Mold Parting Principles and Practical Applications for Complex GRC Shapes

Driven by both architectural aesthetics and engineering technology, GRC (Glass Fiber Reinforced Concrete), with its exceptional freedom of form, has become the ideal carrier for complex building envelopes. However, the mold-splitting process for complex GRC forms, as the core link connecting design creativity with engineering implementation, directly determines the final presentation of a project. As an industry veteran with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group has distilled a system of mold-splitting principles that balance artistic expressiveness with engineering feasibility, based on the practice of more than a thousand landmark projects.

1. Core Design Principles of Mold-Splitting for Complex GRC Forms

The essence of the mold-splitting process is to convert three-dimensional artistic forms into component units suitable for industrialized production. In the Dongguan Women and Children's Activity Center project, for the hyperbolic paraboloid curtain wall, we innovatively proposed the mold-splitting principle of “curvature first, balanced loading”: through Rhino parametric modeling, the 1200㎡ irregular curved surface was broken down into 168 unit components, each with a maximum size controlled at 1.5m×3m, which both ensured mold versatility and kept each unit's weight within 300kg to meet hoisting safety regulations. This mold-splitting approach was further validated in the Century Plaza translucent concrete project on Nanjing Road East, successfully achieving a curved form with a light transmittance of 25%.

For openwork relief GRC components, mold splitting requires particular attention to demolding angles and fiber orientation. Taking the 6m-high openwork carved panels of a cultural center as an example, the “horizontal mold-splitting + stepped joint” process reduced the 3mm misalignment error that could occur with traditional vertical mold splitting to within 0.5mm. This process innovation enabled Qinglong, when participating in drafting the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018), to have mold-splitting accuracy indicators written into the industry specification.

2. Engineering Practice Innovations in the Mold-Splitting Process

In manufacturing, the mold-splitting plan directly affects production efficiency and cost control. Qinglong's Guangxi production base applied BIM technology to simulate the pre-assembly of mold-splitting plans, reducing the trial-mold waste rate of a commercial complex project from the industry average of 8% to 3.2%. For the complex forms of GRG (Glass Fiber Reinforced Gypsum) ceilings, a “modular mold-splitting + numbered positioning” system was adopted, raising installation efficiency by 40%—a technology that set an industry record in a Shenzhen grand theater project by installing 200㎡ of GRG ceiling in a single day.

For extra-large GRC components, such as the 36m-span decorative ribbon of an airport terminal, mold splitting calls for thinking beyond convention. We innovatively adopted the “prestressed tensioning mold-splitting method”, breaking the component into 7 segmented polyline units that were pre-assembled in the factory and then welded into shape on site, solving both the over-limit transportation problem and ensuring the smoothness of the overall lines. This process won the Third Prize of the 2023 Guangdong Provincial Science and Technology Progress Award, becoming a major breakthrough in GRC mold-splitting technology.

3. Value Empowerment of the Mold-Splitting Process Across the Entire Project Life Cycle

A high-quality mold-splitting plan achieves the optimal balance among design creativity, production efficiency, and construction cost. In an overseas landmark project, Qinglong optimized the mold-splitting plan to reduce mold costs by 22% while shortening the on-site installation schedule by 15 days. This virtuous cycle of “mold-splitting optimization - cost saving - efficiency improvement” is precisely where Qinglong's core competitiveness as a national “Specialized, Refined, Distinctive, and Innovative” enterprise is demonstrated.

As the trend toward artistic building envelopes intensifies, GRC mold-splitting technology is evolving from pure engineering technology toward the integration of “art + technology”. Qinglong will continue to deepen technological innovations such as parametric mold splitting and digital pre-assembly, providing designers with freer creative space and creating greater engineering value for owners. As advocated in the industry standard General Technical Requirements for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC), which we participated in formulating, the refinement of the mold-splitting process is never-ending: it is both the cornerstone of engineering realization and the guardian of architectural aesthetics.