Effect of Elastic Modulus of Carbon Fiber-Reinforced Polymer Strands on the Behavior of Posttensioned Segmental Bridges

Abstract

Segmental bridges are widely used for accelerated construction and lower costs and environmental impact. The major concern with such bridges is in the corrosion protection of posttensioning steel strands. Noncorrosive carbon fiber strands can serve as viable alternatives to help reduce maintenance costs. A novel carbon fiber strand was tested for posttensioning of a 3.5∶1 scaled model of the Long Key segmental box girder bridge, and its performance was compared with prior test data for steel strands and another type of carbon fiber. The most important distinction between the two types of carbon fibers is their elastic moduli, which are 77 and 93% of that of steel strands. Numerical simulation was also conducted and the effect of different elastic moduli of the tendons on the structural performance was investigated with a parametric study. While the study confirms the feasibility of both types of carbon fiber strands for segmental bridge applications and their similar serviceability behavior, strands with higher elastic modulus are shown to improve structural performance and minimize displacements after joint opening.