| Author Name | Affiliation | Postcode | | Jie YUAN | 1. School of Transportation Science and Engineering, Harbin Institute of Technology, Harbin 150090, China | 150090 | | Xin CHEN* | 1. School of Transportation Science and Engineering, Harbin Institute of Technology, Harbin 150090, China
2. State Key Laboratory of Safety and Health for In-Service Long Span Bridges, JSTI Group, Nanjing 210019, China
| 210019 | | Mohammed Alazhari | 3. BRE Centre for Innovative Construction Materials, University of Bath, Bath, BA2 7AY, UK | | | Bo Yang | 1. School of Transportation Science and Engineering, Harbin Institute of Technology, Harbin 150090, China | 150090 | | Guorong Zhang | 2. State Key Laboratory of Safety and Health for In-Service Long Span Bridges, JSTI Group, Nanjing 210019, China | 210019 |
|
| 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 |
| Fund: |
