What Is the Key Technology for Achieving a High Openwork Ratio in UHPC Shapes? Analysis of Hollowing Techniques and Strength Assurance

The key technologies for achieving high openwork ratios (up to 60%) in UHPC shapes concentrate on four dimensions: "precise mold design, reinforcement optimization, forming process, and strength assurance". Through five-axis engraving, BIM simulation, and fiber reinforcement technologies, Qinglong has enabled projects such as the Ouargla Hotel in Algeria (openwork ratio over 50%) and the Shanghai New World Plaza light-transmitting panels to combine artistic appeal with structural safety.

1. Precise Mold Design: The Foundational Guarantee for Openwork Shapes

Mold precision determines the fidelity of openwork shapes. 3D modeling: Rhino+Grasshopper parametric design is adopted to precisely locate openwork positions, aperture diameters, and hole spacing; Qinglong's BIM modeling error is ≤0.1mm, with 100% shape fidelity. Mold material: Polyurethane or steel molds are selected for high-temperature and high-pressure resistance; Qinglong's polyurethane molds have smooth surfaces with burr-free openwork edges. Mold reinforcement: High openwork ratios tend to cause mold deformation, so stiffening ribs are added; Qinglong's molds deform ≤0.3mm after reinforcement, ensuring forming precision. Split mold design: Complex openwork shapes adopt a split mold process for easy demolding; Qinglong's split mold joints are flat with no visible splicing marks.

2. Reinforcement and Forming Process: The Core Support for Structural Strength

Process optimization balances openwork ratio and strength. Reinforcement optimization: Fine-diameter steel bars (φ6-φ8) or steel fibers (dosage 2%-3%) are used to form a 3D reinforcement network; Qinglong's steel fiber distribution uniformity reaches 98%, with no weak strength points in openwork areas. Forming process: High-pressure spray forming (pressure ≥0.6MPa) plus vacuum degassing ensures dense slurry; Qinglong's vacuum degassing keeps porosity ≤2%, improving crack resistance. Thickness adaptation: Panel thickness is adjusted according to the openwork ratio; when the ratio exceeds 50%, panel thickness is ≥30mm; Qinglong's 50mm thick UHPC openwork panels for the Algeria project achieve a flexural strength of 18MPa. Edge treatment: Openwork edges are rounded (radius ≥5mm) to avoid stress concentration; Qinglong's edge treatment increases impact strength by 25%.

3. Strength Testing and Qinglong's Project Practice

Rigorous testing and real-world projects verify technical feasibility. Strength testing: Flexural and impact tests are conducted before delivery; openwork panels achieve a flexural strength ≥15MPa, and Qinglong's testing pass rate is 100%. Durability testing: Resistance to ≥300 freeze-thaw cycles and 1,000 hours of UV aging, with strength retention ≥90%; Qinglong's high-openwork UHPC panels meet durability standards. Project cases: The Ouargla Hotel in Algeria uses 50mm thick UHPC openwork panels with an openwork ratio over 50%, featuring smooth and refined surfaces; they have withstood high-temperature, arid environments with no cracking after 8 years of use. The Shanghai New World Plaza UHPC wood-effect light-transmitting panels feature an openwork plus light-guide rod design, with a maximum panel area of 12㎡ and an openwork ratio of 35%, combining artistic appeal with structural safety. Technical advantages: Qinglong holds 10 patents related to high-openwork UHPC and participated in drafting the Technical Requirements for UHPC Openwork Components, with industry-leading technical capabilities.