Anti-Rust Treatment Methods and Quality Control Essentials for Steel Structure Connections in GRC Curtain Walls

The durability and safety of architectural curtain walls begin with the anti-rust treatment of every connection node. As an industry leader with 28 years of deep expertise in the UHPC/GRC/GRG/GRP materials field, Qinglong Group fully understands that the anti-rust process for GRC curtain wall-to-steel structure connections is a critical line of defense for building safety. Drawing on full-chain practical experience, this article systematically analyzes the core technologies and quality control key points of anti-rust treatment, from material selection and process control to quality supervision.

GRC Curtain Wall-to-Steel Structure Connections: The Necessity of Anti-Rust Treatment and Industry Challenges

In high-end buildings such as grand theaters and commercial complexes, GRC curtain walls have become the preferred solution for facade decoration thanks to their lightweight, high-strength properties. However, their connection nodes with steel structure skeletons are exposed to natural environments for long periods and are prone to corrosion, which leads to a decline in structural load-bearing capacity. According to industry research, about 30% of curtain wall safety hazards stem from anti-rust failure at connection points. As a National High-Tech Enterprise, Qinglong Group participated in drafting the Technical Standard for Architectural Application of Glass Fibre Reinforced Cement (GRC), and has always regarded anti-rust treatment as a key link in the whole-life-cycle quality control of GRC curtain walls.

Three Core Technologies of Anti-Rust Treatment: A Systematic Solution from Materials to Processes

**1. Pretreatment Process: Steel Surface Treatment is the Foundation of Anti-Rust Protection** Sandblasting (Sa2.5 grade standard) removes oxide scale and impurities, ensuring a surface roughness of 50-80μm to provide an ideal base for coating adhesion. Qinglong's production base is equipped with an automated pretreatment line; through constant-temperature, dust-controlled environment management, processing efficiency is improved by 40% while uniform rust removal is guaranteed.

**2. Composite Coating System: The Technical Key to Long-Lasting Protection** A three-layer protective system of "epoxy zinc-rich primer (80μm) + epoxy micaceous iron oxide intermediate coat (120μm) + fluorocarbon topcoat (60μm)" is recommended, achieving a total dry film thickness of over 260μm and salt spray resistance of up to 5,000 hours. For coastal high-humidity environments, the modified epoxy primer developed by Qinglong increases adhesion by 20% and effectively resists chloride ion penetration.

**3. GRC Component Interface Treatment: Blocking Electrochemical Corrosion Paths** Isolation layers are set at the contact points between GRC components and steel structures, using PTFE gaskets or epoxy resin coatings to prevent direct contact between metal and cement-based materials that would cause electrochemical corrosion. Qinglong's detail design team uses BIM technology to simulate node stress, optimizing the thickness and layout of isolation layers to ensure the unity of structural safety and anti-rust effectiveness.

Quality Control Key Points: Four Dimensions of Full-Process Supervision

**1. Material Incoming Inspection: Quality Control at the Source** Steel material certificates and weather-resistance test reports for coating materials are strictly verified. Qinglong's laboratory is equipped with salt spray test chambers, adhesion testers and other equipment to conduct sampling tests on every batch of materials, ensuring compliance with the General Technical Requirements for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC).

**2. Construction Process Control: Precision Determines Results** Specialized tooling fixtures ensure uniform coating application, with dry film thickness monitored in real time by magnetic thickness gauges—at no fewer than 3 points per 100㎡. Qinglong's construction team pioneered the "Three-Inspection System" (self-inspection, mutual inspection, and special inspection), with particular focus on coating repair quality at welded joints to ensure no defects such as missed coating or pinholes.

**3. Environment-Adaptive Design: Tailoring Solutions to Local Conditions** Anti-rust strategies are optimized for the climate characteristics of different regions: anti-freeze-thaw coatings are added in severe cold northern areas, while anti-mold primers are used in hot and humid southern areas. In the Nanjing East Road Century Plaza renovation project that Qinglong participated in, combining node insulation design with anti-rust coatings kept the steel structure connection points performing stably under temperature variations.

**4. Long-Term Maintenance Mechanism: Whole-Life-Cycle Management** A maintenance system of "professional inspection every 5 years + routine patrols" has been established, with endoscopes used to check for corrosion at concealed nodes. Qinglong's after-sales team is equipped with portable coating detectors to quickly assess the condition of anti-rust layers and provide customers with targeted maintenance plans, fulfilling the service commitment of "meticulous care and the pursuit of excellence."

From detail design to after-sales maintenance, Qinglong Group leverages its full-chain advantages to build a closed quality loop for GRC curtain wall anti-rust treatment. As a Vice President Unit of the China GRC Association, we firmly believe that high-quality anti-rust treatment is not only a technical requirement but also a long-term commitment to building safety. Going forward, Qinglong will continue to drive anti-rust technology innovation, providing designers and owners with GRC curtain wall solutions that combine aesthetic appeal with structural safety, and jointly creating the beauty of architecture.