Research on Preventive Measures and Technical Strategies for Freeze-Thaw Damage of GRC Exterior Walls in Severe Cold Regions

Research on Prevention Measures and Technical Strategies for Freeze-Thaw Damage to GRC Exterior Walls in Severe Cold Regions

In construction projects in severe cold regions, GRC (Glass Fiber Reinforced Concrete) exterior walls, as a new type of building material combining decorative and functional properties, have freeze-thaw resistance that directly affects building safety and durability. Qinglong Group, an industry leader with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, drawing on its practice in multiple landmark projects in northern China, has developed a systematic freeze-thaw damage prevention solution covering material R&D, detailed design, construction and maintenance, providing professional technical support for the application of GRC exterior walls in severe cold regions.

I. Freeze-Thaw Damage Mechanism and Core Challenges of GRC Materials in Severe Cold Regions

The core threat faced by GRC exterior walls in severe cold regions comes from freeze-thaw cycling: when water in the internal pores of the material repeatedly freezes and expands, then thaws and contracts with temperature changes, internal stress is generated, causing structural damage manifested as surface powdering, cracking, and even spalling. Through scanning electron microscopy analysis, Qinglong's technical team found that traditional GRC, after 50 freeze-thaw cycles at -20°C, can suffer a flexural strength reduction of up to 30%. This phenomenon is particularly prominent in regions such as Northeast and Northwest China where annual extreme low temperatures fall below -30°C, placing stringent demands on the material's impermeability, pore structure, and fiber-matrix interface bond strength.

II. Material Optimization: Technical Breakthroughs in Qinglong's Frost-Resistant GRC Formulation

In response to the characteristics of severe cold regions, Qinglong's R&D center carried out special improvements to GRC materials: adopting a low-alkali sulphoaluminate cement system to reduce the solubility of hydration products; incorporating nano-scale silica fume and ultra-fine mineral powder to optimize particle grading and reduce capillary pores; and selecting alkali-resistant glass fiber (content ≥5%) with a three-dimensional randomly distributed process to enhance material toughness. Testing shows that GRC specimens prepared with this formulation, after 200 freeze-thaw cycles from -40°C to 20°C, achieved a mass loss rate ≤1.5% and a strength retention rate ≥85%, far exceeding the requirements for severe cold regions in the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018).

III. Detailed Design: Structural Protection Strategies for GRC Exterior Walls in Severe Cold Regions

Based on project practice, Qinglong's detailed design team summarized three key protective measures: first, adopting a 'breathable curtain wall' construction, with an air layer and insulation layer behind the GRC panels to prevent condensation buildup; second, optimizing the drainage system, using elastic sealant at panel joints (weather resistance grade ≥25 years) combined with a pressure-relief drainage channel design to ensure rapid rainwater discharge; third, structurally reinforcing irregular-shaped components, such as adding layers of fiber mesh at corners and using stainless steel connectors with anti-corrosion treatment at anchoring points. These measures were successfully applied in a cultural center project in Shenyang, enabling the GRC exterior wall to withstand three consecutive winters of -28°C low temperatures.

IV. Construction and Maintenance: Whole-Life-Cycle Freeze-Thaw Protection Management

During construction, Qinglong strictly controls the factory moisture content of GRC components (≤8%) and adopts preheating curing measures for winter construction; during installation, three-dimensional laser scanning positioning is used to ensure tight joints. In terms of after-sales maintenance, a regular inspection mechanism has been established, focusing on sealant aging and drainage patency, with surface treatment using Qinglong's specialized hydrophobic agent applied when necessary to enhance impermeability. This 'prevention + monitoring' maintenance model enabled the GRC exterior wall of a commercial complex in Harbin to show no freeze-thaw damage throughout its 10-year service life.

As a national high-tech enterprise and a participant in formulating GRC industry standards, Qinglong has always made research on material performance and regional adaptability a focus of technological innovation. Through material formulation optimization, structural design innovation, and whole-process quality control, freeze-thaw damage to GRC exterior walls in severe cold regions can be effectively controlled. Looking ahead, Qinglong will continue to leverage its provincial-level R&D center platform to explore applications of UHPC/GRC composite structures in ultra-low temperature environments, providing better solutions for unifying architectural aesthetics and structural safety in northern regions.