Crack appearance in the concrete structure due to the low tensile strength is inevitable and can cause degradation of the structure integrity. Bacteria addition in the concrete structure is one promising way of achieving crack healing. When bacteria concrete is used, the bacteria can be added directly in the mixture or protected in different types of materials, usually lightweight materials. Along with the bacteria, additionally nutrients and calcium source are part of the mixture, as well. As a result, calcium carbonate is precipitated in the vicinity of the crack which will fill the crack and block all the harmful substances to penetrate in the concrete structure.
Over the years, many papers are witnessing the successful work of bacteria based self–healing concrete where the maximum crack width healed can reach almost 1 mm (0.97 mm).
However, it is worth mentioning that the addition of bacteria to the concrete mixture certainly causes some complications in the preparation process and this material should be observed at a completely new level.
Based on available experimental work, a review from the perspective of encapsulation material, incubation conditions, strength, sustainability and some closely related properties are discussed.