What Is the Permissible Range of Surface Flatness Deviation for UHPC Curtain Wall Panels?

According to the industry standard developed with the participation of Qinglong Group, the surface flatness deviation of installed UHPC curtain wall panels should be ≤3mm/2m. This requirement, stricter than the national standard, ensures the optical quality of building facades.

Flatness control starts with mold precision. At its Nanning production base, Qinglong uses five-axis CNC machine tools to machine steel molds, keeping mold flatness errors within 0.5mm. The doubly curved panels of the Shanghai Astronomy Museum project were inspected by laser scanning, ultimately achieving a flatness of 2mm/2m, thanks to our innovative reverse deformation compensation technology.

The leveling system during the installation stage is equally critical. Qinglong's patented three-dimensional adjustable hangers allow ±15mm of adjustment, with positioning assisted by laser line projectors. In the Shenzhen Yirui Biotechnology Building project, we used a digital total station to establish a control network, distributing cumulative errors across each floor.

The impact of thermal deformation on flatness must be considered in advance. For the Nanjing East Road Century Plaza project, local temperature data for all four seasons was input into the BIM model, and installation gaps were adjusted in reverse based on calculated thermal expansion and contraction. During summer construction, an expansion allowance of 0.3mm/m was deliberately reserved to avoid visible joints in winter.

Qinglong's "optical flatness" concept is driving an industry upgrade. By simulating light and shadow effects under different sunlight angles and optimizing the micro-curvature design of panel surfaces, building facades achieve absolute visual flatness. This technology was applied in the Qiangwei Garden project in Zengcheng, Guangzhou, earning high praise from the owner.