Evaluating Long Term Capacity & Ductility of Carbon Fiber Reinforced Polymer Prestressing and Post Tensioning Strands

Carbon Fiber Reinforced Polymer (CFRP) is a promising alternative for steel as a reinforcing and prestressing material. Numerous studies have been conducted to evaluate the performance of CFRP on the short term such as the flexural and shear performance under static loading. However, some aspects of short-term performance, such as bond length for splices, have not been addressed. In addition, the long-term performance of CFRP has not been thoroughly examined. Long-term performance includes creep rupture, prestress loss due to creep and concrete shrinkage, effect of environmental conditions, and bond fatigue. Furthermore, the performance of CFRP under extreme events, such as severe environmental conditions and exposure to fire or high temperature events, has not been addressed yet. Current American Association of State Highway and Transportation Officials Load Rating Factor Design (AASHTO LRFD) Bridge Design Specifications do not contain guidance on the design of elements using CFRP prestressing or post-tensioning. This imposes a certain limitation on the wide implementation of CFRP in field projects as a reinforcing/prestressing material. The proposed experimental/analytical investigation will address the lack of technical data on the short and long-term behavior of CFRP for developing proper design methodologies and empirical equations. Short and long-term performances in addition to the performance under extreme events will be thoroughly investigated and addressed. The product of this research will benefit the Michigan Department of Transportation (MDOT) and other state Departments of Transportation (DOTs in their deployment of CFRP materials in field projects. This will promote the construction of bridges with longer lifespan and minimum maintenance costs.