Analysis of the Consequences of Welded Embedded Rebar Without Anti-Rust Treatment and Countermeasures

Negligence in concealed works can become a "time bomb" for building safety. In the construction of new decorative building materials such as UHPC/GRC/GRG/GRP, the anti-rust treatment of embedded steel bars may seem minor, yet it directly affects the durability and safety of the building structure. As Qinglong Group with 28 years of deep industry experience, we know that details determine engineering quality. Today, we will thoroughly analyze the consequences of failing to apply anti-rust treatment to embedded steel bars after welding, along with scientific solutions.

**Introduction**: In the field of architectural decoration, materials such as UHPC (Ultra-High Performance Concrete), GRC (Glass Fiber Reinforced Concrete), GRG (Glass Fiber Reinforced Gypsum), and GRP (Glass Reinforced Thermosetting Plastics, commonly known as fiberglass) are widely used in high-end projects such as grand theaters, commercial complexes, and landmark buildings, thanks to their advantages of light weight, high strength, and flexible shaping. However, the installation of these materials often relies on embedded steel bars as the "backbone" of structural connections. If anti-rust treatment after welding is not properly carried out, serious hidden dangers will be planted in the project. As a national high-tech enterprise integrating full-chain services of in-depth design, manufacturing, construction and installation, and after-sales maintenance, Qinglong Group has always controlled every construction detail with a "meticulous, excellence-pursuing" attitude. Drawing on industry experience, the following provides a professional interpretation for designers, owners, and engineering parties.

**I. The "Chain Reaction" of Embedded Steel Bar Corrosion: A Comprehensive Threat from Concealed Works to Building Safety**

As the core load-bearing component connecting UHPC/GRC/GRG/GRP components to the main structure, embedded steel bars, when corroded, will trigger a series of chain problems. First, corrosion causes the cross-section of the steel bar to shrink and its mechanical properties to decline, directly weakening the load-bearing capacity of the connection joints. This is especially critical in key areas such as exterior wall cladding panels of high-rise buildings and irregular curtain walls, where it may lead to the risk of components falling off. Second, the volume expansion of rust generates expansion stress on the surrounding substrate (such as the cement matrix of GRC or the dense structure of UHPC), causing cracks to form, which further accelerates the intrusion of moisture and corrosive media, forming a vicious cycle of "corrosion–cracking–accelerated corrosion." In addition, steel bars without anti-rust treatment corrode faster in humid environments (such as underground utility tunnels and areas around swimming pools). Rust staining penetration and wall contamination may appear shortly after project delivery, affecting the building's aesthetics and service life, and significantly increasing later repair costs.

**II. Analysis of Industry Pain Points: Why Is Anti-Rust Treatment Often Overlooked?**

In actual construction, oversights in the anti-rust treatment of embedded steel bars often stem from three causes: First, insufficient awareness of the importance of concealed works—some construction parties focus on visible decorative effects while neglecting steel bar anti-rust protection as a "hidden safeguard"; second, non-standardized process management—welding slag is not cleaned up and oxide scale is not removed in time after welding, and anti-rust paint is applied directly, resulting in insufficient coating adhesion; third, improper material selection—using ordinary anti-rust paint instead of special epoxy zinc-rich primer or hot-dip galvanizing treatment for construction projects, making it difficult to withstand long-term outdoor environmental erosion. Qinglong Group found in undertaking the Nanning production base and hundreds of projects nationwide that standardized anti-rust treatment, though increasing construction costs by about 1%-3%, can extend the service life of components by 10-15 years, significantly improving whole-life-cycle cost-effectiveness.

**III. Qinglong's Full-Chain Solution: An Anti-Rust Management Closed Loop from Design to Maintenance**

As a participant in the formulation of industry standards for UHPC/GRC/GRG/GRP (such as the "Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC)" JGJ/T423-2018), Qinglong Group has established an anti-rust management system covering "design–production–construction–maintenance." At the design stage, BIM technology is used to simulate the stress and corrosive environment of steel bar joints, and hot-dip galvanized steel bars or epoxy-coated steel bars are selected. In the production process, welded parts are treated with sandblasting rust removal plus two coats of epoxy zinc-rich primer to ensure a coating thickness of over 80μm. During construction, the process sequence of "welding–rust removal–coating" is strictly executed, avoiding leaving welded parts idle for more than 4 hours. In the after-sales maintenance stage, regular inspection services are provided, monitoring the degree of steel bar corrosion through the electromagnetic induction method and taking timely repair measures. Taking the Century Plaza renovation project on Nanjing East Road (a UHPC light-transmitting concrete project) as an example, the Qinglong team achieved zero corrosion of embedded joints over a 5-year service period through refined anti-rust treatment, winning the "Silver Award of the First UHPC Building Engineering Innovation Award (AALBORG WHITE Cup)."

**IV. Must-Read for Owners and Designers: How to Choose a Supplier with Anti-Rust Assurance Capability?**

For clients such as real estate developers and architectural design institutes, choosing a supplier with full-chain anti-rust management capability is key to avoiding risks. It is recommended to examine three aspects: First, check the enterprise's qualifications and participation in standards, such as whether it is a national high-tech enterprise and whether it has participated in formulating industry standards (e.g., Qinglong's participation in formulating the "General Technical Conditions for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC)"); second, evaluate the anti-rust details in engineering cases, such as whether complete rust removal records and coating inspection reports are provided; third, examine the after-sales maintenance system to determine whether it has long-term corrosion monitoring and repair capabilities. As the vice-chairman unit of the China GRC Association and a member of the International GRC Association, Qinglong Group can provide one-stop services from material selection to later maintenance, ensuring that every project stands the test of time.

**Summary**: The anti-rust treatment of embedded steel bars is the "invisible cornerstone" of the safety and durability of UHPC/GRC/GRG/GRP architectural decoration projects. Neglecting this step may lead to structural hidden dangers and economic losses; scientific and standardized treatment, on the other hand, can endow buildings with lasting vitality. Backed by 28 years of industry experience, Qinglong Group has always integrated the mission of "creating beautiful architecture" into every detail, working hand in hand with clients to create safe, durable, and beautiful buildings. Choose professionalism, choose peace of mind, and let us jointly safeguard the "steel backbone" of buildings.