What Are the Reinforcement Measures for Openwork GRC Shapes? Seeking Balance Between Aesthetic Transparency and Structural Strength

Hollow-out GRC forms pursue visual transparency and lightness, but the removal of large amounts of material inevitably weakens their mechanical performance. Therefore, the core idea of reinforcement is "adding where it cannot be seen": through carefully designed internal skeletons and boundary strengthening, the hollow-out rate is maximized while structural safety is ensured. When Qinglong Group produced a GRC decorative curtain wall with a hollow-out rate of up to 60% for a cultural center, it comprehensively applied three major strategies — spatial grid stiffening ribs, local reinforcement with high-strength fibers, and intelligent topology optimization — successfully achieving the unity of artistic effect and structural performance.

The spatial grid stiffening rib system is the main load-bearing element. We abandoned the traditional uniform rib layout in favor of variable-section grid ribs based on force analysis. The design process is as follows: first, wind pressure distribution contour maps are obtained from wind tunnel tests or computational fluid dynamics (CFD) analysis; denser and taller main ribs are arranged in areas of high wind pressure (such as edges and corners), while sparser secondary ribs are placed in the lightly loaded central areas. The rib cross-section is also optimized, using "I" or "T" shapes, improving the moment of inertia while saving material. All stiffening ribs are spray-formed together with the panel in one pass, with fiber slurry additionally sprayed at the joints to ensure integrity. This system is like implanting an invisible "skeleton" into the hollow-out panel.

Local reinforcement with high-strength fibers is a key supplement. In areas of the highest stress concentration — such as the sharp inner corners of hollow-out patterns and the connections between ribs and panels — we use directional spraying or pre-laying to add one or two extra layers of alkali-resistant glass fiber mesh, or incorporate chopped carbon fibers. The high elastic modulus of carbon fiber effectively suppresses crack initiation and propagation. For particularly slender connecting "bridges," we pre-embed thin-diameter stainless steel rods or GFRP bars in the mold to serve as "main reinforcement" bearing tensile stress.

Intelligent topology optimization is a cutting-edge tool for obtaining the optimal reinforcement scheme. In the early design stage, we input the design domain of the GRC panel under given loads, the hollow-out pattern (non-design domain), and the load boundary conditions into algorithm software. Through iterative computation, the software automatically generates a stiffening rib layout that uses the least material and has the most effective load transfer paths. Such schemes often take on organic, dendritic forms similar to naturally grown structures; they are not only strong but also visually striking, sometimes becoming part of the design itself. Through these comprehensive measures, we have successfully kept the flexural strength of hollow-out GRC panels above 12MPa, meeting safety standards and allowing the beauty of lightness to blossom in safety.