Structural Assessment of Basketball Court Concrete Using Impact-Echo and Phase Angle Analysis

Background: The structural integrity of basketball court concrete is critical for both safety and performance, yet systematic nondestructive evaluation (NDE) studies on thin-slab sports flooring remain limited. This research addresses that gap by applying the Impact-Echo (IE) method to assess material uniformity and detect potential flaws in basketball court concrete. Unlike most prior studies that emphasize frequency-domain analysis, this study integrates both Fourier Transform and Phase Angle behavior to enhance diagnostic reliability. Methods: Experimental testing was conducted with small and large hammers at sensor spacings of 10, 20, and 30 cm along three parallel lines of a full-scale court. Signals were processed using Fast Fourier Transform (FFT) and Phase Angle analysis to identify dominant frequency peaks, calculate thickness, and evaluate wave coherence. Results: Results show a clear inverse correlation between frequency and slab thickness, with Line 3 exhibiting the highest uniformity and Line 1 indicating localized variability. Phase Angle analysis revealed strong sensitivity to sensor distance and hammer size: small hammers with short spacing captured fine-scale anomalies, while large hammers and wider spacing yielded smoother generalized responses. To our knowledge, this is among the first studies to systematically evaluate basketball court concrete using both Fourier and Phase Angle analysis across varied sensor and hammer configurations. Conclusion: The findings refine understanding of how test parameters influence IE outcomes in thin concrete layers and provide a foundation for standardized, reliable NDE protocols that support quality control, safety assurance, and long-term monitoring of sports infrastructure.