Self-healing by biocomposite containing metakaolin immobilized bacterial spores in concrete using low-cost corn steep liquor media

Abstract

The present study aimed to develop a biocomposite constituting metakaolin as a suitable carrier material for immobilizing bacterial spores. The biocomposite was stored at 4 °C and 25 °C and showed a sustainable shelf-life of bacterial spores during the storage period of 180 days. Biocomposite was assessed for urease activity and calcium carbonate precipitation in corn steep liquor (CSL) as the growth medium. Significant improvements in strength and permeation were observed at 7 and 28 days of testing in concrete added with biocomposite. The study was extended to test the self-healing capabilities of biocomposite in prismatic specimens using CSL medium. Crack healing showed significant improvement in ultrasonic pulse velocity, indicating progressive healing of the crack, and the repaired surface was examined by water tightness. The precipitated minerals were assessed by scanning electron microscopy and X-ray diffraction. The CSL can be used as low-cost growth media, eventually decreasing the cost of self-healing concrete.

Keywords:

• Metakaolin
• Bacterial spores
• Self-healing
• CSL
• Crack width
• flexural strength
• water tightness
• Ultrasonic pulse velocity

Data availability statement

Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request

Disclosure statement

No potential conflict of interest was reported by the authors.

Acknowledgments

The authors are thankful to the Department of Biotechnology, Ministry of Science and Technology, Govt. of India, for providing the research grant under BT/PR27190/BCE/8/1428/2017.

Additional information

Funding

This work was supported by Department of Biotechnology, Ministry of Science and Technology, India.