## 1 Introduction  
The spalling and collapse of buildings and infrastructure are mainly caused by the corrosion of embedded steel rebars in the concrete. In this case, the corrosion products formed inside the concrete cause internal pressure; therefore, the delamination of reinforced concrete (RC) structures occurs. This is due to the poor quality of the materials used, an improper mixture design, an irregular construction process, poor workmanship, and the cover depth of the steel rebar during installation. Therefore, it is necessary to use proper repair materials to avoid the aforementioned problems in RC structures to enhance their safety and extend their service life. There is a huge investment in the repair of RC structures worldwide. In the USA, the repair of old buildings was estimated to cost 90 billion dollars in 2016 [1], and in Europe, the costs were approximately half of the construction budget [2]. Due to rapid urbanization and industrialization, RC structures suffer from immature distress; therefore, there is a continuous demand for repair materials for the restoration of buildings and infrastructure. Repair materials still cannot guarantee long-term effectiveness [3], as most repair materials fail within 20 years of their service. This is attributed to their weak interfacial bonding with the concrete substrate [4], but they can extend the service life and durability of buildings and infrastructure. Another concern involves the properties of the repair material and the concrete interface needed to achieve high-quality structural repair [5]. Moreover, the interface between the repair material and the concrete substrate is a weak zone. Therefore, researchers have attempted to address these issues by considering the compatibility of different repair materials with concrete, given that most repair materials shrink owing to the difference in their chemical composition and thermal coefficients [6; 7; 8]. Repair materials should exhibit good mechanical performance, strong bond adhesion [9], and chemical resistance to improve the performance of concrete structures. It is suggested in the European standard (EN1504-3) that the bond adhesion of a repair material must be at least 0.8 MPa [10]. Cement-based materials, such as Portland cement, sulfoaluminate cement, and magnesium phosphate cement (MPC) blended with fly ash, blast furnace slag, and silica fume, are the most widely used materials. Such repair materials require a hydration reaction (curing condition) but due to the unavailability of water (non-curing) on concrete surfaces, they suffer from weak bonding and easy delamination, and they exhibit high shrinkage and low flexibility [9]. Epoxy-modified cement has been used as a concrete repair material [11; 12; 13] because of its better bonding adhesion [14]. However, it exhibits poor mechanical properties attributed to the unhardened epoxy resin remaining in the mixture, which hinders the hydration reaction [15]. [PERSON] et al. used asphalt-modified sulfoaluminate cement as a repair material in concrete and mortar samples [16], where they exhibited a negative effect on bonding. In this case, since the concrete surface had large-size pores, it caused weak bonding, resulting in the delamination of the repair material [17]. The use of polymers as concrete repair materials causes the fading and peeling of the coating owing to the difference in the thermal coefficients of concrete and polymers. Stainless steel has been used as a repair material to protect wastewater reservoirs from deterioration [18]. In one study, a stainless steel coating was applied on a concrete surface via an arc thermal spray process, which exhibited excellent corrosion resistance in a sulfuric acid solution, attributed to the formation of Cr\({}^{3+}\)-enriched Cr\({}_{2}\)O\({}_{3}\) as a passive film [19]. In another study, Ti was used as an anti-corrosion and anti-ozone metal and acted as a repair material for concrete [20].