Analysis of Processing Differences Between Single-Curve and Double-Curve GRC Panels

Driven by the dual forces of contemporary architectural aesthetics and engineering technology, GRC materials have become the core medium for shaping the artistic character of building skins, thanks to their outstanding plasticity and structural performance. Among them, single-curved GRC panels and double-curved GRC panels, as two typical forms, not only each possess distinct visual tension, but also exhibit entirely different technical logic at the processing level. As an industry leader with 28 years of deep expertise in UHPC/GRC/GRG/GRP materials, Qinglong Group will provide an in-depth analysis of the processing differences between the two from the dimensions of material properties, process challenges, and quality control, offering a professional selection reference for designers and owners.

1. Form Definitions and Application Scenarios: The Functional Boundaries of Single Curvature vs. Double Curvature

Single-curved GRC panels typically refer to curved components bent along a single direction, such as cylindrical surfaces and single-curvature curtain wall panels. Their curvature radius is relatively large (generally ≥1500mm), and they are commonly used in scenarios with moderate demands for shape precision, such as canopies of commercial complexes and decorative lines of subway stations. Double-curved GRC panels, on the other hand, are complex curved surfaces bent simultaneously along two mutually perpendicular directions, with a minimum curvature radius as low as 300mm. They are widely applied to shaped curtain walls and artistic skins of landmark buildings such as grand theaters and museums. For example, the double-curved honeycomb-shaped exterior wall of a cultural center in Guangzhou realized the design concept of "flowing light and shadow" through more than 2,000 double-curved GRC panels.

2. Mould Technology: The Leap from Standardization to Customization

Mould making for single-curved GRC panels is relatively mature, with steel moulds or fibreglass moulds being sufficient to meet the requirements. Through modular mould design, Qinglong Group achieves mass production of single-curved panels with the same curvature, improving production efficiency by 40% compared to traditional processes. Moulds for double-curved GRC panels, however, rely on 3D scanning and parametric design technology: first, a digital model is built using Rhino+Grasshopper; then a high-density foam master mould is machined via CNC machine tools; finally, an epoxy resin composite mould is cast. The development cycle for a single mould can reach 15-20 days, with costs approximately 3-5 times those of single-curved moulds. Taking an exhibition center project in Nanjing as an example, 87 custom moulds were developed for its double-curved GRC ceiling system, ensuring the precise alignment of every curved unit.

3. Forming Technology: The Balance Between Stress Control and Precision Assurance

In the forming stage, single-curved GRC panels can be produced using a spraying process combined with manual laying of fibreglass mesh, naturally formed by gravity and the mould's curvature, with forming errors controllable within ±2mm/m. Double-curved GRC panels, however, must overcome the challenges of uneven material flow and fiber orientation. Qinglong Group's original "step-by-step spraying + vacuum-assisted forming" process involves first spraying the base material in segments according to the surface curvature, then precisely laying bidirectional fibreglass fabric via robotic arms, and finally applying vacuum to remove air bubbles. This raises the flexural strength of components to above 22MPa and controls surface flatness errors within ±1.5mm/m. In a double-curved GRC curtain wall project for the T3 terminal of an international airport, this process successfully solved the warping and deformation problems of large-span curved surfaces.

4. Quality Control: Technical Safeguards Across the Entire Lifecycle

The focus of quality control for single-curved GRC panels lies in dimensional consistency. Through automated cutting and laser positioning systems, Qinglong has achieved a panel interchangeability rate of over 98%. Double-curved panels, however, require a full-process quality traceability system: from raw material inspection (e.g., glass fiber content ≥5%) and real-time pressure monitoring during the moulding process, to 3D scanning inspection before shipment, with RFID chips embedded at every stage to record data. To address the installation challenges of double-curved panels, Qinglong developed a "BIM pre-assembly + 3D laser positioning" technology. In the Dongguan Women and Children's Activity Center project, on-site installation errors were controlled within ±3mm, far exceeding industry standards.

From the standardized production of single-curved panels to the customized innovation of double-curved panels, the processing differences of GRC panels are, in essence, a comprehensive reflection of technical strength and engineering experience. As a National High-Tech Enterprise and a participant in formulating GRC industry standards, Qinglong Group has always upheld the mission of "creating beautiful architecture." Through 28 years of full-chain experience, it has developed integrated solutions covering everything from design deepening to after-sales maintenance. Whether it is a single-curved project pursuing economy or a double-curved project challenging the limits of aesthetics, Qinglong can empower the realization of architectural creativity with professional expertise, setting a quality benchmark for GRC material applications in the industry. In the future, with the development of UHPC and GRC composite technologies, more possibilities for formal breakthroughs and performance optimization await exploration and realization.