Composite Grids for Reinforcement of Concrete Structures

摘要

This research investigated a new concept that uses fiber-reinforced plastic (FRP) composite grid to reinforce concrete structural members. Prefabricated two- and three-dimensional FRP grid structures were investigated as a possible alternative to conventional one-dimensional steel reinforcement rods. Through laboratory investigations, significant improvements in fiber volume fraction in orthogrid and isogrid systems were achieved. Laboratory-scale samples demonstrated excellent results under loading tests. Concurrent investigations showed that although the FRP grid-reinforced concrete is more flexible than steel-reinforced concrete, its post failure deformation was pseudo-ductile, characterized by continuous structural deformation through multiple low-level brittle failures before the onset of catastrophic failure. It was also found that a combined concrete/composite reinforcement structure, with a higher volume of FRP composite fraction in the concrete, would substantially increase stiffness, load capacity, and postfailure concrete containment. This study addressed not only the possible replacement of steel reinforcement with composite grids, but also investigated enhancement of the composite application through load-sharing with steel reinforcement in a complementary fashion. Various manufacturing improvements also were explored, including the novel use of disposable toolings.