Chen,Mohamed Alazhari,Bo Yang,Guorong Zhang.Characterisation of Bacteria-Based Concrete Crack Rejuvenation by Externally Applied Repair[J].Journal of Harbin Institute Of Technology(New Series),2020,27(4):20-30.DOI:10.11916/j.issn.1005-9113.18134. |
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| Author Name | Affiliation | | Jie Yuan | School of Transportation Science and Engineering, Harbin Institute of Technology, Harbin 150090, China | | Xin Chen | School of Transportation Science and Engineering, Harbin Institute of Technology, Harbin 150090, China
State Key Laboratory of Safety and Health for In-Service Long Span Bridges, JSTI Group, Nanjing 210019, China | | Mohamed Alazhari | BRE Centre for Innovative Construction Materials, University of Bath, Bath BA2 7AY, UK | | Bo Yang | School of Transportation Science and Engineering, Harbin Institute of Technology, Harbin 150090, China | | Guorong Zhang | State Key Laboratory of Safety and Health for In-Service Long Span Bridges, JSTI Group, Nanjing 210019, China |
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| Abstract: |
| Microbiologically-induced calcite-precipitation (MICP) has been increasingly studied in structural repair including self-healing and external applications. Among various MICP pathways, enzymatic urea hydrolysis is suggested to be applied as external repair instead of self-healing. This study comprehensively characterised the enzymatic urea hydrolysis pathway in physical, impermeable, and mechanical rejuvenation of concrete cracks. The visual quality of repaired structures was presented, and the importance of humidity in the remediation of cracks was demonstrated. Moreover, this study investigated the differences in the effectiveness of repair between premixing bacteria with urea and without any premixing. With premixing, there was a concern that the accelerated reactions would precipitate calcite in the shallow spaces of the cracks and impede deeper healing. However, the observed results indicated that neither physical nor impermeable rejuvenation of concrete cracks repair would be detrimentally affected. The results obtained from this study will allow further development in commercialisation since the effectiveness of repair has been confirmed with an improvement in its efficiency. |
| Key words: concrete crack rejuvenation bacteria repair agent relative humidity impermeability chloride penetration flexural strength |
| DOI：10.11916/j.issn.1005-9113.18134 |
| Clc Number:TU57+8 |
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| Descriptions in Chinese: |
| 应用细菌修补技术的混凝土裂缝性能恢复表征 袁杰1, 陈歆1,2*, Mohamed Alazhari3, 杨博1, 张国荣2 (1. 哈尔滨工业大学 交通科学与工程学院，哈尔滨 150090; 2. 苏交科集团股份有限公司在役长大桥梁安全与健康国家重点实验室, 南京 210019; 3. 巴斯大学 建筑材料创新中心, 巴斯 BA2 7AY, 英国) 中文说明：微生物诱导的方解石沉淀（MICP）在结构修复（包括自我修复和外部应用）中得到了越来越多的研究。在各种MICP途径中，酶促尿素水解被建议用作外部修复而不是自我修复。本研究综合描述了酶促尿素水解对混凝土裂缝物理、抗渗和力学性能的恢复效果，展示了修复结构的视觉质量，证明了湿度对裂缝修复的重要性。此外，本研究还考查了细菌与尿素预混合与否带来的修复效果差异。预混合带来的担忧是，其所致的加速反应会在裂缝的浅层空间中沉淀方解石并阻碍更深层空间中的愈合。然而，观察结果表明，混凝土裂缝修补的物理愈合或抗渗恢复都不会受到不利影响。从本研究中获得的结果证实了修复的有效性，同时提高了修复的效率，将进一步促进细菌基混凝土修补技术的商业化。 关键词：混凝土裂缝；性能恢复；细菌；修补剂；相对湿度；抗渗性；氯离子渗透；抗折强度 |
