2 Citations (SciVal)

Abstract

This study determined the impact of oxygen and water on the crack healing performance of bacteria-based self-healing cementitious composites (BBSHCCs). Oxygen and water are considered essential to BBSHCCs using non-ureolytic bacteria, but in practice, the availability of either, for even short periods of time, cannot be guaranteed in the immediate aftermath of a crack forming. In this study, four healing regimes, (i) daily wet-dry cycle, (ii) weekly wet-dry cycle, (iii) semi-submerged and (iv) a deposition medium, were utilised to compare the impact of oxygen and water on the performance of BBSHCCs. Furthermore, an oxygen-releasing coating (ORC) containing calcium peroxide was evaluated and used in this study to further understand the function of oxygen in bacteria-based self-healing. Results showed that bacteria-based self-healing was only effective in wet conditions that also permit oxygen to penetrate the crack. Where there was a possibility for the composite to dry, after cracking, despite being wet some of the time the self-healing was far less efficient. It was observed that an overdose of nutrients and calcium in the healing environment resulted in early rapid healing, followed at a later stage by the dissolution of the initially formed precipitates. Moreover, it was found that the ORC contributed significantly to the recovery of both crack width and water tightness of samples. These findings will aid the development of appropriate test standards for self-healing cementitious composites and for the design and implementation of such cementitious composites in practice.
Original languageEnglish
Article number105201
JournalCement and Concrete Composites
Volume142
Early online date7 Jul 2023
DOIs
Publication statusPublished - 30 Sept 2023

Bibliographical note

Funding Information:
The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Kevin Paine reports financial support was provided by Engineering and Physical Sciences Research Council.The authors acknowledge the Engineering and Physical Sciences Research Council (Grant No. EP/P02081X/1) and Industrial collaborators/partners for funding the Resilient Materials for Life (RM4L) project. The authors gratefully acknowledge the technical staff in the Department of Architecture and Civil Engineering, the Department of Biology and Biochemistry and the Material and Chemical Characterisation Facility (MC2) at the University of Bath (https://doi.org/10.15125/mx6j-3r54) for their key support.

Funding Information:
The authors acknowledge the Engineering and Physical Sciences Research Council (Grant No. EP/P02081X/1 ) and Industrial collaborators/partners for funding the Resilient Materials for Life (RM4L) project . The authors gratefully acknowledge the technical staff in the Department of Architecture and Civil Engineering, the Department of Biology and Biochemistry and the Material and Chemical Characterisation Facility (MC 2 ) at the University of Bath ( https://doi.org/10.15125/mx6j-3r54 ) for their key support.

Publisher Copyright:

Keywords

  • Bacteria
  • Crack
  • Healing regime
  • MICP
  • Oxygen releasing
  • Self-healing
  • Water absorption

ASJC Scopus subject areas

  • General Materials Science
  • Building and Construction

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