## 3 Results and Discussion
### Ultimate Loading Capacity  
The failure loads obtained from the experimental results are presented in Table 6 and Figure 5. It can be noted that the specimens of the GC and GCD group had lower ultimate load values than their counterparts in the CC group when fibers are not used in the GC and GCD specimens. The load-carrying capacity of concentrically loaded plain column in the GC and GCD group was 10% and 16% lower, respectively, than their counterparts of CC group. The ultimate load values of group GC specimens, GC-OF-0E (860 kN), GC-0F-15E (570 kN), GC-0F-35E (335 kN), and GC-OF-50E (250 kN) were decreased by 10%, 20%, 22%, and 25%, respectively, than CC-0F-0E (945 kN), CC-0F-15E (722 kN), CC-0F-35E (430 kN), and CC-0F-50E (330 kN) of group CC. The specimens of GCD group, GCD-0F-0E, GCD-0F-15E, GCD-0F-35E, and GCD-0F-50E, failed at ultimate loads of 790 kN, 515 kN, 292 kN, and 201 kN, respectively, which are 16%, 29%, 32%, and 39% lower than CC-0F -0E, CC-0F-15E, CC-0F-35E, and CC-0F-50E, respectively, of CC group. Figure 4: The general load–displacement response of the column specimens. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Group No**} & **Group** & \multirow{2}{*}{**Column ID**} & **Fiber** & \multirow{2}{*}{**e (mm)**} & **P\({}_{\text{max}}\) (kN)** & \multirow{2}{*}{**Deformation at**} & **Lateral** & \multirow{2}{*}{**Deformation at**} \\  & **ID** & & & & & **P\({}_{\text{max}}\) (mm)** & & **P\({}_{\text{max}}\) (mm)** \\ \hline \multirow{4}{*}{1} & \multirow{4}{  
It can be noted from Figure 5 that load values are influenced by varying the amount of eccentricity in the tested specimens. The load-carrying capacity of column has an inverse relationship with the loading eccentricity, i.e., it decreases with increasing the eccentricity of the axial load. The load values show similar trends for different eccentricities in all the columns of different groups (Figure 5). The load values were decreased drastically as eccentricity was increased from 0 to 15, 35, and 50 mm. This decreasing trend of load values against increasing eccentricities is also consistent with the previous studies [33; 34]. The peak axial load sustained by eccentrically loaded columns of GC group, i.e., GC-0F-15E (570 kN), GC-0F-35E (335 kN), and GC-0F-50E (250 kN), is 30%, 61%, and 71% lower, respectively, than the ultimate load of the concentrically loaded column, i.e., GC-0F-0E (860 kN). The peak load values of eccentrically tested columns of GC group were decreased by 34%, 63%, and 70% for specimens GCD-0F-15E (515 kN), GCD-0F-35E (292 kN), and GCD-0F-50E (201 kN), respectively, when compared with concentrically tested column, i.e., GCD-0F-0E (790 kN). It can be observed from Figure 5 that the load-carrying capacity of GC columns is greater than the ultimate load values of GCD columns. The ultimate load values of group GCD specimens, GCD-0F-0E (790 kN), GCD-0F-15E (515 kN), GCD-0F-35E (292 kN), and GCD-0F-50E (201 kN) were decreased by 8%, 10%, 13%, and 18%, respectively, than their counterparts in group GC, viz., GC-0F-0E (860 kN), GC-0F-15E (570 kN), GC-0F-35E (335 kN), and GC-0F-50E (250 kN), respectively. By comparing the ultimate load values of fiber-reinforced columns with their without-fiber counterparts, a considerable increase in load-carrying capacity can be observed for the former. Generally, the peak load values of fiber-reinforced GC and GCD columns were 20-30% more than the corresponding plain specimens. The load capacities of fiber-reinforced GC specimens were about 5-7% higher than their counterparts in CC group. Meanwhile, the ultimate axial load attained in fiber-reinforced GCD columns was 7-15% more than their without-fiber counterparts in GC group. The increase in strength might be owing to the effective role of fibers in improving the behavior of both the cover concrete and core concrete by arresting microcracks and bridging across the macroracks. This crack-arresting procedure of multiple cracking lasted until the fibers failed or were pulled out [33; 51].