What Are the Rust Prevention Measures for Top-Burst Screws During GRC Component Installation? A Practical Full-Process Anti-Rust Protection Guide

Expansion anchor bolts used for GRC component installation are exposed to outdoor environments for long periods and are susceptible to rusting from wind, rain, humidity, and salt spray, which affects connection strength and curtain wall stability. Implementing comprehensive anti-rust measures is key to ensuring long-term reliable bolt performance. Drawing on years of installation experience, Qinglong analyzes the core protection solutions.

1. Bolt Material Selection: Enhancing Rust Resistance at the Source

Select expansion anchor bolt materials with strong weather resistance to suit different service environments. For standard indoor environments, Grade 8.8 carbon steel expansion anchor bolts are selected, with strict surface anti-rust treatment required; for outdoor open-air environments, stainless steel expansion anchor bolts are preferred—304 stainless steel is suitable for ordinary outdoor environments, while 316 stainless steel offers superior corrosion resistance for coastal high-salt-spray environments; Qinglong used 316 stainless steel expansion anchor bolts exclusively in its Hainan project; for heavy-load connection areas, hot-dip galvanized carbon steel expansion anchor bolts are selected, with a galvanized coating thickness ≥85μm, balancing strength and rust resistance to ensure no obvious corrosion within the design service life.

2. Surface Anti-Rust Treatment: Building Multiple Protective Barriers

Implement precise surface anti-rust treatments tailored to different bolt materials. Carbon steel bolts adopt a triple process of “rust removal–galvanizing–sealing paint”: sandblasting first achieves Sa2.5 grade, removing surface oxide scale and impurities; after hot-dip galvanizing, anti-rust sealing paint is applied to form a dense protective layer. Stainless steel bolt surfaces undergo pickling and passivation to remove the oxide layer generated during processing, enhancing surface corrosion resistance and preventing intergranular corrosion at welded areas. Anti-rust grease or thread adhesive is applied to bolt threads, which enhances sealing while facilitating later disassembly and maintenance. In the Nanning Fengjingwan project, Qinglong effectively improved the anti-rust performance of expansion anchor bolts through this treatment scheme.

3. Installation Joint Sealing Protection: Blocking Corrosive Media Penetration

Sealing installation joints is key to preventing rainwater and moisture intrusion and requires reinforced protective design. After expansion anchor bolts are installed, apply special anti-rust paint to the bolt heads and nuts, fully covering the exposed metal surfaces; install elastic sealing gaskets at the contact areas between bolts and GRC components, using weather-resistant EPDM rubber to prevent electrochemical corrosion caused by direct contact between metal and components; seal around the joints with neutral silicone weatherproof sealant, with a sealant joint width ≥8mm, ensuring complete coverage of the bolt heads and blocking rainwater and moisture penetration. In the Zhongshan Kaiyin New Town project, Qinglong effectively withstood outdoor environmental erosion through joint sealing protection.

4. Anti-Rust Management During Operation and Maintenance: Extending Protection Service Life

Regular maintenance is key to ensuring long-term rust prevention for expansion anchor bolts and must be incorporated into routine operation and maintenance. Establish a regular inspection system to check bolt rust conditions and sealant aging every 6-12 months; if rust spots appear on bolt surfaces, immediately carry out rust removal and touch-up painting; replace aged and cracked sealant promptly to ensure sealing performance; in coastal areas, perform a comprehensive anti-rust upgrade every 2-3 years by reapplying anti-rust paint and sealant. In the Singapore Defence Services Centre international project, Qinglong extended the anti-rust protection period of expansion anchor bolts to more than 15 years through systematic operation and maintenance, ensuring long-term stability of GRC component connections.