How to Determine Whether GRC Components Are Prone to Cracking and Deformation

How to Judge Whether GRC Components Are Prone to Cracking and Deformation — A Technical Analysis Based on 28 Years of Industry Experience

In the field of architectural decoration, GRC (Glass Fiber Reinforced Concrete) is widely used in high-end projects such as grand theaters, commercial complexes, and landmark buildings thanks to its lightweight, high-strength, and richly formable characteristics. However, some GRC components on the market suffer from cracking, deformation, and other problems caused by improper material ratios, production processes, or installation, which not only affects the building's aesthetics but also creates safety hazards. As an industry leader with 28 years of experience in detailed design, manufacturing, and construction of UHPC/GRC/GRG/GRP materials, Qinglong Group will provide designers and owners with a practical guide for scientifically judging the stability of GRC components from three dimensions: material essence, process control, and installation standards.

1. Judging the Crack Resistance and Deformation Resistance of GRC Components from the Material Formulation

The cracking and deformation of GRC components are rooted in the scientific soundness of the material ratio. High-quality GRC requires high-strength low-alkali cement as the base material, combined with alkali-resistant glass fiber (content ≥5%) and specialized additives to form a stable composite material system. Qinglong Group optimizes its formulations through 58 patented technologies, and its GRC products achieve flexural strength of over 20MPa and elastic modulus ≥15GPa, suppressing cracking risk at the material level. By contrast, some low-priced products on the market often substitute ordinary Portland cement for low-alkali cement, with fiber content below 3%, making components highly prone to micro-cracks during wet-dry cycles. Customers are advised to request third-party test reports from suppliers, focusing on two key indicators: “flexural strength” and “drying shrinkage value”; the drying shrinkage value must be ≤0.15mm/m to ensure long-term stability. For more industry information: +WeChat qlfsbl123

2. The Production Process Determines the Structural Integrity of GRC Components

A standardized production process is key to controlling the deformation of GRC components. Qinglong Group adopts an automated spray-up molding process to ensure uniform distribution of glass fiber within components, avoiding fiber agglomeration or layering caused by manual hand lay-up. Meanwhile, steam curing (curing temperature 80±5℃, curing time ≥8 hours) promotes the cement hydration reaction, bringing the early strength of components to over 85% of the design value and effectively reducing later shrinkage deformation. Some small manufacturers, in order to cut costs, use open-air natural curing; uneven moisture evaporation inside the components easily generates internal stress leading to warping. In addition, mold precision cannot be overlooked: Qinglong Group uses CNC-machined steel molds with dimensional error controlled within ±1mm, ensuring the geometric stability of components—a level of precision difficult to achieve with wooden or GRP molds.

3. The Impact of Installation and Later Maintenance on the Durability of GRC Components

Even high-quality GRC components can crack if improperly installed. Qinglong Group uses 3D laser scanning positioning technology in construction, simulating installation nodes through BIM models to ensure anchor point spacing ≤600mm and a bearing capacity of ≥1.5kN per anchor point. For GRC cladding panels with spans exceeding 2m, elastic connection nodes are also installed, allowing components to move ±3mm under temperature changes to avoid stress concentration caused by rigid connections. By contrast, traditional installations using welded fixings or excessively large anchor point spacings are highly prone to cracking under wind loads or thermal stress. As for later maintenance, it is recommended to regularly check the aging of sealant; especially in regions with large temperature differences, weather-resistant sealant should be replaced every 3 years to prevent rainwater from penetrating into components and causing freeze-thaw damage. For more industry information: +WeChat qlfsbl123

As a participating unit in drafting the “Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC)” (JGJ/T423-2018), Qinglong Group has always upheld the mission of “Creating Beautiful Architecture,” establishing a full-chain quality control system from material R&D to project implementation. From the GRC curtain wall of the Dongguan Women and Children's Activity Center to the special-shaped components of Century Plaza on Nanjing East Road, the products' crack resistance and deformation resistance have been verified through more than 10 years of actual application. When selecting GRC components, it is recommended to prioritize examining the manufacturer's production scale (such as Qinglong's annual capacity of 600,000 square meters), technical qualifications (national high-tech enterprise, specialized-refined-distinctive-innovative enterprise), and past project cases, so as to avoid cracking and deformation risks at the source and achieve the unity of architectural aesthetics and structural safety.