Crack sealing evaluation of self-healing mortar with Sporosarcina pasteurii: Influence of bacterial concentration and air-entraining agent. (August 2021)

• Record Type: Journal Article
• Authors: Chen, Bingcheng; Sun, Weiwei; Sun, Xichen; Cui, Chong; Lai, Jianzhong; Wang, Yang; Feng, Jun
• Is Part Of: Process biochemistry. Volume 107(2021)
• Page Start: 100
• Page End: 111
• Publication Date: 2021-08
• Subjects: MICP -- Microbial mortar -- Sporosarcina pasteurii -- Flexural strength -- Bacterial concentration -- Air-entraining agent; Biochemical engineering -- Periodicals; Biotechnology -- Periodicals; Biochemistry -- periodicals; Biotechnology -- periodicals; Chemical Engineering -- periodicals; Génie biochimique -- Périodiques; Biotechnologie -- Périodiques; Biochemical engineering; Biotechnology; Periodicals; 660.63
• DOI: 10.1016/j.procbio.2021.05.001
• Languages: English
• ISSNs: 1359-5113

Abstract

Graphical abstract: Highlights: A novel self-healing mortar is produced with Sporosarcina pasteurii . 0.4-mm-width crack gap can be sealed rapidly within 7 days. About 13% flexural strength regain can be achieved. Abstract: Microbial induced calcium carbonate precipitation has been recognized as a novel pathway to repair concrete cracks. This study aimed to explore the application of Sporosarcina pasteurii in self-healing mortar preparation, and further investigate the influence of bacterial concentration and air-entraining agent content on crack sealing performance. X-ray diffraction and scanning electron microscope tests were carried out to identify the calcium carbonate in vaterite phase for biomineralization precipitations of S. pasteurii which was utilized for self-healing mortar beam specimens production. Subjected to 3-point-bending test, a V-shape crack was induced from the beam bottom with 0.4 mm width which can be automatically healed due to bacteria metabolic activity. Four different S. pasteurii concentrations, i.e., 0, 2 × 10 5, 2 × 10 6 and 2 × 10 7 cells/ml, were comparatively studied with respect to self-healing mortar property. In general, the higher bacterial concentration corresponded to faster crack healing and 2 × 10 6 cells/ml was deemed as the proper bacterial concentration. Afterwards, self-healing mortar with various air-entraining agent contents (0%, 0.005%, 0.01%, 0.015% and 0.02% of cementitious material) was also discussed, implying that best flexural strength regain is achieved at 0.01% air-entraining agent. Finally, the crack filling crystals were examined to find bacterial imprints leaving on the surface of calcium carbonate.