## 3 Results and Discussion  
The flexural strength of the concrete panels was 8.08 MPa for the no-layer specimen (Figure 5), 8.65 MPa for the one-layer specimen (Figure 5), and 9.27 MPa for the two-layer specimen (Figure 5), and increased with the increasing number of carbon fiber grids. Flexural strength increased by 7% with one layer and 15% with two layers compared with no layer (Table 2, Figure 6). The maximum displacement in the middle of the concrete panels was 2.66 mm with no layers, 14.86 mm with one layer, and 16.29 mm with two layers, and increased with increasing number of carbon fiber grids. Concrete reinforced with carbon fiber grid had excellent ductility compared with unreinforced concrete. With more carbon grid fiber reinforcement layers, the maximum load was greater, and the deformation capacity increased as the displacement increased. Sufficient ductility was secured through tensile deformation curing behavior from initial cracking until fracture because of the carbon fiber grid reinforcement. A similar study confirmed that stress increased with increased numbers of carbon grid fiber layers when a carbon fiber grid was applied to Engineered Cementitious Composites (ECC) [1]. This phenomenon was found to grow with increasing number of reinforcement layers.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Results** & **No Layer** & **One Layer** & **Two Layers** \\ \hline Max. load (kN) & 27.3 & 29.2 & 31.3 \\ \hline Max. displacement (mm) & 2.66 & 14.86 & 16.29 \\ \hline Flexural strength (MPa) & 8.08 & 8.65 & 9.27 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Experimental results.  
Figure 4: Energy dissipation capacity.  
Figure 5: Results of flexural strength experiment. (**a**) Flexural strength. (**b**) Flexural strength ratio.  
The energy dissipation capacity of the concrete panels was 0.06 kN\(\cdot\)m with no layers, 1.89 kN\(\cdot\)m with one layer, and 3.52 kN\(\cdot\)m with two layers, and increased with the increasing number of carbon fiber grids (Figure 7). The energy dissipation capacity increased by 30 times with one layer and by 56 times with two layers compared with no layers, showing great improvement in terms of seismic performance. The cumulative energy dissipation capacity of the concrete panels was 23.0 kN\(\cdot\)m with no layers, 219.2 kN\(\cdot\)m with one layer, and 371.6 kN\(\cdot\)m with two layers, and increased with the increasing number of carbon fiber grids. The cumulative energy dissipation capacity increased by 9.5 times with one layer and 16 times with two layers compared with no layers, and showed great improvement in terms of seismic performance.  
Figure 6: Results for specimens. (**a**) Fracture pattern (0 layer). (**b**) Load–displacement curve (0 layer). (**c**) Fracture pattern (1 layer). (**d**) Load–displacement curve (1 layer). (**e**) Fracture pattern (2 layer). (**f**) Load–displacement curve (2 layer).  
Figure 7: Displacement ductility and energy dissipation capacity. (**a**) Energy dissipation capacity (0 layer). (**b**) Cumulative energy dissipation capacity (0 layer). (**c**) Energy dissipation capacity (1 layer). (**d**) Cumulative energy dissipation capacity (1 layer). (**e**) Energy dissipation capacity (2 layer). (**f**) Cumulative energy dissipation capacity (2 layer). (**g**) Energy dissipation capacity (Total). (**h**) Cumulative energy dissipation capacity (Total).