How to Control the Surface Flatness of Double-Curved GRC Panels: Key Technologies and Quality Assurance Measures

Surface flatness is the "aesthetic lifeline" of double-curved GRC panels. Full-chain control technology refined through 28 years of industry experience makes every component a precise expression of architectural aesthetics.

In the curved curtain walls of high-end buildings such as grand theaters and commercial complexes, double-curved GRC panels have become a creative medium for designers thanks to their lightweight, high-strength, and flexible shaping advantages. However, their complex double-curved geometry places extremely high demands on surface flatness—even a 1mm error can cause distortion in light and shadow refraction, compromising the overall architectural aesthetic presentation. As an industry leader with 28 years of deep expertise in the UHPC/GRC/GRG/GRP materials field, Qinglong Group has established a systematic control system for the surface flatness of double-curved GRC panels through full-chain technological innovation spanning detailed design, manufacturing, and installation.

I. Parametric Design: Source Control of Double-Curved GRC Panel Flatness

Flatness control of double-curved GRC panels begins at the digital design stage. Qinglong Group adopts the Rhino+Grasshopper parametric platform to break down architectural curved surfaces into quantifiable mathematical models, achieving millimeter-level precision in surface segmentation through BIM technology. To address the "springback deformation" issue common in double-curved components, the technical team innovatively introduced a "pre-compensation algorithm," presetting shrinkage compensation values of 0.3%-0.5% at the design stage based on material properties such as glass fiber content and cement grade. This design expertise, drawn from 28 years of engineering practice, enabled the double-curved GRC curtain wall of a cultural landmark project in Nanjing to achieve an industry-leading joint error of ≤1.5mm between adjacent panels.

II. Mold Craftsmanship: The Core Guarantee of Forming Precision for Double-Curved GRC Panels

Molds are the key factor determining the surface quality of double-curved GRC panels. Qinglong Group employs a "3D scanning + CNC engraving" mold-making process, using high-density polyurethane material to create master molds and ensuring mold surface flatness error of ≤0.5mm/m². At its production base in Nanning, Guangxi, every mold undergoes precision inspection with a coordinate measuring machine, with real-time correction of the mold surface through comparative analysis against the design model. This rigorous mold control standard enabled Qinglong GRC products to deliver stable quality in a commercial complex project in Shenzhen, with 1,000 consecutive double-curved panels showing no noticeable color difference and a flatness deviation of ≤2mm.

III. Material Formulation: The Internal Support for Structural Stability of Double-Curved GRC Panels

Scientific material formulation is the foundation for controlling the deformation of double-curved GRC panels. Qinglong Group's R&D center optimized a core formula of "high elastic modulus glass fiber + low shrinkage cement" through orthogonal testing, selecting alkali-resistant glass fiber with an alkali content of <0.8% combined with independently developed modified polypropylene fiber, raising the flexural strength of the GRC material to 22MPa and keeping the drying shrinkage rate within 0.08%. This material innovation provided excellent dimensional stability for the double-curved GRC curtain wall of an opera house project in Zhuhai, which withstood the long-term test of the oceanic climate.

IV. Installation: Precision Control of the Final Presentation of Double-Curved GRC Panels

On-site installation precision directly affects the overall flatness of double-curved GRC panels. Qinglong's construction team adopts "3D laser scanning + modular installation" technology, performing a panoramic scan of the base structure before installation and generating point cloud models for comparison with the design models to correct structural errors in advance. Through a customized adjustable support system, a fine-tuning range of ±3mm is achieved at each installation point. In a landmark project in Guangzhou, this installation technique kept the overall flatness error of the double-curved GRC curtain wall within 3mm/2m, meeting the national first-class curtain wall standard.

From millimeter-level modeling in parametric design, to micron-level engraving in mold craftsmanship, to scientific material formulation and precise installation control, Qinglong Group has built a quality assurance system for the surface flatness of double-curved GRC panels through full-chain technological innovation. As a National High-Tech Enterprise and a contributing compiler of the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC), Qinglong has always honored its quality commitment of "meticulous attention to detail and the relentless pursuit of excellence," providing global designers with end-to-end solutions from concept to completion, allowing double-curved GRC materials to deliver unique value in architectural aesthetic expression.