What Are the Key Steps and Technical Points in the Factory Precasting Stage of UHPC Curtain Wall Panel Production

Factory prefabrication is the lifeline of UHPC curtain wall panel quality. With 28 years of industry experience, we can tell you: precise control of every process is a dual commitment to architectural aesthetics and structural safety.

Amid the wave of building facade innovation, UHPC (Ultra-High Performance Concrete) has become the preferred material for landmark building curtain walls thanks to its ultra-high strength, excellent durability, and design freedom. As an industry leader with 28 years of deep expertise in the UHPC/GRC/GRG/GRP materials field, Qinglong Group fully understands the decisive role of the factory prefabrication stage in the final performance of curtain wall panels. This article provides an in-depth analysis of the key steps and technical points in the factory prefabrication of UHPC curtain wall panels, offering designers and owners a full-process quality control perspective from material to finished product.

1. In-Depth Design Before UHPC Curtain Wall Panel Prefabrication: Precision Positioning Driven by Digital Technology

In-depth design is the "blueprint" of prefabricated production, directly determining how well curtain wall panels match the building structure. Relying on BIM technology and parametric design platforms, the Qinglong team converts architectural drawings into producible component models, focusing on three core tasks: first, acquiring building structure error data through 3D scanning to achieve "millimeter-level" component dimension compensation; second, optimizing the rebar framework and fiber distribution scheme to reduce self-weight while meeting structural strength requirements (flexural strength ≥20MPa); third, simulating UHPC material flow paths to avoid defects such as air bubbles and voids in complex shapes. Taking the Nanjing East Road Century Plaza renovation project as an example, the in-depth design of light-transmitting UHPC curtain wall panels achieved a balance between light transmittance and structural stability through Grasshopper algorithms, ultimately winning an industry innovation award.

2. Raw Material Proportioning and Mixing Process: Source Control of UHPC Performance

The outstanding performance of UHPC curtain wall panels stems from scientific material proportioning and advanced mixing processes. Qinglong adopts customized mix proportion designs, strictly controlling the grading of cement, silica fume, and ultra-fine quartz sand, as well as the dosage of steel fibers (13-20mm in length) at a volume fraction of 2%-3%, ensuring material compressive strength ≥150MPa and elastic modulus ≥40GPa. The mixing stage uses a twin-shaft compulsory mixer, with materials added in three stages (dry powder → steel fibers → water), and mixing time controlled at 90-120 seconds to ensure even fiber dispersion without clumping. Notably, the mixing temperature must be maintained at 15-25°C: in summer, ice water is used for cooling, while in winter, warm water is used for preheating, to avoid adverse effects of ambient temperature on the hydration reaction.

3. Mold Making and Casting: The Core Process for Shape Realization and Precision Assurance

Molds are the key vehicle for faithfully reproducing the shapes of UHPC curtain wall panels. Qinglong selects different mold processes based on component complexity: steel molds are used for flat or simple curved surfaces to ensure precision in repeated use, while epoxy resin molds are used for complex shapes such as double-curved surfaces and hollow-out patterns, replicated from 3D-printed master molds to achieve 0.5mm-level surface precision. The casting process employs vacuum-assisted casting technology combined with high-frequency vibration (50-60Hz frequency) to expel air inside the concrete and improve compactness. For extra-large components (single panel area ≥10㎡), segmented casting and secondary grouting processes are adopted to avoid cracking risks caused by concentrated hydration heat.

4. Curing Process and Quality Testing: Dual Verification of Durability and Safety

Scientific curing is the guarantee of UHPC strength development and performance stability. Qinglong adopts a combined "steam curing + natural curing" process: after casting, the panels rest for 2 hours, then enter a 60°C steam curing chamber for 24 hours of curing, followed by 7 days of natural curing in an environment of 20°C and humidity ≥90%, ensuring that 28-day strength meets standards. Quality testing implements a "three-stage inspection system": incoming raw material testing (e.g., steel fiber tensile strength, cement activity index), in-process production testing (e.g., concrete flowability, component dimensional deviation), and finished product performance testing (frost resistance, carbonation depth, anchoring system pull-out force). All testing data is uploaded to Qinglong's digital management platform, enabling full life-cycle quality traceability.

As a national high-tech enterprise and a participant in formulating UHPC industry standards, Qinglong Group integrates 28 years of in-depth design and manufacturing experience into the prefabrication of every UHPC curtain wall panel. From digital modeling to finished product delivery, every process carries the mission of "creating beautiful architecture." Looking ahead, Qinglong will continue to integrate the advantages of UHPC/GRC/GRG/GRP materials, providing designers with solutions offering greater creative freedom and injecting more possibilities into the art of building facades.