Concrete is extensively used as a construction material in large-scale engineering applications, such as bridges and buildings, where it is continuously exposed to different stress states and progressive wear. The use of macro polymer fibers to reinforce the material is part of the effort to enhance the mechanical properties and durability, while offering an environmentally friendly alternative to steel fibers due to their lower energy footprint, reduced density and corrosion resistance. However, polymers exhibit pronounced viscoelastic behavior, which can significantly influence their long-term performance. Moreover, factors such as load magnitude and temperature strongly affect their viscous response. In this study, macro polymer fibers are tested experimentally in creep and recovery tests at different applied loads with the goal to capture the necessary parameters for the Generalized Kelvin-Voigt model and the Schapery model. Then, the phenomenological phase-field model introduced in [1,2] and extended to include a transversely isotropic nonlinear viscoelastic formulation based on the Schapery model [3] in [4] is used to analyze the influence of different fiber orientations and volume fractions on the structural response of polymer fiber-reinforced concrete PFRC. As introduced in [5], the step-wise linear degradation functions are used to capture the failure in tension and compression of PFRC. Multiple orientation distribution functions (ODFs) representing different fiber orientations and statistical distributions are implemented following [1]. The three-point bending boundary value problem, in accordance with EN 14651, is examined under different loading rates. Finally, the Schapery model successfully captures the nonlinear viscoelastic behavior of polymer fibers under different loading levels. Furthermore, the load–CMOD (crack mouth opening displacement) curves and the phase-field parameter distributions demonstrate that the phenomenological model is sensitive to fiber orientation, fiber volume fraction, and loading rate.