In situ structural evaluation of a GFRP bridge deck system

An 18.3 m (60 ft) simple span bridge is South Carolina's first use of a glass fiber reinforced polymer (GFRP) bridge deck system. This paper describes the initial preparation and instrumentation of this structure including the use of surveying techniques to determine overall bridge deflections. Also outlined are the procedures used for in situ load testing the bridge. Critical design criteria such as overall deflections, effective deck widths, bending of the GFRP deck and moment distribution factors are reported for this structure. Data collected indicates that the GFRP deck and steel girders are acting in a composite manner and that the deck system is relatively stiff despite the large girder spacing used. Over the course of the next several years this bridge will be tested on a regular basis to establish the long-term performance of the GFRP deck system.