How Does the Thermal Expansion Coefficient of Exterior Wall GRC Affect Construction? Temperature Deformation Control and Detailing Design by Qinglong Group

GRC material has the physical property of thermal expansion and contraction, with a coefficient of linear expansion of approximately (1.0–1.2)×10⁻⁵/°C. This means that a 6-meter-long GRC panel can change in length by 2.4–2.9 mm in an environment with a 40°C temperature difference. If this seemingly tiny deformation is not fully taken into account during design and construction, it will lead to a series of serious problems such as compression cracking of components, failure of joint seals, and damage to connectors. In the design phase of every GRC curtain wall project, Qinglong Group makes thermal deformation calculation a mandatory review step.

The impact of thermal deformation is directly reflected in three key structural design aspects: 1. Joint design: the joint width must be able to absorb the calculated thermal deformation and include a margin for construction tolerances. The formula is: joint width W ≥ α × L × ΔT + δ (α is the coefficient of linear expansion, L is the panel length, ΔT is the annual extreme temperature difference, and δ is the construction tolerance). In the high-temperature region of Hainan, the joint width we design for long panels is typically above 15 mm. 2. Connection system design: flexible connectors that can slide or rotate must be used, allowing panels to expand and contract freely with temperature changes rather than being rigidly constrained. Qinglong Group's three-dimensionally adjustable anchor system provides sufficient adjustment range to accommodate such deformation. 3. Boundary condition design: isolation joints must be installed where GRC panels meet rigid boundaries such as parapet walls, window openings, and structural columns, and filled with flexible sealing materials to prevent hard collisions.

In the red double-curved curtain wall project of the Wuhan Hanxiu Theater, through precise temperature field analysis and finite element simulation, we predicted the differences in thermal deformation of panels of different colors (darker colors absorb more heat) at different orientations, and made fine adjustments to the anchor point layout and joint width accordingly, ensuring the safe operation of nearly 10,000 square meters of shaped panels under severe winter and summer temperature differences. Respecting the physical properties of the material and channeling deformation through precise structural design is the scientific guarantee for the long-term safety of GRC exterior walls.