Understanding how asphalt concrete (AC) responds to temperature variations is vital for predicting pavement performance and ensuring long‐term durability. Conventional methods are often time‐consuming and require bulky equipment. As a nondestructive alternative, experimental modal analysis (EMA) offers a promising approach. However, EMA applications remain limited—particularly for cylindrical specimens commonly used in laboratory compaction or obtained via field coring. These geometries pose challenges due to high material damping, AC’s heterogeneous internal structure and complex symmetric/asymmetric mode shapes that complicate interpretation and demand careful selection of excitation and response points. This study introduces a simplified yet robust setup that isolates a distinct, temperature‐sensitive mode shape on halved Marshall specimens. EMA was performed from −10 to + 60°C in 5°C increments, using high‐resolution frequency response function (FRF) and coherence measurements. The results revealed a thermally driven softening response, marked by a ~ 28% reduction in average resonance frequency, pronounced damping growth, and spectral broadening, all reflecting the viscoelastic degradation of stiffness and energy retention capacity in AC. These findings confirm that when properly configured, EMA offers a practical and reliable nondestructive method for evaluating temperature‐driven stiffness degradation in AC, directly applicable to pavement design, monitoring, and performance assessment.
Aktaş et al. (Thu,) studied this question.