How to Control the Jointing Precision of Multi-Curved UHPC Forms: Key Technologies and Practical Approaches

Under the dual challenges of architectural aesthetics and engineering precision, joint precision control of multi-curved UHPC shapes has become a core topic for high-end buildings in realizing their design visions. As an industry leader with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group deeply understands that millimeter-level jointing errors affect not only visual presentation but also structural safety and durability. This article systematically breaks down the key technical paths for joint precision control of multi-curved UHPC shapes from three dimensions: material properties, digital technology, and process innovation.

I. Material Property Optimization: The Underlying Guarantee of UHPC Joint Precision

Ultra-High Performance Concrete (UHPC), with its compressive strength exceeding 150MPa and high elastic modulus, provides the material foundation for complex curved shapes, but it also imposes stringent requirements on shrinkage deformation control. Qinglong ensures material stability through three innovations in the production process: first, adopting a composite blending technology of nano-scale silica fume and ultra-fine steel fibers to reduce the hydration heat peak by 20%, minimizing warping caused by thermal stress; second, developing a dedicated retarding admixture that extends the initial setting time to over 6 hours, reserving sufficient adjustment windows for on-site jointing; third, establishing a material performance database to customize mix proportions for different regional climates (such as the hot, humid South China and the cold, dry North), ensuring the shrinkage rate remains stable within 0.03%. These technical details reflect Qinglong's 28 years of technical accumulation in the UHPC materials field as a national-level high-tech enterprise.

II. Digital Full-Process Control: A Precision Closed Loop from Design to Installation

In the Century Plaza renovation project on Nanjing East Road, Qinglong achieved millimeter-level jointing of a light-transmitting UHPC curtain wall through BIM + parametric design. Specifically, Rhino and Grasshopper were used to build a multi-curved digital model, breaking the shape down into 128 special-shaped units, each assigned a unique ID code; in the production stage, industrial-grade 3D scanning was introduced to re-verify mold precision, with any error exceeding 0.5mm immediately sent for rework; on-site installation used a Leica TS60 total station for real-time positioning, combined with a self-developed adjustable bracket system, achieving adjustment precision of ±2mm in three-dimensional space. This digital closed loop of "design-production-installation" won the project the Silver Award of the First UHPC Construction Engineering Innovation Award (AALBORG WHITE Cup), confirming Qinglong's technical strength in complex shape projects.

III. Process Innovation Breakthrough: Practical Wisdom for Solving Jointing Challenges

In response to the three major pain points of multi-curved UHPC jointing, Qinglong's R&D team has developed unique solutions: for the seamless connection of double-curved components, a "mortise-and-tenon + epoxy resin" composite connection process is adopted, which ensures structural strength while allowing minor displacement compensation; to control the installation precision of super-large components (a single piece weighing up to 800kg), an innovative combination of vacuum suction cup hoisting and laser point positioning technology was applied, controlling hoisting deviation within 1mm; for joint treatment, a dedicated flexible sealant was developed with an elongation rate of over 300%, capable of accommodating joint displacement caused by temperature changes. These process innovations stem from the practical experience Qinglong accumulated while participating in the formulation of the industry standard "General Technical Conditions for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC)".

From the GRC curved curtain wall of the Dongguan Women and Children's Activity Center to UHPC special-shaped components for a landmark project in Malaysia, Qinglong has always maintained a "meticulous and excellence-driven" attitude, transforming the joint precision control of multi-curved shapes from a technical challenge into a core competitive strength. As a Vice President Unit of the China GRC Association and a member of the International GRC Association, Qinglong knows well that joint precision control is not merely an engineering and technical issue, but also a form of respect for architectural art. In the future, with the deep integration of parametric design and intelligent construction technology, new materials such as UHPC will shine in more landmark buildings, and Qinglong will continue to leverage its full-chain service capabilities to provide designers and owners with expert-level solutions from concept to realization.