Abstract: To improve the visual environment of tunnel driving and the effect of brightening and pollution resistance of tunnel wall coating on tunnel operation safety and energy saving, and provide a selection basis for tunnel wall coating technology for improving tunnel quality in China, the pollution mechanism and distribution characteristics of the tunnel wall are investigated, and brightening and stainresistant experiments on four coating materials are conducted based on the contact angle and reflectance. The experimental results show the following: (1) Under the same flatness, when the material contact angle is close to the superhydrophobic contact angle, the pollution resistance is better, and the reflectivity can be kept at a high level. (2) It is easy to clean in later operation, and the reflectivity after cleaning is close to that after implementation, indicating that this kind of material used for tunnel wall coating plays a positive role in improving the operation quality of highway tunnel and reducing the operation cost.

Key words: highway tunnel, tunnel wall coating, brightening and pollution resistance test, reflectivity, contact angle