## 7 Conclusions  
This study comprehensively evaluated the structural performance and anchorage behavior of high-modulus (HM) GFRP-reinforced TL-5 concrete bridge barriers under transverse loading. Both preinstalled and postinstalled GFRP bar configurations were examined through full-scale testing and direct pullout experiments. The findings validate the use of GFRP reinforcement for new construction and retrofit applications, offering a corrosion-resistant and structurally reliable alternative to conventional steel reinforcement. The following are the key findings from this research. * **Structural Adequacy**: All six full-scale TL-5 barrier-deck specimens exceeded the factored design moments per CHBDC, with capacity-to-demand ratios ranging from 1.38 to 1.51. Even after applying an environmental reduction factor of 0.85, all ratios remained above 1.17, confirming the robustness of the GFRP anchorage systems. * **Embedment Length**: A 195 mm embedment length was sufficient for both preinstalled and postinstalled GFRP bars, meeting or exceeding the required anchorage strength in all configurations. * **Headed-End Performance**: Headed-end GFRP bars demonstrated superior pullout strength compared to straight-end bars. When combined with a bonded straight portion, the pullout capacity increased by approximately 10%, consistently surpassing the 100 kN threshold required by MTO. * **Failure Mechanisms**: Observed failure modes on the tested actual-size barrier-deck specimens included concrete breakout at the deck-barrier corner or diagonal shear in the barrier wall. No GFRP bar rupture was recorded, and strain measurements confirmed that neither concrete nor GFRP bars reached their ultimate strain limits. * **Postinstalled Bar Viability**: Postinstalled straight GFRP bars bonded with epoxy exhibited comparable performance to preinstalled headed bars, validating their use in retrofitting deteriorated barriers. * **Deck Overhang Behavior**: Specimens with deck overhangs experienced diagonal tension cracking at the barrier-deck corner as the governing failure mode. The developed design equation for the resisting moment due to diagonal cracking (Equation (9)) showed strong agreement with experimental results, with moment ratios of 1.13 and 1.36, confirming its conservatism and applicability in design. * **Reinforcement Detailing**: Doubling the vertical GFRP bars at the traffic face significantly enhanced load resistance, crack control, and deflection performance, particularly at barrier ends. * **Design Implications for Code and Standard Updates:** The results support updating MTO-S110-92 Standard Drawing and CHBDC to recognize 195 mm embedment lengths for GFRP bars and to permit headed-end and postinstalled GFRP anchorage systems as structurally adequate and constructible alternatives to traditional bent bars. Further research is required to investigate the long-term durability and vehicle impact resistance of postinstalled GFRP anchorage systems to simulate real-world service conditions. The long-term performance of epoxy-bonded GFRP anchors under thermal cycling, freeze-thaw exposure, and elevated temperature conditions requires further research. While this study focused on experimental validation, future research should incorporate finite element modeling to simulate stress distributions, crack development, and anchorage behavior in GFRP-reinforced barrier-deck systems. Such models would enable parametric analyses, support the refinement of the proposed design equation for diagonal cracking, and extend the applicability of the findings to a broader range of geometries and loading scenarios. G.D.: Methodology, Validation, Formal analysis, Investigation, Data curation, Writing--original draft, Visualization, Project administration. K.S. : Conceptualization, Investigation, Data curation, Writing--review and editing, Project administration. H.M.A. : Formal analysis, Investigation, Writing--review and editing. A.D.: Formal analysis, Writing--review and editing.