The quality and structural integrity of fiber-reinforced concrete largely depend on the distribution and density of steel fibers within its matrix. This study presents an innovative, non-destructive method to evaluate these characteristics using fully polarimetric Ground Penetrating Radar (GPR) data. Concrete samples with varying fiber distributions and concentrations are prepared and scanned using GPR across multiple polarization configurations. The collected scattering data are analyzed through the H-alpha decomposition method to classify and visualize fiber orientation, accumulation, and homogeneity. Results demonstrated that the fully polarimetric approach provides detailed insights into the internal structure of concrete, surpassing traditional methods in accuracy and depth. This method allows the detection of non-uniform fiber distributions, which can impact mechanical properties, and offers a reliable solution for quality control in construction applications. The findings highlight the potential of GPR and H-alpha classification as advanced tools for improving the performance and durability of fiber-reinforced concrete.