What Are the Special Requirements for Fibreglass Mesh Laying in Double-Curved GRC Panels? Force Flow Guidance and Qinglong Group's Fiber Orientation Technology

The laying process of the glass fiber mesh in double-curved GRC panels directly determines their structural performance, and must follow four special requirements: "surface adaptability, directional reinforcement, continuous distribution, and interface optimization." Unlike traditional flat panels, double-curved panels generate complex spatial stresses under load, so the fiber mesh must be oriented along the principal stress directions. In the wave-shaped roof project of the Hainan International Convention and Exhibition Center, Qinglong Group adopted a robotic directional spraying process, achieving a uniform three-dimensional random distribution of fibers on the double-curved surface with a fiber volume content of 4.5%. Testing showed a flexural strength of 18MPa, far exceeding the 12MPa standard for flat GRC. Fibers are the backbone of the curved surface, and the laying process determines its mechanical intelligence.

Surface Adaptability Laying Technique

On a double-curved surface, the fiber mesh must remain continuous and uninterrupted as the surface changes. We adopt a composite forming process combining pre-laid mesh and spraying: first, a layer of continuous fiber mesh is laid on the mold, then a chopped fiber reinforcement layer is sprayed by robot, forming a composite reinforcement system of "oriented long fibers + randomly distributed short fibers." This process ensures continuous fiber reinforcement in high-stress areas of the curved surface, while short fibers provide overall integrity in low-stress areas.

Stress Path-Oriented Laying Principle

The principal stress trajectories of double-curved panels under wind loads and self-weight are obtained through finite element analysis, based on which the fiber laying direction is optimized. In stress concentration areas such as panel edges and areas around openings, dense laying or additional reinforcing mesh sheets are applied. The double-curved cornice panels of Nanning Wuxiang China Resources MixC One, laid with stress path optimization, achieved a 40% improvement in edge crack resistance.

Interface Treatment and Impregnation Control

Double-curved shapes are prone to interfacial debonding between the fiber mesh and the matrix. By controlling the slurry rheology (flow spread of 650-700mm) and adopting a vacuum dewatering process, we ensure that the fibers are fully encapsulated and impregnated. In the Wuhan Han Show Theatre project, we conducted cut-section inspections of the red double-curved panels, and the intact rate of fiber-to-matrix bonding reached 99.8%.

Quality Control and Testing Standards

Internal control standards for fiber distribution uniformity have been established: fiber count deviation per square meter ≤15%, and fiber orientation angle deviation from the design direction ≤10°. X-ray imaging technology is used for sampling inspection of the internal fiber distribution of finished products to ensure process stability. These standards have been applied to all of our double-curved GRC projects.

Fiber laying in double-curved GRC is a science, and even more, an art. Through digital simulation and process innovation, Qinglong Group enables every fiber to deliver maximum effectiveness exactly where it is needed most.