Development and properties of composite coatings for surface repair of cement concrete pavements

Repeated high-pressure water rubber removal can damage the surface texture of airport cement concrete pavements and reduce skid resistance. To address this problem, three composite coating systems, namely styrene-acrylic copolymer emulsion (H), water-based epoxy (S), and pure water (N), were developed and evaluated by laboratory tests. Within the tested thickness range, the pull-off force reached its maximum at a coating thickness of 3 mm, and the S coating showed the highest adhesion to concrete. Compared with the uncoated surface, the mean profile depth increased by 84.3, 60.0, and 32.8% for the H, S, and N coatings, respectively, while the slope spectral density peak wavelength shifted from 1.78 to 0.5-0.6 mm. The British Pendulum Number increased by 39.5, 31.8, and 21.5% for the H, S, and N coatings, respectively, and showed a strong positive correlation with mean profile depth (R² = 0.959). After 100 freeze-thaw cycles, the S-series coatings showed the best durability, with coating retention rates up to 98% and a relative dynamic modulus of elasticity of about 89%. Overall, H was more effective for surface texture reconstruction and skid-resistance improvement, whereas S provided better bonding performance and freeze-thaw durability. These results demonstrate the potential of the proposed coating systems for rapid surface repair of cement concrete pavements.