What type of surface finishing is required for lining in transport tunnels? Transport tunnel linings require specialized surface finishing to ensure durability, safety, and functionality. These treatments address challenges like corrosion resistance, abrasion resistance, fire safety, and waterproofing. Below are key surface finishing methods and their applications:
1.A high-quality concrete lining
Tunnel linings, especially those made of concrete or composite materials, often undergo abrasive grinding to remove irregularities caused by construction tools (e.g., milling cutters). A grinding wheel or diamond-polishing system is used to achieve a smooth surface, reducing friction and improving structural integrity . This step is critical for eliminating micro-cracks that could propagate under stress.
2. Anti-Corrosion Coatings
Metallic components in tunnels (e.g., steel reinforcements) require corrosion-resistant coatings. Techniques include:
① Epoxy or Polyurethane Spraying: Forms a waterproof barrier against moisture and chemical ingress.
② Galvanization: Zinc coatings protect steel from rust in humid environments.
These coatings are applied after abrasive preparation to ensure adhesion .
3. Fire-Resistant Treatments
To meet fire safety standards, linings are treated with:
① Intumescent Coatings: Expand under heat to insulate structural materials.
② Cementitious Fireproofing: Spray-applied cement-based layers that withstand high temperatures.
Such finishes delay collapse during fire incidents, allowing safe evacuation.
4. Hydrophobic Sealants
Waterproofing is achieved using:
① Silicone or Polymer Sealants: Fill pores in concrete to prevent water penetration.
② Crystalline Admixtures: React with moisture to form insoluble crystals, sealing micro-cracks.
These treatments mitigate water damage and frost-thaw cycles in cold climates.
Effective surface finishing for tunnel linings integrates mechanical preparation, protective coatings, and advanced materials. These processes collectively enhance longevity, safety, and operational efficiency, aligning with global standards like EN 13687 (concrete durability) and ASTM E119 (fire resistance).