Solutions to Thermal Stress Problems in Large-Area GRC Curtain Walls

In modern architectural design, large-area GRC curtain walls have become the preferred solution for landmark buildings and high-end public projects thanks to their outstanding sculptural expressiveness and material properties. However, deformation and cracking caused by thermal stress have always been a key technical challenge for the industry. With 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group presents in this article a systematic analysis of thermal stress solutions for GRC curtain walls across three dimensions—material properties, structural design, and construction technology—providing professional technical reference for designers and owners.

I. Material Science: From Formula Optimization to Performance Breakthrough

The essence of thermal stress is the combined effect of a material's thermal expansion and contraction characteristics and its restraint conditions. Through 28 years of technical accumulation, Qinglong has established a GRC material adaptation system tailored to different climate zones. At the raw material level, high-elastic-modulus glass fibers are combined with low-shrinkage cement-based materials, keeping the linear expansion coefficient of GRC components within 8×10⁻⁶/°C—20% lower than traditional formulas. Meanwhile, nano-scale silica fume and ultra-fine mineral powder are introduced to optimize particle grading and enhance material density, achieving a 28-day flexural strength of 22MPa and ensuring structural stability under cyclic thermal loads.

For projects in extreme climate regions, Qinglong has innovatively developed "gradient-function GRC" technology, achieving internal stress self-equilibrium within components through gradient design of interlayer material properties. For example, in an ice-and-snow venue project in Harbin, a composite structure of inner insulating GRC and outer weather-resistant GRC was adopted, reducing interfacial stress caused by winter temperature differences by 35%, with no cracking observed over three years of monitoring.

II. Structural Design: Systematic Thinking in Dynamic Displacement Control

A scientific structural system is the core of resolving thermal stress. Relying on its national-level R&D center, Qinglong has developed a "three-dimensionally adjustable flexible connection system" that achieves ±50mm planar displacement compensation and ±15° angle adjustment through seismic-resistant connectors. In a commercial complex project in Shenzhen, the system successfully met the challenges of a curtain wall over 100 meters high with annual temperature fluctuations of 60°C; through BIM simulation and on-site measurement, the maximum displacement was kept within the design-permitted range.

For free-form curved GRC curtain walls, Qinglong employs parametric jointing technology, building thermal stress simulation models on the Rhino and Grasshopper platforms to optimize panel dimensions into standard 1.5m×3m units with joint widths precisely controlled at 8–12mm, satisfying both shaping requirements and the release of thermal deformation energy. This design method achieved an installation accuracy of ±2mm in a double-curved curtain wall project for a cultural center in Guangzhou, far exceeding industry standards.

III. Construction Technology: Practical Wisdom in Full-Process Quality Control

Refined operations during construction directly affect the effectiveness of thermal stress control. Qinglong has established a full-process quality control system covering factory prefabrication through on-site installation: at its Guangxi production base, constant temperature and humidity curing kilns (with temperature control precision of ±2°C) ensure that GRC components complete 70% of their shrinkage before leaving the factory; during on-site installation, 3D laser scanning technology is used for real-time positioning, combined with torque wrenches to control the pre-tightening force of connectors, preventing additional stress caused by over-constraint.

To address seasonal construction temperature differences, Qinglong has innovated a "temperature-adaptive installation method": in summer, installation is scheduled for the cooler early-morning and evening hours, while in winter components are preheated, keeping the temperature deviation at installation within 5°C. This technique effectively reduced later-stage deformation caused by construction temperature differences in a landmark project in the Xiong'an New Area.

As a vice-chairman unit of the China GRC Association and a contributing editor of the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC), Qinglong has always driven industry progress through technological innovation. From material R&D to system integration, from standard-setting to engineering practice, we uphold the values of "Honesty, Striving, Trust, and Collaboration," providing global customers with full-chain services for thermal stress solutions. Looking ahead, Qinglong will continue exploring composite application technologies for UHPC and GRC, contributing more wisdom to the balance of safety and aesthetics in architectural curtain walls in its mission of creating beautiful architecture.