The use of fiber reinforced polymer (FRP) bars as internal reinforcement for concrete bridge decks and railings is emerging as a viable technology that responds to the growing demand towards sustainability, especially in areas where corrosion of steel reinforcement and maintenance costs are of concern. Degradation also affects reinforced concrete (RC) railings and in particular their connection to the bridge decks, and may compromise crashworthiness. However, very little research has focused on the development of FRP RC railings and post-deck connections. For new systems, relativelyexpensive crash testing is mandated in Section 13 of the AASHTO LRFD Bridge Design Specifications, where structural and functional crashworthiness are assessed on the basis of the NCHRP Report 350 criteria. In addition, while the structural design of steel RC crash test specimens may be simplistically based on yield line analysis, such approach is not applicable to indeterminate FRP RC systems, due to the linear elastic behavior of FRP reinforcement up to failure. In this paper, a Crash Test Level 3 open-post specimen reinforced with pultruded glass FRP bars is proposed. The design methodology entails the explicit determination of internal forces, deformations, and failure mode, and is pursuant to well established design principles of FRP RC. The structure is shown to meet the transverse strength demand while undergoing very small deformations, similar to crashworthy RC railings. Finally, technological developments are discussed that leverage the light weight and tailorability of FRP shapes to engineer prefabricatedreinforcement systems for enhanced constructability and speed of installation.
Samenvatting