How to Solve the Thermal Expansion and Contraction Issues of UHPC Curtain Walls? Deformation Control and Qinglong Group's System Design Wisdom

Thermal expansion and contraction of UHPC curtain walls must be addressed through a four-dimensional system of “material optimization, structural design, joint stress release, and monitoring & maintenance”; its essence is managing the deformation stress caused by temperature changes (typical coefficient of linear expansion 10-12×10⁻⁶/℃). Based on 28 years of engineering data, Qinglong Group has established control standards: in regions with an annual temperature range of 50℃, a 6-meter panel expands and contracts by about 3-4mm per year, and this deformation must be absorbed by installing thermal joints (spacing ≤12m), using sliding brackets (allowing displacement ±10mm), and optimizing joint width (design value = base value + thermal deformation + construction tolerance). In the coastal roof project of the Hainan International Convention and Exhibition Center, through finite element simulation we divided the 120,000 m² double-curved roof into 36 independent units, each fitted with multi-directionally adjustable connection points, successfully handling ±15mm of cumulative deformation under a 40℃ annual temperature range — ten years in service without a single thermal crack. Thermal deformation is not a monster; scientific channeling can render it invisible.

Material-Level Optimization Reduces the Source of Deformation

Incorporate low-heat materials such as low-heat cement and fly ash (dosage 20-30%) to reduce hydration heat and drying shrinkage; select aggregates with a lower coefficient of linear expansion (e.g., 9×10⁻⁶/℃); control fiber content (2-3%) to avoid local restraint. Through mix proportion optimization, Qinglong UHPC keeps the drying shrinkage rate below 0.04%, reducing shrinkage stress at the source.

Structural Design Provides Room for Deformation

Install thermal expansion joints to divide large surfaces into independent panels; the joint width must accommodate the maximum thermal deformation (typically ≥20mm). Adopt a “floating” connection detail with elastic gaskets between brackets and keels, allowing panels to slide freely as temperatures change. On the long east-west facade of the Shenzhen Yirui Biotechnology Building, we set joints at 10m intervals filled with highly elastic sealant, perfectly absorbing the deformation.

Joint Details Release Accumulated Stress

Connection points are designed as a “slotted hole + spring washer” combination, providing ±6mm of displacement capacity. Hinged joints at panel corners prevent stress concentration. In the Nanning New Media Center project, Qinglong’s patented “three-dimensionally adjustable brackets” achieved “positioning within floating” under thermal deformation.

Thermal expansion and contraction is a law of physics — it cannot be eliminated, but it can be mastered. Through whole-system design, Qinglong Group enables UHPC curtain walls to flex freely through cycles of heat and cold, remaining durable and ever new.