Combined Application of UHPC Curtain Wall and Glass Curtain Wall: Key Considerations and Collaborative Design Solutions

The combination of the texture of UHPC curtain walls and the transparency of glass curtain walls can create building facades with both artistic and modern appeal. However, the differences between the two in material properties, mechanical performance, and construction techniques require scientific design and coordinated collaboration to mitigate risks. With 28 years of experience in composite curtain wall engineering, Qinglong Group participated in the revision discussions of the "Standard for Quality Acceptance of Building Curtain Wall Engineering" and summarized four core considerations—"performance coordination, joint connection, construction adaptation, and waterproof sealing"—successfully completing combined curtain wall projects such as Shanghai New World and a commercial complex in Shenzhen.

1. Performance Coordination: Balanced Adaptation of Load and Thermal Performance

Coordinated load design: UHPC panels (surface density 60-120kg/㎡) differ significantly in weight from glass curtain walls (surface density 30-50kg/㎡), so a unified framing design standard is required, with framing strength reinforced according to the UHPC load class. Qinglong adopts Q355B steel framing, optimized through finite element analysis, ensuring the framing can bear the weight of UHPC while avoiding overdesign in glass curtain wall areas. Thermal performance matching: The thermal conductivity of UHPC (0.8-1.0W/(m·K)) is higher than that of insulating glass (0.2-0.3W/(m·K)), so combined areas require an insulation layer (such as rock wool or extruded polystyrene board). In the Shanghai New World project, Qinglong added a 15mm thick rock wool insulation layer behind the UHPC panels, bringing the overall curtain wall thermal performance up to standard (heat transfer coefficient K≤2.8W/(m²·K)). Coordinated seismic performance: Both curtain wall types use elastic connection designs at their connection joints, allowing horizontal displacement of ±5mm to ensure coordinated deformation under seismic action. Qinglong's self-developed universal elastic joints are compatible with both curtain wall types, simplifying design and construction.

2. Joint Connection: Smooth Transition and Structural Safety

Smooth framing connection: The UHPC curtain wall and glass curtain wall use the same framing system, or achieve smooth framing alignment through adapter connectors, with deviation ≤2mm. Qinglong uses BIM technology for coordinated framing model design to avoid height differences at connection points. Panel junction treatment: Transition edging (such as stainless steel trim strips) is installed at the junction between UHPC panels and glass, with 5-8mm expansion joints reserved and filled with elastic sealant. In the Shenzhen project, Qinglong's edging design made the junction visually smooth with no obvious abruptness. Clear load transfer: The load transfer paths of the two curtain walls are clearly defined to avoid mutual interference—the load of UHPC panels is transferred directly to the main framing, while the glass curtain wall load is transferred through dedicated hangers. In the Guangxi New Media Center project, Qinglong optimized the joints through load calculations to ensure clear transfer paths.

3. Construction Adaptation: Process Coordination and Precision Control

Optimized construction sequence: The framing system is installed first (leveled and fixed as a whole), then UHPC panels and glass curtain walls are installed simultaneously to avoid precision deviations caused by separate construction. Qinglong adopts the "framing first, panels in sync" construction plan, improving installation efficiency by 30%. Unified precision control: Both installations use 3D laser positioning instruments with precision controlled within ±2mm, and panel edge straightness at junctions ≤1mm/m. In the Yangshengtang Pharmaceutical Hangzhou Industrial Park project, Qinglong achieved a 100% acceptance rate for combined curtain wall installation through unified precision standards. Tool and technique adaptation: Vacuum suction lifters are used for UHPC panel installation and glass suction lifters for glass curtain walls; independent work areas are designated during construction to avoid damage caused by mixing tools. Qinglong has formulated special construction plans clarifying the construction technique differences between the two materials.

4. Waterproof Sealing: The Core of Leak Prevention at Junctions

Unified joint sealing: A neutral silicone sealant compatible with both materials (movement capability ±25%) is selected to avoid bond failure caused by reactions between the sealant and the materials. The sealant chosen by Qinglong has passed compatibility testing, with bond strength to both UHPC and glass ≥1.0MPa. Junction waterproofing structure: A "double sealing + drainage channel" system is adopted—the first sealant layer provides waterproofing, while the second incorporates a drainage channel to collect seepage water, which is discharged through drainage holes. In a high-humidity project in Hainan, Qinglong solved the problem of easy leakage at junctions with this structure. Water accumulation prevention design: The junction between UHPC panels and glass adopts an "upper-over-lower" lap joint (lap length ≥50mm) to prevent rainwater from seeping along the joints. In a project in the rainy region of Guangzhou, Qinglong improved waterproofing reliability through this lap design.

The key to combining UHPC curtain walls with glass curtain walls lies in coordinated design and precise construction to fully leverage the advantages of both materials. With deep technical expertise, BIM collaborative design capabilities, and a professional construction team, Qinglong Group provides full-process solutions for combined curtain wall projects, creating building facades that are both beautiful and practical.