**1. Introduction**

Reinforced concrete is a composite material resulting from the strengthening of concrete with steel rods with greater strength. The combination of these materials leads to a new one that will meet the needs of the construction. The reinforcement is done to increase the tensile strength of concrete. On the other hand, steel rods are sensitive to corrosion. Concrete, though, forms an alkaline environment that hinders the oxidation of steel. There are many factors that affect the strength of concrete and contribute to its early wear. A key cause that activates various wear

### **Figure 1.**

*Schematic representation of the healing of cracks in cement with integrated microorganisms in microcontainers and protective sol-gel coating against corrosion of metal rods.*

mechanisms is cracks that dramatically increase the permeability of cement. The microstructure of hardened cement is porous, isolated, and interconnected. The interconnected pores determine the permeability of the material as they allow water and chemical compounds to penetrate the concrete matrix. Permeability essentially increases as the crack connects isolated resources to resource networks. In most concrete wear mechanisms, permeability plays an important role. Specifically, interconnected pores determine the permeability of the material as they allow water and chemical compounds to penetrate the concrete matrix. In the same way, CO2 diffuses through the pores, which reacts with the alkaline components of cement (e.g. Ca (OH)2) in the process called carbonation.

The above points make it clear that cracks in concrete must be reduced and that ideally a mechanism should lead to the sealing or clogging of newly formed cracks, in order to limit the permeability of the uterus. A healing mechanism is ideal when you do not need constant testing for repair, and it is financially lucrative [1]. In recent times, concrete self-healing is proposed to be done using a biological restoration technique through the introduction of bacteria into the concrete. **Figure 1** presents such technology. The idea is based on the incorporation of a bacterium that metabolizes urea and sinks CaCO3 into the crack environment. CaCO3 microbial submersion is certified by a number of factors, such as the concentration of dissolved inorganic carbonate ions and Ca2+ ion concentration. The protection of the bacterium in the cement is done by locking them in micro-containers, the incorporation of which can reduce the strength of the concrete.

The present work deals with the development of coatings to protect steel rods from corrosion and nanocontainers filled with bacteria to induce self-healing.

### **2. Materials and methods**

### **2.1 Chemicals**

The reagents we used are methyl methacrylate (MMA), poly(ethylene glycol) methacrylate (PEG), ammonia solution (30%), 2,2-azobis(2-methylpropionitrile) (AIBN), sodium dodecyl sulphate (SDS), ethylene dimethacrylate (EGDMA),

### *Self-Healing of Concrete through Ceramic Nanocontainers Loaded with Corrosion Inhibitors… DOI: http://dx.doi.org/10.5772/intechopen.93514*

toluene diisocyanate (TDI), tetraethyl orthosilicate(TEOS), ethylene diamine (EDA), diethylene triamine (DETA), polyvinylpyrrolidone (PVP), chloride ammonium, tryptone, yeast extract, and sodium chloride. The solvents we used were distilled water, acetonitrile, acetone, ethanol, 1-octadecene and paraffin. All chemicals were obtained by commercial sources.
