Carbon Fiber Reinforced Polymer (CFRP) for Pretension Applications: Material Acceptance Criteria and Advancing Anchorage Designs

One of the main causes of structural deficiency in concrete bridges is the deterioration of the constituent materials. In order to achieve the goal of a design life of 75 to 100 years, it is imperative that pretensioned elements—girders, piles, and deck panels—contain corrosion-resistant or corrosion-free strands. The Virginia Department of Transportation (VDOT) is using carbon fiber reinforced polymers (CFRP) as a corrosion-free alternative to steel prestressing materials for longer lasting concrete bridge structures in Virginia. The in-service performance of elements can be difficult to evaluate in certain structural applications, such as pretensioned concrete bridges, where instrumentation is often limited and the material cannot be removed for inspection; use of corrosion-free CFRP will eliminate corrosion, the most common deterioration mechanism in reinforced elements. To implement CFRP in pretensioned concrete bridge structures with more confidence, this study was initiated to examine issues pertaining to material durability and quality control, laboratory testing procedures, and improved pretensioning anchorage systems. The experimental approach was intended to establish a testing methodology that can be adopted by VDOT for evaluating the quality and durability of CFRP in concrete structures. Several conclusions were drawn from the results of this study:(1) mechanical testing is important for characterizing CFRP prestressing material and should be supported by analysis of physical and thermal properties;(2) short-term preloading of the CFRP to 75% of the ultimate tensile strength has a significant impact on durability compared to …