What Are the Dimensional Deviation Control Standards for UHPC Components? Precision Control Technology and Acceptance Specifications

Dimensional deviations of UHPC components directly affect installation and jointing precision as well as the architectural appearance. Strictly adhering to dimensional deviation control standards, combined with precision control technology, is key to ensuring project quality. Drawing on 28 years of production experience, Qinglong explains the core points of precision control by clarifying the deviation standards and control methods for different types of components.

1. Core Control Standards for Dimensional Deviations of UHPC Components

According to the industry standard General Technical Conditions for Non-Load-Bearing Ultra-High Performance Concrete (UHPC) Components, the dimensional deviation control standards for UHPC components are as follows. Flat panel components: length/width deviation ≤±3mm, thickness deviation ≤±2mm, diagonal deviation ≤±4mm, surface flatness error ≤2mm/m; Shaped components (such as L-shaped and U-shaped panels): length deviation ≤±4mm, thickness deviation ≤±2mm, angle deviation ≤±0.5°; Decorative lines: straightness deviation ≤2mm/m, verticality deviation ≤2mm/m, cross-sectional dimension deviation ≤±2mm; Oversized components (area ≥8㎡): dimensional deviations may be relaxed to ±5mm, but installation and jointing requirements must still be met. Qinglong applies stricter internal control standards, with flat panel dimensional deviations ≤±2mm, ensuring installation precision for high-end projects.

2. Dimensional Precision Control Technology in the Production Stage

The production stage is the core of dimensional deviation control and requires full-process management covering molds, forming, and curing. Molds are machined with high-precision equipment; steel molds are CNC-milled and ground with dimensional error ≤±0.5mm, and after assembly they undergo overall inspection and may only be used once they pass; Qinglong calibrates its molds regularly to ensure long-term precision stability. In the forming process, automated positioning devices control the pouring height and position of components to avoid manual operation deviations; flat panels are vibrated on vibrating tables to ensure even slurry distribution and reduce shrinkage deformation. Curing takes place in a constant-temperature, constant-humidity environment to prevent dimensional deformation caused by temperature and humidity fluctuations; after curing, a second dimensional inspection is performed, and non-conforming components are ground and corrected. For the oversized UHPC components of Qinglong's Shanghai Century Plaza project, dimensional deviations were controlled within ±3mm through full-process production control.

3. Acceptance Specifications for Dimensional Deviations of Different Types of Components

Different types of UHPC components require differentiated acceptance methods to ensure dimensional deviations meet requirements. Flat panels and decorative lines: inspected with a 2m straightedge, steel tape measure, and laser rangefinder, with no fewer than 3 measurement points per component and the maximum value taken; Shaped curved components: inspected with 3D laser scanning technology and compared against the design model, with surface fitting deviation ≤±3mm; in the hyperbolic UHPC project of the Guangxi New Media Center, Qinglong achieved precise acceptance through 3D scanning; Jointed components: focus on inspecting dimensional deviations at jointing surfaces, with jointing gaps between adjacent components ≤1mm and height differences ≤0.5mm to ensure flush jointing; in the UHPC curtain wall project of the Shenzhen Yirui Biotechnology Building, jointing deviations were controlled within standards, delivering excellent overall appearance.

4. Solutions for Excessive Dimensional Deviations and Preventive Measures

Excessive dimensional deviations must be addressed promptly, and a prevention mechanism should be established to avoid recurrence. Minor excess (deviation within 1.2 times the standard): corrected by mechanical grinding and leveling with repair mortar, with grinding depth ≤3mm; surface flatness after repair must meet the standard; Severe excess (deviation exceeding 1.2 times the standard): the component is scrapped and strictly prohibited from being used in project installation; Qinglong enforces a “scrap-if-non-conforming” policy to ensure all factory products meet precision requirements; Preventive measures include: establishing a mold ledger with regular inspection and maintenance; conducting technical briefings before production to clarify dimensional control points; performing a full dimensional inspection of the first piece of each batch and starting mass production only after confirming conformity; and measuring component dimensions regularly during curing and adjusting curing parameters promptly. Through full-process prevention and control, the dimensional pass rate of Qinglong UHPC components remains stable at above 99%.