How to Control the Surface Flatness of Double-Curved GRC Panels: Key Technologies and Process Optimization Strategies

In the artistic expression of building skins, the flatness of double-curved GRC panels is both a measure of technical precision and the cornerstone of realizing design concepts. As an industry leader with 28 years of deep expertise in UHPC/GRC/GRG/GRP materials, Qinglong Group leverages its full-chain technical strength to provide systematic solutions for surface flatness control of double-curved GRC panels, from material formulation to construction and installation.

As modern architecture pursues the aesthetics of irregular curved surfaces, double-curved GRC panels, with their advantages of light weight, high strength, and flexible shaping, have become the "skin language" of premium projects such as grand theaters, commercial complexes, and landmark buildings. However, the challenge of controlling surface flatness posed by their double-curved geometry has always been a focal point of industry technical research. Backed by its national-level R&D center and 58 patented technologies, Qinglong Group has established a flatness control system covering the entire "design-production-installation" process through material optimization, mold innovation, and construction method innovation.

I. Material Formulation: The Intrinsic Guarantee of Double-Curved GRC Panel Flatness

The surface flatness of double-curved GRC panels depends first on the stability of the material itself. Addressing the load-bearing characteristics of double-curved shapes, Qinglong Group's R&D team adopted customized glass fiber ratios and special cement-based composite materials. By adjusting fiber length (6-12mm) and dosage (3-5%), the material achieves excellent deformation resistance. Under laboratory conditions, Qinglong's double-curved GRC panels reach a 28-day flexural strength of over 20MPa, with dry shrinkage controlled within 0.03%, reducing surface irregularities caused by uneven material shrinkage at the source. Compared with traditional formulations, this formulation reduces the flatness deviation of double-curved components by 40%, laying the foundation for subsequent process optimization.

II. Mold Technology: The Core Process for Precise Replication of Double-Curved Forms

Mold precision directly determines the forming quality of double-curved GRC panels. Qinglong Group introduced industrial-grade 3D scanning and CNC machining technology to convert design models into steel molds with an accuracy of ±0.5mm, ensuring precise replication of the mathematical curvature of double-curved surfaces. To address the "bulging" and "denting" issues common in double-curved components, a modular mold assembly process is adopted, with a 0.2mm allowance for thermal expansion and contraction and elastic support structures to avoid stress concentration during casting. In the Dongguan Women and Children's Activity Center project, the double-curved GRC curtain wall panels produced by Qinglong with this process reach 12㎡ per panel, with surface flatness deviation controlled within 3mm/2m, far exceeding industry standards.

III. Construction and Installation: The Critical Closed Loop for On-Site Error Control

Even with high-precision factory production, cumulative errors during on-site installation can still affect the overall flatness of double-curved GRC panels. Qinglong Group innovatively adopted the "3D laser positioning + modular installation" method: installation paths are pre-simulated using BIM technology, with laser line projectors achieving ±1mm-level positioning accuracy; addressing the hoisting load characteristics of double-curved components, dedicated adjustable supports were developed, allowing ±5mm fine adjustments in three dimensions and ensuring that the joint height difference between adjacent panels is ≤2mm. In the Nanjing East Road Century Plaza renovation project, this method enabled the 8,000㎡ double-curved GRC translucent concrete curtain wall to achieve a "mirror-level" joint effect, becoming a technical benchmark in urban renewal.

From material R&D to project delivery, Qinglong Group has consistently applied the craftsman spirit of "meticulousness and the constant pursuit of excellence" to overcome the surface flatness control challenges of double-curved GRC panels. As a national high-tech enterprise and a participant in GRC industry standard-setting, Qinglong not only provides designers with the technical confidence to realize their creativity, but also delivers building skin systems that combine aesthetic value with structural safety for owners. Going forward, Qinglong will continue to focus on the innovative application of UHPC/GRC/GRG/GRP materials, driving the technological upgrading of the architectural decoration industry with full-chain service capabilities, and turning more double-curved aesthetic visions into reality.