Design and technologies for a smart composite bridge

An all-composite, smart bridge design for shortspan applications is described. The bridge dimensions are 9.14-m (30-ft.) long and 2.74-m (9-ft.) wide. A modular construction based on assemblies of pultruded fiber-reinforced-polymer (FRP) composite tubes is used to meet American Association of State Highway and Transportation Officials (AASHTO) H20 highway load ratings. The hollow tubes are 76 mm (3 in.) square and are made of carbon/vinyl-ester and glass/vinyl-ester. An extensive experimental study was carried out to obtain and compare properties (stiffness, strength, and failure modes) for a quarter portion of the full-sized bridge. The bridge response was measured for design loading, two-million-cycle fatigue loading, and ultimate load capacity. In addition to meeting H20 load criteria, the test article showed almost no reduction in stiffness or strength under fatigue loading and excellent linear elastic behavior up to failure. Fiber optic strain sensors were evaluated on the test article during testing. Sensor characteristics are determined as preparation for permanent field installation.