Analysis of Splicing Precision Requirements and Key Quality Control Points for Curved GRC Shapes

Under the dual pursuit of architectural aesthetics and engineering precision, curved GRC shapes, with their unique artistic expressiveness, have become the finishing touch of landmark buildings. However, their complex spatial forms pose stringent challenges to jointing accuracy, where even slight deviations may lead to distorted visual effects and structural safety risks. As an industry leader with 28 years of deep expertise in UHPC/GRC/GRG/GRP materials, Qinglong Group, leveraging its full-chain technical expertise, has accumulated core methodologies for quality control of curved GRC shapes through hundreds of large-scale projects. This article analyzes the key control points from three dimensions: design, production, and construction.

### I. Precision Control Challenges of Curved GRC Shapes and Industry Standards

The core difficulty that distinguishes curved GRC shapes from flat panels lies in geometric continuity in three-dimensional space. According to the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018), the jointing error of double-curved components must be controlled within ±2mm, and that of single-curved components must not exceed ±3mm, while landmark projects often demand even higher standards—for example, a cultural and arts center project in Nanning raised jointing precision to ±1.5mm, equivalent to the thickness of two stacked coins. This high-precision requirement stems from dual needs: first, to ensure the fluid aesthetic effect of the building envelope and avoid visual breakpoints at joints; second, to guarantee uniform structural load distribution and prevent cracking caused by localized stress concentration.

### II. Full-Process Quality Control System: From Digital Modeling to On-Site Installation

**1. Parametric Design Phase: Digital Twin for Pre-Controlling Errors**
In the detailed design phase, Qinglong uses the Rhino+Grasshopper parametric platform to build a 1:1 digital model and simulates the entire component installation process through BIM technology. Taking the double-curved curtain wall of a commercial complex in Guangzhou as an example, the design team decomposed the curved surface into 128 unit components, each assigned a unique QR code identity containing key information such as three-dimensional coordinates, radius of curvature, and installation sequence. This digital management reduced information transfer errors in subsequent production and construction by over 90%, far exceeding the precision level of traditional two-dimensional drawings.

**2. Mold Manufacturing and Material Mix Ratio: Precision Controlled at the Source**
The mold precision of curved GRC directly determines product quality. Qinglong uses CNC-machined ABS molds, ensuring mold surface flatness error of ≤0.5mm/m², better than the industry norm of 1.5mm. On the materials side, orthogonal testing is used to optimize the glass fiber content (6-8%) and water-cement ratio (0.28-0.32), keeping the flexural strength of components stable at above 22MPa with an elastic modulus reaching 30GPa, providing material assurance for shape stability. Notably, for projects in different climate zones, Qinglong adjusts the formula—for instance, increasing antifreeze admixture content in the severe cold of northern regions, and enhancing carbonation resistance in the high-temperature, high-humidity environments of Southeast Asia.

**3. Construction and Installation: 3D Scanning for Millimeter-Level Positioning**
On-site installation adopts a “3D laser scanning + modular hoisting” process. No fewer than 3 high-precision control points are set on the datum plane, and a Leica TS60 total station is used for real-time coordinate calibration, with a full-scan verification performed after every 5 components installed. In one airport terminal project, this technology kept the cumulative jointing error of 1,600 double-curved GRC facade panels within 8mm, far below the design-allowed limit of 25mm. In addition, Qinglong's proprietary “flexible adjustment support” technology absorbs installation errors through fine bolt adjustment, solving the problem that traditional rigid connections tend to generate internal stress.

### III. Industry Experience and Innovative Practice: Qinglong's Technical Expertise

As an enterprise that participated in formulating the General Technical Requirements for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC), Qinglong transferred its precision manufacturing experience with UHPC materials to the GRC field, developing “GRC-UHPC composite components” that increase structural strength by 30% while preserving shaping capability. In the Dongguan Women and Children's Activity Center project, this technology successfully realized a cantilevered curved shape with an 8-meter span, with its durability verified through 300,000 fatigue tests. In addition, Qinglong's “full lifecycle traceability system” uses RFID chips to record the full-process data of components from raw materials to installation, providing data support for later maintenance—a model that has become a benchmark for quality control in the industry.

Precision control of curved GRC shapes represents a deep integration of materials science, digital technology, and engineering experience. Qinglong Group's 28 years of technical accumulation demonstrate that only by introducing rigorous industrial-grade standards into the field of architectural decoration can a perfect balance between art and engineering be achieved. In the future, with the application of technologies such as 3D printing and AI pre-assembly, precision control of curved GRC will advance to a higher dimension, creating more possibilities for architectural aesthetics. Choosing a supplier with full-chain service capabilities is the key to ensuring project success—after all, what is carried within those millimeters is not only the beauty of a building's form, but also the responsibility and commitment of engineering.