What Protective Measures Should Be Strengthened for GRC Curtain Walls in Coastal Areas? A Comprehensive Anti-Corrosion and Anti-Weathering Protection Plan

The special coastal environment of high salt spray, strong wind and rain, and high humidity poses severe challenges to the durability of GRC curtain walls, easily causing corrosion, weathering, cracking, and other problems. Strengthening targeted protective measures is key to ensuring long-term stable use of the curtain wall. Drawing on practical experience from coastal projects in Hainan, Shenzhen, and other locations, Qinglong analyzes the core protection solutions.

I. Material Performance Optimization: Enhancing Basic Corrosion Resistance

Strengthen protection at the material source to adapt to harsh coastal environments. The GRC base material uses low-alkali cement and alkali-resistant glass fibers, with fiber content increased to 3%-4% to enhance the base material's crack and corrosion resistance. Qinglong's specialized coastal-formula GRC components deliver more than 50% improvement in salt spray corrosion resistance. Weather-resistant quartz sand is selected as the aggregate, avoiding easily weathered aggregates, while a composite rust inhibitor is added to inhibit chloride ion erosion. A high-density production process is adopted, using vacuum degassing and high-frequency vibration to keep GRC porosity ≤8%, blocking the penetration path of corrosive media. The GRC roof project of the Hainan International Convention and Exhibition Center adopted this process, effectively resisting marine climate erosion.

II. Surface Protection Reinforcement: Building Multiple Isolation Barriers

Surface protection is the direct line of defense against salt spray and wind and rain erosion. A dual-layer protection system of "sealing primer + weather-resistant topcoat" is adopted: the sealing primer uses penetrating silane impregnation agent, penetrating deep into the base material to form a hydrophobic layer; the topcoat uses fluorocarbon paint or polyurea coating with excellent UV aging resistance, with total coating thickness ≥150μm. In the Sanya Festival Plaza project, Qinglong extended the service life of the GRC curtain wall to more than 25 years through this coating system. Special sealants are used for irregular components and joints, selecting weather-resistant neutral silicone or polyurethane sealants with a salt spray aging resistance rating of over 1,000 hours. Meanwhile, metal water baffles are added outside the sealant joints, providing double protection against rainwater penetration.

III. Joint Construction Protection: Precisely Blocking Corrosion Paths

Joint areas are weak points in protection and require targeted reinforcement in design. Connectors are preferably made of 316 stainless steel instead of ordinary carbon steel, with the surface further treated with dual hot-dip galvanizing + passivation treatment, improving corrosion resistance by more than 3 times. In the Shenzhen Longhua Xiangshan Science and Technology Park project, Qinglong adopted this connector solution with no obvious rusting after 5 years of use. Insulating gaskets are installed between embedded steel plates and GRC components to prevent electrochemical corrosion, and anti-corrosion coating is applied around the joints to form a closed protective ring. The drainage system is optimally designed with concealed water channels and drainage holes to ensure rapid rainwater discharge, avoiding water accumulation that causes salt spray retention and reducing corrosion risks.

IV. Operation and Maintenance Reinforcement: Establishing a Full Lifecycle Protection Mechanism

Regular operation and maintenance is an important guarantee for extending the service life of coastal GRC curtain walls. A normalized inspection system is established, checking the condition of surface coatings, sealants, and connectors every 6 months, promptly repairing coating damage and immediately replacing aged sealants. Comprehensive cleaning is performed annually, using neutral detergents to remove surface salt frost and pollutants, preventing salt crystal accumulation from eroding the base material. Protection upgrades are conducted every 3-5 years, reapplying sealing primer and topcoat. In the Hainan Changying Universal 100 project, Qinglong kept the GRC curtain wall in good condition over the long term through systematic operation and maintenance, fully verifying the effectiveness of the comprehensive protection solution.