Application of hydrogel encapsulated carbonate precipitating bacteria for approaching a realistic self-healing in concrete

Bacterial-based self-healing is a promising solution for sustainable concrete maintenance. In this study, bacterial spores were first encapsulated into hydrogels and then were incorporated into specimens to investigate their healing efficiency. The precipitation of CaCO₃ by hydrogel-encapsulated spores was demonstrated by Thermogravimetric analysis (TGA). The mortar specimens with hydrogel-encapsulated spores, showed a distinct self-healing superiority: the maximum healed crack width was about 0.5 mm and the water permeability was decreased by 68% in average. Other specimens in non-bacterial series had maximum healed crack width of 0-0.3 mm and the average water permeability was decreased by 15-55% only.