How to Address Thermal Stress in Large-Area GRC Curtain Walls? Temperature Deformation Control and Qinglong Group Technical Measures

The thermal stress problem of large-area GRC curtain walls must be comprehensively addressed through "joint release + flexible connections + material optimization," with the core being the control of expansion and contraction deformation caused by temperature changes. In curtain wall projects exceeding 10,000 square meters, such as the Shenzhen Yirui Biotechnology Building and the Hainan International Convention and Exhibition Center, Qinglong Group scientifically calculated thermal deformation, set expansion joints at reasonable intervals (spacing ≤12m), adopted a three-dimensionally adjustable connection system that allows panels to deform freely, and optimized the GRC mix ratio to lower the coefficient of thermal expansion (controlled within 1.0×10⁻⁵/°C), successfully minimizing the impact of thermal stress. Our calculations show that a 30m-long GRC curtain wall subjected to a 40°C temperature difference can deform by up to 12mm, which must be absorbed through systematic design.

Joint design is the primary measure. Qinglong Group calculates thermal deformation and determines joint spacing based on the local maximum temperature difference, curtain wall color (which affects surface temperature), orientation, and other factors. Typically, horizontal joint spacing is ≤12m, and vertical joints are aligned with structural joints. Joint width is calculated using the formula ΔL=α·L·ΔT, with construction tolerances taken into account; generally, 15-25mm is reserved. In the red curtain wall of the Wuhan Han Show Theatre, we used finite element analysis to subtly conceal the joints within the profile lines, meeting functional requirements without compromising aesthetics.

The connection system must allow for deformation. We use slotted-hole hangers with horizontal adjustment of ≥±10mm, ensuring that panels can expand and contract freely. Elastic washers are installed at connection points to prevent stress concentration caused by hard contact. In hot coastal regions, we also apply heat-reflective coating to the back of panels, reducing surface temperature by more than 15°C.

Optimizing the material's own properties is also crucial. Qinglong GRC incorporates polypropylene fibers to reduce the drying shrinkage value to ≤0.04%, mitigating the compounding effect of thermal stress. We recommend that large-area curtain walls undergo dedicated thermal stress calculations to ensure system safety.