Evaluating Long Term Capacity & Ductility of Carbon Fiber Reinforced Polymer Prestressing & Post Tensioning Strands
|Contract Number:||2013-0065 Z2|
|Subject:||CFRP; Prestressed highway bridges; Creep Rupture, Relaxation; Fire; Environmental Conditions; Freeze-Thaw.|
Comprehensive experimental, analytical, and numerical investigations were executed to establish the main design criteria of bridge beams prestressed with carbon fiber reinforced polymer (CFRP) strands. The investigation evaluated the short and long-term performance of CFRP under various environmental and loading conditions. Main CFRP design parameters such as maximum tensile strength, guaranteed strength, environmental reduction factors, relaxation, creep rupture strength, short and long-term prestress loss, and performance at elevated temperatures have been evaluated and documented. The experimental investigation included testing and evaluating unbonded prestressed CFRP strands as well as half-scale CFRP pretentioned decked bulb T-beams. Various test protocols were adopted and included such as testing and evaluating bonded and unbonded CFRP specimens: (1) at ambient temperature and controlled laboratory conditions, (2) under combined fire/loading events, (3) after exposure to cycles of freezing and thawing, (4) after exposure to outdoor harsh Michigan weather conditions for three years, (5) inside an environmental chamber simulating extremely hot and cold weather conditions, and (6) after exposure to elevated temperatures with and without loading. The results from the experimental investigation were implemented in the development of extensive analytical and numerical investigations that addressed the flexural and shear design of full-scale highway bridge beams. Test results were deployed to establish benchmark design criteria, design guidelines, and recommendations in a format similar to that of AASHTO LRFD to facilitate and promote the design and construction of highway bridges with CFRP components.
|Research Manager||Project Manager||Performing Organization|
|Michael Townley||Matthew Chynoweth||Lawrence Technological University|