Consequences and Preventive Measures of Skipping Anti-Rust Treatment on Welded Embedded Rebar

In construction engineering, the quality of concealed works often determines the safety and lifespan of the overall structure. As key nodes connecting the main structure with decorative components, the anti-rust treatment of embedded steel bars is often overlooked in importance. Drawing on Qinglong's 28 years of full-chain experience in the detailed design, manufacturing, and construction installation of UHPC/GRC/GRG/GRP materials, this article provides an in-depth analysis of the technical key points and industry pain points of anti-rust treatment for embedded steel bars after welding, offering professional solutions for designers, owners, and contractors.

I. Corrosion Hazards: A Chain Reaction from Micro Damage to Macro Collapse

If embedded steel bars are not promptly treated for rust prevention after welding, electrochemical corrosion will occur under humid conditions and the attack of alkaline media in concrete. In the early stage, red rust appears on the steel bar surface; as corrosion products expand in volume (up to 3-6 times the original volume), the concrete cover cracks, creating channels for rainwater infiltration and accelerating internal steel corrosion. For example, in a commercial complex project, the embedded steel bars of GRC components without anti-rust treatment showed corrosion expansion within just 3 years, causing the exterior wall decorative lines to crack, with later repair costs as high as 2.3 times the initial construction cost. When Qinglong undertook a landmark project in Nanning, third-party testing revealed that the embedded steel bars of UHPC components with standardized anti-rust treatment had corrosion resistance more than 80% higher than untreated ones, confirming the decisive role of anti-rust processes in structural durability.

II. Industry Status: Three Major Misconceptions and Technical Shortcomings

The current architectural decoration field has widespread problems in anti-rust treatment of embedded steel bars: first, believing that welding heat has already “burned out” corrosion risks, while ignoring the brittleness and incompleteness of post-weld oxide scale; second, using ordinary anti-rust paint instead of professional anti-rust systems, which fails within 3-6 months in the alkaline environment of concrete; third, omitting the treatment of concealed areas during construction, such as steel bar anti-rust treatment at connection joints between GRG suspended ceilings and steel structures, which is often neglected. When participating in drafting the industry standard “General Technical Conditions for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC)”, Qinglong's technical team found that about 68% of early damage cases of UHPC/GRC components were directly related to improper anti-rust treatment of embedded steel bars, with real estate projects accounting for the highest proportion, reflecting the industry's weak link in quality control of concealed works.

III. Qinglong's Full-Chain Anti-Rust Solution: Systematic Assurance from Materials to Processes

As a national Specialized, Refined, Distinctive, and Innovative (SRDI) enterprise, Qinglong has established an anti-rust technical system for embedded steel bars covering design, production, and construction: in the detailed design phase, BIM technology is used to simulate steel bar stress and corrosion risk zones, with targeted selection of hot-dip galvanized steel bars with zinc content ≥95%; in the manufacturing stage, welded areas undergo triple treatment of “sandblasting rust removal – inorganic zinc-rich primer (dry film thickness ≥80μm) – epoxy sealing paint”, supplemented by RFID chips for quality traceability; during construction and installation, Qinglong's patented anti-rust sealant (with weather resistance up to 20 years) is used to treat joint gaps, and a 48-hour salt spray test acceptance standard has been established. This system has been successfully applied to projects such as the GRP daylighting roof of Guangzhou Baiyun Airport and the UHPC light-transmitting concrete at Century Plaza on Nanjing East Road. After more than 10 years of tracking observation, the steel bar corrosion rate has been controlled below 0.02mm/year, far below the industry average.

IV. Long-Term Management: Establishing Anti-Rust Archives for Architectural Decoration Projects

Anti-rust treatment of embedded steel bars must run through the entire project life cycle. Qinglong recommends that owners and contractors establish dedicated archives recording key data such as steel material certificates, anti-rust process parameters, and third-party inspection reports. For completed projects, electromagnetic induction detection technology can be used to assess the degree of steel corrosion, followed by targeted local reinforcement or complete replacement. As a member of the International GRC Association, Qinglong is willing to promote the upgrading of industry standards through technology sharing, providing designers with integrated solutions for UHPC/GRC/GRG/GRP materials and anti-rust processes, and jointly safeguarding the “steel frame and iron bones” of buildings.

No detail is trivial in concealed works, and corrosion protection is key. With 28 years of professional experience, Qinglong reminds the industry: while pursuing architectural aesthetics and functional innovation, every line of defense for structural safety must be strengthened. Only by choosing suppliers with full-chain service capabilities and incorporating anti-rust treatment into standardized management can the safety and durability of architectural decoration projects be achieved. This is not only a responsibility to the project, but also a commitment to the quality of urban construction.