An all fiber-reinforced-polymer-composite bridge: Design, analysis, fabrication, full-scale experimental structural validation, construction and erection

Bridge 1-351 on Business Route 896 in Glasgow, Delaware, was replaced with one of the first state-owned Fiber Reinforced Polymer (FRP) composite bridges in the nation. FRP composites are durable and lightweight construction materials with superior corrosion resistance resulting in benefits such as ease of construction, rapid erection and substantially reduced maintenance costs. The FRP composite bridge was designed using the American Association of State Highway and transportation Officials (AASHTO) Load and Resistance Factor Bridge Design Specifications. The completed bridge superstructure consists of two 13ft x 32ft sections joined by a unique longitudinal joint. The superstructure sections are web core sandwich construction composed of two facesheets (top of 0.5in and bottom 0.7in thick) and a core (28in deep) that provide flexural and shearing rigidity, respectively. The FRP composite bridge was fabricated with E-glass fiber preforms and vinyl-ester resin. Each FRP section was fabricated to near net shape in a single step by a vacuum assisted resin transfer molding process. The overall structural behavior was accurately predicted with design equations based on laminated plate and sandwich theory for anisotropic materials. Finite Element Modeling was conducted to approximate structural behavior of the bridge due to truck loads. Full scale experimental structural validation of FRP bridge subcomponents was conducted to validate that the design satisfied AASHTO Service I (deflection), Fatigue and Strength I limit states for a bridge service lifetime of 75 years. The structurally redundant longitudinal joint was designed and erected as a butt joint with an adhesively bonded vertical joint and splice plates. Assembly procedures were developed and implemented and transverse testing and structural validation of the full scale longitudinal joint was conducted. The final bridge superstructure sections were proof tested to the Strength I limit state. Both superstructure sections exceeded the performance criteria based on experimentally measured stiffnesses, deformations and facesheet strains. The construction phase included section positioning, anchorage, longitudinal joint assembly and application of the latex modified concrete wearing surface. The bridge was reopened to traffic on November 20, 1998. The completed bridge received the ASCE Delaware section project of the year in February 1999.