How to Solve Thermal Expansion and Contraction Issues in UHPC Curtain Walls — Analysis of Key Technologies and Practical Applications

In contemporary architectural design, UHPC (Ultra-High Performance Concrete) has become a rising choice in the curtain wall field thanks to its outstanding mechanical properties and artistic expressiveness. However, thermal expansion and contraction, a common challenge for building materials, is particularly pronounced in UHPC curtain walls—the material's low elastic modulus combined with the large scale of structures makes thermal stress highly likely to cause deformation and cracking. As an industry leader with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group has built a systematic solution—spanning material modification, structural design, and construction techniques—based on the practice of hundreds of landmark projects.

1. Material Gene Optimization: Suppressing Thermal Deformation Potential at the Source

Solving the thermal expansion and contraction problem of UHPC curtain walls must first start with the material formulation. Qinglong's R&D team has achieved performance breakthroughs through three core technical paths: first, adopting a compound system of nano-scale silica fume and ultra-fine quartz sand to control UHPC's linear expansion coefficient below 8×10⁻⁶/℃, 30% lower than traditional concrete; second, incorporating basalt fibers and steel fibers to form a three-dimensional random distribution, raising the material's ultimate tensile strain to 8‰ and giving curtain wall components greater deformation tolerance; third, introducing microcapsule self-healing technology—when thermal stress causes microcracks, the epoxy resin inside the capsules is automatically released to heal the cracks. These technical innovations have enabled Qinglong's UHPC curtain wall materials to pass thermal cycling tests from -40℃ to 80℃ with a performance decay rate below 5%.

2. Structural System Innovation: Dynamically Buffering Thermal Stress

At the structural design level, Qinglong has created its original “flexible suspension + graded displacement” system. This system comprises three key technologies: first, adjustable stainless steel anchors are used, allowing individual UHPC panels to move freely by ±20mm along the X/Y/Z axes, absorbing thermal deformation through three-dimensional adjustment; second, multiple sealing structures are designed at panel joints—the inner layer uses water-swelling waterstops and the outer layer uses silicone weather-resistant sealant, meeting watertightness requirements while reserving buffer space for deformation; third, for extra-long, large-span curtain walls, the concept of temperature zoning is introduced, with an expansion joint every 30 meters, combined with BIM technology to simulate temperature field distribution across different seasons to ensure structural safety. In the Century Plaza renovation project on East Nanjing Road, Qinglong applied this system to successfully solve the thermal deformation challenge of a 120-meter-long translucent UHPC curtain wall, winning the Silver Award at the first UHPC Construction Engineering Innovation Awards.

3. Construction Technique Upgrade: Precisely Controlling Installation Tolerances

Refined management of the construction phase is the final link in the solution. Qinglong adopts a “3D scanning + prefabricated assembly” construction method: at the factory prefabrication stage, industrial-grade 3D printers produce molds for UHPC components, ensuring geometric precision errors of ≤1mm; before on-site installation, a Leica TS60 total station is used to scan the curtain wall substrate, generating a point cloud model to compare with the design model so that structural deviations can be corrected in advance; during installation, dedicated hydraulic leveling devices achieve a height difference between panels of ≤0.5mm and a joint width error of ≤1mm. This technique enabled the GRC/UHPC composite curtain wall of the Dongguan Women and Children's Activity Center project to achieve an excellent performance of “zero leakage, no deformation,” winning the Silver Award at the GRC Construction Engineering Innovation Awards.

As a National High-Tech Enterprise and a participant in setting UHPC/GRC industry standards, Qinglong Group has always upheld the mission of “creating beautiful architecture,” transforming 28 years of engineering experience into accumulated technical expertise. From material R&D to project delivery, the full-chain solution Qinglong has built not only solves the thermal expansion and contraction challenge of UHPC curtain walls, but also drives new architectural decorative materials toward “high performance, high safety, and high aesthetics.” Looking ahead, Qinglong will continue to focus on UHPC/GRC/GRG/GRP material innovation, providing designers and owners with more valuable expert-level solutions and helping create more architectural masterpieces that stand the test of time.