MOMENT REDISTRIBUTION OF GFRP-RC CONTINUOUS T-BEAMS

摘要

Fiber-reinforced polymer (FRP) bars have proven to be an excellent alternative to steel bars in many concrete structures such as parking garages and overpasses that are susceptible to harsh environments and consequently corrosion of steel reinforcement. In these structures, FRP reinforced concrete (FRP-RC) continuous beams are common members. Moment redistribution in FRP-RC continuous beams has not been well established yet because of the different characteristics of FRP bars such as linear-elastic stress-strain relationship and lower modulus of elasticity compared to conventional steel. Recent studies showed that redistribution of internal forces in Glass (G) FRP-RC continuous beams with a rectangular section is possible. However, no attention was given to continuous beams with a T-section. Therefore, this study aims at investigating the ability of GFRP-RC continuous beams with a T-section to redistribute the moment between the critical sections. In this paper, test results of three large-scale GFRP-RC T-beams are presented. The beams were 6,000-mm long and continuous over two equal spans of 2,800 mm each. The sections had an overall depth of 300 mm, an effective flange width of 600 mm, a flange thickness of 100 mm, and a web width of 200 mm. The test variables included the assumed moment redistribution percentage and the arrangement of shear reinforcement. It was observed that the beam with less stirrup spacing showed better performance in achieving the assumed percentage of moment redistribution and in carrying higher ultimate load compared to its counterparts with larger stirrup spacing.