What Are the Key Technologies for Achieving High Hollow-Out Rates in UHPC Shapes? Analysis and Practice of High Hollow-Out Technology

Achieving a high perforation ratio in UHPC designs (typically a perforation ratio ≥50%) requires overcoming multiple technical bottlenecks in material strength, structural stability, production, and construction, balancing aesthetic creativity with structural safety through precise design and advanced processes. Drawing on practice from high-perforation projects such as the Ouargla Hotel in Algeria, Qinglong analyzes the core key technologies.

I. Material Mix Optimization Technology: The Core of Strength Support

High-perforation UHPC requires higher strength and toughness, and the material mix is the foundation. Fiber reinforcement technology: high alkali-resistant glass fibers are selected, using composite laying of chopped fibers and continuous fibers, with continuous fibers arranged along the load direction; fiber content is increased to 3%-4%, ensuring flexural strength ≥25MPa and bending strength ≥15MPa; Qinglong's high-perforation UHPC has a measured flexural strength exceeding 30MPa. Cement matrix improvement: a low water-binder ratio (≤0.28) formula is selected, combined with active admixtures such as silica fume and nano calcium carbonate to improve material density and bond strength, reduce internal porosity, and enhance crack resistance. Aggregate gradation optimization: fine quartz sand (particle size 0.1-1.2mm) is used to avoid stress concentration caused by coarse aggregates, improving material uniformity and providing strength assurance for high-perforation designs.

II. Structural Design Reinforcement Technology: The Core of Stability Assurance

Scientific structural design is key to the safety of high-perforation designs and requires precise control of load-bearing logic. Perforation shape optimization: parametric design software (such as Rhino+Grasshopper) is used to optimize perforation patterns, prioritizing mechanically sound shapes such as grid and honeycomb patterns while avoiding sharp corners and overly long cantilever structures to reduce stress concentration. Rib support design: reinforcing ribs are set around perforation openings, with rib width ≥50mm and thickness consistent with the main body, forming a complete load-bearing framework that disperses stress in perforated areas; complex high-perforation designs can adopt a double-layer rib structure. In the Shanghai New World project, Qinglong achieved a safe design with a 55% perforation ratio through rib design. Finite element stress analysis: software such as ANSYS is used to simulate the stress state of high-perforation designs under dead weight, wind loads, and other actions, optimizing perforation layout and rib dimensions to ensure maximum stress does not exceed the material's allowable stress.

III. Digital Production and Forming Technology: The Core of Precision Control

High-precision production processes ensure that high-perforation designs are accurately realized, avoiding production defects. Digital mold technology: CNC engraving machines or 3D printers are used to produce high-precision molds with mold surface precision ≤±0.1mm, ensuring accurate dimensions and shapes of perforation openings; complex perforation designs can adopt segmented mold assembly. Qinglong's digital mold technology achieves perforation opening tolerance ≤±0.2mm. Spraying forming process: a high-pressure spraying process is adopted, spraying uniformly mixed UHPC slurry and fibers into the mold to ensure uniform fiber distribution and high material density, avoiding uneven strength caused by manual forming; spraying pressure is controlled at 0.8-1.0MPa. Steam curing technology: high-temperature, high-pressure steam curing (temperature 80-100℃, pressure 0.8MPa) is adopted to accelerate material hydration, increase early strength, and shorten the curing cycle to 48 hours, preventing strength reduction due to insufficient curing.

IV. Construction, Installation, and Reinforcement Technology: The Core of Implementation

Standardized construction and installation ensure the long-term stability of high-perforation designs. Anchoring system reinforcement: multi-point anchoring is adopted, with anchor points set at rib locations; stainless steel connectors are selected, with each connector's load capacity ≥12kN and spacing ≤500mm; large high-perforation components require additional supporting keels. Anti-deformation measures: temporary supports are set during production and installation to prevent component deformation due to dead weight; after installation, stress release testing is required to ensure no residual stress. Long-term protection: a fluorocarbon coating is applied to the surface to improve weathering and corrosion resistance; perforated areas and ribs are inspected quarterly for cracks and deformation and repaired promptly. Qinglong uses an intelligent monitoring system in high-perforation projects to monitor structural conditions in real time, ensuring long-term safety.