Behavior of free and connected double-tee flanges reinforced with carbon-fiber-reinforced polymer

摘要

This paper presents an experimental program conducted to evaluate the performance of precast concrete doubletee flanges reinforced with carbon-fiber-reinforced polymer grids under various types of loading. The experimental program comprised two different studies, with a total of 10 full-scale precast, prestressed concrete double-tee beams subjected to uniform and concentrated loads applied to the top surface of their flanges. The first study included testing two double-tee beams with 2 and 3.5 in. (50 and 89 mm) thick flanges to evaluate the behavior, including the flange bending behavior, under uniformly distributed loads using an enclosed vacuum chamber. In the second study, a total of eight double tees were tested either individually or in connected pairs to determine the load-carrying capacity of the flanges when subjected to concentrated loads applied at various points on the flange. Test results from the first study indicated that the flanges were capable of resisting a maximum applied load significantly higher than their factored design loads. Results of the second study indicated that the concentrated load-carrying capacity of the flange depends on the location of the applied load. Based on this investigation, an idealized failure surface and the corresponding mode of failure were identified for the free and connected flange of prestressed concrete double tees subjected to concentrated loads.