## 3 Test Results and Discussion
### Load-Displacement Relationships  
Figure 11 illustrates the relationship between the jacking load and displacement for all specimens at the preassigned locations, as shown in Figure 6. For specimen B-1, the average uplift of the deck slab and the horizontal displacement at failure were recorded at 0.39 mm and 3.81 mm, respectively. These measurements are deemed acceptable and do not significantly influence the structural performance of the barrier wall. The maximum lateral deflection of the barrier wall at failure is noted to be 26.32 mm, as referenced in Figure 11a, which is relatively minor considering the presence of a non-deformable deck  
Figure 10: View of the crack pattern after the test specimens B-5 and B-6 failed. (**a**) Right side concrete breakout, B-5; (**b**) Left side concrete breakout, B-5; (**c**) Diagonal shear failure at top right side of barrier wall, B-6; (**d**) Diagonal shear failure at top left side of barrier wall, B-6. slab. In the case of specimen B-2, where the sustained load increased due to a greater amount of longitudinal reinforcement at the end location, the average uplift of the deck slab and the horizontal displacement at failure rose to 1.62 mm and 4.27 mm, respectively. It is noteworthy that the maximum lateral deflection of the barrier wall at failure is 23.74 mm, as shown in Figure (b)b, which is smaller than that observed for specimen B-1, despite the increase in the ultimate load. Figure 11: Load–displacement relationships for all specimens. Regarding the interior location of a barrier-deck slab overhang system, as for specimen B-3, the average uplift of the deck slab and the horizontal displacement at the point of failure were measured at 3.66 mm and 8.43 mm, respectively. These measurements surpass those observed in other specimens (B-1 and B-2) due to the less effective tightening of the threaded rods compared to specimens B-1 and B-2. Nonetheless, these measurements can later be utilized to determine the net lateral deflection of the barrier. It is noteworthy that the maximum lateral deflection of the barrier wall at failure reached 44.75 mm, as illustrated in Figure 11c, while the maximum vertical deflection of the deck slab overhang was recorded at 17.57 mm. In contrast, for the end location represented by specimen B-4, the average uplift of the deck slab and the horizontal movement at failure rose to 5.3 mm and 13.42 mm, respectively. These values exceed those of specimen B-3, attributable to the increased failure load. The maximum lateral deflection of the barrier wall at failure was 66.76 mm, while the vertical deflection of the deck slab overhang was 27.88 mm, as shown in Figure 11d. A comparison of the responses from barrier walls utilizing postinstalled GFRP bars and those with preinstalled GFRP bars indicates that, in most instances, the responses associated with postinstalled bars were lower than those of the preinstalled bars. This trend was observed for both interior and end locations. In the case of specimen B-5, the average uplift of the deck slab and the horizontal displacement at failure measured 0.97 mm and 0.73 mm, respectively, which are regarded as minimal values. Likewise, the maximum lateral deflection of the barrier wall at failure was recorded at 8.92 mm, as illustrated in Figure 11e. For specimen B-6 at the end location, the average uplift of the deck slab and the horizontal movement at failure were 0.96 mm and 3.46 mm, respectively, with the maximum lateral deflection of the barrier wall at failure reaching 11.28 mm, as shown in Figure 11f. It is important to note that the failure loads for both scenarios were comparable, with a variation of no more than 5%. Specimen B-5 showed notably lower lateral and vertical displacements compared to deck-overhang specimens. This difference is due to the increased stiffness provided by the thick, non-deformable concrete slab base, which limited barrier rotation and uplift under load. In contrast, the deck-overhang specimens (e.g., B-3, B-4) experienced greater deflections due to cantilever flexibility.