How to Solve the Thermal Expansion and Contraction Problem of UHPC Curtain Walls: Key Technologies and Application Strategies

The Temperature "Dance" of Building Skins: A Systematic Solution to the Thermal Expansion and Contraction Challenge of UHPC Curtain Walls

Driven by the dual forces of contemporary architectural aesthetics and technology, ultra-high performance concrete (UHPC) is becoming a new favorite for landmark building curtain walls thanks to its outstanding mechanical properties and freedom of form. However, when this material that combines rigidity and flexibility encounters thermal expansion and contraction caused by day-night temperature differences and seasonal changes, how can the structural safety and aesthetic integrity of the curtain wall system be ensured? As an industry leader with 28 years of deep expertise in UHPC/GRC/GRG/GRP materials, Qinglong Group will analyze the way to crack this technical challenge from three dimensions: material properties, design optimization, and construction technology.

**Material Genes: UHPC's Thermal Properties and Improvement Path** UHPC itself has a low coefficient of linear expansion (approximately 8-10×10⁻⁶/℃), superior to traditional concrete (10-12×10⁻⁶/℃). Yet in super high-rise buildings, the cumulative expansion and contraction of curtain wall panels can still reach the centimeter level. Through material formulation optimization, Qinglong incorporates nano-scale silica fume and steel fibers into the UHPC substrate, not only raising the elastic modulus to 45-50GPa, but also suppressing thermal stress cracks through the fiber bridging effect. Meanwhile, gradient functional material design is introduced: a low-shrinkage glass fiber reinforced layer (a derivative application of GRC technology) is composited onto the panel surface, forming a composite structure of "rigid core + flexible cushion" that reduces thermal deformation by 15%-20%.

**Structural Wisdom: Engineering Practice of Dynamic Compensation Systems** The core of solving thermal expansion and contraction lies in "channeling rather than resisting." Qinglong's detailed design team pioneered the "three-dimensionally adjustable connection joint," which achieves free panel movement in the X/Y/Z directions through a combined system of stainless steel sliding supports and elastic sealant. In the Nanjing East Road Century Plaza renovation project, this technology successfully withstood temperature fluctuations of ±50℃ in a light-transmitting UHPC curtain wall, and its joint design won a national utility model patent (patent number: omitted). For curved curtain walls, parametric jointing technology is adopted, using BIM models to simulate the annual temperature field distribution and precisely control expansion joint spacing at 1.8-2.4 meters, satisfying structural safety while maintaining visual continuity.

**Full-Chain Control: Temperature Adaptation Strategies from Production to Operation and Maintenance** As a national high-tech enterprise integrating detailed design, manufacturing, and construction installation, Qinglong has established a whole-process temperature control system: at its Guangxi production base, constant-temperature curing kilns (±2℃ control precision) ensure that UHPC components complete more than 70% of their shrinkage before leaving the factory; on construction sites, infrared temperature measurement technology is introduced, and a dynamic construction plan is activated when the ambient temperature falls outside the 5-35℃ range; in the after-sales stage, an intelligent monitoring system with embedded RFID chips collects temperature and strain data in real time, providing a basis for preventive maintenance of existing building curtain walls. This whole-lifecycle management model of "materials-design-construction-operation and maintenance" has enabled projects undertaken by Qinglong, such as the Dongguan Women and Children's Activity Center, to achieve a 15-year zero-repair record for their curtain wall systems.

Today, as building skin technology continues to evolve, the thermal expansion and contraction control of UHPC curtain walls has risen from a purely technical issue to a systematic integration of materials science, structural engineering, and intelligent construction. Building on 28 years of industry experience, Qinglong Group will continue to explore the composite application of UHPC with GRC, GRG, and other materials. Through the technical philosophy of "combining rigidity and flexibility," buildings can not only withstand the "rhythm" of temperature, but also maintain eternal aesthetic tension as time passes. As Qinglong's mission states: "Create Beautiful Architecture"—it is precisely in these invisible technical details that the life and soul of architecture are forged.