Key Steps and Quality Control Points in the Factory Prefabrication Stage of UHPC Curtain Wall Panel Production

In the field of contemporary architectural decoration, Ultra-High Performance Concrete (UHPC) has become an ideal choice for curtain wall systems thanks to its outstanding mechanical properties and design expressiveness. As an industry-leading enterprise with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group deeply understands the decisive role of the factory prefabrication stage in the final quality of curtain walls. This article systematically analyzes the core technical points of UHPC curtain wall panel prefabrication—from material formulation, mold technology, and forming and curing to quality inspection—providing a professional reference for designers and owners.

I. Precise Formulation of the UHPC Material System: The Source Guarantee of High Performance

The mechanical properties and durability of UHPC curtain wall panels begin with scientific material formula design. Leveraging the technical advantages of its provincial-level R&D center, Qinglong Group adopts a ternary system of "cement-silica fume-ultrafine quartz sand" combined with specially made steel fibers (volume content of 2-3%) to achieve microstructural reinforcement. Key control points include: raw material selection must meet the quartz sand gradation requirement of SiO₂ content ≥95%; the length-to-diameter ratio of steel fibers is controlled within 60-80; and the water-binder ratio is strictly limited to the range of 0.16-0.20. A fully automatic metering and mixing system (error ≤±1%) ensures the uniformity of each batch of slurry, laying the foundation for subsequent forming.

II. Process Innovation of the Precision Mold System: Core Support for Shape Fidelity

As customized decorative components, the mold technology of UHPC curtain wall panels directly determines surface precision and shape complexity. Qinglong adopts a composite system of "steel mold + elastic lining," developing modular assembly molds for complex shapes such as double curvature and hollow-out designs, combined with BIM parametric design to achieve millimeter-level error control (flatness ≤0.5mm/m). The mold surface is mirror-polished (Ra≤0.8μm) and treated with a nano coating, ensuring that components achieve a fair-faced concrete effect after demolding. For the special-shaped components of award-winning projects such as the Dongguan Women and Children's Activity Center, innovative 3D-printed mold technology was applied, raising shape fidelity to 99.2%.

III. Integrated Forming and Curing Process: The Key Link to Stable Performance

In prefabrication production, Qinglong adopts a composite forming process of "vacuum casting + vibration densification," expelling air bubbles in a negative pressure environment of 0.08MPa, combined with high-frequency, low-amplitude vibration (frequency 50-60Hz) to ensure the slurry fills completely. Addressing the early-strength characteristics of UHPC, a three-stage curing regime was developed: 24 hours of steam curing at 50°C (relative humidity ≥90%) to promote the hydration reaction, 72 hours of ambient-temperature curing to stabilize strength, and finally 28 days of standard curing to ensure compressive strength ≥150MPa and flexural strength ≥25MPa. In the Nanjing East Road Century Plaza renovation project, optimization of the temperature-control curve kept the light transmittance deviation of translucent UHPC panels within ±2%.

IV. Full-Process Quality Inspection System: Rigorous Control from Raw Materials to Finished Products

As an enterprise that participated in formulating the industry standard "Ultra-High Performance Concrete (UHPC) Exterior Wall Panels," Qinglong has established a quality control system covering the entire production cycle. Raw materials entering the factory are subject to a "three-inspection system," with tensile strength and bending performance tests conducted on each batch of steel fibers; RFID chip embedding technology is used during production to enable component traceability; finished product inspection covers appearance quality (bubble diameter ≤3mm, no more than 5 bubbles per square meter), dimensional deviation (±2mm), mechanical properties (sampling tests for impact resistance and wear resistance), and durability (strength loss rate ≤5% after 200 freeze-thaw cycles). With the testing capabilities of a CNAS-accredited laboratory, 100% of products leaving the factory are guaranteed to meet standard requirements.

Factory prefabrication is the core link in the quality control of UHPC curtain wall panels, requiring collaborative innovation in materials science, mold engineering, and process management. With intelligent production lines boasting an annual capacity of 600,000 square meters, Qinglong Group empowers the UHPC field with its 28 years of manufacturing experience in GRC/GRG/GRP materials and has provided high-quality curtain wall solutions for hundreds of landmark projects at home and abroad. In the future, with the implementation of standards such as "General Technical Conditions for Ultra-High Performance Concrete (UHPC) Non-Load-Bearing Components," the industry will embrace more standardized development opportunities. Qinglong is committed to exploring more possibilities of architectural aesthetics together with designers, upholding a manufacturing spirit of "meticulousness and the relentless pursuit of perfection."