What Protective Measures Should Be Strengthened for GRC Curtain Walls in Coastal Areas? — Qinglong Group's Analysis Based on 28 Years of Coastal Project Protection Experience

GRC curtain walls in coastal areas have long faced severe environmental challenges such as high salt fog, high humidity, and strong typhoons. The scientific rigor and comprehensiveness of protective measures directly determine the service life and safety performance of the curtain wall. As the Qinglong Group with 28 years of deep expertise in the GRC field, we believe—based on hands-on experience from coastal projects such as the Hainan International Convention and Exhibition Center and the Ouargla Hotel in Algeria—that GRC curtain walls in coastal areas need to strengthen protective measures across four dimensions: material modification, structural design, sealing protection, and maintenance monitoring, forming a systematic protective system.

Protection at the material level is fundamental. GRC in coastal areas must use low-alkalinity cement (alkali content ≤0.6%) and alkali-resistant glass fibres with a zirconia content above 16%, improving corrosion resistance at the source. In the 120,000 m² roofing project of the Hainan International Convention and Exhibition Center, Qinglong Group reduced the chloride ion diffusion coefficient to below 1.5×10⁻¹²m²/s by incorporating silica fume and slag powder (dosage 20%-30%). At the same time, migrating corrosion inhibitors (such as calcium nitrite-based inhibitors) were added to the GRC matrix to form a protective film that delays corrosion of the steel reinforcement. This material modification extends the design service life of the curtain wall in coastal environments to over 50 years.

Structural design must give priority to the waterproofing and drainage system. Qinglong Group installs drainage channels and weep holes at panel joints, adopting a pressure-equalized cavity design to prevent rainwater retention. In the Algeria hotel project, we designed a 5% drainage slope for the GRC perforated panels and installed stainless steel flashing at the joints, effectively preventing capillary water seepage. For the connection points between the curtain wall and the main structure, hot-dip galvanized steel connectors (galvanized layer thickness ≥85μm) are used with additional elastic rubber pads to block thermal bridge conduction.

The sealing protection system requires multi-level assurance. Panel joint sealing adopts a double-seal design: the first seal is a compressed sealing gasket (EPDM rubber), and the second is silicone sealant (movement capability ≥25%). In the Shenzhen Yirui Biotechnology Building project, Qinglong Group conducted salt spray accelerated aging tests on the sealant to ensure it would not crack or chalk for 20 years in coastal environments. Meanwhile, a fluorocarbon protective coating (film thickness ≥30μm) is applied to the GRC surface, achieving weather resistance of over 3,000 hours.

Establishing a regular maintenance and monitoring mechanism provides long-term assurance. Qinglong Group customizes dedicated maintenance plans for coastal projects, including semi-annual drone inspections, annual sealant elasticity testing, and triennial torque verification of anchoring parts. In the Hainan Changying Global 100 Paradise project, embedded corrosion sensors monitor real-time changes in the steel reinforcement potential within the panels, enabling early-warning maintenance. This systematic protection allows Qinglong GRC curtain walls to maintain outstanding performance in harsh coastal environments.