## 1 Introduction
\begin{table}
\begin{tabular}{c|c|c|c|c} \hline \hline
**Carrier Material** & **Shape** & **Dimensions** & **Findings** & **References** \\ \hline Glass & \(\begin{array}{c}\mathcal{O}3\text{ mm}\times 60\text{ mm}\\ \mathcal{O}3\text{ mm}\times 400\text{ mm}\end{array}\) & & & \\ Glass fibers & - & & & \\ \hline Soda glass & \(\begin{array}{c}\mathcal{O}6.15\text{ mm}\times 50\text{ mm}\end{array}\) & \(\begin{array}{c}\mathcal{\bullet}\end{array}\) & & \\ Ceramics & \(\begin{array}{c}\mathcal{O}3\text{ mm}\times 60\text{ mm}\\ \mathcal{O}3\text{ mm}\times 400\text{ mm}\end{array}\) & & & \\ \hline Polystyrene (PS) & \(\begin{array}{c}\text{Poly(lactic acid)}\\ \text{Poly (methyl)}\end{array}\) & \(\begin{array}{c}\mathcal{O}1.1-\mathcal{O}3.8\text{ mm}\\ \text{methacrylate}\end{array}\) & & & \\ \hline Hollow glass & \(\begin{array}{c}\mathcal{O}1.2\text{ mm}\times 75\text{ mm}\\ \mathcal{O}2\text{ mm}\times 75\text{ mm}\end{array}\) & \(\begin{array}{c}\mathcal{\bullet}\end{array}\) & & \\ \hline Concentric glass & \(\begin{array}{c}\mathcal{O}11.4\text{ mm}\text{ (outer)}\times\\ 50\text{ mm}\text{ (inner)}\times\\ 50\text{ mm}\text{ (inner)}\times\\ 50\text{ mm}\end{array}\) & \(\begin{array}{c}\mathcal{\bullet}\end{array}\) & & \\ \hline Urea-Formaldehyde & \(\begin{array}{c}\mathcal{O}100\text{-}250\text{ \mu m}\\ \mathcal{O}200\text{ \mu m}\\ 082\text{-}380\text{ \mu m}\\ \mathcal{O}200\text{-}250\text{ \mu m}\end{array}\) & \(\begin{array}{c}\mathcal{\bullet}\end{array}\) & & \\ Urea Formaldehyde & \(\begin{array}{c}\mathcal{O}11.4\text{ mm}\text{ (outer)}\times\\ 50\text{ mm}\text{ (inner)}\times\\ 50\text{ mm}\end{array}\) & \(\begin{array}{c}\mathcal{\bullet}\end{array}\) & & \\ \hline Silica & Spherical & \(\begin{array}{c}\mathcal{O}5-180\text{ \mu m}\\ \mathcal{O}4.15\text{ \mu m}\end{array}\) & & & \\ \hline Polyurethane & \(\begin{array}{c}\mathcal{O}200\text{-}250\text{ \mu m}\\ \mathcal{O}40\text{-}800\text{ \mu m}\end{array}\) & \(\begin{array}{c}\mathcal{\bullet}\end{array}\) & & & \\ \hline Melamine & \(\begin{array}{c}\mathcal{O}2-5\text{ \mu m}\\ \mathcal{O}2-5\text{ \mu m}\end{array}\) & \(\begin{array}{c}\mathcal{\bullet}\end{array}\) & & & \\ \hline Pharmaceutical- & \(\begin{array}{c}\mathcal{O}5.57\text{ mm}\times 15.9\text{ mm}\\ \mathcal{O}88\text{ mm}\end{array}\) & \(\begin{array}{c}\mathcal{\bullet}\end{array}\) & & & \\ \hline Pharmaceutical- & \(\begin{array}{c}\mathcal{O}5.57\text{ mm}\times 15.9\text{ mm}\\ \mathcal{O}8\text{ mm}\end{array}\) & \(\begin{array}{c}\mathcal{\bullet}\end{array}\) & & & \\ \hline
\begin{tabular}{c} Pharmaceutical- \\ Epoxy \& \(\begin{array}{c}\mathcal{E}\text{ }\\ \text{ Glass}\end{array}\) & \(\begin{array}{c}\mathcal{\bullet}\end{array}\) & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Studies on encapsulation method in self-healing of cementitious composites. the bond strength characteristic were the major concerns in enhancing the self-healing concrete ability using the encapsulation method. Despite so many innovative works having been done on the encapsulation methods, [PERSON] et al. [34], [PERSON] et al. [19] and [PERSON] et al. [35] still discovered that the bonding strength of capsule is one of the limited areas in the encapsulation techniques. Understandably, the bonding strength characteristics are strongly governed by the properties of the inter-cement matrix layer and capsule shell, which also indicate the stability of the capsule within the cement matrix. Both bonding strength and inter-cement matrix layer characteristics of the capsule affect the self-healing efficiency and mechanical properties of cement structure [34]. Nevertheless, most researchers explored the variation of capsule shell material and the capsule surface treatment to develop the survival ability of capsule during the mixing. Glass capsules had been mostly used as a healing carrier due to its brittleness characteristic, but were not able to resist stresses during mixing without any surface treatment [19; 36].