Stochasticity on Long-Term Behavior of Steel-/Carbon Fiber-Reinforced Polymer Prestressed Girders

This paper presents the long-term behavior of bridge girders prestressed with steel strands and carbon fiber-reinforced polymer (CFRP) tendons, based on a stochastic process called polynomial chaos expansion (PCE). Benchmark girders are designed pursuant to existing specifications, and their time-dependent responses are predicted up to 100 years by the incremental time steps and modified step function methods, alongside variable performance levels dependent upon the extent of corrosion. The loss of prestress in the steel-prestressed girders is influenced by the degree of corrosion current density up to 45.4%, while the loss of the CFRP-prestressed girders is stable at a maximum of 15.5%. The geometric configuration of the girders dominates the sensitivity of the flexural capacity when subjected to corrosion. The deflections of both steel-and CFRP-prestressed girders, including the corrosion-damaged cases, are within the limit of the American Association of State Highway Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) Bridge Design Specifications. Published design provisions on the camber and deflection of those girders are assessed. Additional practical interests lie in the evaluation of deformability for the CFRP-prestressed girders.