Quantification techniques of self-healing concrete using ureolytic bacteria: a review

Self-healing concrete is an important class of construction materials capable of sealing microcracks developed in structures through bio-mineralization. Microcracks are harmful to the overall health of the structure due to the ingress of moisture and other chemicals. The technique of bacterially induced self-healing enables the closure of cracks via carbonate precipitation. This article presents a detailed account of the various quantification techniques for determining this capability of self-healing concrete. Different bacteria immobilizers and immobilizing strategies reported in the literature have also been discussed in detail. Finally, the challenges being faced by self-healing concrete, such as the availability of triggering mechanisms, healing agent delivery, and long-term durability, have been discussed. These challenges must be overcome to develop industrial-scale self-healing concrete.