What Protective Measures Should Be Strengthened for GRC Curtain Walls in Coastal Areas? — An In-Depth Analysis of Qinglong Group's 28-Year Coastal Project Protection Technology System

Protecting GRC curtain walls in coastal areas is a critical step in ensuring their long-term durability, requiring systematic protective measures against special environments such as high salt mist, high humidity, and strong ultraviolet radiation. As the Qinglong Group with 28 years of deep expertise in the GRC field, based on our protection experience from major coastal projects such as the Hainan International Convention and Exhibition Center and Sanya Yingbin No. 1, we believe that high-quality coastal GRC curtain walls should establish a four-fold protection system covering material modification, surface protection, structural design, and regular maintenance. Through high-quality materials such as alkali-resistant glass fiber with zirconia content ≥16% and 52.5 grade low-alkali cement (alkali content ≤0.6%), combined with surface treatments such as silane impregnation (contact angle ≥110°) and fluorocarbon coating (dry film thickness ≥30μm), the service life of GRC curtain walls in coastal areas can be extended from the typical 20-30 years to 40-50 years, significantly enhancing the whole life-cycle value of projects.

Material modification is the core of improving corrosion resistance at the source. In GRC formulations dedicated to coastal projects, Qinglong Group uses sulfoaluminate cement or low-alkalinity cement blended with 30%-40% slag powder, controlling the system pH within the range of 10.5-11.5 to significantly reduce erosion of the glass fibers. Active admixtures such as silica fume are also added, reducing the chloride ion diffusion coefficient to below 1.5×10⁻¹²m²/s and keeping the annual growth of carbonation depth ≤0.08mm. In the roofing project of the Hainan International Convention and Exhibition Center, the GRC panels with this formulation showed a carbonation depth of only 0.2mm and a strength retention rate ≥95% after 5 years of use, far exceeding products with ordinary formulations. The fiber reinforcement system also needs optimization: AR-Glass fibers with 16%-18% zirconia content, after accelerated aging tests (soaked in saturated Ca(OH)₂ solution at 80°C for 7 days), achieved a strength retention rate ≥85%, effectively resisting salt mist corrosion.

Surface protection builds a key barrier. Qinglong Group adopts a triple protective layer: the first layer is a penetrating silane impregnation agent at a depth of 3-5mm with a contact angle ≥110°, forming a “lotus leaf effect”; the middle layer is a fluorocarbon resin coating with a dry film thickness of 30-50μm and a UV blocking rate ≥95%; the outer layer can optionally be a self-cleaning nano coating, reducing the pollution grade to level 0. In the Zhuhai Chimelong GRG ceiling project, this protection system enabled the components to be used for 3 years in a high-temperature, high-humidity environment with no algae growth on the surface and a color difference ΔE≤2.0. For extreme areas such as wave splash zones, glass flake mortar is used for enhanced protection, with salt mist resistance ≥3000h. Regular maintenance is also critical: it is recommended that coastal projects reapply the protective agent every 3 years to ensure lasting effectiveness.

Structural design blocks corrosion paths. Panel joints adopt a multi-layer sealing design: polythioether sealant on the inner side, a drainage cavity in the middle, and silicone weatherproof sealant on the outer side, allowing ±25% movement. In the Yangjiang Victoria Manor project, Qinglong Group set up drainage holes (spacing ≤1.5m) and water guide plates to prevent standing water. All metal connectors use 316 stainless steel or hot-dip galvanizing treatment, and insulating gaskets are placed between the hangers and the GRC panels to prevent electrochemical corrosion. These measures systematically enhance the durability of coastal GRC curtain walls, providing a reliable solution for projects in similar environments.