UHPC Single-Curved vs. Double-Curved Panels: Differences in Mold Requirements and Key Technical Analysis

The mold is the "first battleground" of UHPC forming. The differences between molds for single-curved panels and double-curved panels directly determine the final presentation of material performance and architectural aesthetics.

In the field of contemporary architectural decoration, ultra-high performance concrete (UHPC) has become the material of choice for the facade design of landmark buildings and commercial complexes, thanks to its outstanding mechanical properties and sculptural potential. As an industry leader with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group deeply understands the decisive role mold technology plays in the quality of UHPC components. This article analyzes the core differences and key technological breakthroughs in mold requirements between UHPC single-curved and double-curved panels from three aspects—mold design, material selection, and manufacturing processes—providing a professional reference for designers and owners.

1. Mold Design: A Leap from "Planar Logic" to "Spatial Reconstruction"

UHPC single-curved panel molds follow a "single-curvature extension" design logic, with the core focus on ensuring curvature precision in a single direction. During the detailed design phase, Qinglong Group typically employs parametric modeling, generating continuous surface data through the Rhino and Grasshopper platforms. Mold frames are mostly welded structural steel structures, combined with adjustable support components to ensure uniform stress release when panels are demolded. Double-curved panel molds, on the other hand, must tackle the spatial challenge of "biaxial curvature." Their design process requires 3D scanning and finite element analysis to simulate pressure distribution during concrete flow, and the mold framework must adopt lightweight aluminum alloy or carbon fiber composite materials to achieve precise replication of complex surfaces. Taking the Nanjing East Road Century Plaza renovation project as an example, the Qinglong team used BIM technology to control the mold error of double-curved UHPC translucent panels within ±1mm, successfully realizing the design vision of "flowing light and shadow."

2. Material Selection: A Technical Balance from "Rigid Load-Bearing" to "Flexible Adaptation"

Material selection for single-curved panel molds focuses more on the balance between cost and durability. Qinglong Group commonly uses 12mm thick cold-rolled steel plates as panel materials, with surfaces treated by sandblasting plus a Teflon coating, which ensures flatness during concrete pouring while reducing demolding resistance. For double-curved panel molds, panel materials must possess "shape-adaptive" properties. Qinglong's R&D team innovatively adopted 0.8mm thick aerospace-grade aluminum alloy sheets combined with elastic resin composite layers, achieving seamless conformity to complex curved surfaces through hydroforming processes. At the same time, RFID chips are embedded on the back of the molds to establish a full life-cycle quality traceability system. Compared with traditional steel molds, although the material cost of double-curved molds increases by 30%, forming efficiency improves by 40%. In a commercial complex project in Shenzhen, Qinglong shortened the production cycle of double-curved UHPC curtain wall panels to 7 days per panel through material optimization.

3. Manufacturing Process: A Capability Upgrade from "Standardized Production" to "Customized Precision Manufacturing"

The manufacturing of single-curved panel molds relies on the automated production lines at Qinglong's Guangxi production base, using laser cutting and robotic welding to achieve a standardized output of 500㎡ per day. Double-curved panel molds, however, require a three-stage process of "digital modeling - CNC machining - manual calibration": first, point cloud data of the design surface is obtained through 3D scanning; then a five-axis machining center performs precision milling of the mold master; finally, craftsmen with more than 20 years of experience carry out 0.05mm-level hand polishing. Qinglong Group's proprietary "modular assembly technology for double-curved molds" breaks large double-curved components down into 6-8 unit modules joined through mortise-and-tenon structures, which both reduces transportation difficulty and guarantees "zero-error" alignment during on-site installation. This technology has been applied to a UHPC double-curved roof project at an international airport in Malaysia.

As a national high-tech enterprise and a participant in establishing UHPC industry standards, Qinglong Group has always taken "creating beautiful architecture" as its mission, continuously innovating mold technology to expand the boundaries of UHPC materials in the field of architectural decoration. Whether it is the efficient mass production of single-curved panels or the artistic expression of double-curved panels, Qinglong can provide full-chain solutions from detailed design to after-sales maintenance. In the future, with the deep integration of BIM technology and intelligent manufacturing, UHPC mold technology will develop toward "parametric-driven, green materials, and intelligent production," injecting more possibilities into facade design.