## 1 Introduction  
Concrete is the world's most prevalently utilized construction material due to unparallel compressive strength (CS), affordability, cost-effectiveness, abundance of raw materials, and durability. However, gradual degradation of concrete-based infrastructures is detrimental unless inhibited. The structural integrity and efficacy of concrete degrades due to water penetration into it. The ingress of water, undesired acidic gases, and fluids containing dissolved aggressive chemicals enable the formation of cracks in concrete at the macro- and micro-scale [1]. Consequently, the aggressive substances and agents pass through these permeable sites, causing rapid deterioration of concrete. Hence, the durability of concrete and its steel reinforcement are negatively impacted, indicating that the concrete performance in the long-term is decided by the environment wherein concrete structures are placed [2]. Reinforcing steel bars can be oxidized and weakened by the permeation of water, oxygen, carbon dioxide and chloride ions. Consequently, the durability of the exposed concrete infrastructure becomes limited [3; 4]. Sometimes, the accessibility and repair of certain cracks in concrete is impossible, as they cannot be seen or associated/exist with unfavorable conditions to repair. The number of cracks and their sizes multiply as the materials undergo permeation, contraction, and expansion [5; 6]. Consequently, an onus is increasingly placed upon the maintenance and inspection processes for prematurely ageing large portfolio of civil infrastructures. The costs associated with the maintenance are exorbitant, particularly for the large-scale infrastructures, challenging the frequent inspection and maintenance methods. Maintenance and repair can also be tricky due to the difficulty in accessing the damaged site of the infrastructures [7; 8]. Consequently, academics in the field have increasingly focused upon the marginal capital and labor needs associated with self-healing concrete that can autonomously repair the hazardous cracks. Thus, numerous approaches have been developed to produce novel self-healing concrete, making it capable and prospective for civil engineering constructions. Total or partial recovery and healing of the materials functionality following the degradation makes up the definition of self-healing materials [9]. Similarly, autonomous repair and identification of the impairment of concrete cracks is another definition of self-healing materials [10]. Thus, manual intervention can be avoided or minimized within the reparation process [11]. The self-healing concrete is the name given for concrete that contains autonomous healing substances which can enter within the existing cracks and heal them without any human manual intervention. Autonomous healing is most frequently achieved by mixing concrete with fibers, crystalline admixtures, bacteria, polymers, and other smart materials. Normally, the chemical reactions and presence of water constitute the autonomous healing procedure that assesses the natural healing mechanisms. Therefore, the strength of the concrete is enhanced subsequent to the diminished width of the cracks via the autonomous healing procedure. Figure 1 portrays the autonomous procedures involved in the artificial autonomous healing. The efficacy of the self-healing mechanism is enhanced via the immobilization, vascular, or encapsulation techniques that incorporate healing agents into the concrete. The self-repairing of damaged concrete surfaces using the bacteria-mediated biological processes has recently been proposed [12; 13; 14; 15; 16]. In the mid-1990s, [PERSON] [17] proposed a sustainable technique to heal concrete cracks wherein ureolytic bacteria was added in the concrete to accelerate the calcium carbonate (CaCO\({}_{3}\)) precipitation within the existing micro-cracked regions.