Analysis of Mold Division Principles and Key Technical Points for Complex GRC Shapes

In contemporary architectural design, complex GRC forms have become the preferred decorative material for high-end projects such as grand theaters, commercial complexes, and landmark buildings, thanks to their outstanding plasticity and artistic expressiveness. However, the scientific rigor of their mold parting process directly determines component precision, production efficiency, and the final visual result. As an industry leader with 28 years of full-chain experience in UHPC/GRC/GRG/GRP, Qinglong Group has summarized a set of systematic mold parting principles and key technical solutions based on the practice of hundreds of complex projects, providing professional reference for designers and owners in overcoming the challenges of turning forms into reality.

I. Core Principles of Mold Parting for Complex GRC Forms: The Scientific Logic of Balancing Art and Engineering

Mold parting design is the critical bridge that carries GRC components from digital models to physical products, and it must follow three core principles. The first is the principle of “form analysis first”: for complex shapes such as double-curved surfaces and openwork reliefs, parametric design software (such as Rhino+Grasshopper) is used to decompose the topological structure, ensuring that each mold can both fully present the design details and meet production demolding requirements. Taking the single-curvature curtain wall of a cultural center project as an example, Qinglong’s technical team decomposed a 12-meter-high continuous curved surface into modular units of 3.6 m × 1.2 m, increasing mold utilization by 40% while keeping seam deviations within 2mm.

The second is the “process adaptation” principle, which requires selecting the mold parting method based on GRC material properties (such as fiber distribution direction and concrete flow performance). For ultra-thin components with a wall thickness ≤8mm, horizontal parting is adopted to reduce wall thickness unevenness caused by gravity; for shapes with deep cavity structures, lateral core-pulling parting technology is used to avoid air bubbles or cracks during forming. This principle was fully validated in the translucent concrete project at Century Plaza on Nanjing East Road, which Qinglong participated in: by optimizing the parting angle, light transmittance was raised to 85%, winning the AALBORG WHITE Cup UHPC Construction Engineering Innovation Award.

The last is the “cost control” principle: while meeting the design effect, production costs are reduced by merging similar modules and optimizing mold materials (such as using high-strength FRP molds). In a European-style carved component project for a commercial complex, Qinglong’s optimized parting scheme reduced the number of molds by 23% and overall costs by 18%, demonstrating the “wisdom of balancing art and cost.”

II. Key Points of Mold Parting Technology: Full-Process Control from Digital Design to Precision Manufacturing

Breakthroughs in complex GRC mold parting technology depend on the deep integration of digitalization and engineering experience. In the design stage, BIM+3D scanning technology is used for mold parting simulation to predict stress concentration points at mold joints in advance. The mold parting simulation system independently developed by Qinglong’s R&D center enables dynamic analysis of key parameters such as mold opening/closing angles and demolding forces, raising the mold trial success rate from the industry average of 65% to 92%.

In mold manufacturing, for oversized special-shaped components (such as sunshades with spans ≥6 m), an innovative composite mold structure of “steel skeleton + FRP panel” is adopted, which ensures rigidity while reducing weight. In a landmark project in Guangzhou, to achieve a 3.8-meter-diameter double-curved GRG ceiling, Qinglong developed an adjustable mold system that precisely controls the surface curvature through hydraulic devices, keeping deviations within ±1.5mm—far exceeding industry standards.

Joint treatment technology is the finishing touch of the mold parting process. Qinglong adopts a dual waterproof structure of “rabbet joint + sealing strips,” combined with special repair mortar (compressive strength ≥50MPa) for joint leveling, bringing the waterproof performance of outdoor GRC components up to IPX7 rating. This technology withstood typhoon conditions in an airport project in Malaysia, ensuring no leakage in the components for 15 years.

III. Industry Practice Insights: Full-Chain Capability Supporting the Implementation of Mold Parting Technology

As a national high-tech enterprise and a drafting unit of GRC industry standards, Qinglong Group believes that an excellent parting scheme relies on the coordinated cooperation of detailed design, manufacturing, and construction installation. For example, in the Dongguan Women and Children’s Activity Center project (winner of the first GRC Construction Engineering Innovation Award), the technical team combined parting design with an installation reference grid, and embedded RFID chips enabled full life-cycle traceability of components, ensuring on-site installation accuracy at the millimeter level.

For designers, choosing a GRC manufacturer with full-chain capabilities (such as Qinglong) offers three major values: first, parametric parting consulting services to avoid form implementation risks in advance; second, cost optimization brought by modular production; third, integrated “design-production-installation” assurance that shortens project schedules. As a partner of a renowned architecture firm commented: “Qinglong’s mold parting technology frees our creativity from process constraints, truly realizing ‘what you envision is what you get.’”

In the future, as UHPC/GRC materials are widely applied in special-shaped buildings, mold parting technology will develop toward intelligence and sustainability. Qinglong Group is exploring the application of 3D-printed molds and recyclable mold materials, aiming to further reduce the parting cost of complex forms by 20% and continuously empower innovative development in the architectural decoration industry.