Introduction The service life of concrete elements in highway bridges is often limited by the corrosion deterioration of reinforcing bars. In cold regions, the corrosion rate of concrete bridge columns is accelerated by the use of deicing solutions during the winter season. The corrosion process causes cracking, spalling, and delamination of the reinforced concrete structures and increases the cost of rehabilitation and maintenance. In Wisconsin, fiberglass wrapping has been used to protect reinforced concrete columns from deicing salts. In this method, the lower part of the column is wrapped with 1/8 to 1/4 in.-thick fiberglass tube to create a barrier between the concrete surface and the deicing salts sprayed by the passing vehicles. Objectives In this study, field tests including wave propagation methods, half-cell potential, and measurement of chloride ion intrusion were conducted on fiberglass wrapped columns in I-90 and I-94 bridges to assess the effectiveness of the fiberglass wrapping in reducing the corrosion- induced degradation rate of the columns. P-wave Velocity Tests To evaluate the integrity of wrapped concrete columns, the P-wave velocity profiles were obtained along different directions. The crosshole and circular-type tomographic images show locations of degraded concrete zones caused by steel corrosion. Acknowledgements The funding was provided by the Wisconsin Highway Research Program (WHRP Project ) and by the Midwest Regional University Transportation Center (MRUTC). The content of this poster does not necessarily reflect the views of the funding agencies. Mr. Alex Summitt collaborated with the field data collection. Half-cell Potential Tests Half-cell potential measurements are used to evaluate the electro- chemical activity generated during corrosion processes (ASTM C876). Chloride Ion Intrusion Measurements Chloride ion (Cl - ) contamination is caused when splashed saline solution progresses by diffusion into the concrete. Cl - content vs. depth profiles are good indicators of the corrosion potential of reinforcing bars in concrete. In some cases, the Cl - content is lower in wrapped columns than in wrapped locations. However in some wrapped columns, the Cl - content may still be greater than the ACI recommended corrosion threshold level. Therefore corrosion conditions remain even after the application of the wrap. Sectional views of half-cell potential readings in wrapped columns. Corrosion, delamination and rehabilitation using fiberglass wraps Conclusions P-wave travel-time tomography, half-cell potential measurements, and Cl - content vs. depth profiles were used to test the effectiveness of fiberglass wraps as a protective barrier against rebar corrosion in concrete columns. The effectiveness of fiberglass wraps can be evaluated by measuring Cl - content in depth. It is observed that Cl - concentrations in wrapped columns are lower than those of unwrapped columns. However, in many of the wrapped columns the conditions for corrosion remain and future maintenance operation will be required. Sampling locations and Cl - content profiles with chloride diffusion solution Corrosion process in reinforced concrete P-wave travel time tomographic images of concrete columns Half cell potential reference values for evaluating corrosion risk Performance Evaluation of Fiberglass Wrapped Concrete Bridge Columns Kyu-Sun Kim, Dante Fratta and José A. Pincheira University of Wisconsin – Madison