What Are the Steps in the Production Process of UHPC Exterior Wall Decorative Lines?

The manufacturing process of UHPC exterior wall decorative lines consists of seven core steps: design development, mold making, raw material proportioning, mixing and casting, curing and demolding, surface treatment, and quality inspection. Through BIM technology, automated production, and refined control, Qinglong ensures precise line shapes and excellent performance, adaptable to various architectural styles. Typical projects include the Shenzhen Yirui Biotechnology Building and Shanghai New World Plaza.

1. Design Development: Precise Adaptation to Building Requirements

Design development is the foundation of the process, ensuring the lines integrate with the building. 3D modeling: based on construction drawings, 1:1 3D models are built using software such as Rhino and Revit to define the cross-sectional dimensions, curvature, and joint nodes of the lines; Qinglong uses BIM technology to perform clash detection against the main structure, avoiding construction conflicts. Performance design: based on installation height, wind pressure, and temperature environment, the UHPC strength grade (≥150MPa), thickness (15-30mm), and fiber type (alkali-resistant glass fiber or steel fiber) are determined; the lines in Qinglong's Shenzhen project are 20mm thick, with wind pressure resistance up to 1.5kPa. Sectional design: long lines (over 3m) are split into modular units (1.5-2.5m) for easier production, transportation, and installation; splicing grooves are set at split points to ensure flat installation; Qinglong's longest modular line is 2.5m, with flatness deviation after splicing ≤1mm/m.

2. Mold Making: Ensuring Shape Precision

Mold quality directly determines the line's shape and dimensional accuracy. Mold selection: complex shapes (such as double-curved and embossed designs) use GRP molds or silicone molds, while straight lines use steel molds; Qinglong's double-curved decorative lines use GRP molds with surface finish up to Ra≤0.8μm. Mold machining: based on the 3D model, a master mold is machined using a CNC engraving machine, then production molds are replicated from it; mold dimensional deviation is ≤±1mm, and Qinglong's mold machining accuracy reaches ±0.5mm, ensuring precise line shapes. Mold pretreatment: the inner surface of the mold is coated with release agent (special water-based release agent), applied evenly 2-3 times to prevent sticking during demolding; Qinglong's release agent has good compatibility with UHPC and does not affect surface texture.

3. Raw Material Proportioning, Mixing and Casting: Ensuring Performance and Density

Raw materials and casting are the core guarantees of line performance. Raw material proportioning: low-alkali cement, quartz sand (0.15-0.6mm), alkali-resistant glass fiber (dosage 2.5%), silica fume, and high-efficiency water reducer are used, with a water-binder ratio of 0.22-0.25; Qinglong's patented formula ensures a balance between flowability and strength. Mixing process: after automated batching, mixing is carried out in a forced-action mixer—first dry-mix cement, aggregate, and silica fume for 2 minutes, then add water and water reducer and wet-mix for 2 minutes, and finally add fibers and mix for 1-2 minutes to ensure uniform fiber dispersion; Qinglong's mixing equipment is equipped with a weighing system, with batching error ≤±1%. Casting process: fresh UHPC is poured into the mold and vibrated on a vibration table (frequency 2000-3000 times/min) to expel air bubbles and ensure density; casting thickness is kept uniform to avoid localized voids; Qinglong monitors flowability in real time during casting, keeping the flow spread at 750-800mm.

4. Curing, Demolding and Surface Treatment: Enhancing Quality and Appearance

Curing and surface treatment determine the final quality of the lines. Curing process: after casting, the lines are covered with plastic film to retain moisture for 24 hours, then transferred to a constant temperature and humidity curing room (temperature 20-25℃, humidity ≥90%) for 7 days, or steam cured (90℃, 48 hours); Qinglong's steam-cured lines reach 150MPa strength at 7 days. Demolding timing: demolding is carried out when strength reaches over 70% of the design strength (about 3-5 days) to avoid deformation caused by premature demolding; Qinglong tests strength with a rebound hammer to ensure safe demolding. Surface treatment: after demolding, flash and burrs are removed and surface defects lightly sanded; for stone-like or metal-like effects, special coatings can be applied or surface sandblasting performed; Qinglong's Shanghai New World lines use wood-grain texture treatment with 95% realism. Quality inspection: dimensional deviation (≤±2mm), surface flatness (≤1mm/m), compressive strength, and freeze-thaw resistance are tested; only products that pass inspection may leave the factory; Qinglong samples 3 specimens from each batch for performance testing, with a 100% pass rate.