Analysis of Anti-Rust Measures and Implementation Points for Top-Burst Screws in GRC Component Installation

### Analysis of Anti-Rust Measures for Expansion Bolts in GRC Component Installation and Key Implementation Points

**Key quote**: Details determine a building's life; anti-rust protection safeguards GRC safety — the technical code distilled from Qinglong's 28 years of industry experience.

In the installation of GRC (glass fiber reinforced concrete) components, expansion bolts serve as key connection nodes between components and the main structure, and their anti-rust performance directly affects the safety and durability of architectural decoration. Especially in humid, high-temperature, or coastal high-salt-spray environments, screw corrosion not only affects component stability but may also create a risk of components falling. As an industry leader with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group has drawn on more than a thousand engineering projects to develop a systematic solution for expansion bolt anti-rust treatment, providing professional technical support for designers, owners, and contractors.

#### I. Hazards of Expansion Bolt Corrosion in GRC Components and Industry Pain Points

GRC components, valued for being lightweight yet high-strength and flexible in shaping, are widely used in high-end projects such as grand theaters, commercial complexes, and landmark buildings. However, expansion bolts, as core parts of concealed works, are often overlooked when it comes to corrosion: on one hand, ordinary screws are prone to electrochemical corrosion under the alkaline concrete environment combined with external moisture, leading to reduced strength; on the other hand, traditional anti-rust treatments (such as simply brushing anti-rust paint) can hardly meet the demanding requirements of GRC components' long-term outdoor use. According to industry research, about 30% of later-stage maintenance problems with GRC components stem from screw corrosion — a pain point that has become a key factor affecting engineering quality.

#### II. Qinglong's Core Technical Solutions for Anti-Rust Treatment of GRC Expansion Bolts

Based on the concept of "full lifecycle quality control," Qinglong Group has formed a triple protection system covering material selection, surface treatment, and construction techniques:

**1. High-Performance Material Selection: Blocking Corrosion Paths at the Source**
316 stainless steel expansion bolts are preferred; their chromium-nickel-molybdenum alloy composition forms a passive film on the surface, with salt spray resistance exceeding 5,000 hours — far surpassing ordinary carbon steel screws (200–500 hours). For special coastal or chemical environments, an additional hot-dip galvanizing + epoxy resin composite coating process is applied, and this dual barrier ensures an anti-rust service life of more than 15 years.

**2. Refined Surface Treatment: Enhancing Anti-Rust Coating Adhesion**
Before installation, screws must undergo a four-step pretreatment of "degreasing → pickling → phosphating → passivation" to remove surface oxide layers and impurities. Qinglong's exclusively developed nano-ceramic anti-rust coating technology uses electrostatic spraying to control coating thickness uniformly at 80–120μm, with adhesion meeting Grade 0 as specified in GB/T 9286, effectively preventing coating peeling.

**3. Construction Process Protection: Strictly Controlling Installation Environment and Technical Details**
During the GRC component installation stage, Qinglong adopts a "dry-wet separation" working method: bolt holes are pre-filled with epoxy resin anchoring adhesive, and after installation, the gaps between the bolt heads and the components are immediately sealed with silicone sealant to form a waterproof isolation layer. Meanwhile, for winter low-temperature or rainy-season construction, dedicated heating and dehumidifying equipment is provided to ensure the anti-rust coating cures in an environment above 5°C with relative humidity ≤85%.

#### III. Implementation Key Points and Quality Acceptance Criteria

Qinglong Group incorporates anti-rust measures into the full-process management of GRC components. Key control points include:
- **Incoming Material Inspection**: Each batch of screws must be accompanied by material certificates and salt spray test reports, with sampling tests for hardness (HV≥200) and coating thickness;
- **Construction Process Monitoring**: Torque wrenches are used to control tightening torque (set at 25–50N·m depending on diameter) to avoid coating damage caused by over-tightening;
- **Acceptance Criteria**: In accordance with the Technical Standard for Application of Glass Fiber Reinforced Cement (GRC) in Buildings (JGJ/T423-2018), a 100% visual inspection is conducted after screw installation — no bubbles, peeling, or exposed substrate allowed — and no rust traces should appear after a 72-hour water immersion test.

#### IV. Qinglong's Full-Chain Service: Anti-Rust Assurance from Design to Maintenance

As a national high-tech enterprise and a participant in establishing GRC industry standards, Qinglong Group not only provides material and construction solutions but also reduces corrosion risk at the source through joint optimization in the detailed design stage (such as concealed screw design and reserved drainage slopes). For completed projects, Qinglong's after-sales team offers regular inspection (using eddy current testing technology) and anti-rust maintenance services to ensure the safe service of GRC components.

From the GRC curtain wall of a large commercial complex in Guangzhou to the decorative moldings of a seaside hotel in Malaysia, Qinglong Group has practiced its mission of "creating aesthetically beautiful buildings" with 28 years of technical accumulation. In GRC component installation, the anti-rust treatment of expansion bolts may seem minor, yet it is the "invisible guardian" of building safety and aesthetics. Only by choosing a professional brand and controlling detail craftsmanship can every GRC decoration withstand the test of time and environment.