Bridge Retrofitting Using FRP-Wrapped Balsa Wood Deck: Experimental Study and Field Evaluation

Abstract

A fairly large amount of existing bridges in the United States are in an urgent need of repairing and upgrading. With the increasing application of fiber-reinforced polymers (FRPs), the FRP-based structural system is a new exploration for bridge rehabilitation. In the present study, a new FRP-wrapped balsa wood bridge deck is adopted to replace the damaged steel deck of a bridge in Louisiana. Comprehensive experimental tests and live load field tests are developed to evaluate and continuously monitor the new composite system throughout its service life. Two innovative monitoring systems, i.e., fiber Bragg grating (FBG)-based moisture monitoring system and optical time-domain reflectometer (OTDR)-based interface slip/debonding monitoring system, are proposed and verified in the laboratory. The field test is then conducted with the objective of assessing the global structural performance, evaluating the adhesively bonded deck-girder interface, and calibrating a numerical model to further study the composite behavior between the deck and girder. The field evaluation reveals the overall structural performance and helps establish the baseline for future condition evaluation.