Structural performance of a FRP bridge deck

摘要

The purpose of this paper is to present fatigue and strength experimental qualifications performed for an all-composite bridge deck. This bridge deck, made up of fiber-reinforced polymer (FRP) was installed on the campus at University of Missouri at Rolla on July 29th, 2000. The materials used for the fabrication of this 30 foot (9.144 m) long by 9 foot (2.743 m) wide deck were 3 inches (76.2 mm) pultruded square hollow glass and carbon FRP tubes of varying lengths. These tubes were bonded using an epoxy adhesive and mechanically fastened together using screws in seven different layers to form the bridge deck with tubes running both longitudinal and transverse to the traffic direction. The cross-section of the deck was in the form of four identical I-beams running along the length of the bridge. Fatigue and failure tests were conducted on a 30 foot (9.144 m) long by 2 foot (609.6 mm) wide prototype deck sample, equivalent to a quarter portion of the bridge deck. The loads for these tests were computed so as to meet American Association of State Highway and Transportation Officials (AASHTO) H-20 truckload requirements based on strength and maximum deflection. The sample was fatigued to 2 million cycles under service loading and a nominal frequency of 4 Hz. Stiffness changes were monitored by periodically interrupting the run to perform a quasi-static test to service load. Results from these tests indicated no loss in stiffness up to 2 million cycles. Following the fatigue testing, the test sample was tested to failure and no loss in strength was observed. The testing program, specimen detail, experimental setup and instrumentation, testing procedure, and the results of these tests are discussed in detail. A finite-element model of the laboratory test was also developed. The results from the model showed good correlation to deflections and longitudinal strains measured during the tests. The design of the bridge deck has been discussed in detail.