Deinococcus radiodurans: A novel bacterium for crack remediation of concrete with special applicability to low-temperature conditions

摘要

Typical bacteria used for the preparation of microbial concrete, such as from the Bacillus species, are sporeforming at low temperatures, which is restrictive for their usage as a self-healing agent in concrete at low-temperature conditions through direct application. In this paper, a novel, non-spore-forming, extremophilic bacterium, Deinococcus radiodurans, is investigated for self-healing of concrete at mom temperature (27 +/- 2 degrees C) as well as at near-freezing temperature (4 +/- 1 degrees C). The bacteria was directly added to the mortar mix in three different cell concentrations, namely, 10(3), 10(5) and 10(7) cells/ml. Results indicate that the inclusion of D. radiodurans as an additive results in significant calcium carbonate precipitation, leading to effective crack-healing at both the tested temperatures. Substantial improvement in the compressive strength and water absorption of the mortar samples are obtained. It is thus concluded that D. radiodurans can be utilized to prepare microbial concrete at both room and low-temperature conditions, without adopting any special application methodologies.