Strengthening Bridge Piers with Fiber Reinforced Polymer (FRP)

The Interstate Highway I-40 passes through Oklahoma City. A large number of bridge piers along this freeway were severely damaged due to corrosion. Conventional retrofit required that a 6- to 8-in. thick layer of reinforced concrete be added to these columns. However, at the location where railroads tracks passed, the additional column thickness would have encroached on the railroad right-of-way, and therefore conventional repair was not acceptable.

Glass Fabric was used for this project. This is a unidirectional glass fabric.

The existing steel reinforcement in the columns was first cleaned, returning the columns to their original 3-ft diameter. The contractor chose to saturate the fabrics by hand. A table was set up on site and the 3-ft wide rolls of fabric were saturated on that table. The fabrics were wrapped around the column in 3-ft wide bands, going two full wraps plus an additional 12-in. overlap at the end.

The entire project, consisting of 13 columns was completed very rapidly, using only a cherry-picker truck. Upon completion of the wrapping, the columns were painted. The repair added less than ¼ inch to the column thickness. The photos on the right and bottom show some of the columns at the completion of the project.

This project was completed in June 1997.

Credits