What Are the Differences in Mold Requirements Between UHPC Single-Curved Panels and Double-Curved Panels?

The core differences in mold requirements between UHPC single-curved panels and double-curved panels are reflected in four dimensions: "surface complexity, machining precision, structural strength, and jointing difficulty." Single-curved panel mold requirements are relatively simplified, while double-curved panel molds require adaptation to higher precision and strength. Through differentiated mold design, Qinglong has achieved a forming pass rate of 99.8% for both types of panels. The Guangxi New Media Center and Shanghai Qingpu projects have verified the reliability of double-curved and single-curved molds respectively.

I. Surface Complexity and Machining Precision: Core Differences

The surface dimension determines mold machining difficulty. Single-curved panel molds: curvature in only one direction (e.g., cylindrical surfaces) with simple surface equations; machining requires only single-axis precision control, with dimensional deviation ≤±1.0mm and surface precision ≤±0.5mm. Qinglong single-curved panel molds use three-axis CNC machining, with efficiency 40% higher than double-curved panels. Double-curved panel molds: curvature in two perpendicular directions (e.g., spherical and parabolic surfaces) with complex surface equations, requiring dual-axis linkage precision control, dimensional deviation ≤±0.5mm, and surface precision ≤±0.3mm. Qinglong double-curved panel molds use five-axis CNC machining, with machining time 2-3 times that of single-curved panels. Inspection requirements: single-curved panel molds use two-dimensional inspection (straightedge + laser rangefinder), while double-curved panels require three-dimensional laser scanning inspection to ensure deviation-free surfaces.

II. Mold Structural Strength and Material Selection: Adapting to Different Loads

Load differences require different mold strengths. Structural strength: single-curved panel molds bear loads evenly, with stiffener spacing ≤800mm, and can use GRP or wooden composite molds; double-curved panel molds experience localized stress concentration during pouring, with stiffener spacing ≤500mm, prioritizing GRP or steel molds. Qinglong double-curved panel molds use square steel stiffeners, with 50% higher stiffness than single-curved panel molds. Material adaptation: single-curved panels in small-batch production can use wooden molds (low cost), while large-batch production uses GRP molds; double-curved panels, due to complex surfaces and high precision requirements, use only GRP or steel molds. Qinglong double-curved steel molds have a service life of ≥100 uses, offering superior reusability. Demolding design: single-curved panel molds can use integral demolding, while double-curved panels require segmented molds (each segment length ≤1.5m) for easy demolding and surface protection. Qinglong double-curved segmented molds have joint gaps ≤0.2mm.

III. Jointing Difficulty and Project Practice: Differentiated Control

Jointing requirements increase with surface complexity. Single-curved panel jointing: when multiple single-curved panels are joined, only single-axis curvature alignment is required, with stone grain/line alignment deviation at joints ≤1.0mm. Qinglong single-curved panel jointing uses chalk-line positioning, achieving an alignment rate of 98%. Double-curved panel jointing: requires simultaneous alignment of dual-axis curvature, with joint alignment deviation ≤0.5mm and smooth, step-free surfaces. Qinglong uses BIM modeling to locate joint points, achieving a jointing pass rate of 99%. Project cases: the single-curved UHPC panels of the Shanghai Qingpu R&D project use integral GRP molds with machining precision of ±0.8mm, delivering smooth lines after jointing; the double-curved UHPC panels of the Guangxi New Media Center use five-axis machined segmented steel molds with surface precision of ±0.3mm; all panel joints show no visible seams, making it a highlight of this architectural landmark.