The use of fiber-reinforced polymer (FRP) for reinforcement and retrofit of structures has become common in recent years. Although considerable research exists on carbon, glass, and aramid fibers, new materials continue to emerge, requiring new knowledge to optimize their use and safe design. This study analyzed the behavior of continuous beams reinforced with FRP bars. The parameters studied were concrete type (normal-strength concrete (NSC) and ultra-high-performance fiber-reinforced concrete (UHPFRC)), fiber material (carbon, glass, and basalt), and environmental exposure (acid, alkaline, and saline environments). Finite element (FE) beam models were developed and validated with published experimental data. The validated models were used to study the aforementioned parameters. Although the basalt fibers provoked higher displacements when compared to carbon and glass fibers, they also provided better bond with the concrete and higher tensile strength, allowing the beams to reach higher load capacity. Exposure to aggressive environments diminished the adhesion between GFRP and BFRP bars and the concrete, but the reduction was not sufficient to initiate the debonding and the failure was governed by FRP bars rupture. However, it was concluded that the load-displacement response was not affected much by the environmental exposure. The UHPFRC provided superior bond strength between concrete and the reinforcement bars, which assured rupture of the fibers in these beams as well. The use of UHPFRC also resulted in an increase in the beams’ load carrying capacity.