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

In the field of contemporary architectural decoration, double-curved GRC panels have become a key material for shaping architectural artistry thanks to their unique curved-surface forming capability. However, controlling their surface flatness has always been a technical challenge in the industry. As the Qinglong Group with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, we understand that surface flatness is not only about visual aesthetics—it is also a core indicator for ensuring structural safety and durability. This article provides a comprehensive analysis of the key technologies and quality assurance system for flatness control of double-curved GRC panels, covering material formulation optimization, mold precision control, production process innovation, and installation technology upgrades.

Material Formulation: The Foundational Guarantee for Flatness Control of Double-Curved GRC Panels

The flatness of double-curved GRC panels depends first on the stability of the material system. Backed by a provincial-level R&D center and 28 years of technological accumulation, Qinglong Group has developed a dedicated formulation system for double-curved shapes. For the glass fiber reinforcement, alkali-resistant glass fiber mesh with an alkali content below 0.8% is used to ensure material uniformity under bending stress; the cement-based materials are optimized with composite admixtures to reduce the hydration heat peak by more than 15%, minimizing surface deformation caused by uneven shrinkage. Meanwhile, nano-scale silica fume is introduced to enhance interfacial bonding strength, allowing the panels' bending strength to consistently reach above 20MPa and laying the foundation for flatness control at the material source.

Mold Technology: The Core Element for Precise Replication of Double-Curved Shapes

Mold precision directly determines the initial flatness of double-curved GRC panels. Qinglong employs 3D scanning and CNC machining technology to achieve a high-precision standard with mold tolerances of ≤0.5mm/m. For double-curved components with a single radius of curvature, a modular steel mold system is used, with adjustable support structures to compensate for material shrinkage; for complex double-curved surfaces, flexible silicone molds are innovatively applied, leveraging their elastic properties to achieve seamless conformity to the curved surfaces. The mold surfaces are mirror-polished to a roughness of Ra≤0.8μm, ensuring that the surface flatness of components after demolding reaches the industry-leading level of ±2mm/2m.

Production Process: The Key Link in Whole-Process Quality Control

In production, Qinglong has established a whole-process digital management system. The material dispensing process uses a robotic automatic distribution system to keep fiber distribution uniformity errors below 3%; in the curing stage, a gradient constant-temperature curing process is innovatively applied, with 24-hour precise temperature control (20-60℃) and humidity regulation (RH85%-95%), allowing moisture inside the components to evaporate evenly and preventing surface cracking. In addition, each double-curved GRC panel is fitted with an RFID chip that records data throughout the entire process from raw materials to curing, enabling full quality traceability.

Installation Technology: The Final Precision Guarantee for On-Site Construction

On-site installation is the last checkpoint in flatness control for double-curved GRC panels. The 3D laser positioning installation system developed by Qinglong monitors installation errors in real time and makes automatic adjustments, keeping joint level differences between adjacent panels at ≤1mm. For large-span double-curved curtain walls, a flexible support system is adopted, with adjustable hangers absorbing thermal deformation to ensure flatness stability over long-term use. In the Nanning ASEAN Culture and Art Center project, Qinglong used this technology to successfully complete the installation of a 28,000㎡ double-curved GRC curtain wall, with the overall flatness error controlled within ±3mm, earning high praise from the owner.

As a national high-tech enterprise and a drafting unit for GRC industry standards, Qinglong Group has always regarded technological innovation as its core competitiveness. From material R&D to engineering application, we have built a quality control system covering the entire life cycle of double-curved GRC panels, which not only resolves industry pain points but also drives the technological upgrading of green architectural decoration materials. Looking ahead, Qinglong will continue to focus on UHPC/GRC/GRG/GRP material innovation and, with an attitude of “meticulous precision and the relentless pursuit of excellence,” provide better architectural decoration solutions for designers and owners worldwide.