Analysis of Key Steps and Technical Points in the Factory Prefabrication Stage of UHPC Curtain Wall Panel Production

**Factory Prefabrication of UHPC Curtain Wall Panels: Precision Manufacturing from Material to Finished Product**

Amid the wave of innovation in building envelopes, ultra-high performance concrete (UHPC) has become the “new favorite” for landmark building curtain walls thanks to its outstanding mechanical properties and artistic expressiveness. As an industry leader with 28 years of deep expertise in the UHPC/GRC/GRG/GRP materials field, Qinglong Group understands that the factory prefabrication stage is the core factor determining the quality of UHPC curtain wall panels. This article provides a systematic analysis of the key steps and technical points of UHPC curtain wall panel factory prefabrication, offering designers and owners a professional perspective on the entire process from material selection to finished product delivery.

**1. Precise Material Proportioning: The Foundation of UHPC Performance**

The outstanding performance of UHPC curtain wall panels begins with scientific proportioning. Qinglong adopts a “quartz sand-steel fiber-cement-based” ternary system, optimizing the aggregate gradation through more than 200 tests to ensure that continuously graded 5-20mm quartz sand accounts for 65%, combined with straight steel fibers at a 1.5% volume fraction (13-19mm in length), achieving mechanical indicators of compressive strength ≥150MPa and flexural strength ≥30MPa. Meanwhile, a composite admixture of silica fume and ultra-fine fly ash is introduced to reduce the water-binder ratio to below 0.2, balancing workability and density. Notably, Qinglong's independently developed super-dispersing admixture can raise material flowability to above 250mm, laying the foundation for casting complex shapes.

**2. Mold Engineering: The First Line of Defense in Precision Control**

The mold is the “skeleton” of UHPC curtain wall panel forming. Qinglong adopts a composite process of “steel mold + elastic liner mold”: the main structure uses 6mm thick Q235 steel plate milled by five-axis machining centers, ensuring flatness error ≤0.5mm/m; for special-shaped components such as double-curved surfaces and hollow-outs, polyurethane elastic liner molds are innovatively employed, leveraging their micro-deformation characteristics to compensate for concrete shrinkage and achieving surface precision at the 0.1mm level. 3D laser positioning technology is applied during mold assembly; by comparing BIM models with on-site scanning data, mold-closing error is kept within ≤1mm, improving efficiency by 300% over traditional processes.

**3. Casting and Curing: Dual Assurance of Strength and Durability**

The casting process of UHPC curtain wall panels is like a “precision chemical experiment”. Qinglong adopts a “layered placement + high-frequency vibration” process, controlling the casting thickness of each layer at 50-80mm, with immersion vibrators running at 1500r/min to ensure air bubbles escape. For special areas such as anchorage zones, pre-embedded stainless steel connectors (tensile load capacity ≥50kN) form a mechanical interlock with the UHPC. The curing stage adopts a dual-stage mode of “steam curing + natural curing”: 48 hours of steam curing at 70℃ accelerates hydration, followed by 28 days of natural curing to stabilize strength, shortening the traditional curing cycle by 50%, with carbonation depth ≤0.5mm and durability improved by more than 20 years.

**4. Quality Inspection: Rigorous Standards for Full-Process Traceability**

As a national high-tech enterprise, Qinglong has established a “three-level quality inspection system”: incoming raw materials must pass X-ray fluorescence spectrometry analysis to ensure heavy metal content complies with the GB 31893 standard; semi-finished product inspection covers 12 indicators including surface flatness (≤2mm/m), dimensional deviation (±3mm), and chloride ion permeability coefficient (≤1×10⁻¹²m/s); finished products undergo four-point bending tests and freeze-thaw cycle (300 cycles) testing before leaving the factory, with a pass rate of 100%. Each curtain wall panel is embedded with an RFID chip, enabling full life-cycle traceability from material to installation—a technology validated in benchmark projects such as the Century Plaza renovation on Nanjing East Road.

From materials science to engineering practice, the factory prefabrication of UHPC curtain wall panels is the crystallization of technology and experience. Supported by 28 years of full-chain experience, Qinglong Group integrates precision manufacturing into every step, not only providing high-performance solutions for building envelopes but also driving the innovative application of UHPC materials in the decoration field. Looking ahead, with the implementation of the industry standard “General Technical Specifications for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC)”, Qinglong will continue to uphold the philosophy of “meticulousness and the pursuit of excellence”, building UHPC curtain wall systems that combine safety and aesthetics for construction projects worldwide.