Degradation Behavior of Surface Wear Resistance of Marine Airport Rigid Pavements

Rigid pavements in marine airports are subjected to severe surface degradation due to the combined effects of salt erosion and repeated aircraft impact loading, which significantly reduces service life and operational safety. This study investigates the degradation behavior and underlying mechanisms governing the surface wear resistance of C40 concrete under simulated marine environmental and mechanical conditions. Specimens were first subjected to repeated drop-weight impact loading, after which abrasion tests were performed to quantify surface wear resistance. Microstructural evolution and corrosion products were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. The results show that repeated impact loading significantly accelerates surface deterioration: after 60 abrasion cycles, cumulative mass loss increased by up to 23.6 g for specimens subjected to 80 impacts, while long-term water absorption rose by up to 7.52% due to impact-induced microcracking. In contrast, moderate salt-fog exposure initially enhanced wear resistance, as cumulative mass loss decreased from 18.1 g (unexposed) to 9.4 g after 30 cycles, attributable to pore filling by CaCO₃ and Friedel's salt. However, prolonged exposure (40 cycles) reversed this trend, leading to strength loss. Under combined impact of salt-fog conditions, the wear resistance deteriorated more rapidly, and the transition from strengthening to weakening occurred earlier than under salt exposure alone, indicating a coupled degradation effect. These findings clarify the coupled chemical-mechanical deterioration mechanism of marine airport pavements and provide a scientific basis for durability design and maintenance optimization.