What Should Be Noted When Combining UHPC Curtain Walls with Glass Curtain Walls?

The combined application of UHPC curtain walls and glass curtain walls is a common design approach in modern architecture, pursued for its contrast between solid and void and the interplay of material textures. However, the two materials differ significantly in physical properties (such as coefficient of linear expansion, stiffness, and deformation characteristics), connection details, visual presentation, and installation techniques, so their combined design requires a high degree of systems integration thinking. In projects such as the Shenzhen Pingshan High-tech Zone Comprehensive Service Center and the Shanghai Astronomy Museum, Qinglong Group has successfully implemented various UHPC-and-glass combination modes. The core considerations can be summarized into four major aspects: "deformation compatibility design, sealing and waterproofing details, visual alignment control, and installation sequence coordination."

Deformation Compatibility Design and Joint Treatment Are Critical

This is the most central technical challenge in combined applications. Glass has a coefficient of linear expansion of approximately 9×10⁻⁶/°C, while UHPC is about 10-12×10⁻⁶/°C; the two are close but still differ. Under temperature effects, the two materials deform at slightly different rates and magnitudes. In design, the two rigid materials must never be rigidly butted within the same plane. A movement joint (typically no less than 20mm) must be provided between them, together with flexible connections (such as slidable pressure plates) or fully independent framing systems. Qinglong typically uses UHPC as decorative spandrel walls, vertical fins, or sunshades, with the glass window system each forming its own independent support and deformation systems, then transitioning through carefully designed sealant joints.

Waterproofing and Drainage Details at Joints Must Be Foolproof

Joints between different materials are high-risk areas for leakage. For combined UHPC and glass nodes, the waterproofing design requires multiple lines of defense: first, structurally ensure that water flow paths are blocked (adopting the "rain screen principle" or "pressure-equalized cavity" design); second, the joint must be filled with high-quality closed-cell foam backer rods as backing; finally, seal with a highly elastic, aging-resistant silicone weatherproof sealant that bonds excellently to both materials. At critical locations such as internal and external corners and drainage outlets, additional waterproof flashing or water guide channels must be designed.

Visual Alignment and Flatness Control Determine the Final Effect

Designers often pursue precise planar alignment or recessed-and-projecting relationships between UHPC panels and glass on the facade. This requires that the supporting framing systems of both be designed, set out, and constructed in a unified manner. Since UHPC panels are usually heavier and thicker than glass panels, their supporting framing may be more complex, requiring integrated modeling and clash detection with BIM during the detailed design stage to ensure the spatial positions of all components are accurate. During installation, unified datum lines must be used to control the setback and projection positions as well as the flatness of both materials, achieving the light-and-shadow effects intended by the design.

Scientific Sequencing of Installation and Finished Product Protection

The construction sequence must be rationally arranged. It is generally recommended to install the main load-bearing framing first, then the UHPC panels (since they demand extremely high installation precision and may serve as the datum for subsequent installation), and finally the glass. Strict finished product protection measures must be established to prevent the installed UHPC panels from being struck or stained during glass installation, and vice versa. Qinglong's project management team develops detailed cross-operation plans and protection schemes to ensure zero damage to both expensive materials during construction.

Therefore, the successful combination of UHPC and glass curtain walls represents a high-level fusion of materials science, structural engineering, waterproofing design, and construction management. Leveraging its deep technical expertise in both systems and extensive cross-disciplinary project experience, Qinglong Group can provide customers with one-stop solutions from design optimization to flawless implementation.