Typical bacteria used for the preparation of microbial concrete, such as from the Bacillus species, are spore-forming 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 room temperature (27±2 ˚C) as well as at near-freezing temperature (4±1 ˚C). The bacteria was directly added to the mortar mix in three different cell concentrations, namely, 10³, 10⁵ and 10⁷ 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.

用于制备微生物混凝土的典型细菌，例如来自芽孢杆菌属的细菌，在低温下会形成孢子，这限制了它们在低温条件下通过直接施用而用作混凝土中的自愈剂。本文研究了一种新型的，无芽孢的，极端的细菌，Deinococcus radiodurans，可在室温（27±2˚C）和接近冰点的温度（4±1˚）下自我修复。 C）。这种细菌是直接加入到砂浆混合物在三个不同的细胞浓度，即，10 ³，10 ⁵和10 ⁷个细胞/ ml。结果表明，包括了D. radiodurans作为添加剂，会导致大量碳酸钙沉淀，从而在两个测试温度下均能有效地修复裂纹。获得了砂浆样品的抗压强度和吸水率的显着改善。因此得出的结论是，可以在不采用任何特殊应用方法的情况下，在室内和低温条件下利用放射线虫来制备微生物混凝土。